TW201830744A - Structure for use in piezoelectric element, braided piezoelectric element, fabric-like piezoelectric element using braided piezoelectric element, and device using these - Google Patents

Abstract

Provided are: a structure having an oriented piezoelectric polymer arranged into a cylindrical or columnar shape, wherein the oriented angle of the oriented piezoelectric polymer is 0-40 DEG or 50-90 DEG with respect to the center axis direction of the cylindrical or columnar shape in which the oriented piezoelectric polymer is arranged, and the piezoelectric polymer includes, as a main component, a crystal polymer of which the absolute value of piezoelectric constant d14 is 0.1-1000 pC/N when the piezoelectric polymer has three orientation axes; and a braided piezoelectric element and a fabric-like piezoelectric element each using the structure.

Description

Structure for piezoelectric element, braided piezoelectric element, cloth-like piezoelectric element using braided piezoelectric element, and device using the same

[0001] The present invention relates to a structure for a piezoelectric element, a braided piezoelectric element in which a piezoelectric fiber is coated with a conductive layer, a piezoelectric element using the braided piezoelectric element, and the like Some devices.

[0002] Conventionally, many techniques related to elements using piezoelectric substances have been disclosed. For example, in Patent Document 1, it is disclosed that an element having a piezoelectric polymer coated with a conductive fiber is excellent in electrical response with respect to friction. Further, in Non-Patent Document 1, an element in which a piezoelectric polymer is wound into a coil shape is disclosed as an electrical response example in which the expansion and contraction of the coil axis direction and the torsion deformation of the coil are performed. Further, Patent Document 2 discloses a fibrous material composed of a piezoelectric polymer, and describes that the fibrous material produces a piezoelectric effect in a force (motion) acting parallel or at right angles to the fiber axis. Big situation. The piezoelectric sheet of Patent Document 3 can output an electric signal by torsional deformation (stress) with respect to the piezoelectric sheet. However, there is a lack of flexibility due to the sheet shape, and it is impossible to use a fiber or a cloth to bend freely. [0003] However, in the above prior art document, in addition to the piezoelectric signal generated effectively with respect to the torsional motion, the specific configuration for generating no piezoelectric signal with respect to the motion other than the torsional motion is not disclosed. Further, even in order to improve the utilization efficiency of the piezoelectric signal, a specific configuration in which charges of opposite polarities (that is, charges of inverse encoding) are generated on the central axis and the outer side of the structure is not disclosed. Therefore, the performance of the piezoelectric element which can be used as a sensor or a absorbing body is also insufficient. [0004] Furthermore, in recent years, so-called wearable sensors have attracted attention, and products such as glasses or watches have begun to appear. However, these devices have the feeling of being worn, preferably in the form of a cloth that is finally wearable, that is, a garment-like shape. As such a sensor, a piezoelectric element using a piezoelectric effect of a piezoelectric fiber is known. For example, Patent Document 1 discloses a piezoelectric element including two conductive fibers and one piezoelectric fiber, which have contacts with each other and which are arranged in piezoelectric units on slightly the same plane. Further, Patent Document 2 discloses a piezoelectric material characterized in that it is a fibrous material composed of a piezoelectric polymer or a molded article, and is applied to the axial directions by being applied thereto. The tension causes piezoelectricity to be formed, and a twist is applied in a direction different from the direction in which the tension acts. [0005] In addition, in recent years, an input device using a so-called touch panel method, that is, a touch input device, has been greatly increased. Not only bank ATMs or station ticket machines, but also in the development of thin display technology in smart phones, mobile phones, mobile game consoles, portable music players, etc., the use of the touch panel method as an input interface has greatly increased. As means for realizing such a touch method, there is known a method of using a piezoelectric sheet or a piezoelectric fiber. For example, Patent Document 4 discloses a touch panel using a piezoelectric sheet composed of L-type polylactic acid having an extending axis oriented in a specific direction. [0006] In the wearable sensor or touch panel type sensor, even if a small stress is generated in the piezoelectric material due to small deformation applied to the piezoelectric material, a large telecommunications is taken out. The number is good. For example, it is preferable to stably take out a large electric signal even if a relatively small stress is generated in the piezoelectric material even if the surface is wiped by bending of a finger or by a finger or the like. [0007] Although the piezoelectric fiber of Patent Document 1 can be applied to an excellent material for various uses, it is not always possible to output a large electric signal to a stress generated by a relatively small deformation, and to obtain a large electric signal. The technology is also not clearly stated. Further, since the piezoelectric element disclosed in Patent Document 1 is easily exposed by the conductive fibers serving as signal lines, it is susceptible to noise, and is further susceptible to deterioration or damage of materials due to external stress. In addition, the piezoelectric element described in Patent Document 1 has a space for improvement in practical use, and the piezoelectric element described in Patent Document 1 is not disclosed. In the piezoelectric fiber of Patent Document 2, the piezoelectric fiber is twisted in advance by a special manufacturing method, and the piezoelectric fiber can be stretched or compressed to output an electric signal. However, in Patent Document 2, there is no technique for producing a sufficient electrical signal with respect to the buckling of the bent or extended piezoelectric fiber or the shear stress caused by the action of wiping the surface of the piezoelectric fiber. Therefore, in the case of using such a piezoelectric fiber, it is difficult to take out a sufficient electric signal only by the stress generated by the relatively small deformation of the wiping surface. [0009] The piezoelectric sheet of Patent Document 4 can output an electric signal by deformation (stress) with respect to the piezoelectric sheet. However, there is a lack of softness due to the sheet shape, and it is impossible to use a cloth that can be bent freely. [PRIOR ART DOCUMENT] [Patent Document 1] [Patent Document 1] International Publication No. 2014/058077 [Patent Document 2] Japanese Laid-Open Patent Publication No. 2000-144545 (Patent Document 3) Japanese Laid-Open Patent Publication No. 2014-240842 [Patent Document 4] Japanese Laid-Open Patent Publication No. 2011-253517 [Non-Patent Document] [Non-Patent Document 1] Japanese Journal of Applied Physics 51 Volume 09LD16

[Problem to be Solved by the Invention] The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a cylindrical or cylindrical piezoelectric structure capable of torsional deformation ( Stress) Selective response, resulting in an electrode that can be utilized efficiently. Further, a second object of the present invention is to provide a fibrous piezoelectric element capable of taking out a large electric signal even by a stress generated by a relatively small deformation, and further suppressing noise. Signal, and it is difficult to be damaged from the outside. Further, a third object of the present invention is to provide a cloth-like piezoelectric element capable of removing a large electric signal even by a stress generated by a relatively small deformation, thereby suppressing the fibrous shape of the noise signal. A piezoelectric element, and a cloth-like piezoelectric element that is easily provided to a substrate such as another fabric. [Means for Solving the Problem] The inventors of the present invention have found that the piezoelectric polymer having the high-voltage electric constant d14 is aligned in a specific direction in order to achieve the above-described first object. The cylindrical or cylindrical structure forcibly deforms the charge of the opposite polarity with respect to the torsional deformation on the side and the outer side of the central axis of the cylindrical or cylindrical shape, and the present invention has been completed. [0016] In order to achieve the above-mentioned second object, the inventors of the present invention have found that as a combination of a conductive fiber and a piezoelectric fiber, a piezoelectric fiber having a braided shape is coated as a core conductive fiber. The surface, and by the braided piezoelectric element provided with the conductive layer around it, the electric signal can be taken out efficiently, and the noise signal can be suppressed, and the core and the piezoelectric fiber can be found by The relationship of the roughness is set to a specific range, and it is possible to overcome the damage from the outside and complete the present invention. [0017] In order to achieve the third object, the inventors of the present invention have found that the combination of the conductive fibers and the piezoelectric fibers is coated with the piezoelectric fibers of the braided shape as the conductive fibers of the core. The surface and the braided piezoelectric element provided with the conductive layer around it can efficiently take out the electrical signal, and can further suppress the noise signal, and find that by fixing the specific shape to the cloth, it can be The present invention has been completed by being difficult to receive damage from the outside and simply providing a substrate to another fabric or the like. [0018] In the meantime, the following (1) to (12) are provided as means for achieving the above-described second object (the first invention). According to a second aspect of the invention, the following (13) to (20) are provided, and as a means for achieving the above third object (third invention), the following (21) to (31) are provided. (1) A structure in which a piezoelectric polymer to be aligned is disposed in a cylindrical or cylindrical structure, and a piezoelectric polymer is cylindrical or cylindrical in which a piezoelectric polymer is disposed. The alignment angle in the direction of the central axis is 0° or more and 40° or less or 50° or more and 90° or less. The piezoelectric polymer includes an absolute value of the piezoelectric constant d14 when the alignment axis is set to 3 axes of 0.1 pC/ A crystalline polymer having a value of N or more and 1000 pC/N or less is used as a main component. (2) The structure according to the above aspect, wherein the piezoelectric polymer contains poly-L-lactic acid or poly-D-lactic acid as a main component. (3) The structure according to (1) or (2), wherein when the central axis of the cylindrical or cylindrical body on which the piezoelectric polymer is disposed is applied as a shaft and is subjected to torsional deformation, The cylindrical and cylindrical central axis side and outer side generate a reverse polarity charge. The structure according to any one of the above aspects, wherein the piezoelectric polymer contains a crystalline polymer having a positive piezoelectric constant d14 as a main component. The P body and the N body containing the negative crystalline polymer as a main component hold a portion having a length of 1 cm with respect to the central axis of the structure, and the alignment axis is wound into a spiral and the P body is disposed in the Z direction. The mass is set to ZP, the alignment axis is wound into a spiral, the mass of the P body is set to SP, and the alignment axis is wound into a spiral. The mass of the N body is set to ZN. When the alignment axis is spirally arranged, the mass of the N body is set to SN, and the smaller one of (ZP+SN) and (SP+ZN) is T1, and the larger one is set to T2. The value of T1/T2 exceeds 0.8. (5) The structure according to any one of (1) to (4), wherein the piezoelectric polymer-like fibrous, fibrillar or ribbon is formed into a braided shape, a string shape, a core yarn shape or It is composed of a yarn. (6) The structure according to any one of (1) to (4), wherein the piezoelectric polymer has a cross section perpendicular to a central axis of a cylindrical shape or a cylindrical shape, and constitutes only one closed region. . (7) An element comprising the structure according to any one of (1) to (6), and a conductor disposed adjacent to the structure. (8) The element according to the above aspect, wherein the piezoelectric polymer is disposed in a cylindrical shape, and the conductor is disposed at a position of a central axis of the cylindrical shape. (9) The woven element according to the above aspect, wherein the conductive system is made of a conductive fiber, and the piezoelectric polymer is woven around the conductive fiber as a piezoelectric fiber. (10) The element according to the item (7), wherein the conductor is disposed on a side of a cylindrical shape or a cylindrical shape on which the piezoelectric polymer is disposed. (11) The element according to the item (10), wherein the conductive system is made of a conductive fiber, and the conductive fiber is knitted in a cylindrical shape or a cylindrical shape in which the piezoelectric polymer is provided. around. (12) A sensor comprising: the element according to any one of (7) to (11); and an output terminal which is in a cylindrical or cylindrical shape in which a piezoelectric polymer is disposed The direction of the central axis is given the electric charge generated when the torsional deformation is applied, and the electric signal generated by the electric conductor is output, and the electric circuit detects the electric signal outputted through the output terminal. (13) A braided piezoelectric element comprising: the element according to (9), wherein the element includes a core portion formed of the conductive fiber, and a braided portion so as to cover the core portion a sheath portion formed of the piezoelectric fiber; and a conductive layer provided around the sheath portion, wherein a ratio d/Rc of a thickness d of the layer composed of the piezoelectric fiber to a radius Rc of the core portion is 1.0 or more. (14) The braided piezoelectric element according to the above aspect, wherein the coating portion of the conductive layer is 25% or more. The braided piezoelectric element according to the item (13), wherein the conductive layer is formed of a fiber. (16) A braided piezoelectric element according to any one of (13) to (15). The fabric-shaped piezoelectric element according to the above aspect, wherein the fabric further includes a conductive fiber that is in contact with at least a part of the knitted piezoelectric element. (18) The fabric-shaped piezoelectric element according to the above aspect, wherein the fiber of the fabric is formed, and 30% or more of the fibers intersecting the braided piezoelectric element are conductive fibers. (19) A device comprising: the braided piezoelectric element according to any one of (13) to (15); and an amplifying means for amplifying from the braided piezoelectric element in response to a pressure to be applied The output electrical signal; and an output means for outputting the electrical signal amplified by the above amplification means. (20) A device comprising the cloth-shaped piezoelectric element according to (17) or (18), and an amplification means for amplifying an electric signal output from the cloth-shaped piezoelectric element in response to a pressure to be applied; and an output Means, which outputs an electrical signal amplified by the above amplification means. (21) A cloth-shaped piezoelectric element in which a braided piezoelectric element having a braided piezoelectric element is fixed to a fabric, wherein the braided piezoelectric element includes: the element described in (9), wherein the element has the above-mentioned a core portion formed of a conductive fiber, and a sheath portion formed of the piezoelectric fiber having a braided shape so as to cover the core portion; and a conductive layer provided around the sheath portion, the braided piezoelectric piece The pull-out strength of the element for each of the above-mentioned fabrics was 0.1 N or more. (22) The cloth-like piezoelectric element according to the above aspect, wherein the braided piezoelectric element constituting the fabric of the fabric has a coverage of more than 30% on both sides of the fabric. (23) The fabric-shaped piezoelectric element according to the above aspect, wherein the braided piezoelectric element is fixed to the fabric in a state of being woven or knitted. (24) The cloth-like piezoelectric element according to (21) or (22), wherein the braided piezoelectric element is interposed between the layers of the double woven fabric or the double woven fabric. The fabric-shaped piezoelectric element according to any one of (21), wherein the braided piezoelectric element is partially exposed from the fabric, and the braided piezoelectric portion is exposed at the exposed portion. The conductive fibers and/or the conductive layer of the element are electrically connected to other members. The cloth-like piezoelectric element according to any one of the aspects of the present invention, wherein the sheath portion of the conductive layer has a coverage of 25% or more. The fabric-shaped piezoelectric element according to any one of (21), wherein the conductive layer is formed of a fiber. The fabric-like piezoelectric element according to any one of the aspects of the present invention, wherein the total fineness of the piezoelectric fiber is one time or more and 20 times the total fineness of the conductive fiber. the following. The cloth-like piezoelectric element according to any one of the aspects of the present invention, wherein the fineness of each of the piezoelectric fibers is 1/20 times or more of a total fineness of the conductive fibers. 2 times or less. The fabric-shaped piezoelectric element according to any one of the aspects of the present invention, wherein the fabric further includes a conductive fiber that is in contact with at least a part of the knitted piezoelectric element. (31) A device comprising: the cloth-like piezoelectric element according to any one of (21) to (30); and a circuit for detecting the pressure of the cloth-like piezoelectric element in response to the applied pressure The electric signal contained in the above-mentioned conductive fiber is output. [Effect of the Invention] According to the first aspect of the invention, it is possible to provide a piezoelectric or cylindrical piezoelectric structure which can be efficiently utilized and which can be efficiently used in response to a torsional deformation (stress). According to the second aspect of the invention, it is possible to provide a fibrous piezoelectric element in which a large electric signal can be taken out by a stress generated by a relatively small deformation, and a noise signal can be further suppressed. Further, according to the third aspect of the invention, there is provided a cloth-like piezoelectric element capable of extracting a large electric signal even by a stress generated by a relatively small deformation, and suppressing the noise signal can be used. A fibrous piezoelectric element and a cloth-like piezoelectric element that is easily provided to a substrate such as another fabric. Further, according to the third aspect of the invention, the coverage of the braided piezoelectric element by the fibers constituting the fabric is such that the both sides of the fabric exceed a specific value, for example, 50%, and it is difficult to receive the external Damage caused by friction, heat, light, etc.

[0023] Hereinafter, the first invention will be described in detail. (Cylindrical or cylindrical piezoelectric structure) The structure (piezoelectric structure) of the present invention includes an aligned piezoelectric polymer, and the aligned piezoelectric polymer is arranged in a cylindrical shape or a cylindrical shape. shape. Fig. 1A is a schematic view showing a cylindrical piezoelectric structure 1-1 according to an embodiment, and Fig. 1B is a schematic view showing a cylindrical piezoelectric structure 1-2 according to an embodiment. The shape of the outer edge and the inner edge of the cylindrical or cylindrical bottom surface on which the piezoelectric polymer is disposed is preferably a perfect circle, and even if it is an elliptical shape, it may be a flat circular shape. (Piezoelectric polymer) The piezoelectric polymer uniaxially aligned polymer molded body contained in the piezoelectric structure of the present invention includes a piezoelectric element having a three-axis alignment axis. A crystalline polymer having an absolute value of the constant d14 of 0.1 pC/N or more and 1000 Pc/N or less is used as a main component. In the present invention, "including ... as a main component" means 50% by mass or more of the constituent components. Furthermore, in the present invention, the crystalline polymer is composed of a crystal portion of 1% by mass or more and a polymer composed of an amorphous portion other than the crystal portion, and the mass of the crystalline polymer is a total of a crystal portion and an amorphous portion. the quality of. The absolute value of the piezoelectric constant d14 when the alignment axis is set to three axes is 0.1 pC/N or more and 1000 pC/, which can be used as the crystalline polymer contained in the piezoelectric polymer of the present embodiment. A crystalline polymer having a value of N or less, such as "Piezoelectricity of biopolymers" (Biyueology, Vol. 3, No. 6, pp. 593), includes cellulose, collagen, keratin, and Fibrin, poly-L-alanine, poly-γ-methyl-L-glutamic acid, poly-γ-benzyl-L-glutamic acid, poly-L-lactic acid. Further, poly-D-alanine, poly-γ-methyl-D-glutamic acid, poly-γ-benzyl-D-glutamic acid, poly-D-, which are optical anisotropic bodies of the polymers. Although the code of d14 is reversed, the absolute value of d14 is assumed to be the same value. Although the value of d14 represents a different value depending on molding conditions, purity, and measurement environment, in order to achieve the object of the present invention, the degree of crystallinity and crystal orientation of the crystalline polymer in the piezoelectric polymer actually used are measured. The crystalline polymer is used to form a uniaxially stretched film having the same degree of crystallinity and crystal orientation, and the absolute value of the film d14 is 0.1 pC/N or more and 1000 pC/N or less in the actual use temperature. The crystalline polymer contained in the piezoelectric polymer of the present embodiment is not limited to the specific crystalline polymer described above. The d14 of the film sample can be measured by various methods, but for example, a metal is vapor-deposited on both sides of the film sample to form a sample of the electrode, and is cut into a rectangle having four sides in a direction inclined by 45 degrees from the extending direction. The value of d14 can be measured by measuring the charge generated at the electrodes on both sides when a tensile load is applied in the longitudinal direction thereof. [0025] In the present embodiment, poly-L-lactic acid and poly-D-lactic acid are particularly preferably used. For example, poly-L-lactic acid and poly-D-lactic acid are easily aligned by uniaxial stretching after melt film formation, and indicate piezoelectricity exceeding 10 pC/N, which is an absolute value of d14. In addition, although the polarization treatment of the polyfluorinated vinylene article of the representative piezoelectric polymer has a high piezoelectric constant of d33, the absolute value of d14 is extremely low, and it cannot be regarded as the crystallinity of the present invention. Use of polymer. Further, the piezoelectric polymer may be used as an alloy of a piezoelectric polymer having no other piezoelectricity, but when it is used as a piezoelectric polymer mainly composed of polylactic acid, The polylactic acid containing at least 60% by mass or more based on the total mass of the alloy is more preferably 70% by mass or more, and most preferably 90% by mass or more. [0027] Examples of the polymer other than polylactic acid in the case of an alloy include polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate copolymer, and poly Methacrylate is a suitable example, but is not limited thereto. (Orientation Angle of Piezoelectric Polymer) In the structure in which the piezoelectric polymer of the present invention is arranged in a cylindrical shape or a cylindrical shape, the piezoelectric polymer is disposed with a piezoelectric polymer. The alignment angle θ in the direction of the central axis of the cylindrical or cylindrical shape (hereinafter, simply referred to as "central axis") is 0° or more and 40° or less or 50° or more and 90° or less. When the piezoelectric structure is subjected to the torsional deformation (torsional stress) centered on the central axis, the piezoelectric polymer of the crystalline polymer contained in the piezoelectric polymer can be efficiently utilized. The piezoelectric effect corresponding to the constant d14 can effectively generate a reverse polarity charge on the central axis side and the outer side of the piezoelectric structure. In addition, when the alignment angle θ of the piezoelectric polymer with respect to the central axis exceeds 40° and is less than 50°, even if the piezoelectric structure is subjected to torsional deformation (torsional stress) with the central axis as the axis, It is also impossible to efficiently generate a reverse polarity charge on the central axis side and the outer side of the piezoelectric structure, so that the electric charge cannot be efficiently extracted as a signal or energy. From such a viewpoint, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is preferably 0° or more and 35° or less, or preferably 55° or more and 90° or less, and 0° or more and 30° or less or 60°. The above 90° or less is preferable, and more preferably 0° or more and 25° or less or 65° or more and 90° or less, and more preferably 0° or more and less than 15° or more than 75° and more preferably 90° or less. When the alignment angle θ of the piezoelectric polymer in the direction of the central axis exceeds 0° and is less than 90°, the spiral direction is drawn in the alignment direction of the piezoelectric polymer. Further, by disposing the piezoelectric polymer in this manner, it is possible to cause shear deformation like the surface of the frictional piezoelectric structure, or bending deformation of the bending central axis, or stretching deformation in the central axis direction. In the piezoelectric structure, the central axis side and the outer side of the piezoelectric structure do not generate a large electric charge, that is, a piezoelectric structure that selectively generates a large electric charge with respect to the torsion centered on the central axis. The alignment angle θ of the piezoelectric polymer in the direction of the central axis is viewed from the side in a cylindrical or cylindrical parallel projection view in which the piezoelectric polymer is disposed, the direction of the central axis, and the central axis The angle formed by the alignment direction of the piezoelectric polymer in the overlapping front portion. For example, FIG. 2 is a view of the cylindrical piezoelectric structure 1 relating to the embodiment in view from the side. In the example of FIG. 2, the piezoelectric structural system winds a strip of a piezoelectric polymer that is aligned in the longitudinal direction into a spiral structure. The straight line indicating the direction in which the center axis CL overlaps the strip in the front direction is OL, and the angle θ between CL and OL (0 degrees or more and 90 degrees or less) is the direction of the piezoelectric polymer with respect to the central axis. Orientation angle. [0030] In FIG. 2, since a thin piezoelectric polymer is used as the strip material, the alignment direction of the piezoelectric polymer is approximately the same as the alignment direction of the surface of the strip viewed from the side, but thick In the case of producing a cylindrical piezoelectric structure by a piezoelectric polymer, or in the case of a cylindrical piezoelectric structure, the alignment direction of the inner surface is larger than the alignment direction of the surface which can be viewed from the side. Close to the central axis, the closer to the direction of the central axis, the difference between the alignment direction of the surface and the inner alignment direction. Furthermore, since the alignment direction of the surface of the strip viewed from the side is S-shaped or inverted S-shaped in appearance, accurate observation requires a high magnification magnification observation. [0031] From this point of view, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is a structure in which a fiber, a filament, or a strip that is aligned in the longitudinal direction is spirally wound (for example, a crepe may be mentioned) In the case of a core yarn, a braid, or the like, it is measured as much as possible by the following method. A photograph of the side of the piezoelectric structure was measured, and the pitch HP of the piezoelectric polymer 2 was measured. The spiral pitch HP is a linear distance from the surface of the piezoelectric polymer 2 to the central axis direction required for the surface to return to the surface as shown in FIG. Further, after the bonding structure is fixed by the bonding agent, a cross section perpendicular to the central axis of the piezoelectric structure is cut to take a photograph, and the outer radius Ro and the inner radius Ri of the portion occupied by the piezoelectric structure are measured. In the case where the outer edge and the inner edge of the cross section are elliptical or flat, the average of the long diameter and the short diameter is set to Ro and Ri. When the piezoelectric structure is a cylinder, it is set to Ri=0. The alignment angle θ of the piezoelectric polymer with respect to the central axis is calculated from the following formula. However, Rm=2 (Ro ³ -Ri ³ ) /3 (Ro ² -Ri ² ), that is, the radius of the piezoelectric structure weighted by the cross-sectional area. [0032] In the photo of the side surface of the piezoelectric structure, the piezoelectric polymer has a uniform surface, or the alignment angle θ of the piezoelectric polymer in the central axis direction is close to 0°, and the like cannot be discriminated. In the case of the pitch of the piezoelectric polymer, the piezoelectric structure fixed by the bonding agent or the like is cut in a plane passing through the central axis, and penetrates in a narrow range from the central axis in a direction perpendicular to the cutting plane. In the X-ray mode, wide-angle X-ray diffraction analysis is performed, and the alignment direction is determined to determine the angle with the central axis, and is set to θ. [0033] As in the case of woven or multi-layer core-spun yarn, two or more spirals having different spiral directions (S捻 or Z捻) or spiral pitch are present for the spiral drawn along the alignment direction of the piezoelectric polymer. In the case of the piezoelectric structure of the spiral, the above-described measurement is performed for each of the spiral direction and the piezoelectric polymer of the spiral, and the piezoelectric polymer of either the spiral direction and the spiral pitch must satisfy the above conditions. . [0034] When the spiral is formed in the alignment direction of the piezoelectric polymer, the spiral direction (S捻 direction or Z捻 direction) does not affect the polarity (encoding) of the electric charge generated by the torsional deformation. However, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 0° or more and 40° or less, and when it is 50° or more and 90° or less, the polarity of the electric charge generated by the torsional deformation is reversed. Further, as in the case of poly-L-lactic acid and poly-D-lactic acid, the piezoelectric polymer containing the crystalline polymer having different codes of d14 is also reversed with respect to the polarity of the electric charge generated by the torsional deformation. Therefore, in order to efficiently generate a reverse polarity charge on the central axis side and the outer side of the piezoelectric structure with respect to the torsional deformation, only the piezoelectric polymer containing the same crystalline polymer as the code of d14 as a main component is used. The alignment angle θ of the piezoelectric polymer in the direction of the central axis in the piezoelectric structure is preferably concentrated in any of 0° or more and 40° or less, or 50° or more and 90° or less. [0035] However, with respect to the expansion and contraction deformation in the central axis direction of the piezoelectric structure, the polarity (encoding) of the charges generated on the side of the central axis and the outside is high in piezoelectricity due to the spiral along the S direction. In the case of the alignment direction of the molecules, when the alignment direction of the same piezoelectric polymer is arranged along the spiral of the Z-direction, the polarities are opposite to each other, and therefore, a certain arrangement is arranged in the spiral along the S axis. In the case where the alignment direction of the piezoelectric polymer is arranged along the Z-direction spiral (for example, a fiber composed of a piezoelectric polymer is used for both the S-direction yarn and the Z-direction yarn) In the case of weaving, since the charge generated by the expansion and contraction is offset by the S and Z directions, only the electric charge corresponding to the torsional deformation can be detected. Therefore, in the embodiment of the present invention, the piezoelectric polymer includes a P body containing a crystalline polymer having a positive piezoelectric constant d14 as a main component, and a negative crystalline polymer as a main component. The N-body has a length of 1 cm in length with respect to the central axis of the piezoelectric structure, and the mass of the P body in which the alignment axis is wound into a spiral is set to ZP, and the alignment axis is wound into a spiral. The mass of the P body in the S direction is set to SP, the alignment axis is wound into a spiral, the mass of the N body disposed in the Z direction is set to ZN, and the alignment axis is wound into a spiral and the N body is disposed in the S direction. The quality is set to SN, and the smaller of (ZP+SN) and (SP+ZN) is set to T1, and when the larger one is set to T2, the value of T1/T2 is preferably more than 0.8, and more than 0.9 is more. good. In particular, the piezoelectric polymer includes a P body containing poly-D-lactic acid as a main component and an N body containing poly-L-lactic acid as a main component, and holds 1 cm of the central axis of the piezoelectric structure. The length of the part, the alignment axis is wound into a spiral. The mass of the P body arranged in the Z direction is set to ZP, and the alignment axis is wound into a spiral. The mass of the P body is set to SP, and the alignment axis is rolled. The mass of the N-body in which the spiral is arranged in the Z direction is set to ZN, and the quality of the N-body in which the alignment axis is wound into a spiral is set to SN, and (ZP+SN) and (SP+ZN) When the smaller one is T1 and the larger one is T2, the value of T1/T2 is more than 0.8, especially more than 0.8 and more preferably 1.0 or more, and more than 0.9, especially more than 0.9 and 1.0 or less. good. Here, even when the value of T1/T2 is not satisfied, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 0° or more and 10° or less, or 80° or more and 90° or less. When the temperature exceeds 10° and is less than 80°, the amount of electric charge generated by the expansion and contraction becomes small, and as a result, the electric signal can be selectively generated with respect to the torsional deformation. Further, as in the case of poly-L-lactic acid and poly-D-lactic acid, when a piezoelectric polymer containing d14 codes of different crystalline polymers is mixed and arranged along a spiral of one of S捻 or Z捻It is desirable because the generated charges with respect to the expansion and contraction cancel each other and selectively respond to the torsional deformation. (Structure of Piezoelectric Structure) As described above, in the piezoelectric structure of the present invention, the alignment angle θ of the piezoelectric polymer in the direction of the central axis exceeds 0° and is less than 90°. In the case, the alignment direction of the piezoelectric polymer traces the spiral. In particular, a piezoelectric structure, a core yarn, a braid, or the like in which a piezoelectric polymer fiber, a filament, or a tape is disposed in the longitudinal direction is preferably used. In the case of using a strip, it is possible to use a strip which is oriented in a direction other than the longitudinal direction of the strip, and it is possible to use a strip which is wound into a spiral shape, or to form a cylinder by making the longitudinal direction and the central axis direction parallel. Strip. From the viewpoint of improving the productivity and the degree of alignment, from the viewpoint of structural stability, by extending the fiber aligned in the longitudinal direction, using the filament or the ribbon, the core yarn, and the weaving. Especially for weaving is especially good. When the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 0°, the alignment direction of the piezoelectric polymer is parallel to the central axis. The piezoelectric structure to be disposed as described above may be, for example, a fiber, a filament or a tape itself which is aligned in the longitudinal direction of the piezoelectric polymer, or a yarn or a composite yarn or a composite yarn It is preferable that the yarn or the core yarn is coated with a piezoelectric polymer. When the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 90°, the alignment direction of the piezoelectric polymer is circular on the surface perpendicular to the central axis. As the piezoelectric structure to be disposed as described above, for example, a strip which is aligned with a piezoelectric polymer perpendicular to the longitudinal direction is used, and it is preferable to form a cylinder by making the longitudinal direction and the central axis direction parallel to each other. Aspect. [0038] When the piezoelectric structural system of the present invention is subjected to torsional deformation in the direction of the central axis, a charge of a reverse polarity is generated on the side of the central axis and the outside. The utilization type is not particularly limited, and may be used for adsorption-desorption of a substance or operation due to gravity/repulsive force, electromagnetic wave generation, electrical stimulation to a living body, etc., but the electric charge is taken out as a signal with high efficiency. Or energy, so the shape of the conductor disposed on the side of the central axis and/or outside is more preferable. In the case where the conductor is disposed on the outer side, the conductor is disposed so as to cover the cylindrical side surface or the cylindrical side surface of the piezoelectric structure, although it is preferable in terms of charge utilization efficiency and use as a shield. However, even if only the electrical conductors are partially disposed. From the viewpoint of productivity, bending durability, and stability of the structure, a piezoelectric structure of a braided shape to be described later is preferable. [Wolen Piezoelectric Element] FIG. 4 is a schematic view showing a configuration example of a braided piezoelectric structure (hereinafter referred to as a braided piezoelectric element) according to an embodiment. The braided piezoelectric element 101 includes a core portion 103 formed of a conductive fiber B, and a sheath portion 102 formed of a braided piezoelectric fiber A so as to cover the core portion 103. The sheath portion 102 is the present invention. A cylindrical piezoelectric structure. The piezoelectric fiber A may contain polylactic acid as a main component. [0040] In the braided piezoelectric element 101, a plurality of piezoelectric fibers A are densely wound around the outer peripheral surface of at least one of the conductive fibers B. When the braided piezoelectric element 101 is deformed, stress is generated by deformation in a plurality of piezoelectric fibers A, and accordingly, an electric field (piezoelectric effect) is generated in each of the piezoelectric fibers A, and as a result, it is estimated The conductive fiber B has a voltage change that overlaps with the electric field of the plurality of piezoelectric fibers A wound around the conductive fiber B. That is, the electric signal from the conductive fiber B is increased as compared with the case where the braided sheath portion 102 of the piezoelectric fiber A is not used. Accordingly, in the braided piezoelectric element 101, a large electric signal can be taken out even by a stress generated by a relatively small deformation. Further, the conductive fibers B may be plural pieces. Here, it is preferable that the signal intensity detected via the conductive fiber B as the core portion is strongly restrained so as not to change the contact state with the sheath fiber, that is, the piezoelectric fiber A. For example, by increasing the tension when the piezoelectric fiber is woven by the braiding machine, it is possible to obtain a more strongly restrained knitting. Further, since the polylactic acid (PLA) fiber has a weak strength and a high friction, there is a case where the yarn is broken in the yarn path of the braiding machine, and the beautiful yarn cannot be obtained. That is, in the weaving process, the fiber is woven by the movement of the carrier of the bobbin in which the fiber is wound on the disk, so that the fiber is instantaneously repeatedly stretched and relaxed due to the pressure accumulation of the bobbin. It is difficult for PLA fibers to apply high tension to weave. However, such difficulties are known to be improved by applying crepe processing to the PLA fibers. Specifically, it is preferred to apply the roving to the PLA fiber at a number of turns of 10 to 5000 T/m. When it is less than 10 T/m, the effect of the crepe is not obtained, and when it is more than 5000 T/m, the fiber is easily twisted, and it is easy to cause trouble at the time of processing. Further, the angle of the direction of the alignment axis of the PLA to the direction of the knitting axis at the time of knitting is not appropriate, and the signal intensity is small. The number of turns is preferably 30 T/m or more, and more preferably 50 T/m or more. Further, as the upper limit of the number of turns, it is preferably 3,000 T/m or less, more preferably 1,500 T/m or less. The method of the crepe processing is not particularly limited, and all known crepe processing methods can be applied. Further, the fiber processed by the crepe is preferably heat-treated, and by heat treatment, the crepe state is fixed and the fiber treatment is facilitated. The method of heat treatment is not particularly limited. Generally, the temperature of Tg to Tm of the selected fiber is preferably the case of treatment under humidity. Here, the piezoelectric fiber A preferably contains polylactic acid as a main component. The lactic acid unit in the polylactic acid is preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 98 mol% or more. In addition, in the braided piezoelectric element 101, even if the sheath portion 102 and the piezoelectric fibers A are combined with each other, the core portion 103 and the conductive portion may be electrically conductive. It is also possible to mix fibers or the like with other fibers other than the fiber B. The length of the braided piezoelectric element composed of the core portion 103 of the conductive fiber B and the sheath portion 102 of the braided piezoelectric fiber A is not particularly limited. For example, even if the braided piezoelectric element is continuously manufactured in the production, it may be used after being cut into a length required later. The length of the braided piezoelectric element is 1 mm to 10 m, preferably 5 mm to 2 m, and preferably 1 cm to 1 m. When the length is too short, the fiber shape is lost, that is, convenience, and when the length is too long, the resistance value of the conductive fiber B needs to be considered. Hereinafter, each configuration will be described in detail. (Electrically Conductive Fiber) As the conductive fiber B, any known fiber can be used as the fiber indicating conductivity. Examples of the conductive fiber B include a fiber composed of a metal fiber, a fiber composed of a conductive polymer, a carbon fiber, a polymer in which a fibrous or granular conductive filler is dispersed, or a fibrous material. A fiber having a conductive layer is provided on the surface. Examples of the method of providing a conductive layer on the surface of the fibrous material include metal coating, conductive polymer coating, and winding of conductive fibers. Among them, metal coating is preferred from the viewpoints of conductivity, durability, flexibility, and the like. The specific method of coating the metal is, for example, vapor deposition, sputtering, electrolytic plating, electroless plating, etc., but plating is preferred from the viewpoint of productivity and the like. The metal thus plated may be referred to as a metal plated fiber. [0045] As the fiber of the substrate to which the metal is applied, well-known fibers can be used regardless of the presence or absence of conductivity, for example, in addition to polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, vinyl chloride fibers, aromatic poly In addition to synthetic fibers such as polyamide fibers, polyfluorene fibers, polyether fibers, and polyurethane fibers, semi-synthetic fibers such as natural fibers such as cotton, hemp, and enamel, and acetate, and hydrazine may be used. Regenerated fiber such as copper amine fiber. The fibers of the substrate are not limited thereto, and any known fibers may be used arbitrarily, and these fibers may be used in combination. The metal of the fiber applied to the substrate represents electrical conductivity, and any one may be used as long as the effect of the present invention is achieved. For example, gold, silver, platinum, copper, nickel, tin, lead, palladium, indium tin oxide, copper sulfide, or the like, and mixtures or alloys thereof may be used. When the conductive fiber B is coated with a metal coated organic fiber having bending resistance, the conductive fiber is broken very rarely, and the durability and safety of the sensor using the piezoelectric element are excellent. [0048] The conductive fiber B may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. Multifilament is preferred from the viewpoint of the stability of the electrical properties. In the case of a monofilament (including a spun yarn), the monofilament diameter is from 1 μm to 5000 μm, preferably from 2 μm to 100 μm. It is preferably 3 μm to 50 μm. In the case of multifilaments, as the number of filaments, it is preferably from 1 to 100,000, preferably from 5 to 500, more preferably from 10 to 100. However, the fineness and the number of the conductive fibers B are the fineness and the number of the cores 103 used in the production of the woven fabric, and the multifilament formed by a plurality of monofilaments (monofilaments) is also counted as one. Conductive fiber B. Here, the core portion 103 is provided to include the entire amount of the fiber even when a fiber other than the conductive fiber is used. [0049] When the diameter of the fiber is small, the strength is lowered and it becomes difficult to handle, and further, in the case where the diameter is large, the flexibility is sacrificed. The cross-sectional shape of the conductive fiber B is preferably a circle or an ellipse from the viewpoint of design and manufacture of the piezoelectric element, but is not limited thereto. [0050] Furthermore, in order to efficiently take out the electrical output from the piezoelectric polymer, it is preferable that the electric resistance is low, and the volume resistivity is 10 ^-1 Ω・cm or less is better, with 10 ^-2 Ω·cm or less is preferred, with 10 ^-3 Ω·cm or less is more preferable. However, the resistivity of the conductive fiber B is not limited to this in order to obtain sufficient strength for detecting the electrical signal. From the viewpoint of the use of the present invention, the conductive fiber B must have resistance to repeated bending or twisting. As its index, the nodule strength is preferably larger. The knot strength can be measured by the method of JIS L1013 8.6. The degree of the knot strength suitable for the present invention is preferably 0.5 cN/dtex or more, more preferably 1.0 cN/dtex or more, more preferably 1.5 cN/dtex or more, and most preferably 2.0 cN/dtex or more. Further, as another index, the bending rigidity is preferably smaller. The bending rigidity is generally measured by a measuring device such as a KES-FB2 pure bending tester manufactured by KATO TECH Co., Ltd. As a degree of bending rigidity suitable for the present invention, a carbon fiber "TENAX" (registered trademark) HTS40-3K manufactured by Toho Tenax Co., Ltd. is preferable. Specifically, the bending rigidity of the conductive fiber is 0.05×10. ^-4 N・m ² /m below is better, to 0.02×10 ^-4 N・m ² Below /m is preferred, to 0.01×10 ^-4 N・m ² Below /m is better. The optical purity of the polylactic acid is preferably 99% or more, more preferably 99.3% or more, and still more preferably 99.5% or more. When the optical purity is less than 99%, the piezoelectricity is remarkably lowered, and it is difficult to obtain a sufficient electric signal by the shape change of the piezoelectric fiber A. In particular, the piezoelectric fiber A contains poly-L-lactic acid or poly-D-lactic acid as a main component, and these optical purity is preferably 99% or more. The piezoelectric fiber A containing polylactic acid as a main component extends at the time of production and is uniaxially aligned in the fiber axis direction. Further, the piezoelectric fiber A is not only uniaxially aligned in the fiber axis direction, but preferably contains fibers of polylactic acid crystals, and more preferably fibers containing uniaxially oriented polylactic acid crystals. Since polylactic acid has high crystallinity and uniaxial alignment, it indicates large piezoelectricity, and the absolute value of d14 becomes high. [0054] Crystallinity and uniaxial alignment are achieved by uniform PLA crystallization degree X _Homo (%) and the crystal orientation degree Ao (%) were determined. As the piezoelectric fiber A of the present invention, the degree of crystallization of the PLA is X. _Homo (%) and the crystal orientation degree Ao (%) satisfy the following formula (1). In the case where the above formula (1) is not satisfied, crystallinity and/or uniaxial alignment are insufficient, and the output value of the electric signal to the operation is lowered, or the sensitivity of the signal to the action in a specific direction is lowered. The value on the left side of the above formula (1) is preferably 0.28 or more, more preferably 0.3 or more. Here, each value is obtained as follows. [0055] The degree of crystallization of homopolylactic acid X _Homo : For the degree of crystallization of homopolylactic acid X _Homo It is obtained by analyzing the crystal structure due to wide-angle X-ray diffraction analysis (WAXD). In the wide-angle X-ray diffraction analysis (WAXD), an ultrax18 type X-ray diffraction apparatus manufactured by Rigaku Co., Ltd. was used, and the X-ray diffraction pattern of the sample was recorded on the image plate by the penetration method using the following conditions. X-ray source: Cu-Kα ray (confocal lens) Output: 45kV × 60mA Slot: 1st: 1mmΦ, 2nd: 0.8mmΦ Photography length: 120mm Accumulated time: 10 minutes Sample: 35mg of polylactic acid fiber and yarn into 3cm Fiber bundles. In the obtained X-ray diffraction pattern, the total scattering intensity Itotal is obtained at the azimuth angle, and the diffraction peaks from the homopolylactic acid crystal appearing in the vicinity of 2θ=16.5°, 18.5°, and 24.3° are obtained here. The sum of the integrated intensities ΣIHMi. From these values, the degree of crystallization of the per-lactic acid is determined according to the following formula (2). _Homo . Homopolymeric crystallization degree X _Homo (%)=ΣI _HMi /I _Total ×100 (2) In addition, ΣI _HMi It is calculated by subtracting the background or amorphous diffuse scattering from the total scattering intensity. (2) Crystal orientation degree Ao: For the crystal orientation degree Ao, in the X-ray diffraction pattern obtained by the above wide-angle X-ray diffraction analysis (WAXD), for 2θ=16.5 appearing in the moving diameter direction The diffraction peak from the homopolylactic acid crystal near °, taking the intensity distribution with respect to the azimuth angle (°), and the total value of the half-value width from the obtained distribution curveΣ _Wi (°) is calculated by the following formula (3). Crystalline orientation Ao (%) = (360-ΣW _i ÷360×100 (3) [0057] In addition, since polylactic acid is a polyester which is rapidly decomposed by water, it is possible to add a known isocyanate compound, an oxazoline compound, or a ring when there is a problem in heat and humidity resistance. A hydrolyzing agent such as an oxygen compound or a carbodiimide compound may also be used. In addition, it is also possible to improve the physical properties by adding an oxidation preventing agent such as a phosphate compound, a plasticizer, a photodegradation preventing agent, or the like, as needed. [0058] The piezoelectric fiber A may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. In the case of a monofilament (including a spun yarn), the monofilament diameter is 1 μm to 5 mm, preferably 5 μm to 2 mm, more preferably 10 μm to 1 mm. In the case of a multifilament, the monofilament diameter is from 0.1 μm to 5 mm, preferably from 2 μm to 100 μm, more preferably from 3 μm to 50 μm. The number of filaments of the multifilament is preferably from 1 to 100,000, preferably from 50 to 50,000, and more preferably from 100 to 20,000. However, the fineness or the number of strips of the piezoelectric fiber A is determined by the fineness and the number of the strips of each carrier at the time of knitting, and the multifilament formed by a plurality of monofilaments (monofilaments) is also counted as A piezoelectric fiber A. Here, in the case where fibers other than the piezoelectric fibers are used in one carrier, the total amount is included. In order to make such a piezoelectric polymer into the piezoelectric fiber A, any one of the well-known methods for forming a fiber from a polymer can be used as long as the effect of the present invention is achieved. For example, a method of performing fibrillation by extrusion molding a piezoelectric polymer, a method of fibrillating a piezoelectric polymer by melt spinning, and a piezoelectricity by dry or wet spinning can be employed. A method in which a molecule is fibrillated, a method in which a piezoelectric polymer is fibrillated by electrospinning, a method of cutting a film after forming a film, and the like. These spinning conditions may be applied to a piezoelectric polymer to be used in accordance with a known method, and a melt spinning method which is industrially easy to produce may be used. Also, after the fibers are formed, the formed fibers are extended. Accordingly, the uniaxially elongated alignment is formed and the piezoelectric piezoelectric fiber A exhibiting large piezoelectricity is contained. Further, the piezoelectric fiber A is subjected to a treatment such as dyeing, crepe, bonding, heat treatment, or the like before the fiber produced as described above is knitted. Further, since the piezoelectric fibers A are frictionally broken or broken during the formation of the weaving, it is preferable that the fibers and the abrasion resistance are relatively high, and the strength is 1.5 cN/dtex. The above is preferable, preferably 2.0 cN/dtex or more, more preferably 2.5 cN/dtex or more, and 3.0 cN/dtex or more. The abrasion resistance can be evaluated by the JIS L1095 9.10.2 B method or the like, and the number of rubbing times is preferably 100 or more, preferably 1,000 or more, more preferably 5,000 or more, and most preferably 10,000 or more. The method for improving the abrasion resistance is not particularly limited, and all known methods can be used, for example, the degree of crystallization can be increased, or fine particles can be added, or surface processing can be performed. Further, when processing into a braid, it is also possible to apply a lubricant to the fibers to reduce friction. Further, it is preferable that the difference between the shrinkage ratio of the piezoelectric fiber and the shrinkage ratio of the conductive fiber is small. When the difference in shrinkage ratio is large, there is a change in the time when the heat is applied or the time is changed after the processing is performed or after the fabric is produced, or when the heat is applied, or the flatness of the fabric is deteriorated, and the piezoelectric signal becomes weak. The situation. When the shrinkage ratio is quantified by the boiling water shrinkage ratio described later, the boiling water shrinkage ratio S(p) of the piezoelectric fiber and the boiling water shrinkage ratio S(c) of the conductive fiber are preferably in the following formula (4). The left side of the above formula (4) is preferably 5 or less, and more preferably 3 or less. Further, it is preferable that the shrinkage ratio of the piezoelectric fiber is smaller than the difference between the shrinkage ratio of the fiber other than the conductive fiber, for example, the insulating fiber. When the difference in shrinkage ratio is large, there is a change in the time when the heat is applied or the time is changed after the processing or after the fabric is produced, or the film is bent, or the flatness of the fabric is deteriorated, and the piezoelectric signal is weakened. Happening. When the shrinkage ratio is quantified by the boiling water shrinkage ratio, the boiling water shrinkage ratio S(p) of the piezoelectric fiber and the boiling water shrinkage ratio S(i) of the insulating fiber satisfy the following formula (5). The left side of the above formula (5) is preferably 5 or less, and more preferably 3 or less. Further, it is preferable that the piezoelectric fiber has a small shrinkage ratio. For example, when the shrinkage ratio is quantified by the boiling water shrinkage ratio, the shrinkage ratio of the piezoelectric fiber is preferably 15% or less, preferably 10% or less, more preferably 5% or less, and most preferably 3% or less. good. As a means for reducing the shrinkage ratio, various methods can be applied. For example, the degree of alignment relaxation or crystallization of the amorphous portion is improved by heat treatment, whereby the shrinkage ratio can be lowered, and the timing of performing the heat treatment is not particularly limited, and extension is exemplified. After the crepe, after the weaving, after the cloth, and so on. Further, the boiling water shrinkage rate was measured by the following method. A skein having a number of rolls of 20 times was produced by a cloth inspection machine of 1.125 m around the outer frame, and a load of 0.022 cN/dtex was applied, and the initial skein length L0 was measured by hanging on a scale plate. Thereafter, the skein was treated in a boiling water bath at 100 ° C for 30 minutes, left to cool, and the above load was applied again, and suspended on a scale plate, and the length L of the skein after shrinkage was measured. The boiling water shrinkage ratio was calculated by the following formula (6) using the measured L0 and L. Boiling water shrinkage ratio = (L0 - L) / L0 × 100 (%) (6) [Coating] The conductive fiber B, that is, the core portion 103 is a piezoelectric fiber A, that is, a braided sheath portion 102 covers the surface. The thickness of the sheath portion 102 covering the conductive fibers B is preferably 1 μm to 10 mm, more preferably 5 μm to 5 mm, still more preferably 10 μm to 3 mm, and most preferably 20 μm to 1 mm. When it is too thin, there is a problem that there is a problem at the point of strength. Further, when it is too thick, the braided piezoelectric element 101 becomes hard and becomes difficult to be deformed. In addition, the sheath portion 102 is referred to herein as a layer adjacent to the core portion 103. In the braided piezoelectric element 101, the total fineness of the piezoelectric fibers A of the sheath portion 102 is preferably 1/2 or more and 20 or less times the total fineness of the conductive fibers B of the core portion 103. It is preferably 1 time or more and 15 times or less, more preferably 2 times or more and 10 times or less. When the total fineness of the piezoelectric fiber A to the total fineness of the conductive fiber B is too small, the piezoelectric fiber A surrounding the conductive fiber B is too small, the conductive fiber B cannot output a sufficient electric signal, and the conductive fiber B is present. Contact with other conductive fibers that are close to each other. When the total fineness of the piezoelectric fiber A is too large for the total fineness of the conductive fiber B, the piezoelectric fiber A surrounding the conductive fiber B is excessively large, and the braided piezoelectric element 101 becomes hard and becomes hard to be deformed. That is, even in either case, the braided piezoelectric element 101 cannot function as a sensor sufficiently. The total fineness referred to herein is the sum of the deniers of the piezoelectric fibers A constituting the sheath portion 102. For example, in the case of generally 8-strand weaving, the total densities of the eight fibers are obtained. Further, in the braided piezoelectric element 101, the fineness of each of the piezoelectric fibers A of the sheath portion 102 is preferably 1/20 or more and 2 or less times the total fineness of the conductive fibers B. It is preferably 1/15 times or more and 1.5 times or less, more preferably 1/10 times or more and 1 time or less. When the fineness of each of the piezoelectric fibers A is too small with respect to the total fineness of the conductive fibers B, the piezoelectric fibers A are too small, the conductive fibers B cannot output a sufficient electric signal, and the piezoelectric fibers A are cut off. Hey. When the fineness of each of the piezoelectric fibers A is excessively large with respect to the total fineness of the conductive fibers B, the piezoelectric fibers A are excessively thick, and the braided piezoelectric element 101 becomes hard and becomes difficult to be deformed. That is, even in either case, the braided piezoelectric element 101 cannot function as a sensor sufficiently. In the case where the conductive fiber B is a metal fiber or the metal fiber is blended in the conductive fiber A or the piezoelectric fiber B, the ratio of the fineness is not limited to the above. In the present invention, the above ratio is important in terms of contact area or coverage ratio, that is, from the viewpoint of area and volume. For example, in the case where the specific gravity of each fiber exceeds 2, the ratio of the average cross-sectional area of the fibers is preferably the ratio of the above-mentioned fineness. [0069] Although the piezoelectric fiber A and the conductive fiber B are preferably as close as possible to each other, in order to improve the adhesion, an anchor layer or a bonding layer may be provided between the conductive fiber B and the piezoelectric fiber A. . [0070] The method of coating is a method in which the conductive fiber B is used as a core yarn, and the piezoelectric fiber A is wound around the braided shape. Further, the braided shape of the piezoelectric fiber A is not limited as long as it can output an electric signal to the stress generated by the applied load, and it is preferable to have the 8-strand braid or the 16-strand weave having the core portion 103. The shape of the conductive fiber B and the piezoelectric fiber A is not particularly limited, and it is preferably as close as possible to a concentric shape. In the case where a multifilament is used as the conductive fiber B, the piezoelectric fiber A may be coated with at least a part of the surface (fiber peripheral surface) of the multifilament of the conductive fiber B, even if It is also possible to coat the surface of the fibrils (fiber peripheral surface) constituting the multifilaments with the piezoelectric fibers A, even if they are not coated. The state in which the piezoelectric fibers A are coated in the respective filaments of the multifilaments of the conductive fibers B may be appropriately set in consideration of performance, workability, and the like of the piezoelectric element. Since the braided piezoelectric element 101 of the present invention does not need to have electrodes on its surface, it is not necessary to further coat the body of the braided piezoelectric element 101, and further, it is difficult to cause an erroneous operation. (Manufacturing Method) The braided piezoelectric element 101 of the present invention covers the surface of at least one of the conductive fibers B by the braided piezoelectric fibers A. However, as a method for producing the same, for example, the following method can be mentioned. In other words, the conductive fiber B and the piezoelectric fiber A are separately produced, and the piezoelectric fiber A is wound into a braided shape to coat the conductive fiber B. In this case, it is preferable to cover as close as possible to a concentric shape. In this case, the spinning and stretching conditions in which the piezoelectric polymer A forming the piezoelectric fiber A is preferably used in the case of using polylactic acid have a melt spinning temperature of 150 ° C to 250 ° C. Preferably, the extension temperature is preferably from 40 ° C to 150 ° C, the stretching ratio is preferably from 1.1 to 5.0, and the crystallization temperature is preferably from 80 ° C to 170 ° C. [0075] As the piezoelectric fiber A wound around the conductive fiber B, a multifilament of a bundle of a plurality of filaments may be used, and even a monofilament (including a textile yarn) may be used. In addition, as the conductive fiber B wound around the piezoelectric fiber A, even if a multifilament of a bundle of a plurality of filaments is used, a single filament (including a textile yarn) may be used. Further, the conductive fiber B may be subjected to crepe processing. [0076] As a preferred embodiment of the coating, the piezoelectric fiber A can be knitted into a braided shape by using the conductive fiber B as a core yarn, and a tubular braid (Tubular Braid) can be produced to be coated. More specifically, an 8-strand woven or a 16-knit woven fabric having a core portion 103 can be cited. In this case, although the piezoelectric fiber A is preferably a fiber subjected to crepe processing, even if all of the piezoelectric fibers are subjected to crepe processing, a part of the piezoelectric fiber may be subjected to crepe processing. Further, all of the piezoelectric fibers A used in the twist direction of the piezoelectric fibers A do not have to be in the same direction. For example, it is possible to use a fiber which is subjected to S twist processing for a fiber which is rotated clockwise during knitting, and a fiber which is subjected to Z twist processing for a fiber which is rotated in the counterclockwise direction. Further, in the case of, for example, 8-strand weaving, it is not necessary to use all of the eight piezoelectric fibers, and other fibers may be used in the range of the signal intensity to be used as the purpose. Of course, it is also possible to use a fiber which is subjected to crepe processing of the conductive fiber of the core and the conductive fiber which becomes a shield layer. However, for example, even if the piezoelectric fiber A is in the form of a braided tube, the conductive fiber B is regarded as a core portion, and the braided tube may be inserted and coated. [0077] By the above-described manufacturing method, the braided piezoelectric element 101 in which the surface of the conductive fiber B is coated with the braided piezoelectric fiber A can be obtained. [0078] The braided piezoelectric element 101 of the present invention can be relatively easily manufactured because it is necessary to form an electrode for detecting an electric signal on the surface. (Protective Layer) A protective layer may be provided on the outermost surface of the braided piezoelectric element 101 of the present invention. The protective layer is preferably insulating, and is preferably composed of a polymer from the viewpoint of flexibility. In the case where the protective layer is insulative, of course, in this case, the protective layer may be deformed together or rubbed on the protective layer, but if the external force reaches the piezoelectric fiber A, it may be induced. When it is polarized, it is not particularly limited. The protective layer is not limited to those formed by coating of a polymer or the like, and may be a wound film, a cloth, a fiber, or the like, or may be combined. [0080] As the thickness of the protective layer, the shear stress is more easily transmitted to the piezoelectric fiber A at a thinner thickness, but when it is too thin, the protective layer itself is easily broken, and the like. 10 nm to 200 μm is preferred, preferably 50 nm to 50 μm, more preferably 70 nm to 30 μm, and most preferably 100 nm to 10 μm. The shape of the piezoelectric element can also be formed by the protective layer. Further, for the purpose of reducing noise, the electromagnetic wave shielding layer may have a woven structure. The electromagnetic wave shielding layer is not particularly limited, but a conductive film, a cloth, a fiber, or the like may be wound even if a conductive material is applied. As the electromagnetic wave shielding layer, the volume resistivity is 10 ^-1 Ω・cm or less is better, with 10 ^-2 Ω·cm or less is preferred, with 10 ^-3 Ω·cm or less is more preferable. However, if the effect of the electromagnetic wave shielding layer is obtained, the resistivity is not limited thereto. The electromagnetic wave shielding layer may be provided on the surface of the piezoelectric fiber A of the sheath portion, and may be provided on the outer side of the protective layer. Of course, even if a plurality of layers of the electromagnetic wave shielding layer and the protective layer are laminated, the order is appropriately determined depending on the purpose. Further, a layer of a plurality of layers of piezoelectric fibers or a layer of a plurality of layers of conductive fibers for taking out signals may be provided. Needless to say, the order of the protective layer, the electromagnetic wave shielding layer, the layer composed of the piezoelectric fibers, and the layer composed of the conductive fibers is appropriately determined depending on the purpose. Further, as a method of winding, a method of forming a woven structure or covering the outer layer of the sheath portion 102 may be mentioned. When the conductor is disposed on the center axis side and the outside of the piezoelectric structure as described above, it can be considered that the conductor on the central axis side and the conductor on the outer side are electrodes of two poles and sandwich piezoelectricity. A capacitor-like piezoelectric element of a polymer (dielectric). In order to effectively take out the electric signal induced by the polarization of the piezoelectric structure by deformation, the value of the insulation resistance between the electrodes is preferably 1 MΩ or more when measured with a DC voltage of 3 V. It is preferably 10 MΩ or more, more preferably 100 MΩ or more. Further, even if the value of the equivalent series resistance Rs and the equivalent series capacitance Cs obtained by the response when the AC voltage of 1 MHz is supplied between the electrodes is analyzed, the value is effectively taken out by the deformation. In the polarization-induced electrical signal of the piezoelectric structure, the responsiveness is improved, so that it is preferably within a specific value range. That is, the value of Rs is preferably 1 μΩ or more and 100 kΩ or less, preferably 1 mΩ or more and 10 kΩ or less, more preferably 1 mΩ or more and 1 kΩ or less, and the value of Cs is divided by the length of the central axis direction of the piezoelectric structure ( The value of cm) is preferably 0.1 pF or more and 1000 pF or less, more preferably 0.2 pF or more and 100 pF or less, and more preferably 0.4 pF or more and 10 pF or less. As described above, when the piezoelectric structure and the element composed of the electrode are in a good state, the equivalent series resistance obtained by supplying a response of supplying an alternating current voltage of 1 MHz between the electrodes is analyzed. The values of the value Rs and the equivalent series capacitance Cs are obtained within a specific range, and it is preferable to use the values for the inspection of the piezoelectric structure. Furthermore, the piezoelectric structure can be inspected not only by the values of Rs and Cs obtained by the analysis of the alternating voltage, but also by analyzing the transient response with respect to other electrical stimuli. (Operation) The braided piezoelectric element 101 of the present invention can be applied, in particular, to a central axis of a cylindrical piezoelectric structure formed from the sheath portion 102, that is, a twist of the conductive fiber B as an axis. In the case of deformation (stress), a large electrical signal is efficiently output. In addition, it does not deform or bend telescopically, and the frictional deformation outputs a large electrical signal. Here, as the torsional deformation supplied to the braided piezoelectric element 101, it is preferable to apply it in a range of the amount of deformation in which the fibers in the unfilled element start plastically deforming. The amount of deformation depends on the physical properties of the fibers used. However, it is not limited to this use without the intention of repeating specifications. (Corrugated Piezoelectric Element) FIG. 5 is a schematic view showing a configuration example of a cloth-like piezoelectric element using a braided piezoelectric element according to an embodiment. The cloth-like piezoelectric element 107 is provided with a fabric 108 including at least one braided piezoelectric element 101. At least one of the fibers (including knitting) constituting the fabric of the fabric 108 is a braided piezoelectric element 101, and the braided piezoelectric element 101 is not limited as long as it functions as a piezoelectric element, and even any braid can be used. . In the case of forming a cloth, as long as the object of the present invention is achieved, it is possible to perform interlacing, interlacing, and the like in combination with other fibers (including knitting). Of course, even if the braided piezoelectric element 101 is used as one of the fibers (for example, warp or weft) constituting the fabric, the braided piezoelectric element 101 can be embroidered on the fabric even if it is joined. In the example shown in FIG. 5, the cloth-like piezoelectric element 107 is a flat fabric in which at least one of the braided piezoelectric element 101 and the insulating fiber 109 is disposed as a warp yarn, and the conductive fiber 110 and the insulating fiber 109 are alternately arranged as a weft. The conductive fiber 110 may be the same type as the conductive fiber B, and may be a different type of conductive fiber, and the insulating fiber 109 will be described later. Further, all or a part of the insulating fibers 109 and/or the conductive fibers 110 may be in a woven form. In this case, when the braided piezoelectric element 107 is deformed by bending or the like, the braided piezoelectric element 101 is also deformed with the deformation, and is output from the braided piezoelectric element 101. The electrical signal can detect the deformation of the braided piezoelectric element 107. Further, since the cloth-like piezoelectric element 107 can be used as a fabric (woven fabric), it can be applied to, for example, a garment-type wearable sensor. Further, in the cloth-like piezoelectric element 107 shown in FIG. 5, the conductive fibers 110 are in contact with the braided piezoelectric element 101. Therefore, the conductive fiber 110 is in contact with at least a part of the braided piezoelectric element 101, and covered, it is possible to shield at least a part of the electromagnetic wave to be applied to the braided piezoelectric element 101 from the outside. Such a conductive fiber 110 has a function of reducing the influence of electromagnetic waves on the braided piezoelectric element 101 by being grounded. That is, the conductive fiber 110 can function as an electromagnetic wave shield of the braided piezoelectric element 101. According to this, even if the conductive fabric for electromagnetic wave shielding is not superposed on the cloth-like piezoelectric element 107, for example, the S/N ratio of the piezoelectric element 107 can be remarkably improved. In this case, from the viewpoint of electromagnetic wave shielding, the higher the ratio of the conductive fibers 110 of the weft yarn (in the case of FIG. 5) crossing the braided piezoelectric element 101, the better. Specifically, it is preferable that 30% or more of the fibers which form the fabric of the fabric 108 and which intersect the braided piezoelectric element 101 are conductive fibers, preferably 40% or more, more preferably 50% or more. In this manner, in the cloth-like piezoelectric element 107, by placing the conductive fibers as at least a part of the fibers constituting the fabric, the piezoelectric element 107 having the electromagnetic wave shield can be provided. [0088] The woven structure of the woven fabric may be exemplified by a three-fold structure such as a plain weave, a twill weave, a satin weave, a modified structure, a double-weave structure such as a double weave, a weft double weave, and the like. Even if it is a warp knitted fabric (weft weaving), it can be used as a warp. As the organization of the circular knitting fabric (weft knitting), it is preferable to exemplify a flat knitting, a rib knitting, a double sided knitting, a reverse stitch knitting, a hanging needle knitting, a floating thread knitting, a half-side knitting, a yarn knitting, and a wool knitting. As a warp knitting organization, a single-sided warp-knit flat weave, a single-sided warp-knitted satin stitch, a double-sided warp-knitted quilt, a velvet-warp woven, a velvet knitting, a jacquard knitting, and the like can be exemplified. The number of layers may be a single layer or a multilayer of two or more layers. Further, it is also possible to form a woven fabric or a woven fabric composed of a bristles and a base tissue portion which are formed by woven wool and/or loops. (Multiple Piezoelectric Elements) Further, in the cloth-like piezoelectric element 107, a plurality of braided piezoelectric elements 101 can be arranged and used. As the arrangement, for example, as the warp yarn or the weft yarn, even if the braided piezoelectric element 101 is used entirely, the braided piezoelectric element 101 may be used for every few or a part. Further, even if a certain portion uses the braided piezoelectric element 101 as a warp yarn, and the other portion uses the braided piezoelectric element 101 as a weft yarn. [0090] In this manner, when the plurality of braided piezoelectric elements 101 are arranged to form the cloth-like piezoelectric element 107, since the braided piezoelectric element 101 does not have an electrode on the surface, it is possible to select it in a wide range. The advantages of arrangement and weaving. Further, in the case where the plurality of woven piezoelectric elements 101 are arranged, since the distance between the conductive fibers B is short, efficiency is obtained in the extraction of the electric signals. (Insulating Fiber) In the cloth-like piezoelectric element 107, an insulating fiber can be used in a portion other than the braided piezoelectric element 101 (and the conductive fiber 110). In this case, the insulating fiber is used for the purpose of improving the flexibility of the cloth-like piezoelectric element 107, and a fiber having a stretchable material or shape can be used. In this way, by arranging the insulating fibers in addition to the braided piezoelectric element 101 (and the conductive fibers 110), the operability of the cloth-like piezoelectric element 107 can be improved (illustration: as a wearable sensor) Activity is easy). [0094] As such an insulating fiber, if the volume resistivity is 10 ⁶ It can be used when Ω・cm or more, to 10 ⁸ Ω·cm or more is preferred, with 10 ¹⁰ Ω·cm or more is more preferable. [0095] As the insulating fiber, for example, in addition to polyester fiber, nylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, vinyl chloride fiber, aromatic polyamide fiber, polyfluorene fiber, polyether fiber, polyamine group In addition to synthetic fibers such as formate fibers, natural fibers such as cotton, hemp, and enamel, semi-synthetic fibers such as acetate, and regenerated fibers such as hydrazine or copper amine can be used. It is not limited to these, and the well-known insulating fiber can be used arbitrarily. In addition, even if these insulating fibers are used in combination, they may be used in combination with fibers having no insulating properties, and may be fibers having overall insulating properties. [0096] Further, it is also possible to use fibers of all known cross-sectional shapes. (Applicable Techniques of Piezoelectric Element) The piezoelectric element such as the braided piezoelectric element 101 or the cloth-like piezoelectric element 107 of the present invention can be output as a braided piezoelectric element even in any aspect. The central axis is the torsional deformation (stress) of the shaft as an electrical signal, and can be utilized as a sensor (device) that detects the magnitude of the stress applied to its piezoelectric element and/or the position to be applied. In the method of arranging the braided piezoelectric element in the piezoelectric element, when the piezoelectric element is bent, stretched, and subjected to deformation or stress such as pressing, the braided piezoelectric element is torsionally deformed. It is also possible to output electrical signals by deformation or stress of bending, stretching, pressing, etc. of the cloth-like piezoelectric element. Further, the electric signal may be used as a power source for powering another device or a power generating element such as power storage. Specifically, it is used for power generation by a movable part of a spontaneous exerciser such as a human, an animal, a robot, or a machine, and the power generation due to the surface of the sole, the dressing, and the structure of the external pressure is caused by the fluid. The shape changes in the power generation. Furthermore, since the electrical signal is emitted by the shape change in the fluid, it is also possible to adsorb or suppress the adhesion of the charged substance in the fluid. 6 is a block diagram showing a device 111 including a piezoelectric element 112 of the present invention. The device 111 includes a piezoelectric element 112 (exemplified by a braided piezoelectric element 101 and a cloth-like piezoelectric element 107), and an electric signal that is arbitrarily selected to amplify the output from the output terminal of the piezoelectric element 112 in response to the applied pressure. The amplifying means 113 and the output means 114 for outputting the electric signal amplified by the arbitrarily selected amplifying means 113, and the transmitting means 115 for transmitting the electric signal outputted from the output means 114 to an external device (not shown) Circuit. When the device 111 is used, the electrical signal outputted according to the contact, pressure, and shape change of the surface of the piezoelectric element 112 can be detected and applied to the piezoelectric element by an external device (not shown). The central axis of the braided piezoelectric element is the magnitude of the torsional deformation (stress) of the shaft and/or the position to be applied. [0099] The arbitrarily selected amplification means 113, the output means 114, and the transmission means 115 may be constructed by, for example, a software program, or may be constructed by a combination of various electronic circuits and software programs. For example, the software program is installed in an arithmetic processing unit (not shown), and the arithmetic processing unit operates in accordance with the software program, thereby realizing the functions of the respective units. Furthermore, the arbitrarily selected amplification means 113, the output means 114, and the transmission means 115 may be realized as a semiconductor integrated circuit for writing a software program for realizing the functions of the respective units. Further, the transmission method by the transmission means 115 may be determined by wireless or wired, and may be appropriately determined in accordance with the sensor configured. Alternatively, even in the device 111, an arithmetic means (not shown) for calculating the magnitude of the stress applied to the piezoelectric element 112 and/or the applied position based on the electrical signal output from the output means 114 may be provided. . Further, not only the amplifying means but also a well-known signal processing means such as a means for removing noise or a means for performing processing in combination with other signals may be used. The order of connection of these means can be appropriately changed depending on the purpose. Of course, even if the electrical signal output from the piezoelectric element 112 is transmitted to the external device as it is, the signal processing can be performed. 7 and FIG. 8 are schematic views showing a configuration example of an apparatus including a braided piezoelectric element according to an embodiment. The amplification means 113 of Figs. 7 and 8 corresponds to the description with reference to Fig. 6, and the output means 114 and the transmission means 115 of Fig. 6 are not shown in Figs. 7 and 8. In the case of constituting the device having the cloth-like piezoelectric element 107, the input terminal of the amplification means 113 is connected to the output terminal of the core portion 103 (formed by the conductive fiber B) of the braided piezoelectric element 101. The wire and the earth terminal are connected to a braided piezoelectric element or conductive fiber 110 which is different from the braided piezoelectric element 101 connected to the input terminal of the amplification means 113. For example, as shown in FIG. 7, in the cloth-like piezoelectric element 107, the drawing wire from the core portion 103 of the braided piezoelectric element 101 is connected to the input terminal of the amplifying means 113, and the weaving pressure is applied. The conductive fibers 110 that the electrical components 101 cross and contact are grounded. Further, as shown in FIG. 8, when the plurality of braided piezoelectric elements 101 are arranged in the cloth-like piezoelectric element 107, the pull-out line from the core portion 103 of one knitted piezoelectric element 101 is connected to The input terminal of the amplification means 113 grounds the pull-out line from the core portion 103 of the other braided piezoelectric element 101 arranged in the braided piezoelectric element 101. When the torsional deformation centering on the central axis of the braided piezoelectric element 101 is generated, the piezoelectric fiber A is polarized. The influence of the arrangement of the positive and negative charges generated by the polarization of the piezoelectric fiber A causes the movement of the electric charge on the drawing line from the output terminal of the conductive fiber B forming the core portion 103 of the braided piezoelectric element 101. On the pull-out line from the conductive fiber B, a slight electrical signal (i.e., current or potential difference) appears in the movement of the electric charge. In other words, the electric signal generated at the time of the torsional deformation of the central axis of the braided piezoelectric element 101 (the central axis of the cylindrical shape in which the piezoelectric polymer is disposed) is outputted from the output terminal. The amplifying means 113 amplifies the electric signal, the output means 114 outputs the electric signal amplified by the amplifying means 113, and the transmitting means 115 transmits the electric signal outputted from the output means 114 to an external device (not shown). The device 111 of the present invention has flexibility, and can be used in any of a braided shape and a cloth-like shape, so that it can be imagined for a very wide range of applications. Specific examples of the device 111 of the present invention include a touch panel that is shaped like a hat, a glove, a sock, and the like, which is a garment, a support, a handkerchief, and the like, and is used as a surface pressure sensor for humans or animals. For example, a sensor that bends, twists, and expands and contracts the joint portion in the shape of a glove, a belt, a support, or the like is detected. For example, when it is used in a person, it is possible to use an information collection for an action such as a joint for medical use, an entertainment use, or an interface for moving a lost tissue or a robot. Further, a surface pressure sensor which is a cloth doll or a robot that mimics an animal or a human type, and a sensor that detects bending, twisting, and expansion of the joint portion can be used. Further, a surface pressure sensor or a shape change sensor which is a bedding, a sole, a glove, a chair, a dressing, a bag, a flag, or the like as a bed sheet or a pillow or the like can be used. [0103] Further, the device 111 of the present invention is It is woven or cloth-like and has flexibility. Therefore, it can be used as a surface pressure sensor or shape change sensor by attaching or covering the surface of all or part of all structures. Moreover, since the device 111 of the present invention can generate sufficient electrical signals only by rubbing the surface of the piezoelectric element 101, it can be used for a touch sensor-like touch input device or pointing device. Further, since the surface of the object to be measured is wiped by the braided piezoelectric element 101, position information or shape information in the height direction of the object to be measured can be obtained, and thus it can be used for surface shape measurement or the like. [0105] Hereinafter, the second invention will be described in detail. (Wolen piezoelectric element) In the braided piezoelectric element according to the second aspect of the invention, the piezoelectric polymer in the structure according to the first aspect of the invention can be arranged in a cylindrical shape. An element having a conductor made of a conductive fiber is disposed at a position of the central axis, that is, an element in which a piezoelectric polymer is woven into a braided shape as a piezoelectric fiber and disposed around the conductive fiber. Hereinafter, the braided piezoelectric element according to the second invention will be described in detail. 10 is a schematic view showing a configuration example of a braided piezoelectric element according to an embodiment. The braided piezoelectric element 201 includes a core portion 203 formed of a conductive fiber B, and a sheath portion 202 formed of a piezoelectric fiber A having a braided shape so as to cover the core portion 203, and a conductive portion of the sheath portion 202. Layer 204. The conductive layer 204 also functions as an electrode that serves as a counter electrode of the conductive fiber of the core portion 203, and the conductive fiber that shields the core portion 203 prevents electromagnetic waves from the outside, and suppresses the noise signal generated by the conductive fiber in the core portion 203. The function of the shield. [0107] The coating ratio of the sheath portion 202 by the conductive layer 204 is preferably 25% or more. Here, the coverage ratio is a ratio of the area of the conductive material 205 contained in the conductive layer 204 when the conductive layer 204 is projected to the sheath portion 202 and the surface area of the sheath portion 202, and the value is preferably 25% or more. More than 50% is preferred, and more preferably 75% or more. When the coverage of the conductive layer 204 is less than 25%, the effect of suppressing the noise signal may not be sufficiently exhibited. When the conductive material 205 is not exposed to the surface of the conductive layer 204, for example, when the fiber containing the conductive material 205 is used as the conductive layer 204 to coat the sheath portion 202, the sheath portion 202 toward the fiber may be applied. The ratio of the area at the time of projection to the surface area of the sheath portion 202 is set as the coverage ratio. The conductive material 205 is a conductive material contained in the conductive layer 204 and corresponds to a known owner. In the braided piezoelectric element 201, a plurality of piezoelectric fibers A are densely wound around the outer peripheral surface of at least one of the conductive fibers B. When the braided piezoelectric element 201 is deformed, stress is generated by deformation of each of the plurality of piezoelectric fibers A. Accordingly, an electric field (piezoelectric effect) is generated in each of the piezoelectric fibers A, and as a result, it is estimated The conductive fiber B has a voltage change that overlaps with the electric field of the plurality of piezoelectric fibers A wound around the conductive fiber B. That is, the electric signal from the conductive fiber B is increased as compared with the case where the braided sheath portion 202 of the piezoelectric fiber A is not used. Accordingly, in the braided piezoelectric element 201, a large electric signal can be taken out even by a stress generated by a relatively small deformation. Further, the conductive fibers B may be plural pieces. From the viewpoint of achieving the object of the second invention, the braided piezoelectric element 201 has a ratio d/Rc of the thickness Rc of the layer composed of the piezoelectric fibers to the radius Rc of the core portion 203, which will be described later. In addition, the configuration shown in FIG. 10 is not particularly limited, but from the viewpoint of selectively outputting a large electric signal to the torsional deformation centered on the central axis thereof, the following configuration is employed. It is better. As the braided piezoelectric element 201 that selectively outputs a large electric signal to the torsional deformation centered on the central axis, the piezoelectric fiber A is arranged in a cylindrical shape using the aligned piezoelectric polymer. The alignment angle of the piezoelectric polymer in the direction of the central axis of the cylindrical shape in which the piezoelectric polymer is disposed is 0° or more and 40° or less, or 50° or more and 90° or less, and 0° or more and 35° or less. The following is preferably 55° or less and 90° or less, more preferably 0° or more and 30° or less, or 60° or more and 90° or less, and more preferably 0° or more and 25° or less or 65° or more and 90° or less. The above is less than 15° or more than 75° and more preferably 90° or less, and more preferably 0° or more and 10° or less, or 80° or more and 90° or less, and the piezoelectric polymer includes the alignment axis. The crystal constant of the piezoelectric constant d14 at the time of the three-axis is a structure in which a crystalline polymer having a value of 0.1 pC/N or more and 1000 pC/N or less is a main component. Further, the piezoelectric polymer is more preferably a structure comprising a P-body having a positive piezoelectric polymer d14 as a main component and a negative crystalline polymer as a main component. The N body has a length of 1 cm for the central axis of the structure, and the alignment axis is wound into a spiral. The mass of the P body disposed in the Z direction is set to ZP, and the alignment axis is wound into a spiral. The mass of the P body is set to SP, the alignment axis is wound into a spiral, the mass of the N body is set to ZN, and the alignment axis is wound into a spiral, and the N is disposed at the S direction. The mass of the body is set to SN, and one of (ZP+SN) and (SP+ZN) is set to T1, and when the larger one is set to T2, the value of T1/T2 exceeds 0.8, especially over 0.8. Below 1.0, or above 0.9, especially above 0.9 and below 1.0. Further, although the value of d14 indicates different values depending on molding conditions, purity, and measurement environment, in the present invention, the degree of crystallization of the crystalline polymer in the piezoelectric polymer actually used is measured. Crystalline alignment degree, using the crystalline polymer to form a uniaxially stretched film having the same degree of crystallinity and crystal orientation, and if the absolute value of the film d14 is 0.1 pC/N or more and 1000 pC in the actual use temperature. In the case of a value of 5% or less, the crystalline polymer contained in the piezoelectric polymer of the present embodiment is not limited to the specific crystalline polymer described later. The d14 of the film sample can be measured by various methods, but for example, a metal is vapor-deposited on both sides of the film sample to form a sample of the electrode, and is cut into a rectangle having four sides in a direction inclined by 45 degrees from the extending direction. The value of d14 can be measured by measuring the charge generated at the electrodes on both sides when a tensile load is applied in the longitudinal direction thereof. When a fiber containing polylactic acid as a main component is used as the piezoelectric fiber of the present invention, the lactic acid unit in the polylactic acid is preferably 90 mol% or more, and more preferably 95 mol% or more. It is better to use 98% or more. In addition, in the braided piezoelectric element 201, even if the sheath portion 202 and the other fibers other than the piezoelectric fiber A are combined with each other, the core portion 203 and the conductive portion may be electrically conductive. It is also possible to mix fibers or the like with other fibers other than the fiber B. The length of the braided piezoelectric element composed of the core portion 203 of the conductive fiber B, the sheath portion 202 of the braided piezoelectric fiber A, and the conductive layer 204 of the sheath portion 202 is not particularly limited. For example, even if the braided piezoelectric element is continuously manufactured in the production, it may be used after being cut into a length required later. The length of the braided piezoelectric element is 1 mm to 10 m, preferably 5 mm to 2 m, and preferably 1 cm to 1 m. When the length is too short, the fiber shape is lost, that is, convenience, and when the length is too long, the resistance value of the conductive fiber B needs to be considered. Hereinafter, each configuration will be described in detail. (Electrically Conductive Fiber) As the conductive fiber B, any known fiber can be used as the fiber indicating conductivity. Examples of the conductive fiber B include a fiber composed of a metal fiber, a fiber composed of a conductive polymer, a carbon fiber, a polymer in which a fibrous or granular conductive filler is dispersed, or a fibrous material. A fiber having a conductive layer is provided on the surface. Examples of the method of providing a conductive layer on the surface of the fibrous material include metal coating, conductive polymer coating, and winding of conductive fibers. Among them, metal coating is preferred from the viewpoints of conductivity, durability, flexibility, and the like. The specific method of coating the metal is, for example, vapor deposition, sputtering, electrolytic plating, electroless plating, etc., but plating is preferred from the viewpoint of productivity and the like. The metal thus plated may be referred to as a metal plated fiber. [0115] As the fiber of the substrate to which the metal is applied, well-known fibers can be used regardless of the presence or absence of conductivity, for example, in addition to polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, vinyl chloride fibers, aromatic poly In addition to synthetic fibers such as polyamide fibers, polyfluorene fibers, polyether fibers, and polyurethane fibers, semi-synthetic fibers such as natural fibers such as cotton, hemp, and enamel, and acetate, and hydrazine may be used. Regenerated fiber such as copper amine fiber. The fibers of the substrate are not limited thereto, and any known fibers may be used arbitrarily, and these fibers may be used in combination. The metal of the fiber applied to the substrate represents electrical conductivity, and any one may be used as long as the effect of the present invention is achieved. For example, gold, silver, platinum, copper, nickel, tin, lead, palladium, indium tin oxide, copper sulfide, or the like, and mixtures or alloys thereof may be used. When the conductive fiber B is coated with a metal coated organic fiber having bending resistance, the conductive fiber is rarely broken, and the durability and safety of the sensor using the piezoelectric element are excellent. [0118] The conductive fiber B may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. Multifilament is preferred from the viewpoint of the stability of the electrical properties. In the case of a monofilament (including a spun yarn), the monofilament diameter is from 1 μm to 5000 μm, preferably from 2 μm to 100 μm. It is preferably 3 μm to 50 μm. In the case of multifilaments, as the number of filaments, it is preferably from 1 to 100,000, preferably from 5 to 500, more preferably from 10 to 100. However, the fineness and the number of the conductive fibers B are the fineness and the number of the core portions 203 used in the production of the knitting, and the multifilament formed by a plurality of monofilaments (monofilaments) is also counted as one. Conductive fiber B. Here, the core portion 203 is provided to include the entire amount of the fiber even when a fiber other than the conductive fiber is used. [0119] When the diameter of the fiber is small, the strength is lowered and it becomes difficult to handle, and further, in the case where the diameter is large, flexibility is sacrificed. The cross-sectional shape of the conductive fiber B is preferably a circle or an ellipse from the viewpoint of design and manufacture of the piezoelectric element, but is not limited thereto. [0120] Furthermore, in order to efficiently take out the electrical output from the piezoelectric polymer, it is preferable that the electric resistance is low, and the volume resistivity is 10 ^-1 Ω・cm or less is better, with 10 ^-2 Ω·cm or less is preferred, with 10 ^-3 Ω·cm or less is more preferable. However, the resistivity of the conductive fiber B is not limited to this in order to obtain sufficient strength for detecting the electrical signal. From the viewpoint of the use of the present invention, the conductive fiber B must have resistance to repeated bending or twisting. As its index, the nodule strength is preferably larger. The knot strength can be measured by the method of JIS L1013 8.6. The degree of the knot strength suitable for the present invention is preferably 0.5 cN/dtex or more, more preferably 1.0 cN/dtex or more, more preferably 1.5 cN/dtex or more, and most preferably 2.0 cN/dtex or more. Further, as another index, the bending rigidity is preferably smaller. The bending rigidity is generally measured by a measuring device such as a KES-FB2 pure bending tester manufactured by KATO TECH Co., Ltd. As a degree of bending rigidity suitable for the present invention, a carbon fiber "TENAX" (registered trademark) HTS40-3K manufactured by Toho Tenax Co., Ltd. is preferable. Specifically, the bending rigidity of the conductive fiber is 0.05×10. ^-4 N・m ² /m below is better, to 0.02×10 ^-4 N・m ² Below /m is preferred, to 0.01×10 ^-4 N・m ² Below /m is better. (Piezoelectric fiber) The piezoelectric polymer, which is a material of the piezoelectric fiber A, may be a piezoelectric polymer such as polyvinylidene fluoride or polylactic acid. In the above-described form, the piezoelectric fiber A preferably contains a crystalline polymer having a high absolute value of the piezoelectric constant d14 when the alignment axis is three axes, and particularly preferably polylactic acid as a main component. In the melt spinning, for example, the melt spinning is easy to align by stretching, and the piezoelectricity is exhibited, and the electric field alignment treatment necessary for polyvinylidene fluoride or the like is not required, and the productivity is excellent. However, this is not intended to exclude the use of piezoelectric materials other than polyvinylidene fluoride when the present invention is practiced. As the polylactic acid, a poly-L-lactic acid obtained by polymerizing L-lactic acid or L-lactide may be used to polymerize D-lactic acid and D-lactide. The poly-D-lactic acid has a stereocomplex polylactic acid or the like formed by the above-described mixed structure, but it can be used if it is a piezoelectric property. From the viewpoint of high piezoelectricity, poly-L-lactic acid and poly-D-lactic acid are preferred. Since poly-L-lactic acid and poly-D-lactic acid have opposite polarizations for the same stress, they can be used in combination according to the purpose. The optical purity of the polylactic acid is preferably 99% or more, more preferably 99.3% or more, and still more preferably 99.5% or more. When the optical purity is less than 99%, the piezoelectricity is remarkably lowered, and it is difficult to obtain a sufficient electric signal by the shape change of the piezoelectric fiber A. In particular, the piezoelectric fiber A contains poly-L-lactic acid or poly-D-lactic acid as a main component, and these optical purity is preferably 99% or more. The piezoelectric fiber A containing polylactic acid as a main component extends at the time of production and is uniaxially aligned in the fiber axis direction. Further, the piezoelectric fiber A is not only uniaxially aligned in the fiber axis direction, but preferably contains fibers of polylactic acid crystals, and more preferably fibers containing uniaxially oriented polylactic acid crystals. Since polylactic acid has high crystallinity and uniaxial alignment, it indicates large piezoelectricity, and the absolute value of d14 becomes high. [0126] Crystallinity and uniaxial alignment are achieved by uniform PLA crystallization degree X _Homo (%) and the crystal orientation degree Ao (%) were determined. As the piezoelectric fiber A of the present invention, the degree of crystallization of the PLA is X. _Homo (%) and the crystal orientation degree Ao (%) satisfy the following formula (1). In the case where the above formula (1) is not satisfied, crystallinity and/or uniaxial alignment are insufficient, and the output value of the electric signal to the operation is lowered, or the sensitivity of the signal to the action in a specific direction is lowered. The value on the left side of the above formula (1) is preferably 0.28 or more, more preferably 0.3 or more. Here, each value is obtained as follows. [0127] The degree of crystallization of homopolylactic acid X _Homo : For the degree of crystallization of homopolylactic acid X _Homo It is obtained by analyzing the crystal structure due to wide-angle X-ray diffraction analysis (WAXD). In the wide-angle X-ray diffraction analysis (WAXD), an ultrax18 type X-ray diffraction apparatus manufactured by Rigaku Co., Ltd. was used, and the X-ray diffraction pattern of the sample was recorded on the image plate by the penetration method using the following conditions. X-ray source: Cu-Kα ray (confocal lens) Output: 45kV × 60mA Slot: 1st: 1mmΦ, 2nd: 0.8mmΦ Photography length: 120mm Accumulated time: 10 minutes Sample: 35mg of polylactic acid fiber and yarn into 3cm Fiber bundles. In the obtained X-ray diffraction pattern, the total scattering intensity Itotal is obtained at the azimuth angle, and the diffraction peaks from the homopolylactic acid crystal appearing in the vicinity of 2θ=16.5°, 18.5°, and 24.3° are obtained here. The sum of the integrated intensities ΣIHMi. From these values, the degree of crystallization of the per-lactic acid is determined according to the following formula (2). _Homo . Homopolymeric crystallization degree X _Homo (%)=ΣI _HMi /I _Total ×100 (2) In addition, ΣI _HMi It is calculated by subtracting the background or amorphous diffuse scattering from the total scattering intensity. (2) Crystal orientation degree Ao: For the crystal orientation degree Ao, in the X-ray diffraction pattern obtained by the above-described wide-angle X-ray diffraction analysis (WAXD), 2θ=16.5 appears in the direction of the moving diameter. The diffraction peak from the homopolylactic acid crystal near °, taking the intensity distribution with respect to the azimuth angle (°), and the total value of the half-value width from the obtained distribution curveΣ _Wi (°) is calculated by the following formula (3). Crystalline orientation Ao (%) = (360-ΣW _i ÷360×100 (3) [0129] In addition, since polylactic acid is a polyester which is rapidly decomposed by water, it is possible to add a known isocyanate compound, oxazoline compound or ring even when there is a problem in heat and humidity resistance. A hydrolyzing agent such as an oxygen compound or a carbodiimide compound may also be used. In addition, it is also possible to improve the physical properties by adding an oxidation preventing agent such as a phosphate compound, a plasticizer, a photodegradation preventing agent, or the like, as needed. [0130] The piezoelectric fiber A may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. In the case of a monofilament (including a spun yarn), the monofilament diameter is 1 μm to 5 mm, preferably 5 μm to 2 mm, more preferably 10 μm to 1 mm. In the case of a multifilament, the monofilament diameter is from 0.1 μm to 5 mm, preferably from 2 μm to 100 μm, more preferably from 3 μm to 50 μm. The number of filaments of the multifilament is preferably from 1 to 100,000, preferably from 50 to 50,000, and more preferably from 100 to 20,000. However, the fineness or the number of strips of the piezoelectric fiber A is determined by the fineness and the number of the strips of each carrier at the time of knitting, and the multifilament formed by a plurality of monofilaments (monofilaments) is also counted as A piece of piezoelectric wire fiber A. Here, in the case where fibers other than the piezoelectric fibers are used in one carrier, the total amount is included. In order to obtain such a piezoelectric polymer as the piezoelectric fiber A, any one of known methods for forming a fiber from a polymer can be used as long as the effect of the present invention is achieved. For example, a method of performing fibrillation by extrusion molding a piezoelectric polymer, a method of fibrillating a piezoelectric polymer by melt spinning, and a piezoelectricity by dry or wet spinning can be employed. A method in which a molecule is fibrillated, a method in which a piezoelectric polymer is fibrillated by electrospinning, a method of cutting a film after forming a film, and the like. These spinning conditions may be applied to a piezoelectric polymer to be used in accordance with a known method, and a melt spinning method which is industrially easy to produce may be used. Also, after the fibers are formed, the formed fibers are extended. Accordingly, the uniaxially elongated alignment is formed and the piezoelectric piezoelectric fiber A exhibiting large piezoelectricity is contained. Further, the piezoelectric fiber A is subjected to a treatment such as dyeing, crepe, bonding, heat treatment, or the like before the fiber produced as described above is knitted. Further, since the piezoelectric fibers A have frictional breakage or breakage when the fibers are formed, it is preferable that the fibers and the abrasion resistance are relatively high, and the strength is 1.5 cN/dtex. The above is preferable, preferably 2.0 cN/dtex or more, more preferably 2.5 cN/dtex or more, and 3.0 cN/dtex or more. The abrasion resistance can be evaluated by the JIS L1095 9.10.2 B method or the like, and the number of rubbing times is preferably 100 or more, preferably 1,000 or more, more preferably 5,000 or more, and most preferably 10,000 or more. The method for improving the abrasion resistance is not particularly limited, and all known methods can be used, for example, the degree of crystallization can be increased, or fine particles can be added, or surface processing can be performed. Further, when processing into a braid, it is also possible to apply a lubricant to the fibers to reduce friction. Further, the difference between the shrinkage ratio of the piezoelectric fiber and the shrinkage ratio of the conductive fiber is preferably small. When the difference in shrinkage ratio is large, there is a change in the time when the heat is applied or the time is changed after the processing is performed or after the fabric is produced, or when the heat is applied, or the flatness of the fabric is deteriorated, and the piezoelectric signal becomes weak. The situation. When the shrinkage ratio is quantified by the boiling water shrinkage ratio described later, the boiling water shrinkage ratio S(p) of the piezoelectric fiber and the boiling water shrinkage ratio S(c) of the conductive fiber are preferably in the following formula (4). The left side of the above formula (4) is preferably 5 or less, and more preferably 3 or less. Further, it is preferable that the shrinkage ratio of the piezoelectric fiber is smaller than the difference between the shrinkage ratio of the fiber other than the conductive fiber, for example, the insulating fiber. When the difference in shrinkage ratio is large, there is a change in the time when the heat is applied or the time is changed after the processing or after the fabric is produced, or the film is bent, or the flatness of the fabric is deteriorated, and the piezoelectric signal is weakened. Happening. When the shrinkage ratio is quantified by the boiling water shrinkage ratio, the boiling water shrinkage ratio S(p) of the piezoelectric fiber and the boiling water shrinkage ratio S(i) of the insulating fiber satisfy the following formula (5). The left side of the above formula (5) is preferably 5 or less, and more preferably 3 or less. Further, it is preferable that the piezoelectric fiber has a small shrinkage ratio. For example, when the shrinkage ratio is quantified by the boiling water shrinkage ratio, the shrinkage ratio of the piezoelectric fiber is preferably 15% or less, preferably 10% or less, more preferably 5% or less, and most preferably 3% or less. good. As a means for reducing the shrinkage ratio, various methods can be applied. For example, the degree of alignment relaxation or crystallization of the amorphous portion is improved by heat treatment, whereby the shrinkage ratio can be lowered, and the timing of performing the heat treatment is not particularly limited, and extension is exemplified. After the crepe, after the weaving, after the cloth, and so on. Further, the boiling water shrinkage rate was measured by the following method. A skein having a number of rolls of 20 times was produced by a cloth inspection machine of 1.125 m around the outer frame, and a load of 0.022 cN/dtex was applied, and the initial skein length L0 was measured by hanging on a scale plate. Thereafter, the skein was treated in a boiling water bath at 100 ° C for 30 minutes, left to cool, and the above load was applied again, and suspended on a scale plate, and the length L of the skein after shrinkage was measured. The boiling water shrinkage ratio was calculated by the following formula (6) using the measured L0 and L. Boiling water shrinkage ratio = (L0 - L) / L0 × 100 (%) (6) [Coated] The conductive fiber B, that is, the core portion 203 is a piezoelectric fiber A, that is, a braided sheath portion 202 covers the surface. The thickness of the sheath portion 202 covering the conductive fibers B is preferably 1 μm to 10 mm, more preferably 5 μm to 5 mm, still more preferably 10 μm to 3 mm, and most preferably 20 μm to 1 mm. When it is too thin, there is a problem that there is a problem at the point of strength. Further, when it is too thick, the braided piezoelectric element 201 becomes hard and becomes difficult to be deformed. In addition, the sheath portion 202 as used herein refers to a layer adjacent to the core portion 203. In the braided piezoelectric element 201, the total fineness of the piezoelectric fibers A of the sheath portion 202 is preferably 1/2 or more and 20 or less times the total fineness of the conductive fibers B of the core portion 203. It is preferably 1 time or more and 15 times or less, more preferably 2 times or more and 10 times or less. When the total fineness of the piezoelectric fiber A to the total fineness of the conductive fiber B is too small, the piezoelectric fiber A surrounding the conductive fiber B is too small, the conductive fiber B cannot output a sufficient electric signal, and the conductive fiber B is present. Contact with other conductive fibers that are close to each other. When the total fineness of the piezoelectric fiber A and the total fineness of the conductive fiber B are excessively large, the piezoelectric fiber A surrounding the conductive fiber B is excessively large, and the braided piezoelectric element 201 becomes hard and becomes hard to be deformed. That is, even in either case, the braided piezoelectric element 201 cannot function as a sensor sufficiently. The total fineness referred to herein is the sum of the fineness of the piezoelectric fibers A constituting the sheath portion 202. For example, in the case of generally 8-strand weaving, the total densities of the eight fibers are obtained. Further, in the braided piezoelectric element 201, the fineness of each of the piezoelectric fibers A of the sheath portion 202 is preferably 1/20 or more and 2 or less times the total fineness of the conductive fibers B. It is preferably 1/15 times or more and 1.5 times or less, more preferably 1/10 times or more and 1 time or less. When the fineness of each of the piezoelectric fibers A is too small with respect to the total fineness of the conductive fibers B, the piezoelectric fibers A are too small, the conductive fibers B cannot output a sufficient electric signal, and the piezoelectric fibers A are cut off. Hey. When the fineness of each of the piezoelectric fibers A is excessively large with respect to the total fineness of the conductive fibers B, the piezoelectric fibers A are excessively thick, and the braided piezoelectric element 201 becomes hard and becomes difficult to be deformed. That is, even in either case, the braided piezoelectric element 201 cannot function as a sensor sufficiently. In the case where the conductive fiber B is a metal fiber or the metal fiber is blended in the conductive fiber B or the piezoelectric fiber A, the ratio of the fineness is not limited to the above. In the present invention, the above ratio is important in terms of contact area or coverage ratio, that is, from the viewpoint of area and volume. For example, in the case where the specific gravity of each fiber exceeds 2, the ratio of the average cross-sectional area of the fibers is preferably the ratio of the above-mentioned fineness. Although the piezoelectric fiber A and the conductive fiber B are preferably as close as possible to each other, in order to improve the adhesion, an anchor layer or a bonding layer may be provided between the conductive fiber B and the piezoelectric fiber A. . The method of coating is a method in which the conductive fiber B is used as a core yarn, and the piezoelectric fiber A is wound around the braided shape. Further, the braided shape of the piezoelectric fiber A is not limited as long as it can output an electric signal to the stress generated by the applied load, and it is preferable to have the 8-strand braid or the 16-knit braid having the core portion 203. The shape of the conductive fiber B and the piezoelectric fiber A is not particularly limited, and it is preferably as close as possible to a concentric shape. In the case where a multifilament is used as the conductive fiber B, the piezoelectric fiber A may be coated with at least a part of the surface (fiber peripheral surface) of the multifilament of the conductive fiber B, even if It is also possible to coat the surface of the fibrils (fiber peripheral surface) constituting the multifilaments with the piezoelectric fibers A, even if they are not coated. The state in which the piezoelectric fibers A are coated in the respective filaments of the multifilaments of the conductive fibers B may be appropriately set in consideration of performance, workability, and the like of the piezoelectric element. (Electrically Conductive Layer) The conductive layer 204 has a function as an electrode that serves as a counter electrode of the conductive fiber of the core portion 203, and the conductive fiber that shields the core portion 203 prevents external electromagnetic waves and suppresses conduction at the core portion 203. The function of the shielding of the noise signal generated by the fiber. Since the conductive layer 204 functions as a shield, it is preferably grounded (connected to the ground or the ground of the electronic circuit). According to this, the S/N ratio (signal-to-noise ratio) of the cloth-like piezoelectric element 207 can be remarkably improved even if the conductive cloth for electromagnetic wave shielding is not overlapped above the cloth-like piezoelectric element 207. As the conductive layer 204, even in the case of coating, even if the film, the cloth, or the fiber is wound, it may be combined. [0145] The coating of the conductive layer 204 may be carried out by using a material containing a substance indicating conductivity, and a known owner is used. For example, a metal, a conductive polymer, and a polymer in which a conductive filler is dispersed may be mentioned. [0146] When the conductive layer 204 is formed by winding a film, a film obtained by using a conductive polymer or a film-forming polymer to disperse a conductive filler is used, and further, conductive is provided on the surface. Thin film can also be used. When the conductive layer 204 is formed by winding of a fabric, a fabric in which a conductive fiber 206 to be described later is used as a constituent component is used. [0148] When the conductive layer 204 is formed by winding a fiber, a cover, a knitted fabric, or a woven fabric can be considered as a means. Further, the fibers to be used are the conductive fibers 206, and the conductive fibers 206 may be of the same type as the conductive fibers B, and may be different types of conductive fibers. Examples of the conductive fiber 206 include a fiber composed of a metal fiber, a fiber composed of a conductive polymer, a carbon fiber, a polymer in which a fibrous or granular conductive filler is dispersed, or a fibrous material. A fiber having a conductive layer is provided on the surface. Examples of the method of providing a conductive layer on the surface of the fibrous material include metal coating, conductive polymer coating, and winding of conductive fibers. Among them, metal coating is preferred from the viewpoints of conductivity, durability, flexibility, and the like. The specific method of coating the metal is, for example, vapor deposition, sputtering, electrolytic plating, electroless plating, etc., but plating is preferred from the viewpoint of productivity and the like. The metal thus plated may be referred to as a metal plated fiber. [0149] As the fiber of the substrate to which the metal is applied, well-known fibers can be used regardless of the presence or absence of conductivity, for example, in addition to polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, vinyl chloride fibers, aromatic poly In addition to synthetic fibers such as polyamide fibers, polyfluorene fibers, polyether fibers, and polyurethane fibers, semi-synthetic fibers such as natural fibers such as cotton, hemp, and enamel, and acetate, and hydrazine may be used. Regenerated fiber such as copper amine fiber. The fibers of the substrate are not limited thereto, and any known fibers may be used arbitrarily, and these fibers may be used in combination. The metal of the fiber applied to the substrate represents electrical conductivity, and any one may be used as long as the effect of the present invention is achieved. For example, gold, silver, platinum, copper, nickel, tin, lead, palladium, indium tin oxide, copper sulfide, or the like, and mixtures or alloys thereof may be used. When the conductive fiber 206 is coated with a metal coated organic fiber having bending resistance, the conductive fiber is rarely broken, and the durability and safety of the sensor using the piezoelectric element are excellent. The conductive fibers 206 may be a multifilament bundled with a plurality of filaments or a monofilament composed of one filament. Multifilament is preferred from the viewpoint of the stability of the electrical properties. In the case of a monofilament (including a spun yarn), the monofilament diameter is from 1 μm to 5000 μm, preferably from 2 μm to 100 μm. It is preferably 3 μm to 50 μm. In the case of multifilaments, as the number of filaments, it is preferably from 1 to 100,000, preferably from 5 to 500, more preferably from 10 to 100. When the diameter of the fiber is small, the strength is lowered and it becomes difficult to handle, and further, in the case where the diameter is large, flexibility is sacrificed. The cross-sectional shape of the conductive fiber 206 is preferably a circle or an ellipse from the viewpoint of design and manufacture of the piezoelectric element, but is not limited thereto. [0154] Furthermore, in order to improve the effect of suppressing the noise signal, it is preferable that the resistance is low, and the volume resistivity is 10 ^-1 Ω・cm or less is better, with 10 ^-2 Ω·cm or less is preferred, with 10 ^-3 Ω·cm or less is more preferable. However, when the suppression effect of the noise signal is obtained, the specific resistance is not limited to this. [0155] The conductive fibers 206 must have resistance to repeated bending or twisting operations in view of the use of the present invention. As its index, the nodule strength is preferably larger. The knot strength can be measured by the method of JIS L1013 8.6. The degree of the knot strength suitable for the present invention is preferably 0.5 cN/dtex or more, more preferably 1.0 cN/dtex or more, more preferably 1.5 cN/dtex or more, and most preferably 2.0 cN/dtex or more. Further, as another index, the bending rigidity is preferably smaller. The bending rigidity is generally measured by a measuring device such as a KES-FB2 pure bending tester manufactured by KATO TECH Co., Ltd. As a degree of bending rigidity suitable for the present invention, a carbon fiber "TENAX" (registered trademark) HTS40-3K manufactured by Toho Tenax Co., Ltd. is preferable. Specifically, the bending rigidity of the conductive fiber is 0.05×10. ^-4 N・m ² /m below is better, to 0.02×10 ^-4 N・m ² Below /m is preferred, to 0.01×10 ^-4 N・m ² Below /m is better. Further, it can be considered as a capacitor-shaped piezoelectric element in which a conductor of a core portion and a conductor of an electromagnetic wave shielding layer are used as electrodes of two poles and a piezoelectric polymer (dielectric body) is sandwiched. In order to effectively extract the polarization generated in the piezoelectric structure by deformation, the value of the insulation resistance between the electrodes is preferably 1 MΩ or more and 10 MΩ or more when measured by a DC voltage of 3 V. Good, more than 100MΩ is better. Further, even if the value of the equivalent series resistance Rs and the equivalent series capacitance Cs obtained by the response when the AC voltage of 1 MHz is supplied between the electrodes is analyzed, the value is effectively taken out by the deformation. In the polarization of the piezoelectric structure, the responsiveness is improved, so that it is preferably within a specific value range. That is, the value of Rs is preferably 1 μΩ or more and 100 kΩ or less, preferably 1 mΩ or more and 10 kΩ or less, more preferably 1 mΩ or more and 1 kΩ or less, and the value of Cs is divided by the length of the central axis direction of the piezoelectric structure ( The value of cm) is preferably 0.1 pF or more and 1000 pF or less, more preferably 0.2 pF or more and 100 pF or less, and more preferably 0.4 pF or more and 10 pF or less. [0157] As described above, when the piezoelectric fiber A and the element composed of the electrode are in a good state, the response is obtained by analyzing the response when an alternating current voltage of 1 MHz is supplied between the electrodes. The value of the series resistance Rs and the equivalent series capacitance Cs are obtained within a specific range, and it is preferable to use the values for the inspection of the braided piezoelectric element. Furthermore, not only the values of Rs and Cs obtained by the analysis of the AC voltage but also the transient response of the other voltages can be analyzed, and the braided piezoelectric element can be inspected. (Protective Layer) A protective layer may be provided on the outermost surface of the braided piezoelectric element 201 of the present invention. The protective layer is preferably insulating, and is preferably composed of a polymer from the viewpoint of flexibility. In the case where the protective layer is insulative, of course, in this case, the protective layer may be deformed together or rubbed on the protective layer, but if the external force reaches the piezoelectric fiber A, it may be induced. When it is polarized, it is not particularly limited. The protective layer is not limited to those formed by coating of a polymer or the like, and may be a wound film, a cloth, a fiber, or the like, or may be combined. [0159] As the thickness of the protective layer, the shear stress is more easily transmitted to the piezoelectric fiber A at a thinner thickness, but when it is too thin, the protective layer itself is easily broken, and the like. 10 nm to 200 μm is preferred, preferably 50 nm to 50 μm, more preferably 70 nm to 30 μm, and most preferably 100 nm to 10 μm. The shape of the piezoelectric element can also be formed by the protective layer. Further, a layer in which a plurality of layers are composed of piezoelectric fibers or a layer in which a plurality of layers are formed by conductive fibers for taking out signals may be provided. Needless to say, the order of the protective layer, the layer composed of the piezoelectric fibers, and the layer composed of the conductive fibers is appropriately determined depending on the purpose. Further, as a method of winding, a method of forming a woven structure or covering the outer layer of the sheath portion 202 may be mentioned. The braided piezoelectric element 201 of the present invention measures the conductivity of the core of the braided piezoelectric element 201 in addition to the deformation or stress that can be detected by the output of the electrical signal caused by the piezoelectric effect described above. The change in electrostatic capacitance between the fiber B and the conductive layer 204 can also detect the deformation caused by the pressure applied to the braided piezoelectric element 201. Further, in the case where a plurality of braided piezoelectric elements 201 are used in combination, by measuring the change in electrostatic capacitance between the conductive layers 204 of the respective braided piezoelectric elements 201, it is also possible to detect application to the braided piezoelectric element 201. The deformation caused by the pressure. (Insulating Fiber) In the cloth-like piezoelectric element 207, an insulating fiber can be used in a portion other than the braided piezoelectric element 201 (and the conductive fiber 210). In this case, the insulating fiber is used for the purpose of improving the flexibility of the cloth-like piezoelectric element 207, and a fiber having a stretchable material or shape can be used. In this way, by arranging the insulating fibers in addition to the braided piezoelectric element 201 (and the conductive fibers 210), the operability of the cloth-like piezoelectric element 207 can be improved (illustration: as a wearable sensor) Activity is easy). [0164] As such an insulating fiber, if the volume resistivity is 10 ⁶ It can be used when Ω・cm or more, to 10 ⁸ Ω·cm or more is preferred, with 10 ¹⁰ Ω·cm or more is more preferable. [0165] As the insulating fiber, for example, in addition to polyester fiber, nylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, vinyl chloride fiber, aromatic polyamide fiber, polyfluorene fiber, polyether fiber, polyamine group In addition to synthetic fibers such as formate fibers, natural fibers such as cotton, hemp, and enamel, semi-synthetic fibers such as acetate, and regenerated fibers such as hydrazine or copper amine can be used. It is not limited to these, and the well-known insulating fiber can be used arbitrarily. In addition, even if these insulating fibers are used in combination, they may be used in combination with fibers having no insulating properties, and may be fibers having overall insulating properties. Further, it is also possible to use fibers of all known cross-sectional shapes. (Manufacturing Method) The knitted piezoelectric element 201 of the present invention covers the surface of at least one of the conductive fibers B by the braided piezoelectric fiber A. However, as a method for producing the same, for example, the following method can be mentioned. In other words, the conductive fiber B and the piezoelectric fiber A are separately produced, and the piezoelectric fiber A is wound into a braided shape to coat the conductive fiber B. In this case, it is preferable to cover as close as possible to a concentric shape. In this case, the spinning and stretching conditions in which the piezoelectric polymer A forming the piezoelectric fiber A is preferably used in the case of using polylactic acid have a melt spinning temperature of 150 ° C to 250 ° C. Preferably, the extension temperature is preferably from 40 ° C to 150 ° C, the stretching ratio is preferably from 1.1 to 5.0, and the crystallization temperature is preferably from 80 ° C to 170 ° C. [0168] As the piezoelectric fiber A wound around the conductive fiber B, a multifilament of a bundle of a plurality of filaments may be used, and even a monofilament (including a textile yarn) may be used. In addition, as the conductive fiber B wound around the piezoelectric fiber A, even if a multifilament of a bundle of a plurality of filaments is used, a single filament (including a textile yarn) may be used. [0169] As a preferred embodiment of the coating, the piezoelectric fiber A can be knitted into a braided shape by using the conductive fiber B as a core yarn, and a tubular braid (Tubular Braid) can be produced to be coated. More specifically, an 8-strand woven or a 16-knit woven fabric having a core portion 203 can be cited. However, for example, even if the piezoelectric fiber A is in the form of a braided tube, the conductive fiber B is regarded as a core portion, and the braided tube may be inserted and coated. [0170] Although the conductive layer 204 is produced by coating or winding of fibers, it is preferable to use a fiber to be wound from the viewpoint of easy production. As the winding method of the fiber, a cover, a knitted fabric, and a woven fabric can be considered, and it can be manufactured by any method. According to the above-described manufacturing method, the braided piezoelectric element 201 in which the surface of the conductive fiber B is coated with the woven piezoelectric fiber A and the conductive layer 204 is provided around the woven piezoelectric fiber A can be obtained. Here, in the braided piezoelectric element of the present invention, the relationship between the diameter of the core portion and the thickness of the layer (sheath portion) composed of the piezoelectric fibers is very important. The piezoelectric element of the present invention is used as it is in the form of a fiber. Although it is woven into a cloth shape as it is, there is a case where the core signal line and the shield layer (conductive layer) are short-circuited during use and processing. As a result of intensive studies by the inventors, the radius Rc of the core and the thickness d of the layer composed of the piezoelectric fibers must have a relationship of d/Rc ≧ 1.0. When the braided piezoelectric element is bent by the curvature R, when the center of the element is bent as a reference line, the deformation rate of the surface of the core becomes (R+Rc)/R. For example, in the case where the radius of curvature R = 2 mm, when Rc = 0.2 mm, the deformation ratio is 1.1, the elongation is 10% on the outer side of the bending, and the relaxation is 10% on the inner side of the bending. At this time, the woven hole pattern of the layer formed of the woven piezoelectric fiber is disordered, and the layer forming the shield layer and the signal line of the core are short-circuited. Here, even if the deformation causes the layer of the piezoelectric fiber to be disordered, the shield layer and the signal line of the core are not short-circuited, and the relationship between the thickness of the layer composed of the piezoelectric fiber and the core needs to be satisfied. The following conditions. It is preferable that the deformation of the surface of the core portion of the braided piezoelectric element is suppressed to 20%, and therefore, the radius of curvature of the utility is clearly determined by the thickness of the core portion. Further, in other words, in this case, the thickness of the layer made of piezoelectric fibers which does not cause a short circuit is determined almost in an almost unambiguous manner. That is, Rc>R/20 is preferred, and Rc>R/10 is preferred. Further, d/Rc is preferably 1.0 or more, more preferably 1.2 or more, and still more preferably 1.5 or more. Further, the layer formed of the piezoelectric fibers may be laminated with a plurality of piezoelectric fibers. Even if the plurality of layers are laminated to have the same thickness, the number of times of lamination is difficult to be short-circuited. When the number of times of lamination is n, d/Rc × n is preferably 0.8 or more, more preferably 1.0 or more, and 1.2 or more. For better. Further, at the point of short-circuiting, the thickness of the layer composed of the piezoelectric fibers is preferably as large as possible, but from the viewpoint of the braided piezoelectric element, the finer the workability, the thinner the shield layer is. It is better. Here, the radius Rc of the core portion of the braided piezoelectric element and the thickness d of the layer composed of the piezoelectric fiber are calculated from the microscopic image of the cross section shown in FIG. 11 as follows. In addition, even if the low-viscosity instant bonding agent "Aron Alpha EXTRA2000" (East Asian Synthetic) is dyed into a braided piezoelectric element and cured, a cross section perpendicular to the long axis of the weaving is cut and the photographing section is taken. Photos are also available. The radius Rc of the core is an average value of the radius of the largest circle X formed by the fiber bundle of the core and the radius of the smallest circle Y completely including the fiber bundle, as shown in Fig. 11-1. As shown in Fig. 11-2, the thickness d of the layer composed of the piezoelectric fibers is a radius from the largest circle X' composed only of the fiber bundle of the piezoelectric fiber including the core portion. And the average of the radii of the smallest circle Y' completely containing the fiber bundle, minus the value of the radius Rc of the core. (Corrugated Piezoelectric Element) FIG. 12 is a schematic view showing a configuration example of a cloth-like piezoelectric element using a braided piezoelectric element according to an embodiment. The cloth-like piezoelectric element 207 is provided with a fabric 208 including at least one braided piezoelectric element 201. At least one of the fibers (including knitting) constituting the fabric of the fabric 208 is a braided piezoelectric element 201, and the braided piezoelectric element 201 is not limited as long as it functions as a piezoelectric element, and even any braid can be used. . In the case of forming a cloth, as long as the object of the present invention is achieved, it is possible to perform interlacing, interlacing, and the like in combination with other fibers (including knitting). Of course, even if the braided piezoelectric element 201 is used as one of the fibers constituting the fabric (for example, warp or weft), even if the braided piezoelectric element 201 is embroidered on the fabric, it may be joined. In the example shown in FIG. 12, the cloth-like piezoelectric element 207 is a flat fabric in which at least one of the braided piezoelectric element 201 and the insulating fiber 209 is disposed as a warp yarn, and the conductive fiber 210 and the insulating fiber 209 are alternately arranged as a weft. The conductive fibers 210 may be the same type as the conductive fibers B, and may be different types of conductive fibers, and the insulating fibers 209 will be described later. Further, all or a part of the insulating fibers 209 and/or the conductive fibers 210 may be in a woven form. In this case, when the braided piezoelectric element 207 is deformed by bending or the like, the braided piezoelectric element 201 is also deformed with the deformation, and is output from the braided piezoelectric element 201. The electrical signal can detect the deformation of the cloth-like piezoelectric element 207. Further, since the cloth-like piezoelectric element 207 can be used as a fabric (woven fabric), it can be applied to, for example, a garment-type wearable sensor. Further, in the cloth-like piezoelectric element 207 shown in FIG. 12, the conductive fibers 210 are in contact with the braided piezoelectric element 201. Therefore, the conductive fiber 210 is in contact with at least a part of the braided piezoelectric element 201, and covered, and at least a part of the electromagnetic wave to be applied to the braided piezoelectric element 201 can be shielded from the outside. Such a conductive fiber 210 has a function of reducing the influence of electromagnetic waves on the braided piezoelectric element 201 by being grounded. That is, the conductive fiber 210 can function as an electromagnetic wave shield of the braided piezoelectric element 201. According to this, even if the conductive fabric for electromagnetic wave shielding is not overlapped above and below the cloth-like piezoelectric element 207, the S/N ratio of the cloth-like piezoelectric element 207 can be remarkably improved. In this case, from the viewpoint of electromagnetic wave shielding, the higher the ratio of the conductive fibers 210 of the weft yarn (in the case of FIG. 12) crossing the braided piezoelectric element 201, the better. Specifically, it is preferable that 30% or more of the fibers which form the fabric of the fabric 208 and which intersect the braided piezoelectric element 201 are conductive fibers, preferably 40% or more, more preferably 50% or more. In this manner, in the cloth-like piezoelectric element 207, by placing the conductive fibers as at least a part of the fibers constituting the fabric, the piezoelectric element 207 having the electromagnetic wave shield can be formed. [0179] The woven structure of the woven fabric may be exemplified by a three-dimensional structure such as plain weave, twill weave, and satin weave, a single-double structure such as a double weave, a double weave, and the like. Even if it is a warp knitted fabric (weft weaving), it can be used as a warp. As the organization of the circular knitting fabric (weft knitting), it is preferable to exemplify a flat knitting, a rib knitting, a double sided knitting, a reverse stitch knitting, a hanging needle knitting, a floating thread knitting, a half-side knitting, a yarn knitting, and a wool knitting. As a warp knitting organization, a single-sided warp-knit flat weave, a single-sided warp-knitted satin stitch, a double-sided warp-knitted quilt, a velvet-warp woven, a velvet knitting, a jacquard knitting, and the like can be exemplified. The number of layers may be a single layer or a multilayer of two or more layers. Further, it is also possible to form a woven fabric or a woven fabric composed of a bristles and a base tissue portion which are formed by woven wool and/or loops. (Plastic Piezoelectric Element) Further, in the cloth-like piezoelectric element 207, a plurality of braided piezoelectric elements 201 can be arranged and used. As the arrangement, for example, as the warp yarn or the weft yarn, even if the braided piezoelectric element 201 is used in all, the braided piezoelectric element 201 may be used for every few or a part. Further, even if a certain portion uses the braided piezoelectric element 201 as a warp yarn, and the other portion uses the braided piezoelectric element 201 as a weft yarn. In this manner, when the plurality of braided piezoelectric elements 201 are arranged to form the cloth-like piezoelectric element 207, since the braided piezoelectric element 201 does not have an electrode on the surface, it is possible to select it in a wide range. The advantages of arrangement and weaving. Further, when the plurality of woven piezoelectric elements 201 are arranged, since the distance between the conductive fibers B is short, efficiency is obtained in the extraction of the electric signals. (Applicable Techniques of Piezoelectric Element) The piezoelectric element such as the braided piezoelectric element 201 or the cloth-like piezoelectric element 207 of the present invention can output contact, pressure, and surface contact with each other even in any aspect. The shape change is used as a signal, and can be utilized as a sensor (device) that detects the magnitude of the stress applied to its piezoelectric element and/or the position to be applied. Further, the electric signal may be used as a power source for powering another device or a power generating element such as power storage. Specifically, it is used for power generation by a movable part of a spontaneous exerciser such as a human, an animal, a robot, or a machine, and the power generation due to the surface of the sole, the dressing, and the structure of the external pressure is caused by the fluid. The shape changes in the power generation. Furthermore, since the electrical signal is emitted by the shape change in the fluid, it is also possible to adsorb or suppress the adhesion of the charged substance in the fluid. 6 is a block diagram showing a device 111 including the piezoelectric element 112 of the present invention. The device 111 includes a piezoelectric element 112 (exemplified by a braided piezoelectric element 201 and a cloth-like piezoelectric element 207), and an amplification means for arbitrarily selecting and amplifying an electric signal output from the piezoelectric element 112 in response to the applied pressure. 113, and an output means 114 for outputting the electric signal amplified by the arbitrarily selected amplification means 113, and a circuit for transmitting the electric signal outputted from the output means 114 to the transmission means 115 of an external device (not shown). When the device 111 is used, the electrical signal outputted according to the contact, pressure, and shape change of the surface of the piezoelectric element 112 can be detected and applied to the piezoelectric element by an external device (not shown). The magnitude of the stress and/or the location to be applied. The arbitrarily selected amplification means 113, the output means 114, and the transmission means 115 may be constructed, for example, in the form of a software program, or may be constructed by a combination of various electronic circuits and software programs. For example, the software program is installed in an arithmetic processing unit (not shown), and the arithmetic processing unit operates in accordance with the software program, thereby realizing the functions of the respective units. Furthermore, the arbitrarily selected amplification means 113, the output means 114, and the transmission means 115 may be realized as a semiconductor integrated circuit for writing a software program for realizing the functions of the respective units. Further, the transmission method by the transmission means 115 may be determined by wireless or wired, and may be appropriately determined in accordance with the sensor configured. Alternatively, even in the device 111, an arithmetic means (not shown) for calculating the magnitude of the stress applied to the piezoelectric element 112 and/or the applied position based on the electrical signal output from the output means 114 may be provided. . Further, not only the amplifying means but also a well-known signal processing means such as a means for removing noise or a means for performing processing in combination with other signals may be used. The order of connection of these means can be appropriately changed depending on the purpose. Of course, even if the electrical signal output from the piezoelectric element 112 is transmitted to the external device as it is, the signal processing can be performed. [Fig. 13] Fig. 13 is a schematic view showing a configuration example of an apparatus including a braided piezoelectric element according to an embodiment. The amplifying means 113 of Fig. 13 corresponds to the description with reference to Fig. 6, and the output means 114 and the transmitting means 115 of Fig. 6 are not shown in Fig. 13. In the case of constituting the device including the braided piezoelectric element 201, the input terminal of the amplifying means 113 is connected to the drawing line from the core portion 203 of the braided piezoelectric element 201, and the earth terminal is connected to the braided piezoelectric element. Conductive layer 204 of element 201. For example, as shown in FIG. 13, in the braided piezoelectric element 201, a pull-out line from the core portion 203 of the braided piezoelectric element 201 is connected to an input terminal of the amplification means 113 to make a braided piezoelectric element. The conductivity 204 of the element 201 is earthed. 14 to 16 are schematic views showing a configuration example of an apparatus including a braided piezoelectric element according to an embodiment. The amplification means 113 of Figs. 14 to 16 corresponds to the description with reference to Fig. 6, and the output means 114 and the transmission means 115 of Fig. 6 are not shown in Figs. In the case of constituting the device having the cloth-like piezoelectric element 207, the input terminal of the amplification means 113 is connected to the pull-out line from the core portion 203 of the braided piezoelectric element 201 (formed by the conductive fiber B), and is grounded. (earth) a braided piezoelectric element different from the braided piezoelectric element 201 connected to the conductive layer 204 of the braided piezoelectric element 201 or the conductive fiber 210 of the cloth-like piezoelectric element 207 or the input terminal of the amplification means 113 . For example, as shown in FIG. 14, in the cloth-like piezoelectric element 207, a pull-out line from the core portion 203 of the braided piezoelectric element 201 is connected to an input terminal of the amplification means 113 to make a braided piezoelectric element. Conductive layer 204 of element 201 is earthed. Further, for example, as shown in FIG. 15, in the cloth-like piezoelectric element 207, the pull-out line from the core portion 203 of the braided piezoelectric element 201 is connected to the input terminal of the amplification means 113, and the knitting is performed. The conductive fibers 210 that are in contact with each other are in contact with each other. Further, as shown in FIG. 16, when the plurality of braided piezoelectric elements 201 are arranged in the cloth-like piezoelectric element 207, the pull-out line from the core portion 203 of one knitted piezoelectric element 201 is connected to The input terminal of the amplification means 113 grounds the pull-out line from the core portion 203 of the other braided piezoelectric element 201 arranged in the braided piezoelectric element 201. [0189] When the braided piezoelectric element 201 is deformed, the piezoelectric fiber A is deformed to generate polarization. The influence of the arrangement of the positive and negative charges generated by the polarization of the piezoelectric fiber A causes the movement of electric charges on the drawing line from the conductive fiber B forming the core portion 203 of the braided piezoelectric element 201. On the pull-out line from the conductive fiber B, a slight electrical signal (i.e., current) flows in the movement of the electric charge. The amplifying means 113 amplifies the electric signal, the output means 114 outputs the electric signal amplified by the amplifying means 113, and the transmitting means 115 transmits the electric signal outputted from the output means 114 to an external device (not shown). [0190] The device 111 of the present invention has flexibility, and can be used in any of a braided shape and a cloth-like shape, so that it can be imagined in a very wide range of applications. Specific examples of the device 111 of the present invention include a touch panel that is shaped like a hat, a glove, a sock, and the like, which is a garment, a support, a handkerchief, and the like, and is used as a surface pressure sensor for humans or animals. For example, a sensor that bends, twists, and expands and contracts the joint portion in the shape of a glove, a belt, a support, or the like is detected. For example, when it is used in a person, it is possible to use an information collection for an action such as a joint for medical use, an entertainment use, or an interface for moving a lost tissue or a robot. Further, a surface pressure sensor which is a cloth doll or a robot that mimics an animal or a human type, and a sensor that detects bending, twisting, and expansion of the joint portion can be used. Further, a surface pressure sensor or a shape change sensor which is used as a bedding, a sole, a glove, a chair, a dressing, a bag, a flag, or the like as a bed sheet or a pillow, etc. [0191] Further, the device 111 of the present invention It is woven or cloth-like and has flexibility. Therefore, it can be used as a surface pressure sensor or shape change sensor by attaching or covering the surface of all or part of all structures. Moreover, since the device 111 of the present invention can generate a sufficient electrical signal only by rubbing the surface of the piezoelectric element 201, it can be used for a touch sensor-like touch input device or pointing device. Further, since the surface of the object to be measured is wiped by the braided piezoelectric element 201, position information or shape information in the height direction of the object to be measured can be obtained, and thus it can be used for surface shape measurement or the like. [0193] Hereinafter, the third invention will be described in detail. (Wolen piezoelectric element) In the braided piezoelectric element according to the third aspect of the invention, the piezoelectric polymer in the structure according to the first aspect of the invention can be arranged in a cylindrical shape. An element having a conductor made of a conductive fiber is disposed at a position of the central axis, that is, an element in which a piezoelectric polymer is woven into a braided shape as a piezoelectric fiber and disposed around the conductive fiber. Hereinafter, the braided piezoelectric element according to the third invention will be described in detail. 10 is a schematic view showing a configuration example of a braided piezoelectric element according to an embodiment. The braided piezoelectric element 201 includes a core portion 203 formed of a conductive fiber B, and a sheath portion 202 formed of a piezoelectric fiber A having a braided shape so as to cover the core portion 203, and a conductive portion of the sheath portion 202. Layer 204. The conductive layer 204 also functions as an electrode that serves as a counter electrode of the conductive fiber of the core portion 203, and the conductive fiber that shields the core portion 203 prevents electromagnetic waves from the outside, and suppresses the noise signal generated by the conductive fiber in the core portion 203. The function of the shield. [0195] The coverage of the sheath portion 202 by the conductive layer 204 is preferably 25% or more. Here, the coverage ratio is a ratio of the area of the conductive material 205 contained in the conductive layer 204 when the conductive layer 204 is projected to the sheath portion 202 and the surface area of the sheath portion 202, and the value is preferably 25% or more. More than 50% is preferred, and more preferably 75% or more. When the coverage of the conductive layer 204 is less than 25%, the effect of suppressing the noise signal may not be sufficiently exhibited. When the conductive material 205 is not exposed to the surface of the conductive layer 204, for example, when the fiber containing the conductive material 205 is used as the conductive layer 204 to coat the sheath portion 202, the sheath portion 202 toward the fiber may be applied. The ratio of the area at the time of projection to the surface area of the sheath portion 202 is set as the coverage ratio. [0196] The conductive material 205 is a conductive material contained in the conductive layer 204, and corresponds to a well-known owner. In the braided piezoelectric element 201, a plurality of piezoelectric fibers A are densely wound around the outer peripheral surface of at least one of the conductive fibers B. When the braided piezoelectric element 201 is deformed, stress is generated by deformation of each of the plurality of piezoelectric fibers A, and accordingly, an electric field (piezoelectric effect) is generated in each of the piezoelectric fibers A, and as a result, The conductive fiber B generates a voltage change that overlaps with the electric field of the plurality of piezoelectric fibers A wound around the conductive fiber B. That is, the electric signal from the conductive fiber B is increased as compared with the case where the braided sheath portion 202 of the piezoelectric fiber A is not used. Accordingly, in the braided piezoelectric element 201, a large electric signal can be taken out even by a stress generated by a relatively small deformation. Further, the conductive fibers B may be plural pieces. The braided piezoelectric element 201 is not particularly limited as long as it has the configuration shown in FIG. 10, and is selectively outputted from the torsional deformation centered on the central axis. From the viewpoint of the electric signal, it is preferable to have the following configuration. (Wound piezoelectric element that selectively outputs a large electric signal to the torsional deformation) As the braided piezoelectric element 201 that selectively outputs a large electric signal to the torsional deformation centered on the central axis, In the piezoelectric fiber A, the uniaxially oriented polymer molded body may have an absolute value of a piezoelectric constant d14 when the alignment axis is set to three axes of 0.1 pC/N or more and 1000 pC/N or less. A piezoelectric polymer having a crystalline polymer as a main component. In the present invention, "including ... as a main component" means 50% by mass or more of the constituent components. Furthermore, in the present invention, the crystalline polymer is composed of a crystal portion of 1% by mass or more and a polymer composed of an amorphous portion other than the crystal portion, and the mass of the crystalline polymer is a total of a crystal portion and an amorphous portion. the quality of. Further, although the value of d14 indicates different values depending on molding conditions, purity, and measurement environment, in the present invention, the degree of crystallinity and crystal orientation of the crystalline polymer in the piezoelectric polymer actually used are measured. The crystalline polymer is used to form a uniaxially stretched film having the same degree of crystallinity and crystal orientation, and the absolute value of the film d14 is 0.1 pC/N or more and 1000 pC/N or less in the actual use temperature. The crystalline polymer contained in the piezoelectric polymer of the present embodiment is not limited to the specific crystalline polymer described below. The d14 of the film sample can be measured by various methods, but for example, a metal is vapor-deposited on both sides of the film sample to form a sample of the electrode, and is cut into a rectangle having four sides in a direction inclined by 45 degrees from the extending direction. The value of d14 can be measured by measuring the charge generated at the electrodes on both sides when a tensile load is applied in the longitudinal direction thereof. Further, in the braided piezoelectric element 201 in which the large electric signal is selectively outputted by the torsional deformation centered on the central axis, the direction of the central axis and the alignment direction of the piezoelectric polymer (alignment) The angle θ) is 0° or more and 40° or less or 50° or more and 90° or less. When the condition is satisfied, by applying the torsional deformation (torsional stress) centered on the central axis to the braided piezoelectric element 201, the pressure of the crystalline polymer contained in the piezoelectric polymer can be efficiently utilized. The piezoelectric effect corresponding to the electric constant d14 can effectively generate a reverse polarity charge on the central axis side and the outer side of the braided piezoelectric element 201. From such a viewpoint, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is preferably 0° or more and 35° or less, or preferably 55° or more and 90° or less, and 0° or more and 30° or less or 60°. The above 90° or less is preferable, and more preferably 0° or more and 25° or less or 65° or more and 90° or less, and more preferably 0° or more and less than 15° or more than 75° and more preferably 90° or less. When the alignment angle θ of the piezoelectric polymer in the direction of the central axis exceeds 0° and is less than 90°, the spiral direction is drawn in the alignment direction of the piezoelectric polymer. Further, by disposing the piezoelectric polymer in this manner, it is possible to cause shear deformation similar to the surface of the friction-wound piezoelectric element 201, or bending deformation of the bending central axis, or stretching in the central axis direction. The deformation is such that a large electric charge is not generated on the central axis side and the outer side of the braided piezoelectric element 201, that is, the braided piezoelectric element 201 that selectively generates a large electric charge with respect to the torsion centered on the central axis. When the spiral is formed in the alignment direction of the piezoelectric polymer, the spiral direction (S捻 direction or Z捻 direction) does not affect the polarity of the charge generated by the torsional deformation. However, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 0° or more and 40° or less, and when it is 50° or more and 90° or less, the polarity of the electric charge generated by the torsional deformation is reversed. Further, as in the case of poly-L-lactic acid and poly-D-lactic acid, the piezoelectric polymer containing the crystalline polymer having different codes of d14 is also reversed with respect to the polarity of the electric charge generated by the torsional deformation. Therefore, in order to efficiently generate a reverse polarity charge on the central axis side and the outer side of the braided piezoelectric element 201 with respect to the torsional deformation, only the piezoelectric polymer having the same code as the d14 is used as the main component, and the piezoelectricity is high. The alignment angle θ of the molecule and the piezoelectric polymer with respect to the direction of the central axis of the braided piezoelectric element 201 is preferably only 0° or more and 40° or less, or 50° or more and 90° or less. The alignment angle θ is measured as much as possible by the method described below. The side view of the photographic braided piezoelectric element 201 (corresponding to the piezoelectric structure 1 in FIG. 3) was measured, and the helical pitch HP of the piezoelectric polymer 2 was measured. The spiral pitch HP is a linear distance from the surface of the piezoelectric polymer 2 to the central axis direction required for the surface to return to the surface as shown in FIG. Further, after the bonding structure is fixed by the bonding agent, the cross section perpendicular to the central axis of the braided piezoelectric element 201 is cut to take a photograph, and the outer radius Ro and the inner radius Ri of the portion occupied by the sheath portion 202 are measured. In the case where the outer edge and the inner edge of the cross section are elliptical or flat, the average of the long diameter and the short diameter is set to Ro and Ri. The alignment angle θ of the piezoelectric polymer with respect to the central axis is calculated from the following formula. However, Rm=2 (Ro ³ -Ri ³ ) /3 (Ro ² -Ri ² That is, the radius of the braided piezoelectric element 201 which is weighted and averaged by the sectional area. In the photo of the side surface of the braided piezoelectric element 201, the piezoelectric polymer has a uniform surface, and when the helical pitch of the piezoelectric polymer cannot be determined, the bonding agent is cut by a plane passing through the central axis. The fixed braided piezoelectric element 201 is subjected to wide-angle X-ray diffraction analysis in a direction perpendicular to the cut surface to penetrate X-rays through a narrow range of the central axis, and determines the alignment direction to determine the angle from the central axis. , set to θ. In the braided piezoelectric element 201 according to the present invention, the spiral drawn along the alignment direction of the piezoelectric polymer simultaneously has a spiral direction (S捻 or Z捻 direction) or a spiral pitch. In the case of two or more different spirals, the above-described measurement is performed for each of the spiral directions and the spiral piezoelectric polymer, and the piezoelectric polymer of either the spiral direction and the spiral pitch must satisfy the above conditions. The piezoelectric polymer includes a positive value including a piezoelectric constant d14 from the viewpoint of not generating a large electric charge on the central axis side and the outer side of the braided piezoelectric element 201 with respect to the elastic deformation. A P-body having a crystalline polymer as a main component and an N-body containing a negative crystalline polymer as a main component, and having a length of 1 cm for the central axis of the braided piezoelectric element 201, the alignment axis is wound into a spiral The mass of the P body arranged in the Z direction is set to ZP, the alignment axis is wound into a spiral, the mass of the P body disposed in the S direction is set to SP, and the alignment axis is wound into a spiral and arranged in the direction of the Z direction. The mass of the body is set to ZN, and the quality of the N body in which the alignment axis is wound into a spiral is set to SN, and the smaller one of (ZP+SN) and (SP+ZN) is set to T1. When the larger one is T2, the value of T1/T2 is more than 0.8, particularly preferably more than 0.8 and preferably 1.0 or less, and more preferably 0.9 or more and more than 0.9 and more preferably 1.0 or less. Here, even when the value of T1/T2 is not satisfied, the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 0° or more and 10° or less, or 80° or more and 90° or less. When the temperature exceeds 10° and is less than 80°, the amount of electric charge generated by the expansion and contraction becomes small, and as a result, the electric signal can be selectively generated with respect to the torsional deformation. When a fiber containing polylactic acid as a main component is used as the piezoelectric fiber of the present invention, the lactic acid unit in the polylactic acid is preferably 90 mol% or more, and more preferably 95 mol% or more. It is better to use 98% or more. In addition, in the braided piezoelectric element 201, even if the sheath portion 202 and the other fibers other than the piezoelectric fiber A are combined with each other, the core portion 203 and the conductive portion may be electrically conductive. It is also possible to mix fibers or the like with other fibers other than the fiber B. The length of the braided piezoelectric element composed of the core portion 203 of the conductive fiber B, the sheath portion 202 of the braided piezoelectric fiber A, and the conductive layer 204 of the sheath portion 202 is not particularly limited. For example, even if the braided piezoelectric element is continuously manufactured in the production, it may be used after being cut into a length required later. The length of the braided piezoelectric element is 1 mm to 10 m, preferably 5 mm to 2 m, and preferably 1 cm to 1 m. When the length is too short, the fiber shape is lost, that is, convenience, and when the length is too long, the resistance value of the conductive fiber B needs to be considered. [0210] Hereinafter, each configuration will be described in detail. (Electrically Conductive Fiber) As the conductive fiber B, any known fiber can be used as the fiber indicating conductivity. Examples of the conductive fiber B include a fiber composed of a metal fiber, a fiber composed of a conductive polymer, a carbon fiber, a polymer in which a fibrous or granular conductive filler is dispersed, or a fibrous material. A fiber having a conductive layer is provided on the surface. Examples of the method of providing a conductive layer on the surface of the fibrous material include metal coating, conductive polymer coating, and winding of conductive fibers. Among them, metal coating is preferred from the viewpoints of conductivity, durability, flexibility, and the like. The specific method of coating the metal is, for example, vapor deposition, sputtering, electrolytic plating, electroless plating, etc., but plating is preferred from the viewpoint of productivity and the like. The metal thus plated may be referred to as a metal plated fiber. [0212] As the fiber of the substrate to which the metal is applied, well-known fibers can be used regardless of the presence or absence of conductivity, for example, in addition to polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, vinyl chloride fibers, aromatic poly In addition to synthetic fibers such as polyamide fibers, polyfluorene fibers, polyether fibers, and polyurethane fibers, semi-synthetic fibers such as natural fibers such as cotton, hemp, and enamel, and acetate, and hydrazine may be used. Regenerated fiber such as copper amine fiber. The fibers of the substrate are not limited thereto, and any known fibers may be used arbitrarily, and these fibers may be used in combination. The metal of the fiber applied to the substrate represents electrical conductivity, and any one may be used as long as the effect of the present invention is achieved. For example, gold, silver, platinum, copper, nickel, tin, lead, palladium, indium tin oxide, copper sulfide, or the like, and mixtures or alloys thereof may be used. When the conductive fiber B is coated with a metal coated organic fiber having bending resistance, the conductive fiber is rarely broken, and the durability and safety of the sensor using the piezoelectric element are excellent. [0215] The conductive fiber B may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. Multifilament is preferred from the viewpoint of the stability of the electrical properties. In the case of a monofilament (including a spun yarn), the monofilament diameter is from 1 μm to 5000 μm, preferably from 2 μm to 100 μm. It is preferably 3 μm to 50 μm. In the case of multifilaments, as the number of filaments, it is preferably from 1 to 100,000, preferably from 5 to 500, more preferably from 10 to 100. However, the fineness and the number of the conductive fibers B are the fineness and the number of the core portions 203 used in the production of the knitting, and the multifilament formed by a plurality of monofilaments (monofilaments) is also counted as one. Conductive fiber B. Here, the core portion 203 is provided to include the entire amount of the fiber even when a fiber other than the conductive fiber is used. [0216] When the diameter of the fiber is small, the strength is lowered and it becomes difficult to handle, and further, in the case where the diameter is large, the flexibility is sacrificed. The cross-sectional shape of the conductive fiber B is preferably a circle or an ellipse from the viewpoint of design and manufacture of the piezoelectric element, but is not limited thereto. [0217] Furthermore, in order to efficiently take out the electrical output from the piezoelectric polymer, it is preferable that the electric resistance is low, and the volume resistivity is 10 ^-1 Ω・cm or less is better, with 10 ^-2 Ω·cm or less is preferred, with 10 ^-3 Ω·cm or less is more preferable. However, the resistivity of the conductive fiber B is not limited to this in order to obtain sufficient strength for detecting the electrical signal. From the viewpoint of the use of the present invention, the conductive fiber B must have resistance to repeated bending or twisting. As its index, the nodule strength is preferably larger. The knot strength can be measured by the method of JIS L1013 8.6. The degree of the knot strength suitable for the present invention is preferably 0.5 cN/dtex or more, more preferably 1.0 cN/dtex or more, more preferably 1.5 cN/dtex or more, and most preferably 2.0 cN/dtex or more. Further, as another index, the bending rigidity is preferably smaller. The bending rigidity is generally measured by a measuring device such as a KES-FB2 pure bending tester manufactured by KATO TECH Co., Ltd. As a degree of bending rigidity suitable for the present invention, a carbon fiber "TENAX" (registered trademark) HTS40-3K manufactured by Toho Tenax Co., Ltd. is preferable. Specifically, the bending rigidity of the conductive fiber is 0.05×10. ^-4 N・m ² /m below is better, to 0.02×10 ^-4 N・m ² Below /m is preferred, to 0.01×10 ^-4 N・m ² Below /m is better. (Piezoelectric fiber) The piezoelectric polymer, which is a material of the piezoelectric fiber A, may be a piezoelectric polymer such as polyvinylidene fluoride or polylactic acid. In the above-described form, the piezoelectric fiber A preferably contains a crystalline polymer having a high absolute value of the piezoelectric constant d14 when the alignment axis is three axes, and particularly preferably polylactic acid as a main component. For example, the polylactic acid exhibits piezoelectricity by being easily aligned by stretching after melt spinning, and is excellent in productivity without requiring an electric field alignment treatment necessary for polyvinylidene fluoride or the like. However, this is not intended to exclude the use of piezoelectric materials other than polyvinylidene fluoride [0220] as polylactic acid, and depending on the crystal structure, L-lactic acid and L-lactide may be used. a poly-L-lactic acid obtained by polymerizing poly-L-lactic acid, a poly-D-lactic acid obtained by polymerizing D-lactic acid and D-lactide, and a stereocomplex polylactic acid formed by the above-mentioned mixed structure, but When it is used to indicate piezoelectricity, it can be used. From the viewpoint of high piezoelectricity, poly-L-lactic acid and poly-D-lactic acid are preferred. Since poly-L-lactic acid and poly-D-lactic acid have opposite polarizations for the same stress, they can be used in combination according to the purpose. The optical purity of the polylactic acid is preferably 99% or more, more preferably 99.3% or more, and still more preferably 99.5% or more. When the optical purity is less than 99%, the piezoelectricity is remarkably lowered, and it is difficult to obtain a sufficient electric signal by the shape change of the piezoelectric fiber A. In particular, the piezoelectric fiber A contains poly-L-lactic acid or poly-D-lactic acid as a main component, and these optical purity is preferably 99% or more. The piezoelectric fiber A containing polylactic acid as a main component extends at the time of production and is uniaxially aligned in the fiber axis direction. Further, the piezoelectric fiber A is not only uniaxially aligned in the fiber axis direction, but preferably contains fibers of polylactic acid crystals, and more preferably fibers containing uniaxially oriented polylactic acid crystals. Since polylactic acid has high crystallinity and uniaxial alignment, it indicates large piezoelectricity, and the absolute value of d14 becomes high. [0223] Crystallinity and uniaxial alignment are achieved by uniform PLA crystallization degree X _Homo (%) and the crystal orientation degree Ao (%) were determined. As the piezoelectric fiber A of the present invention, the degree of crystallization of the PLA is X. _Homo (%) and the crystal orientation degree Ao (%) satisfy the following formula (1). In the case where the above formula (1) is not satisfied, crystallinity and/or uniaxial alignment are insufficient, and the output value of the electric signal to the operation is lowered, or the sensitivity of the signal to the action in a specific direction is lowered. The value on the left side of the above formula (1) is preferably 0.28 or more, more preferably 0.3 or more. Here, each value is obtained as follows. [0224] The degree of crystallization of homopolylactic acid X _Homo : For the degree of crystallization of homopolylactic acid X _Homo It is obtained by analyzing the crystal structure due to wide-angle X-ray diffraction analysis (WAXD). In the wide-angle X-ray diffraction analysis (WAXD), an ultrax18 type X-ray diffraction apparatus manufactured by Rigaku Co., Ltd. was used, and the X-ray diffraction pattern of the sample was recorded on the image plate by the penetration method using the following conditions. X-ray source: Cu-Kα ray (confocal lens) Output: 45kV × 60mA Slot: 1st: 1mmΦ, 2nd: 0.8mmΦ Photography length: 120mm Accumulated time: 10 minutes Sample: 35mg of polylactic acid fiber and yarn into 3cm Fiber bundles. In the obtained X-ray diffraction pattern, the total scattering intensity Itotal is obtained at the azimuth angle, and the diffraction peaks from the homopolylactic acid crystal appearing in the vicinity of 2θ=16.5°, 18.5°, and 24.3° are obtained here. The sum of the integrated intensities ΣIHMi. From these values, the degree of crystallization of the per-lactic acid is determined according to the following formula (2). _Homo . Homopolymeric crystallization degree X _Homo (%)=ΣI _HMi /I _Total ×100 (2) In addition, ΣI _HMi It is calculated by subtracting the background or amorphous diffuse scattering from the total scattering intensity. (2) Crystal orientation degree Ao: For the crystal orientation degree Ao, in the X-ray diffraction pattern obtained by the above wide-angle X-ray diffraction analysis (WAXD), 2θ=16.5 appears in the direction of the moving diameter. The diffraction peak from the homopolylactic acid crystal near °, taking the intensity distribution with respect to the azimuth angle (°), and the total value of the half-value width from the obtained distribution curveΣ _Wi (°) is calculated by the following formula (3). Crystalline orientation Ao (%) = (360-ΣW _i ÷360×100 (3) [0226] In addition, since polylactic acid is a polyester which is rapidly decomposed by water, it is possible to add a known isocyanate compound, an oxazoline compound, or a ring when there is a problem in heat and humidity resistance. A hydrolyzing agent such as an oxygen compound or a carbodiimide compound may also be used. In addition, it is also possible to improve the physical properties by adding an oxidation preventing agent such as a phosphate compound, a plasticizer, a photodegradation preventing agent, or the like, as needed. [0227] The piezoelectric fiber A may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. In the case of a monofilament (including a spun yarn), the monofilament diameter is 1 μm to 5 mm, preferably 5 μm to 2 mm, more preferably 10 μm to 1 mm. In the case of a multifilament, the monofilament diameter is from 0.1 μm to 5 mm, preferably from 2 μm to 100 μm, more preferably from 3 μm to 50 μm. The number of filaments of the multifilament is preferably from 1 to 100,000, preferably from 50 to 50,000, and more preferably from 100 to 20,000. However, the fineness or the number of strips of the piezoelectric fiber A is determined by the fineness and the number of the strips of each carrier at the time of knitting, and the multifilament formed by a plurality of monofilaments (monofilaments) is also counted as A piezoelectric fiber A. Here, in the case where fibers other than the conductive fibers are used in one carrier, the total amount is included. In order to obtain such a piezoelectric polymer as the piezoelectric fiber A, any one of the well-known methods for forming a fiber from a polymer can be used as long as the effect of the present invention is achieved. For example, a method of performing fibrillation by extrusion molding a piezoelectric polymer, a method of fibrillating a piezoelectric polymer by melt spinning, and a piezoelectricity by dry or wet spinning can be employed. A method in which a molecule is fibrillated, a method in which a piezoelectric polymer is fibrillated by electrospinning, a method of cutting a film after forming a film, and the like. These spinning conditions may be applied to a piezoelectric polymer to be used in accordance with a known method, and a melt spinning method which is industrially easy to produce may be used. Also, after the fibers are formed, the formed fibers are extended. Accordingly, the uniaxially elongated alignment is formed and the piezoelectric piezoelectric fiber A exhibiting large piezoelectricity is contained. Further, the piezoelectric fiber A is subjected to a treatment such as dyeing, crepe, bonding, heat treatment, or the like before the fiber produced as described above is knitted. Further, since the piezoelectric fibers A have frictional breakage or breakage when the fibers are formed, it is preferable that the piezoelectric fibers A are relatively high in strength and abrasion resistance, and the strength is 1.5 cN/dtex. The above is preferable, preferably 2.0 cN/dtex or more, more preferably 2.5 cN/dtex or more, and 3.0 cN/dtex or more. The abrasion resistance can be evaluated by the JIS L1095 9.10.2 B method or the like, and the number of rubbing times is preferably 100 or more, preferably 1,000 or more, more preferably 5,000 or more, and most preferably 10,000 or more. The method for improving the abrasion resistance is not particularly limited, and all known methods can be used, for example, the degree of crystallization can be increased, or fine particles can be added, or surface processing can be performed. Further, when processing into a braid, it is also possible to apply a lubricant to the fibers to reduce friction. Further, the difference between the shrinkage ratio of the piezoelectric fiber and the shrinkage ratio of the conductive fiber is preferably small. When the difference in shrinkage ratio is large, there is a change in the time when the heat is applied or the time is changed after the processing or after the fabric is produced, or the film is bent, or the flatness of the fabric is deteriorated, and the piezoelectric signal is weakened. Happening. When the shrinkage ratio is quantified by the boiling water shrinkage ratio described later, the boiling water shrinkage ratio S(p) of the piezoelectric fiber and the boiling water shrinkage ratio S(c) of the conductive fiber are preferably in the following formula (4). The left side of the above formula (4) is preferably 5 or less, and more preferably 3 or less. Further, it is preferable that the shrinkage ratio of the piezoelectric fiber is smaller than the difference between the shrinkage ratio of the fiber other than the conductive fiber, for example, the insulating fiber. When the difference in shrinkage ratio is large, there is a change in the time when the heat is applied or the time is changed after the processing is performed or after the fabric is produced, or when the heat is applied, or the flatness of the fabric is deteriorated, and the piezoelectric signal becomes weak. The situation. When the shrinkage ratio is quantified by the boiling water shrinkage ratio, the boiling water shrinkage ratio S(p) of the piezoelectric fiber and the boiling water shrinkage ratio S(i) of the insulating fiber satisfy the following formula (5). The left side of the above formula (5) is preferably 5 or less, and more preferably 3 or less. Further, it is preferable that the piezoelectric fiber has a small shrinkage ratio. For example, when the shrinkage ratio is quantified by the boiling water shrinkage ratio, the shrinkage ratio of the piezoelectric fiber is preferably 15% or less, preferably 10% or less, more preferably 5% or less, and most preferably 3% or less. good. As a means for reducing the shrinkage ratio, various methods can be applied. For example, the degree of alignment relaxation or crystallization of the amorphous portion is improved by heat treatment, whereby the shrinkage ratio can be lowered, and the timing of performing the heat treatment is not particularly limited, and extension is exemplified. After the crepe, after the weaving, after the cloth, and so on. Further, the boiling water shrinkage rate was measured by the following method. A skein of 20 times was produced by a cloth inspection machine of 1.125 m around the outer frame, and a load of 0.022 cN/dtex was applied, and the initial skein length L0 was measured by hanging on a scale plate. Thereafter, the skein was treated in a boiling water bath at 100 ° C for 30 minutes, left to cool, and the above load was applied again, and suspended on a scale plate, and the length L of the skein after shrinkage was measured. The boiling water shrinkage ratio was calculated by the following formula (6) using the measured L0 and L. Boiling water shrinkage ratio = (L0 - L) / L0 × 100 (%) (6) [Coated] The conductive fiber B, that is, the core portion 203 is a piezoelectric fiber A, that is, a braided sheath portion 202 covers the surface. The thickness of the sheath portion 202 covering the conductive fibers B is preferably 1 μm to 10 mm, more preferably 5 μm to 5 mm, still more preferably 10 μm to 3 mm, and most preferably 20 μm to 1 mm. When it is too thin, there is a problem that there is a problem at the point of strength. Further, when it is too thick, the braided piezoelectric element 201 becomes hard and becomes difficult to be deformed. In addition, the sheath portion 202 as used herein refers to a layer adjacent to the core portion 203. In the braided piezoelectric element 201, the total fineness of the piezoelectric fibers A of the sheath portion 202 is preferably 1/2 or more and 20 or less times the total fineness of the conductive fibers B of the core portion 203. It is preferably 1 time or more and 15 times or less, more preferably 2 times or more and 10 times or less. When the total fineness of the piezoelectric fiber A to the total fineness of the conductive fiber B is too small, the piezoelectric fiber A surrounding the conductive fiber B is too small, the conductive fiber B cannot output a sufficient electric signal, and the conductive fiber B is present. Contact with other conductive fibers that are close to each other. When the total fineness of the piezoelectric fiber A and the total fineness of the conductive fiber B are excessively large, the piezoelectric fiber A surrounding the conductive fiber B is excessively large, and the braided piezoelectric element 201 becomes hard and becomes hard to be deformed. That is, even in either case, the braided piezoelectric element 201 cannot function as a sensor sufficiently. The total fineness referred to herein is the sum of the fineness of the piezoelectric fibers A constituting the sheath portion 202. For example, in the case of generally 8-strand weaving, the total densities of the eight fibers are obtained. Further, in the braided piezoelectric element 201, the fineness of each of the piezoelectric fibers A of the sheath portion 202 is preferably 1/20 or more and 2 or less times the total fineness of the conductive fibers B. It is preferably 1/15 times or more and 1.5 times or less, more preferably 1/10 times or more and 1 time or less. When the fineness of each of the piezoelectric fibers A is too small with respect to the total fineness of the conductive fibers B, the piezoelectric fibers A are too small, the conductive fibers B cannot output a sufficient electric signal, and the piezoelectric fibers A are cut off. Hey. When the fineness of each of the piezoelectric fibers A is excessively large with respect to the total fineness of the conductive fibers B, the piezoelectric fibers A are excessively thick, and the braided piezoelectric element 201 becomes hard and becomes difficult to be deformed. That is, even in either case, the braided piezoelectric element 201 cannot function as a sensor sufficiently. In the case where the conductive fiber B is a metal fiber or the metal fiber is mixed with the conductive fiber B or the piezoelectric fiber A, the ratio of the fineness is not limited to the above. In the present invention, the above ratio is important in terms of contact area or coverage ratio, that is, from the viewpoint of area and volume. For example, in the case where the specific gravity of each fiber exceeds 2, the ratio of the average cross-sectional area of the fibers is preferably the ratio of the above-mentioned fineness. [0238] Although the piezoelectric fiber A and the conductive fiber B are preferably as close as possible to each other, in order to improve the adhesion, an anchor layer or a bonding layer may be provided between the conductive fiber B and the piezoelectric fiber A. . [0239] The method of coating is a method in which the conductive fiber B is used as a core yarn, and the piezoelectric fiber A is wound around the braided shape. Further, the braided shape of the piezoelectric fiber A is not limited as long as it can output an electric signal to the stress generated by the applied load, and it is preferable to have the 8-strand braid or the 16-knit braid having the core portion 203. The shape of the conductive fiber B and the piezoelectric fiber A is not particularly limited, and it is preferably as close as possible to a concentric shape. In the case where a multifilament is used as the conductive fiber B, the piezoelectric fiber A may be coated with at least a part of the surface (fiber peripheral surface) of the multifilament of the conductive fiber B, even if It is also possible to coat the surface of the fibrils (fiber peripheral surface) constituting the multifilaments with the piezoelectric fibers A, even if they are not coated. The state in which the piezoelectric fibers A are coated in the respective filaments of the multifilaments of the conductive fibers B may be appropriately set in consideration of performance, workability, and the like of the piezoelectric element. (Electrically Conductive Layer) The conductive layer 204 has a function as an electrode that serves as a counter electrode of the conductive fiber of the core portion 203, and the conductive fiber that shields the core portion 203 prevents external electromagnetic waves and suppresses conduction at the core portion 203. The function of the shielding of the noise signal generated by the fiber. Since the conductive layer 204 functions as a shield, it is preferably grounded (connected to the ground or the ground of the electronic circuit). According to this, the S/N ratio (signal-to-noise ratio) of the cloth-like piezoelectric element 207 can be remarkably improved even if the conductive cloth for electromagnetic wave shielding is not overlapped above the cloth-like piezoelectric element 207. As the conductive layer 204, even in the case of coating, even if the film, the cloth, or the fiber is wound, it may be combined. [0242] The coating of the conductive layer 204 may be carried out by using a material containing a substance indicating conductivity, and a known owner is used. For example, a metal, a conductive polymer, and a polymer in which a conductive filler is dispersed may be mentioned. In the case where the conductive layer 204 is formed by winding a film, a film obtained by using a conductive polymer or a film-forming polymer to disperse a conductive filler is used, and further, conductive is provided on the surface. Thin film can also be used. When the conductive layer 204 is formed by winding of a fabric, a fabric in which a conductive fiber 206 to be described later is used as a constituent component is used. [0245] In the case where the conductive layer 204 is formed by winding a fiber, a cover, a knitted fabric, or a woven fabric can be considered as a means. Further, the fibers to be used are the conductive fibers 206, and the conductive fibers 206 may be of the same type as the conductive fibers B, and may be different types of conductive fibers. Examples of the conductive fiber 206 include a fiber composed of a metal fiber, a fiber composed of a conductive polymer, a carbon fiber, a polymer in which a fibrous or granular conductive filler is dispersed, or a fibrous material. A fiber having a conductive layer is provided on the surface. Examples of the method of providing a conductive layer on the surface of the fibrous material include metal coating, conductive polymer coating, and winding of conductive fibers. Among them, metal coating is preferred from the viewpoints of conductivity, durability, flexibility, and the like. The specific method of coating the metal is, for example, vapor deposition, sputtering, electrolytic plating, electroless plating, etc., but plating is preferred from the viewpoint of productivity and the like. The metal thus plated may be referred to as a metal plated fiber. [0246] As the fiber of the substrate to which the metal is applied, well-known fibers can be used regardless of the presence or absence of conductivity, for example, in addition to polyester fiber, nylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, vinyl chloride fiber, aromatic poly In addition to synthetic fibers such as polyamide fibers, polyfluorene fibers, polyether fibers, and polyurethane fibers, semi-synthetic fibers such as natural fibers such as cotton, hemp, and enamel, and acetate, and hydrazine may be used. Regenerated fiber such as copper amine fiber. The fibers of the substrate are not limited thereto, and any known fibers may be used arbitrarily, and these fibers may be used in combination. The metal of the fiber applied to the substrate represents electrical conductivity, and any one may be used as long as the effect of the present invention is achieved. For example, gold, silver, platinum, copper, nickel, tin, lead, palladium, indium tin oxide, copper sulfide, or the like, and mixtures or alloys thereof may be used. When the conductive fiber 206 is coated with a metal coated organic fiber having bending resistance, the conductive fiber is rarely broken, and the durability and safety of the sensor using the piezoelectric element are excellent. [0249] The conductive fiber 206 may be a multifilament in which a plurality of filaments are bundled, or a monofilament composed of one filament. Multifilament is preferred from the viewpoint of the stability of the electrical properties. In the case of a monofilament (including a spun yarn), the monofilament diameter is from 1 μm to 5000 μm, preferably from 2 μm to 100 μm. It is preferably 3 μm to 50 μm. In the case of multifilaments, as the number of filaments, it is preferably from 1 to 100,000, preferably from 5 to 500, more preferably from 10 to 100. [0250] When the diameter of the fiber is small, the strength is lowered and it becomes difficult to handle, and further, in the case where the diameter is large, flexibility is sacrificed. The cross-sectional shape of the conductive fiber 206 is preferably a circle or an ellipse from the viewpoint of design and manufacture of the piezoelectric element, but is not limited thereto. [0251] Furthermore, in order to improve the suppression effect of the noise signal, the resistance is preferably low, and the volume resistivity is 10 ^-1 Ω・cm or less is better, with 10 ^-2 Ω·cm or less is preferred, with 10 ^-3 Ω·cm or less is more preferable. However, when the suppression effect of the noise signal is obtained, the specific resistance is not limited to this. From the viewpoint of the use of the present invention, the conductive fibers 206 must have resistance to repeated bending or twisting. As its index, the nodule strength is preferably larger. The knot strength can be measured by the method of JIS L1013 8.6. The degree of the knot strength suitable for the present invention is preferably 0.5 cN/dtex or more, more preferably 1.0 cN/dtex or more, more preferably 1.5 cN/dtex or more, and most preferably 2.0 cN/dtex or more. Further, as another index, the bending rigidity is preferably smaller. The bending rigidity is generally measured by a measuring device such as a KES-FB2 pure bending tester manufactured by KATO TECH Co., Ltd. As a degree of bending rigidity suitable for the present invention, a carbon fiber "TENAX" (registered trademark) HTS40-3K manufactured by Toho Tenax Co., Ltd. is preferable. Specifically, the bending rigidity of the conductive fiber is 0.05×10. ^-4 N・m ² /m below is better, to 0.02×10 ^-4 N・m ² Below /m is preferred, to 0.01×10 ^-4 N・m ² Below /m is better. (Protective Layer) A protective layer may be provided on the outermost surface of the braided piezoelectric element 201 according to the present invention. The protective layer is preferably insulating, and is preferably composed of a polymer from the viewpoint of flexibility. In the case where the protective layer is insulative, of course, in this case, the protective layer may be deformed together or rubbed on the protective layer, but if the external force reaches the piezoelectric fiber A, it may be induced. When it is polarized, it is not particularly limited. The protective layer is not limited to those formed by coating of a polymer or the like, and may be a wound film, a cloth, a fiber, or the like, or may be combined. Further, the fabric relating to the present invention described later can be used as a protective layer, and it is preferable from the viewpoint of simplification of the constitution. [0254] As the thickness of the protective layer, the shear stress is more easily transmitted to the piezoelectric fiber A at a thinner thickness, but when it is too thin, the protective layer itself is easily broken, and the like. 10 nm to 200 μm is preferred, preferably 50 nm to 50 μm, more preferably 70 nm to 30 μm, and most preferably 100 nm to 10 μm. The shape of the piezoelectric element can also be formed by the protective layer. Further, a layer in which a plurality of layers are composed of piezoelectric fibers or a layer in which a plurality of layers are formed of conductive fibers for taking out signals may be provided. Needless to say, the order of the protective layer, the layer composed of the piezoelectric fibers, and the layer composed of the conductive fibers is appropriately determined depending on the purpose. Further, as a method of winding, a method of forming a woven structure or covering the outer layer of the sheath portion 202 may be mentioned. [0256] The braided piezoelectric element 201 of the present invention measures the conductivity of the core of the braided piezoelectric element 201 in addition to the deformation or stress that can be detected by the output of the electrical signal caused by the piezoelectric effect described above. The change in electrostatic capacitance between the fiber B and the conductive layer 204 can also detect the deformation caused by the pressure applied to the braided piezoelectric element 201. Further, in the case where a plurality of braided piezoelectric elements 201 are used in combination, by measuring the change in electrostatic capacitance between the conductive layers 204 of the respective braided piezoelectric elements 201, it is also possible to detect application to the braided piezoelectric element 201. Deformation caused by piezoelectric. (Corrugated Piezoelectric Element) The cloth-like piezoelectric element of the present invention is characterized in that at least one braided piezoelectric element is fixed to the fabric. In this way, not only can the fabric itself be processed into a desired shape such as clothes, but also can be sewn or adhered to various methods such as ready-made clothes or structures without a sensor function. This makes it easy and convenient to have sensor functions. Fig. 17 is a schematic view showing a configuration example of a cloth-like piezoelectric element using a braided piezoelectric element according to an embodiment. [0258] In the example of FIG. 17, the cloth-like piezoelectric element 207 is fixed to the fabric 208 by at least one braided piezoelectric element 201. At least one of the fibers (including knitting) constituting the fabric of the fabric 208 is a braided piezoelectric element 201, and the braided piezoelectric element 201 is not limited as long as it functions as a piezoelectric element, and even any braid can be used. . In the case of forming a cloth, as long as the object of the present invention is achieved, it is possible to perform interlacing, interlacing, and the like in combination with other fibers (including knitting). Of course, even if the braided piezoelectric element 201 is used as one of the fibers constituting the fabric (for example, warp or weft), even if the braided piezoelectric element 201 is embroidered on the fabric, it may be joined. In the example shown in Fig. 17, the cloth-like piezoelectric element 207 is a flat fabric in which at least one of the braided piezoelectric element 201 and the insulating fiber 209 is disposed as a warp yarn, and the insulating fiber 209 is disposed as a weft. The insulating fiber 209 will be described later. Further, all or a part of the insulating fibers 209 may be in a woven form. In this case, when the braided piezoelectric element 207 is deformed by bending or the like, the braided piezoelectric element 201 is also deformed with the deformation, and is output from the braided piezoelectric element 201. The electrical signal can detect the deformation of the cloth-like piezoelectric element 207. Further, since the cloth-like piezoelectric element 207 can be used as a fabric (woven fabric), it can be applied to, for example, a garment-type wearable sensor. Further, in the configuration in which the insulating fibers of the weft yarns of the cloth-like piezoelectric element 207 shown in FIG. 17 are partially replaced by the conductive fibers 210 (FIG. 18), the conductive fibers 210 and the braided pressure are used. The electrical components 201 are crossed and in contact. Therefore, the conductive fibers 210 are in contact with at least a portion of the conductive layer 204 of the braided piezoelectric element 201, and such conductive fibers 210 can be connected to the electronic circuit replacing the conductive layer 204. The conductive fibers 210 may be of the same type as the conductive fibers B, and may be of a different type of conductive fibers, even if all or a part of them are in a woven form. In the braided piezoelectric element of the present invention, the pull-out strength of the braided piezoelectric element per 5 cm of the fabric is 0.1 N or more. In this way, since the difference between the deformation of the cloth and the deformation of the braided piezoelectric element is minimized, the amount of deformation of the braided piezoelectric element detected by the electric signal of the braided piezoelectric element can be used to make the estimation. The error at the time of deformation of the cloth is minimized, and the reproducibility can be improved. When the braided piezoelectric element has a pull-out strength of less than 0.1 N per 5 cm of the fabric, for example, even if the fabric is stretched and deformed, slippage occurs between the braided piezoelectric element and the fabric, and the braided piezoelectric element is not Fully telescopic deformation, the amount of expansion and contraction detected by the electric signal of the braided piezoelectric element is significantly smaller than that of the cloth, and the reproducibility is low. From such a viewpoint, the pull-out strength per 5 cm of the braided piezoelectric element is preferably 0.2 N or more, more preferably 0.3 N or more, and particularly preferably 0.4 or more. Further, it is preferable that the pulling strength is equal to or higher than the strength of the braided piezoelectric element. In the present invention, the "drawing strength per 5 cm of the braided piezoelectric element to the fabric" is determined in the following manner. First, in the case where the woven piezoelectric element is exposed from the cloth-like piezoelectric element, the woven piezoelectric element is held by one of the workpieces held by the tensile testing machine, and the woven piezoelectric element is separated from the gripping side. A portion of the fixed end of the element of 5 cm cuts the braided piezoelectric element and the cloth-like piezoelectric element. The braided piezoelectric element is fixed to a portion of the 5 cm portion of the fabric except for a region within 1 mm from the braided piezoelectric element, and the workpiece is held in a U-shape by 5 cm in the longitudinal direction of the braided piezoelectric element. It is controlled and connected to the other side of the holding workpiece of the tensile testing machine. Further, in this state, the tensile test was carried out at a speed of 10 mm/min, and the maximum strength was measured, and the pull-out strength was measured. In the case where the braided piezoelectric element is not sufficiently exposed from the cloth-like piezoelectric element, one of the fabrics (a portion other than the braided piezoelectric element) is cut to expose the braided piezoelectric element, and the above-described manner is performed. Just measure. In addition, when it is difficult to ensure that the length of the portion in which the braided piezoelectric element is fixed to the fabric is 5 cm, the pull-out strength is measured at a fixed portion of an arbitrary length, and the strength may be converted into a strength of 5 cm. The braided piezoelectric element of the present invention preferably has a coverage of the braided piezoelectric element of the fabric constituting the fabric of more than 30% on both sides of the fabric. In this way, not only the braided piezoelectric element increases the pull-out strength of the fabric, but also the difference between the deformation of the fabric and the deformation of the braided piezoelectric element is minimized, and it is difficult to be caused by external friction, heat, light, or the like. Damage. From such a viewpoint, the coverage of the braided piezoelectric element due to the fibers constituting the fabric is preferably more than 50% on both sides of the fabric, more preferably more than 70%, and most preferably 100%. [0264] The coverage of the braided piezoelectric element due to the fibers constituting the fabric is calculated from the image when viewed from one of the faces of the cloth-like piezoelectric element, and the projected area with respect to the braided piezoelectric element is calculated. The area ratio of the portion of the braided piezoelectric element is shielded by the fibers constituting the fabric. Even if the observation image is viewed from the other side, the same evaluation is performed, and the coverage ratio is calculated on both sides of the cloth. In such a case, in the fabric caused by the usual woven fabric (plain, twill, satin, etc.), although the coverage is difficult to exceed 50% on both sides, the tissue is changed by plain weave or twill weave. When weaving, we use textile yarn or multifilament, or increase the density of the yarn orthogonal to the braided piezoelectric element, or make the density of the yarn parallel to the braided piezoelectric element relatively low, which can be made on both sides of the fabric. Over 50% coverage rate. However, since the density of the yarn orthogonal to the braided piezoelectric element is increased, when the tension of the yarn orthogonal to the braided piezoelectric element is excessively lowered, the force for restraining the braided piezoelectric element is weakened. As a result, the desired pull-out strength cannot be achieved, which is not preferable. Furthermore, by fabricating the fabric by sandwiching the braided piezoelectric element between the double-layer fabric or the layer of the double-layer fabric, the coverage of both sides of the fabric can be greatly improved, and it can be made 100% or Close to 100%. Further, when the coverage ratio is 30% or less, the braided piezoelectric element is exposed from the fibers of the fabric, and the protection is insufficient. Even if the fibers constituting the fabric are transparent, they are considered to be covered. In the case where the braided piezoelectric element is provided with a protective layer on the outer layer of the conductive layer 204, the protective layer is also considered to be a braided piezoelectric element. (Multiple Piezoelectric Element) Further, in the cloth-like piezoelectric element 207, a plurality of braided piezoelectric elements 201 can be arranged and used. As the arrangement, for example, as the warp yarn or the weft yarn, even if the braided piezoelectric element 201 is used in all, the braided piezoelectric element 201 may be used for every few or a part. Further, even if a certain portion uses the braided piezoelectric element 201 as a warp yarn, and the other portion uses the braided piezoelectric element 201 as a weft yarn. 19 is a schematic view showing another configuration example of a cloth-like piezoelectric element using a braided piezoelectric element according to an embodiment. The cloth-like piezoelectric element 207 is provided with a fabric 208 including at least two braided piezoelectric elements 201, and the braided piezoelectric elements 201 are arranged to be slightly parallel. The cloth 208 is at least two of the fibers (including knitting) constituting the fabric, and is a braided piezoelectric element 201. The braided piezoelectric element 201 is not limited as long as it functions as a piezoelectric element, even if it is any braid. can. In the example shown in FIG. 19, the cloth-like piezoelectric element 207 is a flat fabric in which at least two braided piezoelectric elements 201 and insulating fibers 209 are disposed as warp yarns, and insulating fibers 209 are disposed as weft yarns. The insulating fiber 209 will be described later. Further, all or a part of the insulating fibers 209 may be in a woven form. Further, as in the case of Fig. 18, the insulating fibers of the weft of the cloth-like piezoelectric element 207 shown in Fig. 19 may be partially replaced with conductive fibers. [0267] Although the piezoelectric signal is emitted when the braided piezoelectric element 201 is deformed, the signal also changes in size or shape in response to the deformation. In the case of the cloth-like piezoelectric element 207 shown in FIG. 19, when the line orthogonal to the two braided piezoelectric elements 201 of the cloth-like piezoelectric element 207 is a curved portion and is bent and deformed, two The braided piezoelectric element 201 has the same deformation. Therefore, the same signal is detected from the two braided piezoelectric elements 201. Further, in the case where a complicated deformation such as a twist is applied, the two braided piezoelectric elements 201 are individually induced to be deformed, and the signals generated by the respective braided piezoelectric elements 201 are different. According to this principle, the plurality of braided piezoelectric elements 201 are combined, and the signals generated by the respective braided piezoelectric elements 201 are compared and calculated, whereby the complicated deformation analysis of the braided piezoelectric elements 201 can be performed. For example, by comparing the results obtained by comparing the polarity, amplitude, phase, and the like of the signal generated by each of the braided piezoelectric elements 201, it is possible to detect a complicated deformation such as torsion. [0268] In the above-described configuration, the two braided piezoelectric elements 201 are disposed at intervals from each other from the viewpoint of different deformation of the two braided piezoelectric elements 201 with respect to the bending of the fabric, specifically The distance between the portions where the piezoelectric fibers are closest to each other is 0.05 mm or more and 500 mm or less, preferably 0.1 mm or more and 200 mm or less, and more preferably 0.5 mm or more and 100 mm or less. Further, in the case where the fabric contains signal detection without using a braided piezoelectric element, even if the distance between the braided piezoelectric element and the other braided piezoelectric element is less than 0.05 mm. As described above, by combining the plurality of braided piezoelectric elements 201, the signals generated in the respective braided piezoelectric elements 201 are compared and calculated, and complicated deformation analysis such as bending or torsion can be performed. Therefore, for example, it can be applied to, for example, Wearable sensors in the shape of clothing. In this case, when the braided piezoelectric element 207 is deformed by bending or the like, the braided piezoelectric element 201 is also deformed in accordance with the deformation thereof, and therefore, according to the electric signal output from the braided piezoelectric element 201, The deformation of the cloth-like piezoelectric element 207 can be detected. Further, since the cloth-like piezoelectric element 207 can be used as a fabric (woven fabric), it can be applied to, for example, a garment-type wearable sensor. (Insulating Fiber) In the cloth-like piezoelectric element 207, an insulating fiber can be used in a portion other than the braided piezoelectric element 201 (and the conductive fiber 210). In this case, the insulating fiber is used for the purpose of improving the flexibility of the cloth-like piezoelectric element 207, and a fiber having a stretchable material or shape can be used. In this way, by arranging the insulating fibers in addition to the braided piezoelectric element 201 (and the conductive fibers 210), the operability of the cloth-like piezoelectric element 207 can be improved (exemplified as a wearable sensor) Activity is easy). [0272] As such an insulating fiber, if the volume resistivity is 10 ⁶ It can be used when Ω・cm or more, to 10 ⁸ Ω·cm or more is preferred, with 10 ¹⁰ Ω·cm or more is more preferable. [0273] As the insulating fiber, for example, in addition to polyester fiber, nylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, vinyl chloride fiber, aromatic polyamide fiber, polyfluorene fiber, polyether fiber, polyamine group In addition to synthetic fibers such as formate fibers, natural fibers such as cotton, hemp, and enamel, semi-synthetic fibers such as acetate, and regenerated fibers such as hydrazine or copper amine can be used. It is not limited to these, and the well-known insulating fiber can be used arbitrarily. In addition, even if these insulating fibers are used in combination, they may be used in combination with fibers having no insulating properties, and may be fibers having overall insulating properties. [0274] Further, it is also possible to use fibers of all known cross-sectional shapes. (Manufacturing Method) The woven piezoelectric element 201 according to the present invention covers the surface of at least one of the conductive fibers B by the woven piezoelectric fiber A, but the method for producing the same may be, for example, the following method. . In other words, the conductive fiber B and the piezoelectric fiber A are separately produced, and the piezoelectric fiber A is wound into a braided shape to coat the conductive fiber B. In this case, it is preferable to cover as close as possible to a concentric shape. In this case, the spinning and stretching conditions in which the piezoelectric polymer is formed as the piezoelectric fiber A and the polylactic acid is used preferably have a melt spinning temperature of 150° C. to 250° C. Preferably, the extension temperature is preferably from 40 ° C to 150 ° C, the stretching ratio is preferably from 1.1 to 5.0, and the crystallization temperature is preferably from 80 ° C to 170 ° C. [0277] As the piezoelectric fiber A wound around the conductive fiber B, even if a multifilament of a bundle of a plurality of filaments is used, a single filament (including a textile yarn) may be used. In addition, as the conductive fiber B wound around the piezoelectric fiber A, even if a multifilament of a bundle of a plurality of filaments is used, a single filament (including a textile yarn) may be used. [0278] As a preferred embodiment of the coating, the piezoelectric fiber A can be knitted into a braided shape by using the conductive fiber B as a core yarn, and a tubular braid (Tubular Braid) can be produced and coated. More specifically, an 8-strand woven or a 16-knit woven fabric having a core portion 203 can be cited. However, for example, even if the piezoelectric fiber A is in the form of a braided tube, the conductive fiber B is regarded as a core portion, and the braided tube may be inserted and coated. [0279] Although the conductive layer 204 is produced by coating or winding of fibers, it is preferable to use a fiber to be wound from the viewpoint of easy production. As the winding method of the fiber, a cover, a knitted fabric, and a woven fabric can be considered, and it can be manufactured by any method. According to the above-described manufacturing method, the braided piezoelectric element 201 in which the surface of the conductive fiber B is coated with the braided piezoelectric fiber A and the conductive layer 204 is provided around it can be obtained. The braided piezoelectric element 207 of the present invention is produced by weaving and arranging. As long as the object of the present invention is achieved, it may be interlaced, cross-linked, cross-linked, etc., in combination with other fibers (including weaving). Of course, even if the braided piezoelectric element 201 is used as part of the fiber (for example, warp or weft) constituting the fabric, even if the braided piezoelectric element 201 is embroidered on the fabric, even if it is joined, even if it is combined These methods are also possible. Further, it is preferable that the strip-shaped cloth-like piezoelectric element in which the cloth is present only in the vicinity of the braided piezoelectric element 201 can be easily provided by sewing or pasting on other fabrics. In this case, the distance between the end of the tape and the braided piezoelectric element (the distance in the width direction of the tape) is preferably 1 mm or more and 100 mm or less, more preferably 3 mm or more and 50 mm or less, and still more preferably 5 mm or more and 20 mm or less. In the case of a strip-shaped piezoelectric element, it is possible to manufacture a wide-sized piezoelectric element in parallel with the braided piezoelectric element 201, but from the viewpoint of simplifying the manufacturing process, It is preferable to embroider and bond the braided piezoelectric element 201 on the tape during the weaving and preparation of the tape, and interlacing, interlacing, and interlacing. [0282] The woven structure of the woven fabric may be exemplified by three original structures such as plain weave, twill weave, and satin weave, a single structure, a double weave, a double weave, and the like. Even if it is a warp knitted fabric (weft weaving), it can be used as a warp. As the organization of the circular knitting fabric (weft knitting), it is preferable to exemplify a flat knitting, a rib knitting, a double sided knitting, a reverse stitch knitting, a hanging needle knitting, a floating thread knitting, a half-side knitting, a yarn knitting, and a wool knitting. As a warp knitting organization, a single-sided warp-knit flat weave, a single-sided warp-knitted satin stitch, a double-sided warp-knitted quilt, a velvet-warp woven, a velvet knitting, a jacquard knitting, and the like can be exemplified. The number of layers may be a single layer or a multilayer of two or more layers. Further, it is also possible to form a woven fabric or a woven fabric composed of a bristles and a base tissue portion which are formed by woven wool and/or loops. [0283] From the viewpoint of simplifying the manufacturing process, the improvement of the pull-out strength, and the coverage ratio, it is preferable that the braided piezoelectric element is fixed to the fabric in a state of being woven or knitted, so as to be woven. It is more preferable that the piezoelectric element is sandwiched between the layers of the multi-layer woven fabric or the multi-woven fabric. Multilayer means two or more layers. (Applicable Techniques of Piezoelectric Element) The piezoelectric element such as the braided piezoelectric element 201 or the cloth-like piezoelectric element 207 of the present invention can output contact, pressure, and surface contact with each other even in any aspect. The shape change is used as a signal, and can be utilized as a sensor (device) that detects the magnitude of the stress applied to its piezoelectric element and/or the position to be applied. Further, the electric signal may be used as a power source for powering another device or a power generating element such as power storage. Specifically, it is used for power generation by a movable part of a spontaneous exerciser such as a human, an animal, a robot, or a machine, and the power generation due to the surface of the sole, the dressing, and the structure of the external pressure is caused by the fluid. The shape changes in the power generation. Furthermore, since the electrical signal is emitted by the shape change in the fluid, it is also possible to adsorb or suppress the adhesion of the charged substance in the fluid. 6 is a block diagram showing a device 111 including the piezoelectric element 112 of the present invention. The device 111 includes a piezoelectric element 112 (the cloth-like piezoelectric element 207), and an amplification means 113 for arbitrarily selecting and amplifying the electric signal output from the output terminal of the piezoelectric element 112 in response to the applied pressure, and outputting the The output means 114 for amplifying the arbitrarily selected amplification means 113 and the means for transmitting the electric signal outputted from the output means 114 to the transmission means 115 of an external device (not shown). When the device 111 is used, the electrical signal outputted according to the contact, pressure, and shape change of the surface of the piezoelectric element 112 can be detected and applied to the piezoelectric element by an external device (not shown). The magnitude of the stress and/or the location to be applied. The arbitrarily selected amplification means 113, the output means 114, and the transmission means 115 may be constructed, for example, in the form of a software program, or may be constructed by a combination of various electronic circuits and software programs. For example, the software program is installed in an arithmetic processing unit (not shown), and the arithmetic processing unit operates in accordance with the software program, thereby realizing the functions of the respective units. Furthermore, the arbitrarily selected amplification means 113, the output means 114, and the transmission means 115 may be realized as a semiconductor integrated circuit for writing a software program for realizing the functions of the respective units. Further, the transmission method by the transmission means 115 may be determined by wireless or wired, and may be appropriately determined in accordance with the sensor configured. Alternatively, even in the device 111, an arithmetic means (not shown) for calculating the magnitude of the stress applied to the piezoelectric element 112 and/or the applied position based on the electrical signal output from the output means 114 may be provided. . Further, not only the amplifying means but also a well-known signal processing means such as a means for removing noise or a means for performing processing in combination with other signals may be used. The order of connection of these means can be appropriately changed depending on the purpose. Of course, even if the electrical signal output from the piezoelectric element 112 is transmitted to the external device as it is, the signal processing can be performed. 20 to 22 are schematic views showing a configuration example of an apparatus including a braided piezoelectric element according to an embodiment. The amplification means 113 of Figs. 20 to 22 corresponds to the description with reference to Fig. 6, and the output means 114 and the transmission means 115 of Fig. 6 are not shown in Figs. When the device having the cloth-like piezoelectric element 207 is configured, the input terminal of the amplification means 113 is connected to the output terminal of the core portion 203 (formed by the conductive fiber B) of the braided piezoelectric element 201. The wire or ground terminal is connected to the conductive layer 204 of the braided piezoelectric element 201 or the conductive fiber 210 of the cloth-like piezoelectric element 207 or a braid different from the braided piezoelectric element 201 connected to the input terminal of the amplification means 113. Piezoelectric element. For example, as shown in FIG. 20, in the cloth-like piezoelectric element 207, a pull-out line from an output terminal of the core portion 203 of the braided piezoelectric element 201 is connected to an input terminal of the amplification means 113 to be woven. The conductive layer 204 of the piezoelectric element 201 is grounded. Further, for example, as shown in FIG. 21, in the cloth-like piezoelectric element 207, the pull-out line from the core portion 203 of the braided piezoelectric element 201 is connected to the input terminal of the amplification means 113, and the knitting is performed. The conductive fibers 210 that are in contact with each other are in contact with each other. Further, as shown in FIG. 22, when the plurality of braided piezoelectric elements 201 are arranged in the cloth-like piezoelectric element 207, the pull-out from the output terminal of the core portion 203 of the one knitted piezoelectric element 201 is pulled out. The line is connected to the input terminal of the amplification means 113, and the pull-out line from the core portion 203 of the other braided piezoelectric element 201 arranged in the braided piezoelectric element 201 is grounded. [0288] When the braided piezoelectric element 201 is deformed, the piezoelectric fiber A is deformed to generate polarization. The influence of the arrangement of the positive and negative charges generated by the polarization of the piezoelectric fiber A causes the movement of the electric charge on the drawing line from the output terminal of the conductive fiber B forming the core portion 203 of the braided piezoelectric element 201. On the pull-out line from the conductive fiber B, a slight electrical signal (i.e., current or potential difference) appears in the movement of the electric charge. That is, in response to the electric charge generated when the braided piezoelectric element 201 is deformed, the amplifying means 113 that outputs an electric signal from the output terminal amplifies the electric signal, and the output means 114 outputs the electric signal amplified by the amplifying means 113. Since the polarity, amplitude, phase, and the like of the electric signal output from the output means 114 are different by the type of deformation of the braided piezoelectric element 201, the polarity, amplitude, phase, and the like of the electric signal output from the output means 114 are used. The results obtained by the comparison are compared to determine the complex deformation of the torsion and the like. [0289] By connecting the braided piezoelectric element and the electronic circuit such as the amplifying means 113 in FIGS. 20 to 22, the braided piezoelectric element and other members (connectors or wires, etc.) are electrically connected, and the braided piezoelectric element is used. It is difficult to connect the components as they are covered by the fabric. Therefore, the braided piezoelectric element is partially exposed from the fabric, and in the exposed portion, the conductive fibers and/or the conductive layer of the braided piezoelectric element are electrically connected to other members. The exposed portion is preferably 2 mm or more and 100 mm or less, more preferably 5 mm or more and 50 mm or less, and more preferably 10 mm or more and 30 mm or less, from the viewpoint of the ease of connection work and the balance of performance. [0290] After the provision of the exposed portion to the cloth-shaped piezoelectric element, it is necessary to perform partial cutting or the like of the fabric, and it is not preferable because the physical properties of the fabric are damaged, so that the manufacturing of the piezoelectric element is performed. It is preferable to woven and prepare the structure in which the braided piezoelectric element is exposed at a joint with other members. [0291] The device 111 of the present invention has a cloth shape, and has a wide range of applications because of its flexibility. Specific examples of the device 111 of the present invention include a touch panel that is shaped like a hat, a glove, a sock, and the like, which is a garment, a support, a handkerchief, and the like, and is used as a surface pressure sensor for humans or animals. For example, a sensor that bends, twists, and expands and contracts the joint portion in the shape of a glove, a belt, a support, or the like is detected. For example, when it is used in a person, it is possible to use an information collection for an action such as a joint for medical use, an entertainment use, or an interface for moving a lost tissue or a robot. Further, a surface pressure sensor which is a cloth doll or a robot that mimics an animal or a human type, and a sensor that detects bending, twisting, and expansion of the joint portion can be used. Further, a surface pressure sensor or a shape change sensor which is used as a bedding, a sole, a glove, a chair, a dressing, a bag, a flag, or the like as a bed sheet or a pillow, etc. [0292] Further, the device 111 of the present invention It is woven or cloth-like and has flexibility. Therefore, it can be used as a surface pressure sensor or shape change sensor by attaching or covering the surface of all or part of all structures. Moreover, since the device 111 of the present invention can generate a sufficient electrical signal only by rubbing the surface of the piezoelectric element 201, it can be used for a touch sensor-like touch input device or pointing device. Further, since the surface of the object to be measured is wiped by the braided piezoelectric element 201, position information or shape information in the height direction of the object to be measured can be obtained, and thus it can be used for surface shape measurement or the like. [Examples] Hereinafter, the present invention will be further described by way of Examples, but the present invention is not limited thereto. The characteristics of the piezoelectric fiber (piezoelectric structure), the braided piezoelectric element, and the cloth-like piezoelectric element shown in the present embodiment are determined by the following methods. [Piezoelectric fiber] (1) Poly-L-lactic acid crystallinity X _Homo : For poly-L-lactic acid crystallinity X _Homo It is obtained by analyzing the crystal structure due to wide-angle X-ray diffraction analysis (WAXD). In the wide-angle X-ray diffraction analysis (WAXD), an ultrax18 type X-ray diffraction apparatus manufactured by Rigaku Co., Ltd. was used, and the X-ray diffraction pattern of the sample was recorded on the image plate by the penetration method using the following conditions. X-ray source: Cu-Kα ray (confocal lens) Output: 45kV × 60mA Slot: 1st: 1mmΦ, 2nd: 0.8mmΦ Photography length: 120mm Accumulated time: 10 minutes Sample: 35mg of polylactic acid fiber and yarn into 3cm Fiber bundles. In the obtained X-ray diffraction pattern, the total scattering intensity I is obtained at the azimuth angle _Total Here, the sum of the integrated intensities of the respective diffraction peaks from the poly-L-lactic acid crystals appearing in the vicinity of 2θ=16.5°, 18.5°, and 24.3° is determined. _HMi . From these values, the degree of crystallization of poly-L-lactic acid is determined according to the following formula (3). _Homo . [Formula 3] Poly-L-lactic acid crystallization degree X _Homo (%)=ΣI _HMi /I _Total ×100 (3) In addition, ΣI _HMi It is calculated by subtracting the background or amorphous diffuse scattering from the total scattering intensity. (2) poly-L-lactic acid crystal orientation degree A: for the poly-L-lactic acid crystal orientation degree A, in the X-ray diffraction pattern obtained by the above wide-angle X-ray diffraction analysis (WAXD), For the diffraction peak from the poly-L-lactic acid crystal appearing in the vicinity of 2θ = 16.5° in the radial direction, the intensity distribution with respect to the azimuth angle (°) is taken from the total value of the half-value width of the obtained distribution curve. _Wi (°) is calculated by the following formula (4). [Formula 4] Poly-L-lactic acid crystal orientation degree A (%) = (360-ΣW _i ) ÷ 360 × 100 (4) [0298] (3) Optical purity of polylactic acid: 0.1 g of polylactic acid fiber constituting one of the fabrics (one bundle in the case of multifilament), plus 5 m / liter 1.0 mL of a sodium hydroxide aqueous solution and 1.0 mL of methanol were placed in a water bath shaker set at 65 ° C, and the polylactic acid was added to a uniform solution for about 30 minutes, and 0.25 mol was added to the solution for completion of hydrolysis. The ear/liter of sulfuric acid was neutralized to pH 7, 0.1 mL of its decomposition solution was taken and diluted by a high speed liquid chromatography (HPLC) mobile phase solution of 3 mL, and filtered through a membrane filter (0.45 μm). The HPLC solution of the adjusted solution was carried out to quantify the ratio of the L-lactic acid polymer to the D-lactic acid polymer. When the amount of the polylactic acid fiber is less than 0.1 g, the amount of the other solution used is adjusted in accordance with the amount that can be taken, and the concentration of the polylactic acid in the sample solution for HPLC measurement is changed from the above-described equivalent to one-hundredth of a range. [HPLC measurement conditions] Column: Sumitomo Analytical Center Co., Ltd. manufactured "SUMICHIRAL (registered trademark)" OA-5000 (4.6 mm φ × 150 mm) Mobile phase: 1.0 mmol/L liter of copper sulfate aqueous solution Mobile phase flow: 1.0 ml / Minute detector: UV detector (wavelength 254 nm) Injection amount: 100 μl The peak area from the L lactic acid polymer is set to S _LLA , the peak area from the D-lactic acid polymer is set to S _DLA Time, due to S _LLA And S _DLA Molar concentration M with L-lactic acid polymer _LLA And the molar concentration of D-lactic acid polymer M _DLA Proportional, so will S _LLA And S _DLA The value of the middle one is set to S _MLA The optical purity is calculated by the following formula (5). [Formula 5] Optical purity (%) = S _MLA ÷(S _LLA +S _DLA ) × 100 (5) [0299] [Wrapped Piezoelectric Element] (4) Pull-out strength In the case where a braided piezoelectric element is exposed from a cloth-like piezoelectric element, a tensile tester (Orientec shares) Co., Ltd. manufactured a universal testing machine "Tensilon RTC-1225A") to hold the exposed braided piezoelectric element, and cut the braided pressure at a portion 5 cm away from the fixed end of the braided piezoelectric element on the gripping side. Electrical components and cloth-like piezoelectric components. The braided piezoelectric element is fixed to a portion of the 5 cm portion of the fabric except for a region within 1 mm from the braided piezoelectric element, and the workpiece is held in a U-shape by 5 cm in the longitudinal direction of the braided piezoelectric element. It is controlled and connected to the other side of the holding workpiece of the tensile testing machine. In this state, the tensile test was performed at a speed of 10 mm/min, and the maximum strength was measured, and the pull-out strength was measured. In the case where the braided piezoelectric element is not sufficiently exposed from the cloth-like piezoelectric element, one of the fabrics (a portion other than the braided piezoelectric element) is cut to expose the braided piezoelectric element, and the above-described manner is performed. measuring. In addition, when it is difficult to ensure that the length of the portion in which the braided piezoelectric element is fixed to the fabric is 5 cm, the pull-out strength is measured at a fixed portion of an arbitrary length, and the strength may be converted into a strength of 5 cm. (5) Covering at any three points of the braided piezoelectric element in the cloth-like piezoelectric element, the photographs of the six photographs taken by the microscope from both sides of the front and back are covered with respect to the weave. The ratio of the area calculated from the product of the width of the braid and the length of the observation portion to the area calculated from the product of the width of the braid and the length of the observation portion is calculated as the ratio of the area of the portion where the surface of the braid is exposed and visible. The value obtained by subtracting the ratio from % is set as the coverage ratio, and the average value of the three photos on the surface is set as the coverage ratio (table), and the average value of the three photos on the back surface is set as the coverage ratio (back). (6) Measurement of the electric signal The piezoelectric element is connected to the electric conductor of the piezoelectric element via a coaxial cable (core: Hi pole, shield: Lo pole) via a coaxial cable (core: B2987A) The current value was measured at intervals of 50 m seconds while performing the following bending operation. (6-1) The bending test uses two clamps having an upper portion and a lower portion, and the lower clamp is fixed to a rail that operates only in the vertical direction, and is always loaded with a load of 0.5 N in the downward direction. The upper clamp is located above 72mm of the lower clamp, and the upper clamp moves on a hypothetical circumference where the line connecting the two clamps is set to a diameter, and the diameter from the center of the hypothetical circle to the left and right 16mm is 15mm. The circle is fixed as two cylinders of the profile (a flat woven fabric composed of 50 yarns on the side), and a piezoelectric element is fixed between the two cylinders, and the two cylinders are used. The fulcrum is subjected to a bending deformation test device, and the cloth-like piezoelectric element is held by the upper and lower jigs in a manner of holding the braided piezoelectric element in the upper and lower jigs, and the upper jig is set on the hypothetical circumference. When the lower jig is set to the position of 6 o'clock, the position of the upper jig is repeated 10 times from the position of 12 o'clock through the position of 1 o'clock and 2 o'clock on the hypothetical circumference, and the flower is taken at a certain speed. After moving to the position of 3 o'clock in 0.9 seconds, it takes 1.8 seconds to move to the position of 9 o'clock through the position of 12 o'clock. Again, it takes 0.9 seconds to return to the 12 o'clock position to perform the reciprocating bending motion, and the current between the two is measured. The value is taken as the peak value of the current value between the position moved from the 12 o'clock position to the 3 o'clock position, and the average value of the round trip motion is used as the value of the signal. (7) Appearance of the braided piezoelectric element After performing a bending test of 1000 times (6-1), the braided piezoelectric element in the cloth-like piezoelectric element was pulled out, and the surface of the outer conductive layer was observed with a microscope. Silver plated peeling off. Those who are completely invisible to the exfoliation are considered to be qualified, and some are considered to be qualified, and those who frequently see the exfoliation are set as unqualified. [Woven piezoelectric element] (8) The alignment angle θ of the piezoelectric polymer in the direction of the central axis The alignment angle θ of the piezoelectric polymer in the direction of the central axis is calculated by the following formula. However, Rm=2 (Ro ³ -Ri ³ ) /3 (Ro ² -Ri ² ), that is, the radius of the braided piezoelectric element (or other structure) weighted by the cross-sectional area. The outer peripheral radius Ro and the inner radius Ri of the spiral pitch HP and the braided piezoelectric element (or other structure) are measured as follows. (8-1) In the case of a braided piezoelectric element (when the coating is performed other than the piezoelectric polymer of the braided piezoelectric element, the coating can be removed from the side as required) In the photograph of the side of the electrophotographic polymer, the helical pitch HP (μm) of the piezoelectric polymer was measured at five arbitrary positions as shown in FIG. 3, and the average value was obtained. In addition, the low-viscosity instant bonding agent "Aron Alpha EXTRA2000" (East Asian Synthetic) is dyed into a braided piezoelectric element and solidified, and then a cross section perpendicular to the long axis of the weaving is cut out to take a photograph of the cross section. In the cross-sectional photograph, the outer radius Ro (μm) and the inner radius Ri (μm) of the portion occupied by the braided piezoelectric element were measured as described later, and the same measurement was performed on another arbitrary cross section 5 to obtain an average value. When the piezoelectric polymer and the insulating polymer are simultaneously incorporated, for example, when a piezoelectric fiber or an insulating fiber is used, or four fibers of 8 strands are piezoelectric polymers, When the remaining four fibers are in the form of an insulating polymer, when the cross section is obtained at various positions, the region in which the piezoelectric polymer is present and the region in which the insulating polymer is present alternate with each other, so that the piezoelectricity is high. The region of the molecule and the region where the insulating polymer is present together are regarded as a portion occupied by the braided piezoelectric element. However, the portion in which the insulating polymer and the piezoelectric polymer are not incorporated at the same time is not considered to be a part of the braided piezoelectric element. For the outer radius Ro and the inner radius Ri, the measurement was performed as follows. As shown in the cross-sectional view of Fig. 9A, the region occupied by the piezoelectric structure (the sheath portion 2 formed of the piezoelectric fiber A) (hereinafter referred to as PSA) is defined, and the central portion of the PSA is not the PSA. The area (described later as CA). The average diameter of the smallest perfect circle that is located on the outer side of the PSA, which does not overlap with the PSA, and the diameter of the largest perfect circle that does not pass through the outside of the PSA (even if CA passes) are set to Ro (Fig. 9B). Further, the average value of the diameter of the smallest perfect circle which is not located outside the CA, and the diameter of the largest perfect circle which does not pass through the CA is set to Ri (Fig. 9C). (8-2) In the case of a core-spun yarn-shaped piezoelectric element, the winding speed at the time of winding the piezoelectric polymer core is T times/m (the piezoelectric polymer per unit length of the core yarn) When the number of rotations is), the pitch of the spiral becomes HP (μm) = 1000000 / T. In addition, the low-viscosity instant bonding agent "Aron Alpha EXTRA2000" (East Asian Synthetic) is dyed into a core-spun yarn-shaped piezoelectric element, and after solidification, a cross section perpendicular to the long axis of the weaving is cut out, and a photograph of the cross-section is taken. A cross-sectional photograph is measured in the same manner as in the case of a braided piezoelectric element, and the outer radius Ro (μm) and the inner radius Ri (μm) of the portion occupied by the core-spun piezoelectric element are measured, and the same measurement is performed for another arbitrary The measurement was performed at section 5, and the average value was obtained. When the piezoelectric polymer and the insulating polymer are simultaneously coated, for example, when the piezoelectric fiber and the insulating fiber are coated, or the piezoelectric fiber and the insulating fiber are simultaneously packaged When the cross-section is not overlapped, when the cross-section is obtained at various positions, the region in which the piezoelectric polymer is present and the region in which the insulating polymer is present alternate with each other, so that the region of the piezoelectric polymer exists and there is insulation. The regions of the polymer are collectively considered to be part of the core-spun piezoelectric element. However, when the insulating polymer and the piezoelectric polymer are not coated at the same time, even if any cross section is taken, the insulating polymer is always located inside or outside the piezoelectric polymer, and is not regarded as a package. One part of the core-shaped piezoelectric element. (9) Measurement of the electric signal The piezoelectric element is connected to the electric conductor of the piezoelectric element via a coaxial cable (core: Hi pole, shield: Lo pole) via a coaxial cable (core: B2987A). The current value was measured at intervals of 50 m seconds while performing the operation test of any of the following 9-1 to 5. (9-1) Tensile test Using a universal testing machine "Tensilon RTC-1225A" manufactured by Orientec Co., Ltd., the piezoelectric element was grasped by a jig at intervals of 12 cm in the longitudinal direction of the piezoelectric element, and the element was loosened. The state was set to 0.0 N, the displacement was set to 0 mm in a state of stretching to a tension of 0.5 N, and the film was stretched to 1.2 mm at an operating speed of 100 mm/min, and repeated 10 times to 0 mm to -100 mm/min. The action of the motion speed return. (9-2) Torsing test In the two clamps that hold the piezoelectric element, one of the clamps is placed on a rail that is free to move in the longitudinal direction of the piezoelectric element without performing a twisting operation, and is always pressed. The electric component is in a state of applying a tension of 0.5 N, and the other jig is designed to be a torsion test device that does not operate in the longitudinal direction of the piezoelectric element and is twisted, and is interposed between 72 mm in the longitudinal direction of the piezoelectric element. The piezoelectric element is grasped by the clamps, and the clamp is viewed from the center of the element in a clockwise twisting manner, and is repeated 10 times at a speed of 100°/s from 0° to 45°, at a speed of -100°/s. Round-trip twisting from 45° to 0°. (9-3) The bending test uses two clamps with upper and lower parts. The lower clamp is fixed. The upper clamp is located above 72mm of the lower clamp. The upper clamp is set to the assumed circumference of the line connecting the two clamps. In the test device that moves up, the piezoelectric element is held by the jig and fixed. When the upper jig is set to 12 o'clock on the circumference and the lower jig is set to 6 o'clock, the pressure is applied. After the electric component is slightly deflected into a convex state at the 9 o'clock direction, the upper jig is repeated 10 times from the position of 12 o'clock through the 1 o'clock and 2 o'clock positions on the circumference, and the movement is performed at a constant speed for 0.9 seconds to 3 After the position of the point, it takes 0.9 seconds to move to the round-trip bending action at the position of 12 o'clock. (9-4) Shear test The length of the central portion of the piezoelectric element is sandwiched from the upper and lower sides by sandwiching the straight metal plate of the plain woven fabric woven with the cotton yarn of 50 yarn counts on the surface. (The lower metal plate is fixed to the base), a vertical load of 3.2 N is applied from above, and the upper metal plate is applied 10 times in a state where the cotton cloth and the piezoelectric element which maintain the surface of the metal plate are not slid. After a load of 0 N to 1 N was applied to the longitudinal direction of the piezoelectric element, a shearing operation of returning the tensile load to 0 N was applied for 1 second. (9-5) The pushing test was performed using the universal testing machine "Tensilon RTC-1225A" manufactured by Orientec Co., Ltd.), and the length of the central portion of the piezoelectric element on the straight and straight metal table was 64 mm. The rigid metal plate is placed as an upper crosshead, and the piezoelectric element is horizontally clamped, and the application is repeated 10 times for 0.6 seconds to cause the reaction force from the piezoelectric element toward the upper metal plate to be 20N from 0.01N, and the upper crosshead is lowered. It was pressed, and the action of depressurizing was performed by applying a reaction force of 0.6 N for 0.6 seconds. [0306] A fabric for a piezoelectric element was produced by the following method. (Production of Polylactic Acid) The polylactic acid used in the examples was produced by the following method. For 100 parts by mass of L-lactide (manufactured by Musashino Chemical Research Institute, 100% optical purity), 0.005 parts by mass of tin octylate was added, and the mixture was stirred at 180 ° C in a reactor equipped with a stirring blade under a nitrogen atmosphere. After reacting for 2 hours, 1.2 times equivalent of phosphoric acid with respect to tin octoate was added, and then the remaining lactide was removed under reduced pressure at 13.3 Pa, and fragmented to obtain poly-L-lactic acid (PLLA1). The obtained PLLA1 had a mass average molecular weight of 152,000, a glass transition point (Tg) of 55 ° C, and a melting point of 175 °C. (Piezoelectric Fiber) PLLA1 melted at 240 ° C was discharged from a 24-hole cap at 20 g/min, and pulled at 887 m/min. The unstretched polyfilament was extended by 2.3 times at 80 ° C and heat-set at 100 ° C to obtain a polyfilament uniaxially stretched yarn PF1 of 84 dTex/24 filament. Further, the melted PLLA1 at 240 ° C was discharged from a 12-hole cap at 8 g/min, and pulled at 1050 m/min. The unstretched polyfilament was extended by 2.3 times at 80 ° C and heat-set at 150 ° C to obtain a 33 dTex/12 filament multifilament uniaxially stretched yarn PF2. These piezoelectric fibers PF1 and PF2 are used as piezoelectric polymers. The poly-L-lactic acid crystallinity, poly-L-lactic acid crystal orientation and optical purity of PF1 and PF2 were measured by the above method, as shown in Table 1. [0309] (Electrically Conductive Fiber) Silver-plated nylon manufactured by San Fuji Co., Ltd., product name "AGposs" 100d34f (CF1) was used as the conductive fiber B. The resistivity of CF1 is 250 Ω/m. Further, silver-plated nylon manufactured by San Fuji Co., Ltd., product name "AGposs" 30d10f (CF2) was used as the conductive fiber B and the conductive fiber 206. The conductivity of CF2 is 950 Ω/m. (Insulating Fiber) The 84dTex/24 filament extension yarn IF1 produced by melt-spinning and extending polyethylene terephthalate, and the 33dTex/12 filament extension yarn IF2 are respectively provided. It is an insulating fiber. (Example 1) In the present embodiment, the piezoelectric element used in the first to third inventions, in particular, the value of the alignment angle θ and T1/T2 of the piezoelectric polymer is relatively Investigate the effects of telescopic deformation of the electrical signal. (Example A) As the sample of Example 1, as shown in FIG. 10, the conductive fiber CF1 was used as the core yarn, and the piezoelectric fiber PF1 was placed in 8 of the 8-strand circular braiding machine. In the carrier, the four carriers are placed on the Z-direction and the four carriers are placed in the S-direction, and are woven, whereby the piezoelectric fiber PF1 is spirally wound around the core yarn. The braided piezoelectric element 1-AA is wound around the Z-direction and the S-direction. (Example AB) The braided piezoelectric element 1-AA is used as a core yarn, and the conductive fiber CF2 is placed in eight carriers of a braiding machine, and is incorporated into four carriers of the Z direction and is incorporated into the S carrier. All of the four carriers are woven, and the elements around the braided piezoelectric element 1-AA are covered with conductive fibers to form a braided piezoelectric element 1-AB. (Example AC) In place of the woven piezoelectric element 1-AA, PF2 was used instead of the PF1 to form a braided piezoelectric element, and the braided piezoelectric element 1-AA was used. In the core yarn, an element covered with a conductive fiber like the braided piezoelectric element 1-AB is produced, and the braided piezoelectric element 1-AC is formed. (Example AD) Using CF2 instead of CF1, a braided piezoelectric element was produced in the same manner as the braided piezoelectric element 1-AA except that the winding speed was adjusted, and the braided piezoelectric element 1-AA was used. In the core yarn, an element covered with a conductive fiber like the braided piezoelectric element 1-AB is produced, and the braided piezoelectric element 1-AD is formed. (Example AE) The conductive fiber CF1 is used as a core yarn, and the piezoelectric fiber PF1 is placed in a carrier of 16 strands of a 16-strand circular braiding machine, and is incorporated into the carrier of the Z-direction and the carrier. The eight carriers of the S-direction are all woven and woven, and the piezoelectric fiber PF1 is spirally wound around the core yarn in the Z-direction and the S-shaped woven piezoelectric layer. In the element, the braided piezoelectric element is used as a core yarn, and an element covered with a conductive fiber like the braided piezoelectric element 1-AB is produced, and the braided piezoelectric element 1-AE is formed. (Example AF) CF1 was used as the core yarn, and PF1 was wound around the core yarn at a number of times of 3,000 times/m in the S direction, and on the outside, PF1 was further 3,000 times/ The number of times of coating of m is wound in the Z direction, and on the outside, CF2 is further wound in the S direction at the number of times of coating of 3000 times/m, and on the outside, CF2 is further made 3000 times/m. The number of times of coating is wound in the Z direction, and the piezoelectric fiber PF1 is spirally wound around the Z-direction and the S-direction in the spiral direction, and the outer core-spun yarn-like piezoelectric body is covered with the conductive fiber. Element 1-AF. (Example AG) CF1 was used as the core yarn, and PF1 was wound around the core yarn at the number of times of coating of 6000 times/m in the S direction, and on the outside, PF1 was further 6000 times/ The number of times of coating of m is wound in the Z direction, and on the outside, CF2 is further wound in the S direction at the number of times of coating of 3000 times/m, and on the outside, CF2 is further made 3000 times/m. The number of times of coating is wound in the Z direction, and the piezoelectric fiber PF1 is spirally wound around the Z-direction and the S-direction in the spiral direction, and the outer core-spun yarn-like piezoelectric body is covered with the conductive fiber. Element 1-AG. (Example AH) A braided piezoelectric element is produced in the same manner as the braided piezoelectric element 1-AA except that IF1 is used instead of PF1, and the braided element is used as a core yarn to fabricate a braided piezoelectric element. 1-AB is also an element covered with conductive fibers, and becomes a braided element 1-AH. (Example AI) A core-spun yarn-like element is formed as a core-spun yarn-like element 1-AI, except that IF1 is used instead of PF1. (Examples AJ, AK) In addition to changing the winding speed of PF1 or PF2, two braided piezoelectric elements are formed in the same manner as the braided piezoelectric elements 1-AB and 1-AC, and the braided pressure is obtained. Electrical components 1-AJ and 1-AK. (Example AL) A braided piezoelectric element 1-AL was produced in the same manner as the braided piezoelectric element 1-AB except that IF1 was used instead of the PF1 wound in the S direction. (Example AM) A braided piezoelectric element 1-AM was produced in the same manner as the braided piezoelectric element 1-AC except that IF2 was used instead of the PF2 wound in the Z direction. (Example AN) A core-spun yarn-like piezoelectric element 1-AN was produced in the same manner as the core-spun yarn-shaped piezoelectric element 1-AF except that IF1 was used instead of the PF1 wound in the Z-direction. The Ri, Ro, and HP of each piezoelectric element were measured, and the values of the calculated alignment angle θ of the piezoelectric polymer in the direction of the central axis and the value of T1/T2 are shown in Table 2. In the braided piezoelectric element, Ri and Ro are measured together as a region occupied by the piezoelectric element in a region where the piezoelectric fiber and the insulating fiber are present in the cross section. In the core-spun yarn-shaped piezoelectric element, Ri and Ro are measured in a region where piezoelectric fibers are present in a cross section as a region occupied by the piezoelectric element. Further, each piezoelectric element was cut into a length of 15 cm, the conductive fiber of the core was set to a Hi-pole, and the conductive mesh of the metal mesh or the sheath portion around the shield was set to a Lo pole and connected to a potentiometer (Keysight) Society B2987A), monitors the current value. Table 2 shows the current values at the time of the tensile test, the torsion test, the bending test, the shear test, and the pressing test. Further, since the examples AH and AI do not contain a piezoelectric polymer, the values of θ and T1/T2 cannot be measured. [0327] From the results of Table 2, it is understood that when the alignment angle θ of the piezoelectric polymer in the direction of the central axis is more than 40° and less than 50°, a large signal is generated with respect to the twisting operation (torsional deformation). On the other hand, when the alignment angle θ of the piezoelectric polymer in the direction of the central axis is 0° or more and 40° or less or 50° or more and 90° or less, a large signal is generated with respect to the twisting operation (torsion deformation). Further, as in the case of AA to AG, when the value of T1/T2 exceeds 0.8 and is 1.0 or less, a large signal is generated with respect to the twisting operation (torsion deformation), and a large signal is not generated in the operation other than the torsion. An element that selectively responds to a twisting action. Further, in the comparative examples AA to AE, AL and AM, and the examples AF, AG, and AN, it is understood that the torsion test is performed when θ is 0° or more and 40° or less, and when θ is 50° or more and 90° or less. The polarity of the signal is reversed, and θ corresponds to the polarity of the signal during the torsion test. [0329] Moreover, although there is no display in the table, when the components of the examples AA to AG and AL to AN are compared, the signal when the twist is applied to the S direction and the signal when the twist is applied to the Z direction are compared. It can be seen that these elements are suitable for the quantification of the load or displacement due to the generation of signals whose polarities are opposite to each other and whose absolute values are approximately the same. In addition, when the components of the example AJ and the example AK are compared with the signal when the twist is applied to the S direction, and the signal when the twist is applied to the Z direction, it is known that the same situation occurs when the polarities are opposite to each other. Therefore, these components are not suitable for the quantification of the load or displacement. Furthermore, although there is no display in the table, the noise level in the torsion test of Example AB is lower than that in the torsion test of Example AA, and it is known that the braided piezoelectric element (piezoelectric structure) On the outer side, a conductive layer made of conductive fibers is disposed to be a shielded element, and noise can be reduced. (Example 2) A fabric for a piezoelectric element according to the second invention was produced by the following method. (Production of Polylactic Acid) The polylactic acid used in the examples was produced by the following method. For 100 parts by mass of L-lactide (manufactured by Musashino Chemical Research Institute, 100% optical purity), 0.005 parts by mass of tin octylate was added, and the mixture was stirred at 180 ° C in a reactor equipped with a stirring blade under a nitrogen atmosphere. After reacting for 2 hours, 1.2 times equivalent of phosphoric acid with respect to tin octoate was added, and then the remaining lactide was removed under reduced pressure at 13.3 Pa, and fragmented to obtain poly-L-lactic acid (PLLA1). The obtained PLLA1 had a mass average molecular weight of 152,000, a glass transition point (Tg) of 55 ° C, and a melting point of 175 °C. (Piezoelectric Fiber) PLLA1 melted at 240 ° C was discharged from a 24-hole cap at 22 g/min, and pulled at 1300 m/min. The unstretched multifilament was stretched by 2.0 times at 80 ° C and heat-set at 150 ° C to obtain a piezoelectric fiber A1 of 84 dTex/24 filament. Further, the melted PLLA1 at 240 ° C was discharged from a 12-hole cap at 8 g/min, and pulled at 1300 m/min. The unstretched multifilament was stretched by 2.0 times at 80 ° C and heat-set at 150 ° C to obtain a piezoelectric fiber A2 of 33 dTex/12 filament. (Electrically Conductive Fiber) Silver-plated nylon manufactured by San Fuji Co., Ltd., product names "AGposs" 100d34f and 30d10f were used as the conductive fiber B, the conductive fiber 6, and the conductive fiber 10. The volume resistivity of the fiber is 1.1×10 ^-3 Ω·cm. (Knitted Piezoelectric Element) As the sample of Example 2-1, the conductive fiber "AGposs" 100d34f was used as a core yarn, and the piezoelectric fiber A1 was wound around the eight core yarns. In the woven shape, the braided piezoelectric element 1A is formed by braiding the conductive fibers "AGposs" 30d10f around the piezoelectric fibers A1 of the sheath portion in a braided shape to form a shield layer. Here, the winding angle α of the piezoelectric fiber A1 to the fiber axis CL of the conductive fiber B is set to 30°. Further, the d/Rc of the braided piezoelectric element 1A was 1.76. [0334] As the sample of Example 2-2, the conductive fiber "AGposs" 100d34f was used as a core yarn, and the piezoelectric fiber A2 was wound into a braided shape around eight core yarns, and weaved by eight strands. The piezoelectric fiber 2 is wound into another eight braids in another layer above the weave. In addition, the conductive fibers "AGposs" 30d10f are wound into a shield layer around the piezoelectric fibers A2 to form a shield layer, and the braided piezoelectric element 1B is formed. Here, the winding angle α of the piezoelectric fiber A to the fiber axis CL of the conductive fiber B is set to 30°. Further, the d/Rc of the braided piezoelectric element 1B was 1.52. The woven piezoelectric element 1C was formed in the same manner as in the first embodiment except that the piezoelectric fiber A2 was used instead of the piezoelectric fiber A1 of Example 2-1. Further, the d/Rc of the braided piezoelectric element 1C was 0.84. (Compilation) The circular knitting units 1 to 3 are produced by using the above-described braided piezoelectric elements 1A to 1C, respectively. (Performance Evaluation and Evaluation Results) The evaluation results of the braided piezoelectric elements 1A to 1C and the circular knitting units 1 to 3 are as follows. (Example 2-1) The conductive fiber B in the braided piezoelectric element 1A is used as a signal line, and is connected to an oscilloscope via a 100-fold amplification circuit via a wiring (Yokogawa Digital Oscilloscope DL6000 Series) The product name "DL6000" is used, and the conductive layer 204 of the braided piezoelectric element 1A is grounded (Earth). Torsional deformation is applied to the braided piezoelectric element 1A. As a result, as the output from the braided piezoelectric element 1A, it was confirmed that a potential difference of about 10 mV was detected by the oscilloscope, and a sufficiently large electric signal was detected by the deformation of the braided piezoelectric element 1A. Furthermore, even for the circular unit 1, the core and the shielded wire are not short-circuited, and a signal corresponding to the deformation can be detected. (Embodiment 2-2) The conductive fiber B in the braided piezoelectric element 1B is used as a signal line, and is connected to an oscilloscope via a 100-times amplifying circuit via a wiring (Yokogawa Electric Co., Ltd. digital oscilloscope DL6000 series) The product name "DL6000"), and the conductive layer 204 of the braided piezoelectric element 1B is grounded (Earth). Torsional deformation is applied to the braided piezoelectric element 1B. As a result, as the output from the braided piezoelectric element 1B, it was confirmed that a potential difference of about 10 mV was detected by the oscilloscope, and a sufficiently large electric signal was detected by the deformation of the braided piezoelectric element 1B. Furthermore, even for the circular unit 2, the core and the shielded wire are not short-circuited, and a signal corresponding to the deformation can be detected. (Comparative Example 2-1) The conductive fiber B in the braided piezoelectric element 1C is used as a signal line, and is connected to an oscilloscope via a 100-fold amplification circuit via a wiring (Yokogawa Digital Oscilloscope DL6000 Series) The product name "DL6000" is used, and the conductive layer 204 of the braided piezoelectric element 1C is grounded (Earth). Torsional deformation is applied to the braided piezoelectric element 1C. As a result, as the output from the braided piezoelectric element 1C, it was confirmed that a potential difference of about 10 mV was detected by the oscilloscope, and a sufficiently large electric signal was detected by the deformation of the braided piezoelectric element 1C. However, for the circular unit 3, the core and the shield are short-circuited, and the signal corresponding to the deformation cannot be detected. (Example 3) A cloth-like piezoelectric element according to the third invention was produced by the following method. (Wolen piezoelectric element) As shown in Fig. 10, the piezoelectric fiber PF1 is placed on a carrier of eight strands of an 8-strand circular braiding machine, and the conductive fiber CF1 is used as a core yarn. On the four carriers, the insulating fibers IF1 are placed on the four carriers that are knitted in the S direction and woven, whereby the piezoelectric fibers PF1 are spirally wound around the core yarn. A braided piezoelectric element wound around the Z direction. Next, the braided piezoelectric element is used as a core yarn, and the conductive fibers CF2 are placed in eight carriers of the braiding machine, and are incorporated into the four carriers of the Z direction and the four carriers that are incorporated into the S direction. Then, it is woven, and a conductive layer made of a conductive fiber is coated on the periphery of the braided piezoelectric element to form a braided piezoelectric element 201. (Embodiment) (Example 3-1) Five cylindrical portions were formed in parallel with the warp yarn between the layers of the two-layer braid (width: 16 mm, thickness: 0.3 mm) by the spinning of the polyester, and the cylindrical portion was formed. A cloth-like piezoelectric element woven by the braided piezoelectric element 201 is placed in the cylinder. The cylindrical portion is composed of 16 warp yarns of 84dTex in total, and the portion other than the cylindrical portion is composed of warp yarns of 167dTex. The weft yarn uses 84dTex yarn. Two (one layer each) 167dTex warp yarns were placed between the five braided piezoelectric elements. The braided piezoelectric element 201 at the center of the piezoelectric element was measured for the extraction strength and the coverage, and the signal strength of the bending test and the appearance of the outer conductive layer of the braided piezoelectric element after the bending test were confirmed. The results are shown in Table 3. (Example 3-2) A portion of the warp yarn of the plain woven fabric of the warp yarn and the weft yarn was used for the polyester yarn (330dTex/72 filament) to form a fabric-like pressure which was knitted using the braided piezoelectric element 201. Electrical components. The warp density of the plain woven fabric is higher than that of the weft yarn, and there is almost no gap between the warp yarns. The braided piezoelectric element 201 in the braided piezoelectric element was measured for the extraction strength and the coverage, and the signal strength of the bending test and the appearance of the outer conductive layer of the braided piezoelectric element after the bending test were confirmed. The results are shown in Table 3. (Example 3-3) In the same manner as in Example 3-2, a portion of the weft yarn of the plain woven fabric woven by the warp yarn and the weft yarn of the polyester yarn was used, and the braided piezoelectric element 201 was used. Braided piezoelectric element. The braided piezoelectric element 201 in the braided piezoelectric element was measured for the extraction strength and the coverage, and the signal strength of the bending test and the appearance of the outer conductive layer of the braided piezoelectric element after the bending test were confirmed. The results are shown in Table 3. (Example 3-4) On the plain woven fabric woven by the embodiment 3-2, the woven piezoelectric element 201 was placed so as to pass over the woven piezoelectric element 201 by 60 pieces. A zigzag-shaped piezoelectric element was fixed to a plain woven fabric by a zigzag slit (width: 2 mm, pitch: 1 mm) of a polyester yarn of a number of yarns. The braided piezoelectric element 201 in the braided piezoelectric element was measured for the extraction strength and the coverage, and the signal strength of the bending test and the appearance of the outer conductive layer of the braided piezoelectric element after the bending test were confirmed. The results are shown in Table 3. (Comparative Example 3-1) A cloth-like piezoelectric element was produced in the same manner as in Example 3-4 except that the width of the zigzag slit of the polyester spun yarn was changed to 4 mm and the pitch was changed to 2 mm. The braided piezoelectric element 201 in the braided piezoelectric element was measured for the extraction strength and the coverage, and the signal strength of the bending test and the appearance of the outer conductive layer of the braided piezoelectric element after the bending test were confirmed. The results are shown in Table 3. [0347] From the results of Table 3, it was found that in Examples 3-1 to 3-4 in which the pull-out strength per 5 cm was 0.1 N or more, a strong signal was observed in the bending test, and in this case, less than 0.1. In Comparative Example 3-1 of N, only weak signals were observed in the bending test, and it was found that the piezoelectric elements of Examples 3-1 to 3-4 were excellent as sensors. Further, in Examples 3-1 to 3-4 in which the surface and back coverage ratios were all more than 30%, the deterioration of the conductive layer of the braided piezoelectric element after the bending test was suppressed as compared with Comparative Example 3-1, and it was found that The cloth-like sensor has excellent durability.

[0349]

1‧‧‧Piezoelectric structures

1-1‧‧‧Cylindrical piezoelectric structure

1-2‧‧‧Cylindrical piezoelectric structure

2‧‧‧Piezoelectric polymer

OL‧‧‧ alignment direction

HP‧‧‧spiral spacing

A‧‧‧Piezoelectric fiber

B‧‧‧ Conductive fiber

101, 201‧‧‧ braided piezoelectric elements

102, 202‧‧ ‧ sheath

103, 203‧‧ ‧ core

107, 207‧‧‧ cloth-shaped piezoelectric elements

108, 208‧‧‧ cloth

109, 209‧‧‧Insulating fiber

110, 210‧‧‧ Conductive fiber

111‧‧‧ device

112‧‧‧Piezoelectric components

113‧‧‧Amplification means

114‧‧‧ means of output

115‧‧‧ means of transmission

204‧‧‧ Conductive layer

205‧‧‧Electrical substances

206‧‧‧ Conductive fiber

X‧‧‧The largest circle consisting only of the fiber bundles of the core

Y‧‧‧The smallest circle Y of the fiber bundle that completely contains the core

X'‧‧‧The largest circle consisting only of fiber bundles containing piezoelectric fibers of the core

Y’‧‧‧The smallest circle containing the bundle of piezoelectric fibers

CL‧‧‧Center shaft or fiber shaft

‧‧‧‧Wrap angle

[ Fig. 1A] Fig. 1A is a schematic view showing a cylindrical piezoelectric structure according to an embodiment of the first invention. Fig. 1B is a schematic view showing a cylindrical piezoelectric structure relating to an embodiment of the first invention. Fig. 2 is a side view showing a cylindrical piezoelectric structure according to an embodiment of the first invention. FIG. 3 is a schematic view illustrating a calculation method of the alignment angle θ. Fig. 4 is a schematic view showing a configuration example of a braided piezoelectric element according to an embodiment of the first invention. Fig. 5 is a schematic view showing a configuration example of a cloth-like piezoelectric element according to an embodiment of the first invention. Fig. 6 is a block diagram showing an apparatus including piezoelectric elements according to an embodiment of the first to third inventions. Fig. 7 is a schematic view showing a configuration example of an apparatus including a cloth-like piezoelectric element according to an embodiment of the first invention. Fig. 8 is a schematic view showing another configuration example of an apparatus having a cloth-like piezoelectric element according to an embodiment of the first invention. Fig. 9A is a photomicrograph showing a cross section of a braided piezoelectric element according to an embodiment. Fig. 9B is a photomicrograph showing a cross section of a braided piezoelectric element according to an embodiment. Fig. 9C is a photomicrograph showing a cross section of the braided piezoelectric element according to the embodiment. FIG. 10 is a schematic view showing a configuration example of a braided piezoelectric element according to an embodiment of the second invention and the third invention. Fig. 11 is a photomicrograph showing a cross section of a braided piezoelectric element according to an embodiment of the second invention. Fig. 12 is a schematic view showing a configuration example of a cloth-like piezoelectric element according to an embodiment of the second invention. FIG. 13 is a schematic view showing a configuration example of an apparatus including a braided piezoelectric element according to an embodiment of the second invention. Fig. 14 is a schematic view showing a configuration example of an apparatus including a cloth-like piezoelectric element according to an embodiment of the second invention. Fig. 15 is a schematic view showing another configuration example of an apparatus having a cloth-like piezoelectric element according to an embodiment of the second invention. Fig. 16 is a schematic view showing another configuration example of an apparatus having a cloth-like piezoelectric element according to an embodiment of the second invention. Fig. 17 is a schematic view showing a configuration example of a cloth-like piezoelectric element according to an embodiment of the third invention. Fig. 18 is a schematic view showing another configuration example of the cloth-like piezoelectric element according to the embodiment of the third invention. Fig. 19 is a schematic view showing another configuration example of the piezoelectric element according to the embodiment of the third invention. FIG. 20 is a schematic view showing a configuration example of an apparatus including a cloth-like piezoelectric element according to an embodiment of the third invention. Fig. 21 is a schematic view showing another configuration example of the apparatus including the cloth-like piezoelectric element according to the embodiment of the third invention. Fig. 22 is a schematic view showing another configuration example of the apparatus including the cloth-like piezoelectric element according to the embodiment of the third invention.

Claims (31)

A structure in which a piezoelectric polymer to be aligned is arranged in a cylindrical or cylindrical structure, and a piezoelectric polymer is disposed on a cylindrical or cylindrical central axis of a piezoelectric polymer. The alignment angle in the direction is 0° or more and 40° or less or 50° or more and 90° or less. The piezoelectric polymer includes an absolute value of the piezoelectric constant d14 when the alignment axis is set to 3 axes of 0.1 pC/N or more and 1000 pC. A crystalline polymer having a value of /N or less is used as a main component. The structure according to claim 1, wherein the piezoelectric polymer contains poly-L-lactic acid or poly-D-lactic acid as a main component. The structure according to claim 1 or 2, wherein the cylindrical shape or the cylindrical shape is applied to the central axis of the cylindrical or cylindrical body on which the piezoelectric polymer is disposed, and is subjected to torsional deformation. The central axis of the shape forms an opposite polarity charge on the side and the outside. The structure according to any one of claims 1 to 3, wherein the piezoelectric polymer comprises a P-body containing a crystalline polymer having a positive piezoelectric constant d14 as a main component, and a negative The N-body in which the crystalline polymer is a main component holds a portion having a length of 1 cm with respect to the central axis of the structure, and the mass of the P body in which the alignment axis is wound into a spiral and arranged in the Z direction is set to ZP. The alignment axis is wound into a spiral, and the mass of the P body is set to SP, and the alignment axis is wound into a spiral. The mass of the N body is set to ZN, and the alignment axis is wound into a spiral. The quality of the N body disposed in the S direction is SN, and the smaller of (ZP+SN) and (SP+ZN) is T1, and the larger one is T2, the value of T1/T2. More than 0.8. The structure according to any one of claims 1 to 4, wherein the piezoelectric polymer-like fibrous, fibrillar or ribbon is formed into a braided shape, a string shape, a core yarn shape or a It is composed of yarn. The structure according to any one of claims 1 to 4, wherein the piezoelectric polymer has a cross section perpendicular to a central axis of a cylindrical shape or a cylindrical shape, and constitutes only one closed region. An element comprising: the structure according to any one of claims 1 to 6, and a conductor disposed adjacent to the structure. The element according to claim 7, wherein the piezoelectric polymer is disposed in a cylindrical shape, and the conductor is disposed at a position of a central axis of the cylindrical shape. The element according to claim 8, wherein the conductive system is made of a conductive fiber, and the piezoelectric polymer is arranged as a piezoelectric fiber in a braided shape around the conductive fiber. The element according to claim 7, wherein the conductor is disposed on a side of a cylindrical shape or a cylindrical shape on which the piezoelectric polymer is disposed. The element according to claim 10, wherein the conductive system is made of a conductive fiber, and the conductive fiber is knitted and arranged around a cylindrical or cylindrical shape in which the piezoelectric polymer is provided. A sensor comprising: the element according to any one of claims 7 to 11; and an output terminal which is oriented in a direction of a central axis of a cylindrical or cylindrical body in which a piezoelectric polymer is disposed The electric charge generated when the torsional deformation is applied, the electric signal generated by the electric conductor is output, and the electric circuit detects the electric signal outputted through the output terminal. A braided piezoelectric element comprising: the element according to claim 9, comprising: a core portion formed of the conductive fiber; and the piezoelectric fiber formed in a braided shape so as to cover the core portion The sheath portion and the conductive layer are provided around the sheath portion, and a ratio d/Rc of a thickness d of the layer composed of the piezoelectric fibers to a radius Rc of the core portion is 1.0 or more. The braided piezoelectric element according to claim 13, wherein a coverage of the sheath portion by the conductive layer is 25% or more. The braided piezoelectric element according to claim 13 or 14, wherein the conductive layer is formed of a fiber. A cloth-like piezoelectric element comprising: the braided piezoelectric element according to any one of claims 13 to 15. The fabric-shaped piezoelectric element according to claim 16, wherein the fabric further comprises a conductive fiber that is in contact with at least a portion of the braided piezoelectric element. The fabric-like piezoelectric element according to claim 17, wherein the fibers of the fabric are formed, and 30% or more of the fibers intersecting the braided piezoelectric element are conductive fibers. A device comprising: the braided piezoelectric element according to any one of claims 13 to 15; and an amplifying means for amplifying an electric signal output from the braided piezoelectric element in response to a pressure to be applied; And an output means for outputting an electrical signal amplified by the amplifying means. A device comprising: a cloth-like piezoelectric element according to claim 17 or 18; and an amplifying means for amplifying an electric signal output from the cloth-shaped piezoelectric element in response to a pressure to be applied; and an output means, It outputs an electrical signal that is amplified by the above amplification means. A cloth-like piezoelectric element comprising: a cloth-like piezoelectric element in which a braided piezoelectric element is fixed to a fabric, wherein the braided piezoelectric element includes: the element described in claim 9, wherein the element has the conductive a core portion formed of a fiber, and a sheath portion formed of the piezoelectric fiber in a braided shape so as to cover the core portion; and a conductive layer provided around the sheath portion, the braided piezoelectric element The pull-out strength per 5 cm of the above fabric was 0.1 N or more. The cloth-like piezoelectric element according to claim 21, wherein a coverage of the braided piezoelectric element formed by the fibers constituting the fabric exceeds 30% on both sides of the fabric. The fabric-shaped piezoelectric element according to claim 21 or 22, wherein the braided piezoelectric element is fixed to the fabric in a state of being woven or knitted. The cloth-like piezoelectric element according to claim 21 or 22, wherein the braided piezoelectric element is sandwiched between layers of a double woven fabric or a double woven fabric. The cloth-like piezoelectric element according to any one of claims 21 to 24, wherein the braided piezoelectric element is partially exposed from the fabric, and the conductive fiber of the braided piezoelectric element is exposed at the exposed portion And/or the above conductive layer and other members are electrically connected. The cloth-like piezoelectric element according to any one of claims 21 to 25, wherein a coating ratio of the sheath portion by the conductive layer is 25% or more. The cloth-like piezoelectric element according to any one of claims 21 to 26, wherein the conductive layer is formed of a fiber. The fabric-like piezoelectric element according to any one of claims 21 to 27, wherein the total fineness of the piezoelectric fibers is 1 time or more and 20 times or less the total fineness of the conductive fibers. The cloth-like piezoelectric element according to any one of claims 21 to 28, wherein the fineness of each of the piezoelectric fibers is 1/20 times or more and 2 times or less of the total fineness of the conductive fibers. The fabric-shaped piezoelectric element according to any one of claims 21 to 29, wherein the fabric further comprises a conductive fiber that is in contact with at least a portion of the braided piezoelectric element. A device comprising: a cloth-like piezoelectric element according to any one of claims 21 to 30; and a circuit for detecting said conductive layer contained in said cloth-like piezoelectric element in response to a pressure to be applied The electrical signal that the fiber is output.