CN111820900B - Flexible sensor - Google Patents

Abstract

A flexible sensor includes a first elastic circuit module, a second elastic circuit module and a hot melt adhesive film. The first elastic circuit module comprises a first elastic film and a first conductive pattern, the first elastic film can be stretched and elastically deformed and is provided with a printing carrying layer and a thermal bonding layer which are laminated, and the first conductive pattern is formed on the surface of the printing carrying layer in a printing mode. The second elastic circuit module comprises a second elastic film and a second conductive pattern, the second elastic film can be stretched and elastically deformed, and the second conductive pattern is formed on the second elastic film in a printing mode and matched with the first conductive pattern in shape and size. The hot melt adhesive film is jointed with the first elastic circuit module and the second elastic circuit module in a hot pressing mode and can be stretched and elastically deformed together, and the first conductive pattern and the second conductive pattern correspond to each other in position and form a capacitor structure together with the hot melt adhesive film. Therefore, the convenience of combining the flexible sensor and the carrier is improved.

Description

flexible sensor

technical field

The invention relates to a flexible sensor, in particular to a flexible sensor that utilizes stretching and elastic deformation to generate capacitance or resistance changes.

Background technique

The flexible sensor can be applied to wearable electronic devices. The flexible sensor can be elastically deformed with the stretching movement of the surface of the living body or the flexion and extension movement of the joint to measure the biological information or motion information of the living body. For example, a capacitive sensing sheet disclosed in Taiwan Patent Publication No. TW201701830A includes a sensor body and a stretchable cloth integrated with the sensor body. Electrical layer, first electrode layer and second electrode layer, the dielectric layer includes elastomer composition, the first electrode layer and the second electrode layer are respectively formed on the surface and the back of the dielectric layer. The conductive material of the electrode layer adopts carbon nanotubes and is formed on the surface of the dielectric layer by coating. In addition, the fabric is laminated on the front side and the back side of the sensor body through an adhesive layer.

As mentioned above, the electrode layer of the sensor body is made by coating the conductive material on the surface of the dielectric layer, and its manufacturing process is not only cumbersome but also difficult to control. Moreover, when the sensor body is to be combined with the fabric, it needs to be glued with an additional adhesive layer, which is inconvenient in application.

Contents of the invention

One of the objectives of the present invention is to provide a flexible sensor that is easy to manufacture and easily combined with a carrier.

In some embodiments, the flexible sensor of the present invention includes a first elastic circuit module, a second elastic circuit module and a hot-melt adhesive film. The first elastic circuit module includes a first elastic film and a first conductive pattern, the first elastic film can be stretched and elastically deformed and has a stacked printing carrier layer and a thermal bonding layer, the printing carrier layer is used to set the first A conductive pattern, the thermal bonding layer can be thermally melted and used for bonding with the carrier through thermal compression, and the first conductive pattern is formed on the surface of the printing carrier layer by printing. The second elastic circuit module includes a second elastic film and a second conductive pattern, the second elastic film can be stretched and elastically deformed, the second conductive pattern is formed on the second elastic film by printing and has the same shape and size as the first A conductive pattern matches. The hot-melt adhesive film is bonded to the first elastic circuit module and the second elastic circuit module through thermal compression bonding and can be stretched and elastically deformed together. The conductive pattern is joined to the second conductive pattern, and the positions of the first conductive pattern and the second conductive pattern are corresponding, and together with the hot-melt adhesive film, a capacitor structure is formed.

In some embodiments, the second elastic film has the same structure as the first elastic film, and also has a laminated printing carrier layer and a thermal bonding layer, and the second conductive pattern is formed on the second elastic film by printing surface of the printing carrier.

In some embodiments, the first conductive pattern and the second conductive pattern are formed by conductive silver paste.

In some implementation aspects, the first conductive pattern has a plurality of sensing portions connected in parallel.

In some implementation aspects, the sensing parts jointly form a geometric figure, and the geometric figure contains a plurality of hollowed out regions to separate the sensing parts.

In some implementation aspects, the geometric figure is a quadrangle, and each of the hollowed out areas is linear and parallel to each other.

In some implementation aspects, the geometric figure is a circle, and each of the hollowed out areas is linear and parallel to each other.

In some implementation aspects, the geometric figure is a circle, and each of the hollowed-out areas is arc-shaped and arranged rotationally symmetrically with the center of the circle.

In some implementation aspects, the first conductive pattern has a plurality of connected sensing parts, and each sensing part has at least one hollow area.

In some implementation aspects, each sensing portion is in a spiral shape.

In some embodiments, the flexible sensor of the present invention includes an elastic circuit module. The elastic circuit module includes an elastic film and a conductive pattern, the elastic film can be elastically deformed by stretching and has a laminated printing carrier layer and a thermal bonding layer, the printing carrier layer is used to arrange the conductive pattern, and the thermal bonding layer can be thermally It is melted and combined with the carrier through heat and pressure, and the conductive pattern is formed on the surface of the printed carrier layer by printing and is used for resistance sensing and has at least one sensing part.

In some embodiments, a protective film is further included, the protective film covers the conductive pattern and can be stretched and elastically deformed together with the elastic circuit module.

In some embodiments, the protective film is a hot-melt adhesive film and is combined with the elastic circuit module by thermal compression.

In some embodiments, the protective film is formed by covering the conductive pattern with ink by printing.

In some embodiments, the conductive pattern is formed by conductive silver paste.

In some implementation aspects, the sensing part is a winding circuit to increase the total length of the conductive path.

In some implementation aspects, the sensing part is mirror-symmetric.

In some implementation aspects, the sensing part is in the shape of a spiral that turns outwards from the center for multiple turns.

In some implementation aspects, the conductive pattern has a plurality of sensing parts arranged in parallel.

The present invention has at least the following beneficial effects: the elastic film of the elastic circuit module has a printed carrier layer for printing conductive patterns and a thermal bonding layer for thermocompression bonding with the carrier, not only is it easy to make conductive patterns and the flexible sensor does not need to be recoated The adhesive layer can be combined with the carrier, thereby increasing the convenience of combining the flexible sensor with the carrier.

Description of drawings

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein:

Fig. 1 is a schematic side view of the first embodiment of the flexible sensor of the present invention;

Figure 2 is a three-dimensional exploded schematic diagram of the first embodiment;

Fig. 3 is a schematic flow chart illustrating the steps of the first embodiment of the method;

4 is a schematic diagram illustrating a conductive pattern of a second embodiment of the flexible sensor of the present invention;

5 to 10 are schematic diagrams illustrating variations of the conductive pattern of the first embodiment;

11 is a schematic side view of a third embodiment of the flexible sensor of the present invention;

FIG. 12 is a schematic diagram illustrating a conductive pattern of the third embodiment; and

13 to 17 are schematic diagrams illustrating variations of the conductive pattern of the third embodiment.

Detailed ways

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numerals.

Referring to FIG. 1 and FIG. 2 , the first embodiment of the flexible sensor 100 of the present invention is a capacitive sensor, which includes two elastic circuit modules 1 and a hot-melt adhesive film 2 . Each elastic circuit module 1 includes an elastic film 11 and a conductive pattern 12. The elastic film 11 can be stretched and elastically deformed, and has a printed carrier layer 111 and a thermal bonding layer 112 stacked together. The printed carrier layer 111 For disposing the conductive pattern 12 , the thermal bonding layer 112 can be thermally melted and bonded with a carrier 4 (see FIG. 3 ) by thermal compression. The conductive pattern 12 is formed on the surface of the printing carrier layer 111 by printing. The material of the elastic film 11 can be, for example, polyurethane (Polyurethane, PU), thermoplastic polyurethane (Thermoplastic polyurethanes, TPU) and the like. Since the printed carrier layer 111 must not be thermally deformed during the printing of the conductive pattern 12 and the heat-melt bonding process of the thermal bonding layer 112 and the carrier 4, the softening point of the printed carrier layer 111 needs to be higher than that of the printed conductive pattern 12. The process temperature and the thermal fusion bonding temperature of the thermal bonding layer 112 . In this embodiment, the main components of the printing carrier layer 111 and the thermal bonding layer 112 are polyurethane (polyurethane), but the softening point of the printing carrier layer 111 is 184° C., and the softening point of the thermal bonding layer 112 is 105°C. Moreover, in this embodiment, the thickness of the printing carrier layer 111 is about 44 μm, and the thickness of the thermal bonding layer 112 is about 45 μm.

The shapes and sizes of the conductive patterns 12 of the two elastic circuit modules 1 match, that is to say, the two conductive patterns 12 are mirror symmetric when they are arranged opposite to each other. In this embodiment, the conductive pattern 12 is illustrated by taking a sensing portion 121 as an example, and the conductive pattern 12 also has a connecting portion 122 extending from the sensing portion 121, and the connecting portion 122 is used for connecting external wires. (not shown). In a variable embodiment, the conductive pattern 12 may have a plurality of sensing portions 121 , which will be further described in the following embodiments. In this embodiment, the conductive pattern 12 is formed by conductive silver paste. The hot-melt adhesive film 2 is sandwiched between the two elastic circuit modules 1 and bonded to the two elastic circuit modules 1 through thermal compression bonding, and can be stretched and elastically deformed together. Both sides of the hot-melt adhesive film 2 are respectively bonded to the conductive patterns 12 of the two elastic circuit modules 1 in a hot-melt manner. The positions of the conductive patterns 12 of the two elastic circuit modules 1 correspond to each other and form a capacitive structure together with the hot-melt adhesive film 2. The adhesive film 2 is the dielectric material of the capacitor structure. Since the hot-melt adhesive film 2 is bonded with the conductive pattern 12 in a hot-melt manner, it can produce better bonding force, which can make the entire capacitor structure have better structural strength and reliability. The deformation amount of the flexible sensor 100 can be calculated by measuring the change of the capacitance value of the flexible sensor 100 .

Referring to Fig. 3, the production step flow process of the present embodiment is illustrated:

Firstly, the elastic circuit module 1 and the hot melt adhesive film 2 are prepared respectively. When preparing the elastic circuit module 1, the elastic film 11 can be arranged on the substrate 3 to support the elastic film 11, and the thermal bonding layer 112 of the elastic film 11 is connected to the substrate 3 to expose the printing carrier layer 111, and then the conductive silver paste is printed on the The conductive pattern 12 is formed on the printing carrier layer 111 of the elastic film 11 . The substrate 3 is specifically, for example, release paper.

Next, the two prepared elastic circuit modules 1 and the substrate 3 are arranged opposite to each other with the conductive pattern 12 and the hot melt adhesive film 2 is placed between the two elastic circuit modules 1, wherein the sensing parts 121 of the two conductive patterns 12 and the hot melt The adhesive film 2 is opposite to each other up and down, and the hot-melt adhesive film 2 and the elastic circuit module 1 are hot-melt bonded and fixed by using a hot-pressing machine. After the hot-melt adhesive film 2 is combined with the elastic circuit module 1 , the hot-melt adhesive film 2 is interposed between the sensing portions 121 of the two conductive patterns 12 , while the connecting portion 122 of the two conductive patterns 12 is exposed outside the hot-melt adhesive film 2 . In this way, the fabrication of the flexible sensor 100 can be completed, and the substrate 3 can be used to protect the elastic film 11 and can be removed before being combined with the carrier 4 . In addition, an elastic film 11 with a larger area can be used to print multiple conductive patterns 12 at a time when printing the conductive pattern 12. After the elastic film 11 is combined with the hot-melt adhesive film 2 to form a plurality of flexible sensors 100, then use a knife The molding machine cuts to form a plurality of independent flexible sensors 100 and makes each flexible sensor 100 have a proper shape and size.

Further, the flexible sensor 100 can be combined with different carriers 4 according to the usage requirements, and the carrier 4 can be materials for wearing articles such as cloth and shoe materials. To combine the flexible sensor 100 with application items (such as wristbands, clothes, trousers, hats, knee pads, shoes, etc.), first remove the substrate 3, then cover the carrier 4 on the thermal bonding layer 112 of the elastic film 11 and The carrier 4 and the thermal bonding layer 112 are thermally welded in a thermal compression bonding manner. Although in this embodiment the two elastic films 11 are of the same double-layer structure, in a variable embodiment, one of the elastic films 11 can be of a single-layer structure for printing the conductive pattern 12, and only through the other The combination of the elastic film 11 with the thermal bonding layer 112 and the carrier 4 is also possible.

Referring to FIG. 4 , the difference between the second embodiment of the flexible sensor 100 of the present invention and the first embodiment is that, in the second embodiment, the conductive pattern 12 of each elastic circuit module 1 has a plurality of sensing sensors arranged in parallel. part 121 to increase the working range of the flexible sensor 100 . When preparing the elastic circuit module 1, a plurality of sensing parts 121 can be printed on the elastic film 11 and each sensing part 121 extends a connecting part 122, and then, the required number of sensing parts 121 can be added separately according to the usage requirements. Connected with wires to form a parallel capacitor structure. That is to say, when printing a plurality of sensing parts 121 on a large-area elastic film 11, a plurality of independent capacitive structures can be produced at one time, and then a plurality of flexible sensing parts with one capacitive structure can be formed by cutting. It is also possible to connect some of the sensing parts 121 in parallel by wires so that a single flexible sensor 100 has multiple parallel-connected capacitive structures. This can increase the flexibility of production and reduce the cost of stock preparation.

Referring to Fig. 5 to Fig. 7, it is a variation of the conductive pattern 12 of the first embodiment. The conductive pattern 12 has a plurality of sensing parts 121 connected in parallel, and the sensing parts 121 together form a geometric figure and the geometric figure A plurality of hollow areas 125 are included to separate the sensing portion 121 . As shown in FIG. 5 , the geometric figure formed by the sensing portion 121 of the conductive pattern 12 is a quadrangle, and each of the hollowed out regions 125 is linear and parallel to each other. As shown in FIG. 6 , the geometric figure formed by the sensing portion 121 of the conductive pattern 12 is a circle, and the hollowed out areas 125 are linear and parallel to each other. As shown in FIG. 7 , the geometrical figure formed by the sensing portion 121 of the conductive pattern 12 is a circle, and the hollowed out areas 125 are arc-shaped and arranged rotationally symmetrically with the center of the circle. A plurality of parallel sensing parts 121 can detect the actions of different positions of the user and then connect them to the overall sensing signal in parallel. For example, the flexible sensor 100 is used to detect the bending degree of the user's knee. When the knee is bent, only a few of the sensing parts 121 are stretched, and when the knee is bent to a large extent, more sensing parts 121 are stretched, because the sum of the capacitance values generated by the different amounts of stretching of the sensing parts 121 It also changes accordingly, so that the bending position of the knee can be judged.

Referring to FIG. 8 to FIG. 10 , there are variations of the conductive pattern 12 of the first embodiment. The conductive pattern 12 has a plurality of connected sensing portions 121 and each sensing portion 121 has at least one hollow area 125 . The distribution area of the sensing part 121 can be designed according to the part to be sensed, and each sensing part 121 forms a local electrode. Through multiple local electrodes corresponding to multiple local areas that need to be sensed, local muscles and joints can be targeted. detection. As shown in FIG. 8 , the conductive pattern 12 has three sensing portions 121 in a spiral shape. As shown in FIG. 9 , the conductive pattern 12 has two spiral sensing portions 121 . As shown in FIG. 10 , the conductive pattern 12 has two square sensing portions 121 , and each sensing portion 121 has two hollow areas 125 .

11 and 12, the third embodiment of the flexible sensor 100 of the present invention is a resistive sensor, which includes an elastic circuit module 1 and a protective film 2'. The difference between the elastic circuit module 1 of the third embodiment and the first embodiment is that the sensing part 123 of the conductive pattern 12 of the third embodiment is a winding circuit to increase the total length of the conductive path, and the two ends of the sensing part 123 Each of the connecting ends 124 is extended to connect to an external wire (not shown), and the deformation of the flexible sensor 100 can be calculated by the change of the resistance value generated when the sensing part 123 is stretched. The protective film 2' covers the conductive pattern 12 and can be stretched and elastically deformed together with the elastic circuit module 1 to seal and waterproof the conductive pattern 12. In a variant implementation, it can also be implemented without the protective film 2'. In the third embodiment, the protective film 2' is a hot-melt adhesive film and is combined with the elastic circuit module 1 by thermal compression. The manufacturing method of the third embodiment is substantially the same as that of the first embodiment, except that one flexible circuit module 1 is omitted. Likewise, in the third embodiment, the thermal bonding layer 112 of the elastic film 11 of the elastic circuit module 1 can also be thermally welded to the carrier 4 (refer to FIG. 3 ). In a modified embodiment, the protective film 2' can also be formed by covering the conductive pattern 12 with ink, and the printing ink can be used to cover the entire surface of the elastic film 11 or only cover the conductive pattern 12 by partial printing. , as long as the conductive pattern 12 can be covered, and the ink can be an insulating material or a conductive material, which can be adjusted according to the use requirements.

In the third embodiment, the conductive pattern 12 is illustrated by taking one sensing part 123 as an example. scope of action. Similar to the aforementioned capacitive flexible sensor 100, in the third embodiment, when printing the conductive pattern 12 on the elastic film 11, a plurality of independent sensing parts 123 can be printed at one time, and then cut according to the usage requirements, if necessary When multiple sensing parts 123 are in the same flexible sensor 100, the multiple sensing parts 123 can be connected in parallel through connecting wires, so as to increase the flexibility in manufacturing and reduce the cost of stock preparation.

Referring to FIG. 13 and FIG. 14, it shows the variation of the conductive pattern 12 in the third embodiment. The sensing part 123 shown in FIG. 13 and FIG. 14 is mirror-symmetrical, and the sensing part 123 shown in FIG. However, the sensing part 123 shown in FIG. 14 has a square waveform.

Referring to Fig. 15 and Fig. 16, it shows the variation of the conductive pattern 12 in the third embodiment. The sensing part 123 shown in Fig. 15 and Fig. 16 is in the shape of a spiral winding multiple times from one center to the outside, and the sensing part 123 shown in Fig. 15 The measuring part 123 is a circular spiral, while the sensing part 123 shown in FIG. 16 is a square spiral. The local force change can be detected by the concentrically wound sensing portion 123 .

Referring to FIG. 17 , it shows the variation of the conductive pattern 12 in the third embodiment. The sensing part 123 is formed into two squares, which can detect corresponding to two local areas, and can detect local force changes in different areas.

In summary, the elastic film 11 of the elastic circuit module 1 has a printed carrier layer 111 for printing the conductive pattern 12 and a thermal bonding layer 112 for thermocompression bonding with the carrier 4, not only making the conductive pattern 12 easy but also making the flexible sensor 100 It can be combined with the carrier 4 without coating the adhesive layer again, thereby increasing the convenience of combining the flexible sensor 100 with the carrier 4 .

The above is only an embodiment of the present invention, and should not limit the scope of the present invention with this, that is, all simple equivalent changes and modifications made according to the claims of the present invention and the contents of the description are still within the scope of this invention. the scope of the invention.

Claims (19)

1. A flexible sensor, characterized in that: comprising: The first elastic circuit module includes a first elastic film and a first conductive pattern. The first elastic film can be stretched and elastically deformed and has a stacked printing carrier layer and a thermal bonding layer. The printing carrier layer is used to set the first elastic circuit module. A conductive pattern, the thermal bonding layer can be thermally melted and used for thermocompression bonding with the carrier, and the first conductive pattern is formed on the surface of the printing carrier layer by printing; The second elastic circuit module includes a second elastic film and a second conductive pattern. The second elastic film can be stretched and elastically deformed. The second conductive pattern is formed on the second elastic film by printing and has the same shape and size as the first elastic film. a conductive pattern to match; and The hot-melt adhesive film is bonded to the first elastic circuit module and the second elastic circuit module through thermal compression bonding and can be stretched and elastically deformed together, and the two sides of the hot-melt adhesive film are respectively bonded to the first The conductive pattern is joined to the second conductive pattern, and the positions of the first conductive pattern and the second conductive pattern are corresponding, and together with the hot-melt adhesive film, a capacitor structure is formed. 2. The flexible sensor according to claim 1, characterized in that: the second elastic film has the same structure as the first elastic film, and also has a stacked printing carrier layer and a thermal bonding layer, and the second conductive Patterns are formed on the surface of the printing carrier layer of the second elastic film by printing. 3. The flexible sensor according to claim 1, wherein the first conductive pattern and the second conductive pattern are formed by conductive silver paste. 4. The flexible sensor according to claim 1, wherein the first conductive pattern has a plurality of sensing portions connected in parallel. 5 . The flexible sensor according to claim 4 , wherein the sensing parts jointly form a geometric figure, and the geometric figure contains a plurality of hollowed out regions to separate the sensing parts. 6 . The flexible sensor according to claim 5 , wherein the geometric figure is a quadrangle, and the hollowed-out areas are linear and parallel to each other. 7 . The flexible sensor according to claim 5 , wherein the geometric figure is a circle and the hollowed-out areas are linear and parallel to each other. 8 . The flexible sensor according to claim 5 , wherein the geometric figure is a circle, and the hollowed-out areas are arc-shaped and arranged rotationally symmetrically with the center of the circle. 9. The flexible sensor according to claim 1, wherein the first conductive pattern has a plurality of connected sensing parts, and each sensing part has at least one hollow area. 10. The flexible sensor according to claim 9, wherein each sensing portion is in a spiral shape. 11. A flexible sensor, characterized in that: comprising: The elastic circuit module includes an elastic film and a conductive pattern. The elastic film can be elastically deformed by stretching and has a laminated printing carrier layer and a thermal bonding layer. The printing carrier layer is used to set the conductive pattern. The thermal bonding layer can be thermally It is melted and combined with the carrier through heat and pressure, and the conductive pattern is formed on the surface of the printed carrier layer by printing and is used for resistance sensing and has at least one sensing part. 12 . The flexible sensor according to claim 11 , wherein the flexible sensor further comprises a protective film, the protective film covers the conductive pattern and can be stretched and elastically deformed together with the elastic circuit module. 13 . 13 . The flexible sensor according to claim 12 , wherein the protective film is a hot-melt adhesive film and is combined with the elastic circuit module by thermocompression. 14 . 14. The flexible sensor according to claim 12, wherein the protective film is formed by covering the conductive pattern with ink by printing. 15. The flexible sensor according to claim 11, wherein the conductive pattern is formed by conductive silver paste. 16 . The flexible sensor according to claim 11 , wherein the sensing portion is in the form of a winding circuit to increase the total length of the conductive path. 17 . 17. The flexible sensor according to claim 16, wherein the sensing part is mirror-symmetric. 18 . The flexible sensor according to claim 16 , wherein the sensing part is in the shape of a spiral that turns outwards from the center for multiple turns. 19 . 19. The flexible sensor according to claim 11, wherein the conductive pattern has a plurality of sensing parts arranged in parallel.

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