HK1113019B - Electroactive polymer transducers - Google Patents

Abstract

Electroactive polymer constructions that convert electrical energy to mechanical energy and vice versa are disclosed. The subject transducers (actuators, generators, sensors or combinations thereof) share the requirement of a frame or fixture element used in preloading elastomeric film electrodes and dielectric polymer in a desired configuration. The structures are either integrally biased in a push-pull arrangement or preloaded/biased by another element.

Description

Electroactive polymer transducer

Technical Field

The present invention relates generally to electroactive polymer structures that can convert electrical energy to mechanical energy and vice versa. In particular, the present invention relates to a frame and mesh configuration of pre-strained polymer actuators and transducers.

Background

A large variety of devices currently in use rely on one or the other actuator (activator) to convert electrical energy into mechanical energy. The actuator "lives" the products, driving them into operation. Conversely, many power generation applications operate by converting mechanical motion into electrical energy. This type of actuator used to extract mechanical energy in this manner may be referred to as a generator. Likewise, when such a structure is used to convert a physical stimulus, such as vibration or pressure, into an electrical signal for measurement purposes, it may be referred to as a transducer. However, the term "transducer" may be used to generically refer to these devices. Regardless of the name, a new class of elements utilizing electroactive polymers can be configured to provide these functions.

Particularly for actuator and generator applications, many design considerations focus on selecting and using transducers based on advanced electroactive polymer technology. These considerations include potential force (momentum), power density, energy conversion/consumption, size, weight, cost, response time, duty cycle, operating requirements, environmental impact, and the like. Electroactive Polymer Artificial Muscle (EPAM) developed by SRI International and license Artificial muscle^TM) The technology is leading in each category relative to other available technologies. In many applications, EPAM^TMThe technology is a perfect replacement for piezoelectric Shape Memory Alloys (SMAs) and electromagnetic devices such as motors and solenoids.

As an actuator, EPAM^TMThe technique operates by applying a voltage across two elastic thin film electrodes separated by an elastic dielectric polymer. When a voltage difference is applied to the electrodes, the oppositely charged members attract each other, thereby creating a pressure on the polymers between each other. This pressure pulls the electrodes together, causing the dielectric polymer to become thinner (z-axis component shrinkage) and to expand in the planar direction (x-and y-axis elongation of the polymer film). Another factor drives thinning and stretching of polymer films. Is distributed atSimilar (identical) charges on each elastic membrane electrode cause conductive particles embedded within the membrane to repel each other, thereby stretching the elastic electrode and dielectric to which the polymer membrane is attached.

With this "shape memory" technology, artifical Muscle corporation is developing a range of new solid state devices for a wide variety of industrial, medical, consumer, and electronic applications. The current product system comprises: actuators, motors, transducers/sensors, pumps and generators. The actuator is enabled by the operations discussed above. Generators and sensors rely on changing capacitance to enable when a material is physically deformed.

The Artificial Muscle company has now introduced a number of basic "turn-ready" type devices that can be used as building blocks to replace existing devices. Each device employs a scaffold or frame structure to pre-strain (pre-strain) the dielectric polymer. It is observed that the pre-strain improves the dielectric strength of the polymer, thereby improving the conversion between electrical and mechanical energy by allowing higher field potentials.

Of these actuators, the "spring roller" type linear actuator is obtained by covering the EPAM around a helical spring^TMA layer of material. Will EPAM^TMThe material is attached to the cap/cover at the end of the spring to fix its position. Spring body support pair EPAM^TMWhile compression of the spring length provides axial pre-strain. The applied voltage causes the membrane to press down in thickness and relax in length, allowing the spring (and thus the entire device) to expand. By forming the electrodes to produce two or more separately treated portions around the circumference, electrically activating one such portion causes the roller to extend and the entire structure to bend away from that side.

Bending beam actuators are formed by affixing one or more layers of extended EPAM along the surface of the beam^TMA material. When a voltage is applied, the EPAM^TMThe material shrinks in the direction of the thickness,elongated in the length direction. The increase in length along one side of the beam causes the beam to bend away from the active layer.

Pairs of dielectric elastomer films (or a full set of actuator assemblies such as the "spring-roll" described above) may be arranged in a "push-pull" configuration. Switching the voltage from one actuator to another can move the position of the component back and forth. The opposite sides of the activation system cause the assembly to be fixed at the neutral point. So configured, the actuator acts like opposing bicep and triceps muscles that control movement of the human arm. An EPAM, whether the push-pull configuration comprises a film portion secured to a planar frame, one or more opposed spring rollers, or the like^TMThe structure can be used as another EPAM^TMStructural biasing members and vice versa.

Another type of device places one or more membrane sections in a closed linkage or spring hinge frame structure. When using a linkage frame, the EPAM is typically pre-strained with a biasing spring^TMA film. The spring hinge structure may inherently include the necessary biasing. In any event, application of a voltage will change the configuration of the frame or linkage, thereby providing the desired mechanical output.

The diaphragm actuator (diaphragm activator) is made by extending the EPAM over an opening in a rigid frame^TMA film. Known examples of diaphragm actuators are by springs, by arrangements in springs and EPAMs^TMWith an intermediate rod or plunger therebetween, biased (i.e., pushed in/out or pushed up/down) directly by a resilient foam material or air pressure. The bias ensures that the membrane will move in the direction of the bias when the electrode active/thickness shrinks rather than just cockling. Diaphragm actuators are capable of displacing volume, making them suitable for use as pumps or speakers, etc.

More complex actuators can also be constructed. "inch-word" and slew output type devices provide examples. Further description and details regarding the above-mentioned devices, as well as other devices, may be found in the following patents and/or patent application publications:

6,812,624 electroactive polymers

6,809,462 electroactive polymer sensor

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6,781,284 electroactive polymer transducer and actuator

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6,707,236 non-contact electroactive polymer electrode

6,664,718 monolithic electroactive polymers

6,628,040 electroactive polymer thermoelectric generator

6,586,859 electroactive polymer moving device

6,583,533 electroactive polymer electrode

6,545,384 electroactive polymer device

6,543,110 electroactive polymer manufacture

6,376,971 electroactive polymer electrodes

6,343,129 elastic body dielectric polymer film acoustic wave actuator

20040217671 rolled electroactive polymers

20040263028 electroactive polymers

20040232807 electroactive polymer transducer and actuator

20040217671 rolled electroactive polymers

20040124738 electroactive polymer thermoelectric generator

20040046739 method and apparatus for navigating a pliable device

20040008853 electroactive polymer device for moving fluids

20030214199 electroactive polymer device for controlling fluid flow

20030141787 non-contact electroactive polymer electrode

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20020185937 electroactive polymer rotary motor

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20020175594 electroactive polymer system of variable hardness

20020130673 electroactive polymer sensor

20020050769 electroactive polymer electrode

20020008445 energy-saving electroactive polymer and electroactive polymer device

20020122561 elastic body dielectric polymer film acoustic wave actuator

20010036790 electroactive polymer moving device

20010026165 monolithic electroactive polymers

These disclosures are hereby incorporated by reference in their entirety in order to provide background and/or further details regarding the basic techniques and features used in connection with or in connection with the inventive aspects set forth herein.

Although the apparatus described above provides an EPAM^TMHigh performance examples of technical transducers, but continue to be motivated by developing more efficient EPAMs^TMA transducer. As provided by the transducer according to the inventionThe efficiency gains offered can be achieved in terms of improvements in pre-strain, interface with driven/driven components, output, machinability, etc. Those skilled in the art will appreciate these applicable advantages.

Disclosure of Invention

The present invention provides a number of EPAMs^TMThe transducer is designed to expand the range of "turn-key" tools offered by this assignee of technology (Artificial Muscle corporation). Both of these designs require a frame member or a fixed member for preloading the elastomeric membrane electrode and dielectric polymer in a desired configuration.

Some embodiments include push-pull subassemblies. One aspect of the present invention may include complex frame structures to tightly couple different types of actuators. Another aspect of the invention includes a frame structure with alternative push-pull actuator configurations for in-plane and/or out-of-plane input/output. Yet another aspect of the present invention is directed to making actuator structures that are stronger and/or easier to machine. In this regard, a frustum-shaped diaphragm actuator is fabricated, wherein the top of the structure includes a cap. The cap may be a solid disk, ring, or other form of construction. The cap provides a stable interface between the opposing frustums and/or provides a mechanical preload means such as a spring. The invention also includes advantageous applications of the subject transducer construction.

One such application is for pumps. The pump may use a single frustum actuator design or a double frustum actuator design. In the former case, the frustum cap provides a stable surface against which to mechanically bias the structure. This structure can be made very strong and compact. The dual frustum design does not require an additional pre-load source. Also, it is configured to be used as a double-acting pump. Furthermore, the use of two actuators placed in series offers the possibility of doubling the swing (stroke). Other series actuator configurations are also contemplated in the present invention.

Another application is for cameras, where the position of the lens is manipulated by a frustum type actuator. In addition, either a single frustum or a double frustum design may be used. A dual frustum solution may be desirable from the standpoint of using one of the sides for position detection and preloading and the other side for actuation. Another camera application uses a complex framework in which a frustum-type actuator controls the position of the lens and one or more planar actuator components control zoom.

Further possible applications for the subject transducers include valves, or valve control elements, loudspeaker diaphragms, multi-axis position sensors/joysticks, vibrators, haptic or force feedback control devices, multi-axis actuators, and the like.

A "frustum" is technically a portion of a geometric body that lies between two parallel planes. A frustum is generally considered to be the base of a cone or pyramid formed by cutting away the top with a plane generally parallel to the base. Of course, a frustum-type actuator according to the invention may take the form of a truncated cone, thereby having a circular cross-section, or various cross-sectional configurations may be used.

Depending on the application, desirable alternative cross-sectional geometries include triangular, square, pentagonal, hexagonal, and the like. Generally, a symmetrically shaped member will be desirable from the standpoint of consistent material properties. However, for a given application, particularly those with limited space, an elliptical, oblong, rectangular, or other shape may prove preferable. Further variations of the subject "frustum" transducers are also contemplated, i.e., the top and/or bottom of the form need not be flat or planar, nor need they be parallel. In the most general sense, the "frustum" shape as used in the present invention can be considered to be a body with a volume truncated or capped at one end. Typically with ends having a smaller diameter or smaller cross-sectional area.

The actions of the various devices may be driven by specific actuators described herein or other actuators. However, each device incorporates a diaphragm in its design. Advantageously, the cap of the actuator and the membrane of the device are one and the same, thereby incorporating the sub-assembly.

Drawings

These figures illustrate exemplary aspects of the present invention. These figures are:

FIGS. 1A and 1B show EPAM^TMOpposite sides of the layer;

FIG. 2 is an EPAM^TMAssembly drawing of the stack;

FIG. 3 is an EPAM^TMAssembly drawing of planar actuator

FIGS. 4A and 4B are an assembly view and a perspective view, respectively, of a planar transducer configuration;

FIG. 5 is a top view of the device of FIGS. 4A and 4B electrically connected for planar actuation;

FIGS. 6A and 6B are an assembly view and a perspective view, respectively, of the transducer of FIGS. 4A and 4B, arranged in an alternative frustum configuration for out-of-plane actuation;

7A-7C illustrate the geometry and operation of a frustum-shaped actuator;

FIG. 8 is a top view of a multi-phase frustum-shaped actuator;

FIG. 9A is an assembly view of another frustum-shaped actuator, and FIG. 9B is a side view of the same basic actuator with a staggered frame structure;

fig. 10 is a cross-sectional perspective view of a parallel stacked type frustum transducer;

FIG. 11 is a side cross-sectional view showing an alternative output shaft arrangement with a frustum-shaped transducer;

FIG. 12 is a side cross-sectional view of an alternative inverted frustum transducer configuration;

FIG. 13 is a cross-sectional perspective view of a coil spring biased single frustum transducer;

FIG. 14 is a perspective view of a leaf spring biased single frustum transducer;

FIG. 15 is a perspective view of a weight biased single frustum transducer;

FIG. 16 is a perspective view of frustum-shaped transducers equipped in series to increase wobble;

FIG. 17 is a perspective view of a preliminary, reconfigurable system providing various types of transducers, and FIGS. 18A-18C are assembly views relating to various alternative configurations of the system of FIG. 17;

FIG. 19A is a cross-sectional perspective view of a camera lens assembly utilizing a frustum actuator to control focus; FIG. 19B is an assembly view of the camera component with the system shown in FIG. 19A;

FIG. 20 is a cross-sectional perspective view of a camera lens assembly utilizing another type of frustum actuator to control focus;

FIG. 21A is a cross-sectional perspective view of another camera lens assembly that utilizes a combination of actuators to control each of zoom and focus, and FIG. 21B is an assembled view of the camera components with the system shown in FIG. 21A;

FIGS. 22A and 22B are perspective views showing an alternative means of controlling zoom, and FIGS. 23A-23C are perspective views showing progressive stages of actuation of the transducer arrangement of FIGS. 22A and 22B, respectively;

FIG. 24A is an assembly view of the valve mechanism, and FIGS. 24B and 24C are side sectional views of the valve of FIG. 24 illustrating actuation of the valve;

FIGS. 25-27 are side sectional views of different valve configurations;

FIG. 28 is a side cross-sectional view of a pressure measuring transducer according to the present invention;

FIG. 29A is a side cross-sectional view of the active check valve; FIG. 29B is a perspective view of the structure shown in FIG. 29A;

FIGS. 30A and 30B are side sectional views of an inline valve disposed within a dedicated housing;

FIGS. 31A and 31B are cross-sectional perspective views illustrating variations of the first pump utilizing a frustum-shaped actuator;

FIGS. 32 and 33 are cross-sectional perspective views showing other pump variations utilizing frustum-shaped actuators;

FIG. 34 is a perspective view of an integrated flow control system utilizing the various valves and pumps illustrated above;

FIG. 35 is an assembled perspective view showing the pump housing with an integrated check valve formed in conjunction with the pump diaphragm;

FIG. 36 is an assembled perspective view showing another pump assembly incorporating a check valve;

FIG. 37 is a perspective view of a vibrator component;

FIG. 38 is a cross-sectional perspective view of the haptic feedback controller; and

fig. 39 is a perspective view of a speaker system utilizing a number of frustum and/or dual frustum transducers.

Variations in accordance with the invention as shown in the figures are contemplated.

Detailed Description

Various exemplary embodiments of the invention are described below. Various actuator/transducer embodiments are first described. Next, a system optionally incorporating such a device is described. Finally, the processing techniques, uses and methods of application of the kit are described, followed by a discussion of contemplated variations. The labels given to these examples are not intended to be limiting. They are provided to more broadly illustrate the applicable aspects of the invention.

Energy converter

FIGS. 1A and 1B show EPAM^TMOn opposite sides of the layer 10. The layer comprises a dielectric polymer sandwiched between elastic film electrodes. FIG. 1A shows the side of the layer on which the "hot" electrodes 12 and 14 are drawn. Each electrode is connected to a lead 16. Fig. 1B shows the opposite side of the layer 10, depicted with a common "ground" electrode 18, the electrode 18 being connected to a single lead 16.

As shown in fig. 2, a plurality of film layers 10 are stacked and held in a stretched state within a frame member 20. A plurality of individual EPAMs^TMThe layers 10 are advantageously stacked to form a composite layer 10'. This increases the potential of the system. The number of layers stacked ranges from 2 to 10 or more. Typically, an even number of layers should be stacked so that the ground electrode is facing any exposed surface to provide maximum safety. In any event, EPAM^TMLayer or plurality of EPAMs^TMA layer may be collectively referred to as an EPAM^TM"film".

Due to the one or more layers of material secured in the frame, the frame can be used to construct complex transducer mechanisms. Fig. 3 shows such a structure known in the prior art. Here, a separate cartridge (cartridge) component 22 is secured to an auxiliary or main body frame portion 24. Any of the film frame members and intermediate frame members may be combined to provide a combined (i.e., joined by fasteners as shown, bonded together, etc.) frame structure 26. The spacer 28 provides a contact surface for an input/output rod 30 that is supported by the frame via guide holes 32. The spacers are joined to the membrane by complementary brackets 34, the brackets 34 using the spacers to bond or hold the EPAM^TMA film.

To start the device constructed according to fig. 3, a voltage is applied to one of the electrodes 12 or 14. By applying a voltage to one side, the side expands, while the other side looses its preload and contracts. Other start-up modes are referred to above.

The first device according to the invention may be similarly constructed and operated. Fig. 4A and 4B provide an assembly view and a perspective view of a transducer 40 according to the present invention that can alternatively be configured for planar actuation (e.g., the device of fig. 3) and out-of-plane actuation. As with the device described with reference to the previous figures, frame 20 supports ground electrode outward facing layer 10/10'.

In addition, the individual chuck members 22 are stacked with the sub-frames 24 and spacers 28 therebetween, which provide an interface for input/output rods 30 supported by the frames. However, the septum 28 in this configuration is connected to a generally square cap 42 element. A more symmetrical contact surface portion provides advantages as will be explained below. Fig. 4B shows the assembled device. Here, the frame 26 is shown as a complete unit.

With respect to the actuation of the device, fig. 5 shows a basic circuit diagram in which the a and B sides of the circuit are energized relative to ground, causing the rod 30 to reciprocate along the X axis relative to the frame.

However, in another configuration, the same EPAM^TMThe layer chuck can be used to fabricate transducers suitable for out-of-plane or Z-axis input/output. Fig. 6A and 6B illustrate such an apparatus. In addition, the transducer 50 assembly may use a thicker body frame 24'. By utilizing such a frame and omitting spacers, when the caps 42 are fastened to each other, they create deep concave shapes 52 that face or move away from each other. To drive the transducer for simple Z-axis motion, one of the concave/frustum sides is expanded and the other relaxed by applying a voltage. Such action increases the depth of one concave shape 52 and decreases the depth of the other concave shape. In the simplest case, the resulting movement is generally perpendicular to the plane of the cap.

Fig. 7A-7C illustrate the operation of these concave/convex or frustum shaped actuators in a simplified two dimensional mode. Fig. 7A illustrates the origin of the transducer frustum shape. Whether from aboveWhether conical, square, oval, etc. when viewed, the shape 60 providing a truncated apex from the side is obtained by modifying the construction of the existing diaphragm actuator by capping the top (or bottom) of the structure. When under tension (under tension), cap 42 alters the EPAM^TMLayer 10/10' should have a shape. In this example, when a concentrated load stretches the membrane, the membrane may appear conical (as indicated by the dashed line defining the triangular top 62). However, when capped or otherwise modified to form a more rigid top structure, this shape is truncated as indicated by solid line 64 in FIG. 7A.

Such a modification of the structure substantially changes its performance. First, it distributes the pressure that would otherwise be concentrated at the midpoint of the structure 66 rather than around the periphery 68 of the body. To influence this force distribution, to the EPAM^TMThe layer is capped. Adhesive bonding may be used. Additionally, the assembly may be bonded using any feasible technique, such as thermal bonding, friction welding, ultrasonic welding, or mechanically locking or clamping the assembly together. Moreover, the capping structure may include a portion of the membrane that is sufficiently made more rigid by some thermal, mechanical, or chemical process such as vulcanization.

Typically, the cap portion will be sized to create a perimeter of sufficient length to adequately distribute the pressure applied to the material. Size and support of the cap EPAM^TMThe ratio between the diameters of the frames of the layers may vary. Obviously, the size of the disk, square, etc. used for the cap will become larger at higher pressure/force applications. For EPAM^TMThe relative truncation of this structure (as compared to a cone of concentrated load, a pressure-biased dome, etc.) is particularly important to reduce the overall volume/space occupied by the transducer in use, for a given amount of stretching of the layer. Also, in a frustum-type diaphragm actuator, a cap or diaphragm 42 element may be used as the active element (e.g., valve seat in a given system, etc.).

More or substantially rigid due to formation or appropriate arrangementThe cap portion of the frame, so that the EPAM is enclosed by the frame^TMWhen the material is stretched in a direction perpendicular to the cap (as can be observed by comparing the EPAM/frame configurations shown in FIGS. 4A/4B and 6A/6B), it will produce a truncated shape. Otherwise, EPAM-^TMThe film remains substantially flat or planar.

Returning to fig. 7A, the attached EPAM of this structure is due to the cap 42 defining a stable top/bottom surface^TMPolymer side 10/10' is at an angle. When not activated, EPAM is set^TMMay range from 15 to about 85 degrees. More typically, the angle may be in the range of about 30 to 60 degrees. When a voltage is applied to compress the EPAM^TMWhen the material is grown along a planar extent, it assumes a second angle β, within nearly the same extent plus about 5 to 15 degrees. The optimum angle may be determined according to the technical requirements of the application.

Single sided frustum transducers as well as double sided configurations are within the contemplation of the present invention. For preloading, the single-sided device utilizes any spring in contact with the cap (e.g., a coil, constant or rolling spring, leaf spring, etc.), pneumatic or hydraulic pressure, magnetic attraction, a weight (so that its weight provides a preload to the system), or any combination of these methods, among others.

In a two-sided frustum transducer, one side typically provides a preload to the other side. Also, such devices include additional biasing elements/components. Fig. 7B illustrates a basic "double frustum" architecture 70. Here, EPAM along the connecting portion 27^TMOpposite layers of material or EPAM-^TMOne side of the film and one side of the substantially elastic polymer are held together under tension. This connecting portion 27 generally comprises one or more rigid or semi-rigid cap elements 42. However, by adhering the two layers of polymer together at their junction, the bonded region of material alone provides a cap region of considerable stiffness or less flexibility in the most basic manner to give a stable transducer connection portion.

However constructed, the double frustum transducerThe machine operates as shown in fig. 7B. When one membrane side 74 is energized, it relaxes and pulls with less force, releasing the stored elastic energy in the biased side 74 and working through force and oscillation. This movement is indicated by the dashed line in fig. 7B. If both thin-film elements comprise EPAM^TMThe membrane, then the actuator may be moved inward/outward or upward/downward relative to a central position (represented by solid lines in fig. 7A and 7B), as indicated by double arrow 80.

If only one active side 74/76 is provided, the forced movement is limited to one side of the central location 82. In this case, the inactive side of the device may simply comprise an elastic polymer to provide the preload/bias (as mentioned above), or an EPAM^TMA material electrically connected to sense changes in capacitance exclusively or to act as a generator to recover motion or vibration input in the device in the form of a regenerative capacitance.

Further optional variations of transducers according to the present invention include providing multi-angle/multi-axis sensing or activation. FIG. 8 shows a circular EPAM with three (92, 94, 96) independently addressable areas or phases^TMChuck 90 configuration. When configured as an actuator, the member expands differently by applying different voltages, thereby causing the cap 42 to tilt at an angle. Such multiphase devices can provide multi-directional tilt and translation depending on the control scheme. When configured for sensing, an input to the cap from a stem or other fastener or connector causes an angular deflection, which can be measured by a change in the capacitance of the material.

EPAM as shown in FIG. 8^TMThe parts are circular. Fig. 9A provides an assembly view of a circular frustum transducer 100. The body frame member 24 used is solid, similar to that used in the modular or collapsible actuator shown in fig. 4A-6B above. However, the device shown in FIG. 9A is a dedicated diaphragm-type actuator (although it is possible to use a multi-phase configuration as shown in FIG. 8). An alternative construction of such an actuator is shown in figure 9B. Here, the unitary frame member 24 is replaced with a simple frame spacer 24 ".

Fig. 10 shows another variation of the construction in which the transducer includes multiple chuck layers 22 on each side of the dual frustum apparatus 100. The individual caps 42 are combined or stacked together. To accommodate the increased thickness, multiple frame members 24 may also be stacked on top of each other.

Recall that each chuck 22 may use a composite EPAM^TMLayer 10'. One or both methods are used together to increase the output potential of the device. Furthermore, at least one chuck member in a stacked form (on one or both sides of the device) may be provided for sensing, as opposed to activation, which facilitates active actuator control or operational verification. With respect to such control, any type of feedback technique, such as a PI or PID controller, may be used in this system to control the position of the actuator very accurately and/or precisely.

Figure 11 is a side cross-sectional view showing an alternative output shaft arrangement with a frustum-type transducer 110. Threaded bosses 112 on either side of the cap member provide a connection means for a mechanical output. The sleeve may be a separate component connected to the cap or may be formed integrally with the cap. Although an internally threaded device is shown, an externally threaded shaft may also be used. Such a device may include a single shaft that rotates through the cap and is secured to either side with a nut in a typical jam-nut configuration. Other fastener or attachment options are also possible.

FIG. 12 is a side cross-sectional view of an alternative transducer 120 configuration in which, instead of using two mutually remote concave structures, the two concave/frustum components 122 face each other. For EPAM for forced film formation^TMThe preload or bias of the layers is maintained by a spacer or spacer 124 between the caps 42. As shown, the spacer includes a ring body. In this and other variations of the invention, the cap may further include an opening. It is also noted that the inward facing variation of the present invention in fig. 12 does not require intermediate frame members 24 between the individual chuck components 22. In fact, EPAM on both sides of the device^TMLayer can be in phase withAre in contact with each other. Therefore, this variation of the present invention can provide assistance in situations where installation space is limited. Further uses of this device configuration are discussed below. However, other biasing methods for frustum-type actuators are described first.

In particular, fig. 13 provides a cross-sectional perspective view of a coil spring biased single frustum transducer 130. Here, a coil spring 132 interposed between the cap 42 and a baffle wall 134 associated with the frame (or a portion of the frame itself) biases the EPAM^TMAnd (5) structure. In the transducer 140 shown in fig. 14, a leaf spring 142 biases the cap portion of the transducer. The leaf spring 142 is shown connected to a bushing 144 on the other side of the cap by a bolt 146 or spacer secured between the bolt and a nut (not shown). Both ends of the leaf spring are guided by brackets 148. In another transducer example 150 illustrated in FIG. 15, an EPAM^TMThe membrane may be biased by a single weight 152 attached to the cap 42 or integrally formed with the cap 42. Although the device is shown tilted upward for ease of viewing, it generally runs horizontally so that gravitational pull on the weight can symmetrically bias the transducer along the Z-axis.

Based on the foregoing, it should be apparent that many parameters of the subject transducer may be varied to suit a given application. A non-exhaustive list includes: output fasteners or connections to the cap (which may be threaded sleeves, spacers, shafts, rings, discs, etc.); EPAM^TMPre-strain (magnitude, angle or direction, etc.) on the film; film type (silicone, acrylic, polyurethane, etc.); the thickness of the film; active versus inactive layers; the number of layers; the number of film chucks; the number of phases; the number of device "sides" and the orientation of the device sides.

System for controlling a power supply

Any of the subject transducers may also be used in more complex assemblies. Fig. 16 provides an example transducer 160 in which a number of frustum-type transducer subunits 100 are stacked in series for increased swing. Also, the inwardly facing double frustum transducer 120 provides a second output phase by connecting with its frame 20. When the height of this member is stabilized by its internal space (as referred to above), the position of the frame can be moved to provide a second stage output or input.

In addition to the center stage 120, a simple spacer is used between the outer transducers 100 for the purpose of increasing the fundamental oscillation. To further increase the oscillation, a further such stack may then be provided on the first stack. To provide another start-up phase, other inwardly facing transducers may be employed. Yet another variation contemplates an actuator-sensor pair with an outwardly facing transducer and an inwardly facing transducer paired. Naturally, other combinations are also within the scope of the invention.

Another very flexible problem solving method or experimental method provided by the present invention is illustrated in connection with fig. 17. Here, a reconfigurable preliminary system 170 is shown that can provide various types of transducers. Fig. 18A-18C are assembly views of various alternatives to the system of fig. 17. The system 170 is adapted to be used as a planar actuator using a component stacking apparatus 172 as shown in fig. 18A. The system 170 is adapted to function as a diaphragm actuator using a component stacking apparatus 174 as shown in fig. 18B. The system 170 is adapted to function as a diaphragm pump using a component stacking apparatus 176 as shown in fig. 18C. This pump will be described in further detail below. As far as the system 170 is concerned, it suffices to say here that the subject architecture itself tends to have great flexibility.

Fig. 19A provides a view of another application using the present invention. This figure details the use of a frustum-type actuator 182 to control the focused camera lens assembly 180. The cap or diaphragm of the transducer 184 is open in a ring shape so that light can pass to a lens 186 disposed within a housing 188. The illustrated leaf spring 190 is in contact with the housing to bias the EPAM^TMA film.

As shown in fig. 19B, the completed camera assembly will include at least a shroud or cover 192, an inner frame member 194,a CCD196 (charge coupled device) for acquiring images, and electronics 198. The electronics can be integrated to drive the entire device, or the electronics on board 200 can simply provide an EPAM^TMThe voltage required by the actuator is raised and controlled.

Suitable power modules for this use include the Q, E, F, G module by EMCO High Voltage Corp. (California) and the series VV unit by Pico Electronics, Inc. Of course, a custom power supply may also be used. In any event, the noted power source may be used not only in the camera embodiment, but in any system that varies the subject transducer.

Fig. 20 shows another camera lens assembly 226. However, in addition to leaf springs, this design uses a double frustum type actuator 100, where the preload side of the device 228 may not be an EPAM^TMA film, but only an elastomeric web. However, if side/layer 228 includes EPAM^TMMaterial, it may be most advantageously used to sense position based on changes in capacitance.

In another variation of the present invention, FIG. 21A shows a camera assembly 210 that utilizes an actuator assembly 212 to control zoom and focus. As previously mentioned, the apparatus includes a focusing stage driven by a diaphragm actuator 214 according to the present invention. Furthermore, the apparatus comprises a zoom table support of the planar actuator 216. Typically focus adjustment requires movement between 0.1 and 2.0 mm; zooming typically requires 5 to 10 times that amount of swing.

Thus, zooming is handled by different types of actuators. In fig. 21A, the zoom function is initiated by a pair of interdigitated (across) planar transducers 216. The benefit is that each of the planar and diaphragm actuators consists of an EPAM that extends over or above a common frame member 218^TMA thin film is formed. This functionality is provided by the dual lens arrangement shown. The implementation of zoom changes the distance between lens 186 and lens 220. The overall movement of lens 220 relative to lens 186 is accomplished by a robotic arm 222 connected to a zoom lens frame 224.

The combined use of the frame provides another option according to the invention, which can be adapted to any situation where a global motion and fine adjustment is required, or where a separate motion part is required (as in a camera). Although not shown, it is also contemplated that multiple faces of the modular frame may carry either the diaphragm actuators or the planar actuators on their own. Still further, non-right angle frame geometries may be used.

With the camera application of the invention, the aforementioned system can be made very compact. As such, they are particularly well suited for use in compact digital or cellular telephone cameras.

When there is more space available, it may be desirable to provide an EPAM that is suitable for longer zoom strokes^TMA zoom/focus engine to increase the operating range of the device. Fig. 22A and 22B are perspective views illustrating an alternative planar camera system 230 in which a telescopic arrangement 232 of planar actuators is provided to control zoom. These figures show the minimum and maximum zoom positions as indicated by arrows 232, 234, respectively.

The connection and manner of operation of the actuator is clearly illustrated by the enlarged cross-sectional views provided by fig. 23A-23C which illustrate the actuation stages of the transducer stack. This progressive movement is achieved as follows: by connecting the continuous output rod 238 (partially hidden) to the frame part 20, the final output rod 340 and the connected rod 30 float or, more suitably, drive the zoom element.

The present invention further includes a plurality of flow control devices. These devices include valves, mixers and pumps.

Fig. 24A is an assembly view of the valve mechanism. The valve 240 includes the components that make up the dual frustum type actuator 100 as discussed above. That is, the valve includes an EPAM^TMA membrane stretched within the frame member and secured by the cap. Further, the valve 240 includes a cap 242 that houses fittings 244, 246 therein.

Fig. 24B and 24C are side cross-sectional views of the valve in fig. 24A illustrating valve actuation. In fig. 24B the valve is closed. The cap/caps 42 act as a diaphragm, which blocks the fitting 244 in operation in the "normally closed" configuration, in the case of a central membrane (energized or not). In fig. 24C, the valve is opened by activating the transducer to drive the cap 42 in the direction of arrow 248 to allow flow through a cavity 250 formed within the device.

Figure 25 shows another single-sided double frustum diaphragm valve 260. This device differs only in that a tapered needle device 262 is provided for a wider range of control.

Fig. 26 shows a three-way mixing valve 270. The inlet fitting 272 is connected to lines (not shown) that are in fluid communication with various fluid/gas sources (not shown). The outlet fittings 274, 276 are connected to common outlet lines (not shown). The position of the cap/diaphragm 42, which may vary as indicated by the double-headed arrow 278, dictates the proportion of each different flow that can enter the outlet fitting. Of course, this device may also include tapered needle valves, such as the other valves previously described, and the other devices described herein may also include tapered needle valves as well.

Fig. 27 shows a coaxial valve 280. The foregoing valve uses a non-porous diaphragm, in which case diaphragm 282 includes a through hole 284. In this manner, fluid can flow from one side of the device to the other through fittings 286 and 288, with diaphragm 282 regulating the flow that can pass through or into the operating fitting 288.

Fig. 28 is a side cross-sectional view of a pressure measuring transducer 290 according to the present invention. Fluid pressure entering chamber 292 may be sensed by correlating changes in capacitance, which are sensed by extending the EPAM^TMCaused by the film. Compared with the conventional EPAM^TMThe cap 42 provides a new level of robustness to the system compared to a diaphragm transducer.

Fig. 29A and 29B illustrate a variable "cracking pressure" check valve 294. EPAM of actuator 296^TMThe material is stretched so that the cap is covered withA constant pressure is fixed to the distal end of the valve stem 244. When a voltage is applied to the material, its thickness contracts and extends in the direction of arrow 298, thereby reducing the preload at the valve connection. When so relaxed, fluid under relatively low pressure can leak past the cap 42 (or valve needle, etc.) and out through the fitting 246.

Fig. 30A and 30B provide views of a coaxial valve configuration 300 in which a frustum-type valve 302 is disposed within a dedicated housing 304. In this case, the housing is configured to replace a vapor canister vent valve for internal combustion engine applications. FIG. 30A shows the valve in a closed configuration; fig. 30B shows the valve in an open configuration. The valve is normally closed in response to EPAM^TMThe membrane is turned on with a voltage applied. This valve includes a stem 306 that is integrally formed with a cap or diaphragm 308. In addition to biasing using a double frustum design, the coil spring 310 may be used in a single sided design.

As to other applications of the subject system, a number of pumps will next be illustrated. These pumps may be used for fluid or gas delivery under pressure, or for creating a vacuum. The valve structure may be mounted to or formed in/integral with the pump body.

Fig. 31A and 31B show a variation of the first pump 320 and 320' using the double frustum type actuator 100. Each device comprises a single cavity 322 diaphragm pump. EPAM can be provided in combination with various dual frustum transducer designs^TMThe actuator components are used for single or two phase actuation as discussed above. The pump includes a pair of passive check valves 324, 326 in which the movement of a diaphragm 328 propelled by fluid (including gas) pressure alternatively opens and closes the valve, as will be apparent.

The pump 320' in fig. 31B is identical to the pump in fig. 31A except that it includes a diaphragm wall 330 added to the cap/diaphragm 42 portion. And EPAM used in a previous pump variation^TMThe wall 330 provides an overall improved cavity wall interface (e.g., on the one hand less susceptible to elastic deformation and more so than the membrane itself)Good material compatibility with corrosive chemicals).

Similar to the previous arrangement, the pump 340 shown in fig. 32 uses passive check valves 324, 326. However, it varies from device to device, as it can be implemented as an integrated dual chamber 342, 344 or a duplex pump. Further, the actuator may be a single phase or dual phase type transducer.

Fig. 33 shows a pump 350 for one chamber. Of course, it can be reassembled into a dual chamber design as shown in pump 340 of FIG. 32. However, it is of interest that the check valves used in the device are not passive, but instead are similar to or as described above with respect to fig. 28 for EPAM^TMValves 352, 354. Of course, other EPAMs may be used^TMA valve configuration (e.g., a device as shown in fig. 24A-24C).

In fact, FIG. 33 provides an illustration of the assembly of the various fluid flow components to produce an integrated EPAM that is highly advantageous over known systems^TMAnd (5) controlled devices. FIG. 34 illustrates how the subject device can be combined by itself or with other devices to provide a system with greater usability in accordance with the present invention. A "complete" fluid treatment system 360 as depicted in fig. 34 includes a pump 350, a flow control valve 280, and/or a pressure sensor 290. Of course, such a system may suitably use a pipe to probe (plunger), perhaps as indicated by arrow 362. One potential application of such a system may be in filling or controlling the charge of an air bag or reservoir as a lumbar support in a car seat. Of course, other applications and system configurations are equally possible. Generally, the pump chambers may be connected in series to increase the amount of pressure available for the pumping process, or in parallel to increase the pumping capacity. When using a combination of such couplings, a bank of pumps may be provided as well.

Further, some pump or flow connection component may be integrated into the design of the actuator itself. Fig. 35 provides an example of a pump 400 in which a flow conduit 402 is integrated into the device structure. EPAM^TM10/10' the film stretches to form each frustum/diaphragm member 60 and part of the check valve404. The disk 406 is attached to the diaphragm and is preloaded against the valve seat 408 by the tension in the diaphragm. When the disk is unseated from its seat, fluid flows through the center of the disk. The disks 406 are bonded to the film, one on each side of the film.

This configuration is highly advantageous from the standpoint of using the same membrane to define the pump and actuator in a single flow system. Further, by offsetting the valve structure to the side of the transducer body, the thickness of the overall structure can be minimized. This form factor may be desirable in certain applications where a "thinner" design is desired.

Fig. 36 shows yet another example pump 410. Here, a check valve 412 is formed in a side plate assembly 414 of the pump housing. This design provides a modular and compact approach to using the basic transducer architecture in pump applications. Moreover, this design offers the potential for a smaller "footprint" compared to the design in fig. 35. When only the second side plate 416 is provided to complete the assembly, the two check valve type flat plates are instead used to provide a duplex pump that is conceptually similar to the duplex pump shown in fig. 32.

With respect to other possible applications of the subject technology, FIG. 37 illustrates a vibrator-type device 370. In a dual frustum actuator configuration, the reciprocating motion of the mass 372 is transferred to a larger device housing connected to the transducer frame 26.

Whether or not a mass is provided to generate vibrations, another application of the subject transducer is shown in fig. 38 for a haptic feedback controller 380. The controller may be a game console device with a "joystick" 382 that communicates tactile or force feedback of the vibration generator to the user. In another variation, the joystick is coupled to a multi-phase transducer 384 that is capable of sensing or signaling user manipulation in a user input or control device due to a change in capacitance that occurs when deformed. Applications for such devices range from gaming console configurations to providing surgeons with high precision interfaces to facilitate robotic surgery.

Finally, fig. 39 illustrates a variation of the present invention in which a speaker system 390 is provided that uses multiple frustum and/or dual frustum transducers 392, 394, 396. The "tweeter" driver 392 is the smallest, followed by a larger "midrange" driver 394, and finally a large "woofer" driver 396. Due to the improved performance of the frustum geometry, large and small (low and high frequency tuned) loudspeakers can be produced. They can be driven at high power and still provide a lightweight high performance speaker because of the lack of heavy magnets or coils required as is typical for electromagnetic speakers. Moreover, the unobtrusive appearance of the transducer can be adapted to the design variations of the speaker cabinet 398, thereby providing the hi-fi enthusiast with an indispensable style option.

Machining

Regardless of the configuration of the transducer of the subject matter, a variety of processing techniques may be conveniently employed. In particular, for batch configurations, it is useful to use a mask plate fixture (not shown) to precisely position the mask used to shape the electrodes. Also, for batch configurations, it is useful to use an assembly jig (not shown) to accurately position multiple components. Additional details regarding the processing should be understood in conjunction with the above-mentioned patents and publications, and the knowledge generally known or understood by those skilled in the art.

Method

Consider methods associated with the subject transducers, wherein the methods are by EPAM^TMAn actuator. These methods may also be performed using the subject apparatus or other apparatus. These methods all include the act of providing a suitable transducer arrangement. This provisioning may be performed by the end user. In other words, "providing" (e.g., a pump) merely requires the end user to acquire, use, access, place, set, activate, power on, or other action to provide the requisite device in the subject methods.

Complete set of elements

Yet another aspect of the invention includes a kit of parts having any combination of the devices described herein, whether provided in a packaged combination or assembled by a skilled artisan for operational use, instructions for use, and the like.

The kit includes any number of transducers according to the present invention. The kit includes various other components for use with the transducer, including mechanical or electrical connections, power supplies, and the like. The subject kit also includes written instructions for use of the device or its components.

The kit of parts instructions may be printed on a substrate, such as paper or plastic, and the like. Likewise, the instructions may also be provided in the kit as a package insert, in a label of a package of the kit, or in a combination thereof (e.g., in connection with a package or sub-package), etc. In other embodiments, the instructions are provided as electronically stored data files on a suitable computer readable storage medium, such as a CD-ROM, diskette, or the like. In yet another embodiment, the actual instructions are not in the kit, but rather a method is provided for obtaining the instructions from a remote source, such as the Internet. An example of such an embodiment is where the kit of parts contains a web address where the instructions can be browsed and/or downloadable. As with the instructions, the means for obtaining the instructions can be recorded on a suitable medium.

Variations in

As to other details of the invention, materials and related alternative configurations may be used which fall within the level of knowledge of a person skilled in the relevant art. The above description is equally applicable with respect to method-based aspects of the invention, as well as additional acts that are commonly used or logically used. Furthermore, although the present invention has been described with reference to several examples and may optionally incorporate various features, the invention is not limited to the features described or indicated in view of each variation relating to the invention. Various changes may be made to the invention described, and equivalents may be substituted, without departing from the spirit and scope of the invention, whether set forth herein or otherwise included for the sake of brevity. Any number of the individual components or subassemblies shown may be integrated into their design. The design criteria for the assembly may undertake or direct such changes or other changes.

It is also contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with one or more of the features described herein. Reference to a single item includes the possibility that there are many of the same items. In particular, as used herein and in the appended claims, the singular forms "a," "an," "said," and "the" include plural referents unless the content clearly dictates otherwise. In other words, in the description above and in the claims that follow, use of the article allows the subject item "at least one". It is further noted that the claims may be designed to exclude any optional components. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as "solely," "exclusively," and the like in connection with the recitation of claim elements, or use of a "negative" limitation. If such exclusive terminology is not used, the term "comprising" in the claims shall allow for the inclusion of any additional component-whether a given number of components are listed in the claims or additional features are considered to alter the nature of the components recited in the claims. For example, the addition of a fastener or boss, complex surface geometry, or another feature to a "diaphragm" as set forth in the claims should not prevent the claims from proceeding to recite the claimed structure. Statement of other aspects unless specifically defined herein, all technical and scientific terms used herein are to be given the broadest possible commonly understood meaning while maintaining the validity of the claims.

The scope of the invention is not limited by the examples provided. So, i claim.

Claims (18)

1. A transducer arrangement comprising:

an open frame;

an electroactive polymer material secured within the frame, and a central region of the electroactive polymer material forming a membrane,

wherein the central region has a lower flexibility than an adjacent electroactive polymer material, and wherein a spring stretches the electroactive polymer material into a concave or convex shape.

2. The transducer arrangement of claim 1, wherein the arrangement comprises one of a speaker, a pump, a valve, and a lens.

3. The transducer arrangement of claim 2, wherein the spring biases the electroactive polymer material out of the plane of the diaphragm or out of the plane of the frame.

4. The transducer arrangement of claim 1, wherein the diaphragm forms a frustum structure.

5. The transducer arrangement of claim 1, wherein the frame is flat and the output motion of the diaphragm is out of the plane of the diaphragm or out of the plane of the frame.

6. The transducer arrangement according to claim 1, wherein the central region is rigid.

7. The transducer arrangement according to claim 1, wherein the central region is non-porous.

8. The transducer arrangement of claim 1, wherein the central region has an open interior portion.

9. The transducer arrangement according to claim 1, wherein the arrangement is adapted to be used as one of a sensor, an actuator or a generator.

10. The transducer arrangement of claim 1, comprising at least two diaphragms stretched into a frustum configuration.

11. The transducer arrangement of claim 10 wherein one diaphragm biases the other diaphragm.

12. The transducer arrangement of claim 10, wherein portions of the frustum face oppositely from each other.

13. The transducer arrangement of claim 10, wherein portions of the frustums face each other.

14. The transducer arrangement of claim 10, wherein the central regions are fixed together.

15. The transducer arrangement according to claim 1, wherein the electroactive polymer material comprises a plurality of individually addressed portions.

16. A transducer assembly comprising a plurality of stacked diaphragms of claim 1.

17. The transducer assembly of claim 16, wherein the stacked diaphragms are connected in series.

18. The transducer assembly of claim 16, wherein the stacked diaphragms are connected in parallel.