Electrostatic actuator

Abstract

An electrostatic actuator according to one aspect of the present disclosure comprises a flexible shell, a dielectric liquid contained inside the shell, and a plurality of electrodes positioned outside the shell. The shell comprises a junction part positioned at the center, and a plurality of pump parts that communicate with the junction part and are aligned in the circumferential direction centered on the junction part. The pump part has a first side surface positioned at one end in the circumferential direction, and a second side surface positioned at the other end in the circumferential direction. The plurality of electrodes are positioned on the first side surface and the second side surface of each pump part.

Description

Electrostatic Actuator

[0001] This application claims priority based on Japanese Patent Application No. 2024-146549, filed on August 28, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to electrostatic actuators.

[0003] Electrostatic actuators are known that use electrostatic attractive force generated between two electrodes as a driving force.

[0004] As such electrostatic actuators, HASEL (hydraulically amplified self-healing electrostatic) actuators have recently been attracting attention. HASEL actuators have a structure in which a pair of electrodes are provided on both ends of a shell filled with a dielectric liquid. When a voltage is applied to the pair of electrodes, the dielectric liquid inside the shell is polarized, generating an electrostatic attraction between the electrodes. This attracts the pair of electrodes, causing the dielectric liquid inside the shell to move and deform the shell. HASEL actuators can use this shell deformation to, for example, push or pull up an object. HASEL actuators are a type of artificial muscle, and are expected to be used in soft robots.

[0005] Patent Document 1 discloses an electrostatic actuator in which a plurality of electrodes are arranged around a circumferential surface of a doughnut-shaped shell having a single internal space.

[0006] U.S. Pat. No. 1,099,5779

[0007] The above-mentioned conventional techniques have room for further improvement in terms of increasing the amount of dielectric liquid discharged. Note that the "amount of dielectric liquid discharged" here refers to the total amount of dielectric liquid that moves when a voltage is applied to the electrodes.

[0008] The present disclosure provides a technique that can obtain a larger amount of dielectric liquid discharged in an electrostatic actuator.

[0009] An electrostatic actuator according to one aspect of the present disclosure includes a flexible shell, a dielectric liquid located inside the shell, and a plurality of electrodes located outside the shell. The shell includes a central collection section and a plurality of pump sections that are in communication with the collection section and are arranged in a circumferential direction around the collection section. The pump sections have a first side surface located at one end in the circumferential direction and a second side surface located at the other end in the circumferential direction. The plurality of electrodes are located on the first side surface and the second side surface of each of the pump sections.

[0010] According to the present disclosure, a larger amount of dielectric liquid can be discharged in the electrostatic actuator.

[0011] FIG. 1 is an explanatory diagram of the basic operation of an electrostatic actuator. FIG. 2 is a cross-sectional view of a HASEL according to the first embodiment when no voltage is applied. FIG. 3 is a cross-sectional view of a HASEL according to the first embodiment when a voltage is applied. FIG. 4 is a cross-sectional view taken along line II-II in FIG. 2. FIG. 5 is a cross-sectional view taken along line III-III in FIG. 3. FIG. 6 is an enlarged view of portion M1 in FIG. 2. FIG. 7 is a cross-sectional view of a HASEL according to a first modified example of the first embodiment when no voltage is applied. FIG. 8 is a cross-sectional view of a HASEL according to a first modified example of the first embodiment when a voltage is applied. FIG. 9 is a cross-sectional view taken along line IV-IV in FIG. 7. FIG. 10 is a cross-sectional view taken along line V-V in FIG. 8. FIG. 11 is a schematic plan view showing an example of the configuration of a HASEL according to a second modified example of the first embodiment. FIG. 12 is a schematic plan view showing an example of the configuration of a HASEL according to a third modified example of the first embodiment. FIG. 13 is a development view of a shell. FIG. 14 is a development view of a shell according to the modified example. FIG. 15 is a diagram (part 1) showing an example of an arrangement of multiple HASELs. FIG. 16 is a diagram (part 2) showing an example of an arrangement of multiple HASELs. FIG. 17 is a cross-sectional view showing an example of the configuration of a HASEL according to a fourth modified example of the first embodiment. FIG. 18 is a diagram showing an example of the configuration of an output section according to the modified example. FIG. 19 is a diagram showing an example of mounting the HASEL according to the first embodiment. FIG. 20 is a cross-sectional view of a HASEL according to a second embodiment. FIG. 21 is a schematic plan view of an electrode section of a HASEL according to the second embodiment. FIG. 22 is a cross-sectional view (part 1) taken along line VI-VI in FIG. 20. FIG. 23 is a cross-sectional view (part 2) taken along line VI-VI in FIG. 20. FIG. 24 is a cross-sectional view (part 1) taken along line VII-VII in FIG. 20. FIG. 25 is a cross-sectional view (part 2) taken along line VII-VII in FIG. 20. FIG. 26 is a cross-sectional view of a HASEL according to a first modified example of the second embodiment. Fig. 27 is a schematic plan view of an electrode portion of a HASEL according to a first modified example of the second embodiment. Fig. 28 is a cross-sectional view showing a state when stacked. Fig. 29 is a diagram (part 1) showing an example of mounting an electrostatic actuator structure. Fig. 30 is a diagram (part 2) showing an example of mounting an electrostatic actuator structure. Fig. 31 is a diagram (part 3) showing an example of mounting an electrostatic actuator structure. Fig. 32 is a cross-sectional view of a HASEL according to a second modified example of the second embodiment.FIG. 33 is a schematic plan view of an electrode portion of a HASEL according to a second modified example of the second embodiment. FIG. 34 is a diagram (part 1) showing a modified example of an output portion in an electrostatic actuator structure. FIG. 35 is a diagram (part 2) showing a modified example of an output portion in an electrostatic actuator structure. FIG. 36 is a diagram showing an example of the configuration of a control device according to a third embodiment. FIG. 37 is a flowchart showing a processing procedure executed by the control device. FIG. 38 is a diagram (part 1) showing an example of calibration information. FIG. 39 is a diagram (part 2) showing an example of calibration information. FIG. 40 is a diagram showing other examples of calibration information. FIG. 41 is a flowchart showing the processing procedure for setting a voltage on / off pattern of a module. FIG. 42 is a diagram showing an example of step S205.

[0012] Hereinafter, embodiments of the present disclosure (hereinafter referred to as "present embodiments") will be described in detail with reference to the drawings. In the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0013] The present disclosure will be described in the following order: 1. Overview 2. First Embodiment 3. Second Embodiment 4. Third Embodiment 5. Modification 6. Conclusion

[0014] <<1. Overview>> First, an overview of the electrostatic actuator according to this embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram of the basic operation of the electrostatic actuator.

[0015] The electrostatic actuator according to this embodiment is a HASEL actuator. Hereinafter, this HASEL actuator will be abbreviated as "HASEL" as appropriate. As shown in FIG. 1 , a HASEL 300 includes a shell 301, a first electrode 302, a second electrode 303, and a dielectric liquid 500.

[0016] The shell 301 has flexibility and toughness. That is, the shell 301 has the characteristics of being flexible and not easily stretched. The shell 301 is made of, for example, an oriented polypropylene (OPP) film or a polyethylene film. The shell 301 is formed into any shape by, for example, heat welding.

[0017] The first electrode 302 is a Vcc electrode (positive electrode) to which a power supply voltage is supplied. The second electrode 303 is a GND electrode (negative electrode) to which a ground potential is connected. The first electrode 302 and the second electrode 303 are conductive and flexible. The first electrode 302 and the second electrode 303 are made of, for example, conductive nonwoven fabric, aluminum foil tape, carbon grease, or the like.

[0018] The dielectric liquid 500 is sealed in the shell 301. The dielectric liquid 500 has insulating properties and low viscosity fluidity. Examples of the dielectric liquid 500 include natural ester electrical insulating oil, machine oil, cooking oil, NOVEC (registered trademark), transformer oil, and deionized water.

[0019] 1 , in the HASEL 300, when a voltage is applied to the first electrode 302, the dielectric liquid 500 inside the shell 301 is polarized, generating an electrostatic attraction between the electrodes. This attracts the first electrode 302 and the second electrode 303, causing the dielectric liquid 500 inside the shell 301 to move to areas where the first electrode 302 and the second electrode 303 are not present, deforming the shell 301.

[0020] HASEL 300 can, for example, push or pull up an object by utilizing the deformation of shell 301. Figure 1 shows an example in which the shell 301 is pulled up by tensioning the portion of the shell 301 that does not have first electrode 302 or second electrode 303. For example, if an object is hung from shell 301, the object can be pulled up.

[0021] In the HASEL 300, it is desirable to provide a location where the distance between the first electrode 302 and the second electrode 303 is narrow. The narrower the distance between the electrodes, the smaller the voltage required for operation. Specifically, when voltage is applied to the HASEL 300, the electrodes first attract each other at the location where the distance between the electrodes is narrow. When the electrodes attract each other at this narrow location, the distance between the electrodes in the vicinity also becomes smaller, and the electrodes in the vicinity also attract each other. This chain reaction is repeated, and eventually the electrodes close. This is called the "zipper effect" because the electrodes close like a zipper.

[0022] In Figure 1, the shell 301 has an elliptical shape in cross section, and the first electrode 302 and the second electrode 303 are arranged from the top to the center in the longitudinal direction of the shell 301, showing how the electrodes close together in a chain reaction starting from the top of the shell 301 where the distance between the electrodes is close.

[0023] In this embodiment, a configuration example for obtaining a larger amount of discharged dielectric liquid 500 in such a HASEL 300 will be described. Such a configuration example will be described later as a first embodiment. In addition, in this embodiment, a configuration example for obtaining a larger amount of discharged dielectric liquid 500 in such a HASEL 300 as well as for making it easier to control the amount of deformation of the output section, which is the section that is deformed when the dielectric liquid 500 is discharged, will be described. Such a configuration example will be described later as a second embodiment. In addition, in this embodiment, a configuration example of a control device that controls the HASELs according to the first and second embodiments will be described. Such a configuration example will be described later as a third embodiment.

[0024] In the following description, at least a partial area of ​​the shell that corresponds to the pair of electrodes will be referred to as a "pump section." The combination of this pump section and the pair of electrodes will be referred to as a "module."

[0025] In addition, for ease of understanding, each of the drawings shown below appropriately illustrates an orthogonal coordinate system with three axes, X, Y, and Z. In such an orthogonal coordinate system, the view from the positive side of the Z axis is considered to be a plan view.

[0026] Furthermore, in the drawings shown below, when the same reference numerals are used for multiple identical parts, the same reference numerals will be used for at least two identical parts in order to make the drawings easier to read.

[0027] <<2. First Embodiment>> Fig. 2 is a cross-sectional view of a HASEL 310 according to a first embodiment, taken along the XY plane, when no voltage is applied. Fig. 3 is a cross-sectional view of the HASEL 310 according to the first embodiment when a voltage is applied. Fig. 4 is a cross-sectional view taken along line II-II in Fig. 2. Fig. 5 is a cross-sectional view taken along line III-III in Fig. 3. Fig. 6 is an enlarged view of a portion M1 in Fig. 2.

[0028] 2 and 3, the HASEL 310 has a star-shaped configuration in a plan view and includes a shell 311 and a plurality of first electrodes 312 and second electrodes 313.

[0029] Shell 311 is filled with dielectric liquid 500. Shell 311 also includes a centrally located collection section 314 and a plurality of pump sections 315 that communicate with collection section 314 and are arranged in a circumferential direction around collection section 314.

[0030] The multiple pump portions 315 are arranged to extend radially from the collection portion 314. Each pump portion 315 has a first side surface 315a located at one end in the circumferential direction and a second side surface 315b located at the other end in the circumferential direction. As shown in Figures 2 to 5, the first electrode 312 and the second electrode 313 are provided on the first side surface 315a and the second side surface 315b of each pump portion 315, respectively.

[0031] 4 and 5, the assembly portion 314 has an output portion 316. The assembly portion 314 has an opening at its upper end. The output portion 316 is a flexible film that closes the opening of the assembly portion 314. The output portion 316 is fixed by, for example, an elastic photocurable resin. The output portion 316 is preferably made of, for example, a rubber type.

[0032] When a voltage is applied to the HASEL 310, the pump sections 315 close as shown in Fig. 3, and the dielectric liquid 500 in each pump section 315 moves to the collecting section 314. The pressure of the dielectric liquid 500 that has moved to the collecting section 314 pushes up the output section 316 as shown in Fig. 5, causing the output section 316 to expand and deform. This allows the HASEL 310 to function as an actuator.

[0033] By providing the collecting portion 314, the HASEL 310 can increase the volume of the dielectric liquid 500 sealed in the shell 311 by the amount of the collecting portion 314. In other words, the HASEL 310 can increase the amount of the dielectric liquid 500 discharged.

[0034] Furthermore, the HASEL 310 has a pump section 315 that is elongated and slender in the radial direction and extends radially from the collection section 314 as a center. This allows the driving voltage to be kept low compared to, for example, a case in which the pump section has a wide shape that is elongated in the circumferential direction, since the distance between the electrodes is shorter.

[0035] 6, the HASEL 310 has a first side surface 315a and a second side surface 315b that are curved concavely toward each other at the tip of the pump portion 315 (see part M2 in the figure). This allows the HASEL 310 to easily achieve a zipper effect.

[0036] Next, a HASEL 310A according to a first modified example of the first embodiment will be described. Fig. 7 is a cross-sectional view of the HASEL 310A according to the first modified example of the first embodiment when no voltage is applied. Fig. 8 is a cross-sectional view of the HASEL 310A according to the first modified example of the first embodiment when a voltage is applied. Fig. 9 is a cross-sectional view taken along line IV-IV in Fig. 7. Fig. 10 is a cross-sectional view taken along line V-V in Fig. 8.

[0037] 7, the HASEL 310A is provided such that the width W1 in the circumferential direction of the pump portion 315 increases toward the collecting portion 314. This allows the HASEL 310A to increase the volume of the collecting portion 314. In other words, the HASEL 310A can increase the amount of dielectric liquid 500 discharged.

[0038] 7 to 10, the outer circle C1 corresponds to the inner diameter of the assembly portion 314 when no voltage is applied, and the inner circle C2 corresponds to the inner diameter of the assembly portion 314 when a voltage is applied.

[0039] 8, when a voltage is applied to the HASEL 310A, the pump sections 315 close, and the dielectric liquid 500 in each pump section 315 moves to the collecting section 314. At this time, the HASEL 310A deforms the shell 311 so as to narrow the inner diameter of the collecting section 314 from the outer circle C1 to the inner circle C2.

[0040] As a result, the HASEL 310A can not only increase the amount of discharged dielectric liquid 500 but also increase the pressure of the dielectric liquid 500 when a voltage is applied. That is, as shown in Fig. 10, the HASEL 310A can deform the output section 316 at a higher internal pressure than, for example, the example shown in Fig. 4.

[0041] Next, a HASEL 310B according to a second modified example of the first embodiment will be described. Fig. 11 is a schematic plan view showing an example of the configuration of a HASEL 310B according to the second modified example of the first embodiment.

[0042] 11 , the HASEL 310B is provided such that the first electrode 312 is positioned across the first side surface 315a of one of the multiple pump sections 315 and the second side surface 315b of another pump section 315 adjacent to the one pump section 315. This allows the HASEL 310B to reduce the number of first electrodes 312 to be controlled relative to the number of pump sections 315.

[0043] Next, a description will be given of a HASEL 310C according to a third modified example of the first embodiment. Fig. 12 is a schematic plan view showing an example of the configuration of a HASEL 310C according to the third modified example of the first embodiment.

[0044] 12 , in the HASEL 310C, a plurality of pump sections 315 are arranged at intervals in the circumferential direction. The collection section 314 has a connection section 317 that is arc-shaped in plan view between one of the plurality of pump sections 315 and another pump section 315 adjacent to the one pump section 315.

[0045] By intentionally leaving the connection portion 317 as a structure, the HASEL 310C can maintain an inner diameter that does not shrink relative to the assembly portion 314 when no voltage is applied. In other words, the HASEL 310C suppresses deformation of the assembly portion 314 at the connection portion 317, so the connection portion 317 can be used as a fixing portion for the HASEL 310C. This is based on the idea that fixing is difficult if the entire assembly, including the assembly portion 314, is deformed, so intentionally providing a portion that is less likely to deform makes fixing easier.

[0046] When fixing, as shown in FIG. 12, for example, by arranging a support member having a support axis ax1 along each connecting portion 317, fixing of the HASEL 310C can be facilitated.

[0047] Next, a description will be given of a method for forming the shell 311. Fig. 13 is a development view of the shell 311. Fig. 14 is a development view of the shell 311 when it has an output section 316A according to a modified example.

[0048] As shown in Figure 13, the shell 311 is cut out from a material such that, for example, first side surfaces 315a on which the first electrodes 312 are located and second side surfaces 315b on which the second electrodes 313 are located are arranged alternately, and further, an upper cover portion 318 and a bottom cover portion 319 are arranged one above the other.

[0049] 13, shell 311 is folded in a mountain or valley shape, and top lid portion 318 and bottom lid portion 319 are assembled three-dimensionally and heat-sealed to form the top and bottom lids. Dielectric liquid 500 is then filled inside, and shell 311 is formed by heat-sealing output portion 316 to the opening of top lid portion 318 that communicates with the opening of collection portion 314. In this embodiment, first side surface 315a and second side surface 315b are heat-sealed to top lid portion 318 and bottom lid portion 319, respectively, but the mountain or valley folds of first side surface 315a and second side surface 315b may also be heat-sealed.

[0050] As shown in FIG. 14, an output section 316A according to a modified example is provided separately from the shell 311, and includes an expandable body 316a and a passage section 316b.

[0051] The expandable body 316a expands and contracts in response to changes in the pressure inside the expandable body 316a. One end of the passage 316b is connected to the upper cover 318 so as to communicate with the assembly part 314 of the shell 311, and the other end is connected to the expandable body 316a, connecting the inside of the shell 311 with the inside of the expandable body 316a.

[0052] When the output section 316A having the expandable body 316a and the passage section 316b is heat-welded to the upper cover section 318, the output section 316A needs to be heat-welded in parallel to the upper cover section 318. An example of the configuration of the output section 316A having the expandable body 316a and the passage section 316b will be described further below with reference to FIG.

[0053] Next, an example of the layout of the plurality of HASELs 310 will be described. Fig. 15 is a diagram (part 1) showing an example of the layout of the plurality of HASELs 310. Fig. 16 is a diagram (part 2) showing an example of the layout of the plurality of HASELs 310.

[0054] As shown in Fig. 15, a plurality of HASELs 310 can be arranged in parallel to perform linked or combined operations. Also, as shown in Fig. 16, a plurality of HASELs 310 can be arranged in a stack to perform linked or combined operations. Note that these arrangement examples can also be applied to the HASELs 310A, 310B, and 310C according to the respective modifications.

[0055] Next, a HASEL 310D according to a fourth modification of the first embodiment will be described. Fig. 17 is a cross-sectional view showing an example of the configuration of the HASEL 310D according to the fourth modification of the first embodiment. Note that Fig. 17 corresponds to Fig. 4, for example.

[0056] 17, the HASEL 310D has a height that is longer vertically (longer in the Z-axis direction) than, for example, the HASEL 310 in FIG. 4. By simply increasing the height, as in the HASEL 310D, the amount of discharge of the dielectric liquid 500 inside the shell 311 can be increased.

[0057] 17, the HASEL 310D is arranged such that the first electrode 312 and the second electrode 313 overlap the outer edges (the tip of the pump portion 315) of the first side surface 315a and the second side surface 315b, respectively, thereby enhancing the zipper effect of the HASEL 310D.

[0058] Next, a configuration example of the output section 316A according to the above-described modified example will be further described. Fig. 18 is a diagram showing a configuration example of the output section 316A according to the modified example. As shown in Fig. 18, the output section 316A has an expandable body 316a and a passage section 316b. Furthermore, the output section 316A may have a flow meter section 316c and an electromagnetic valve section 316d.

[0059] The expandable body 316a is, for example, a rubber actuator. The flow meter unit 316c measures the flow rate of the dielectric liquid 500 flowing through the passage unit 316b. The measurement result of the flow meter unit 316c can be used, for example, to control the expandable body 316a. Specifically, the measurement result of the flow meter unit 316c can be used, for example, to control the on / off of voltage application to each pump unit 315 (each module).

[0060] The electromagnetic valve unit 316d is controlled based on the measurement results of the flow meter unit 316c, and adjusts the flow rate of the dielectric liquid 500 flowing into the expandable body 316a. Note that the flow meter unit 316c may be replaced by a pressure gauge that measures the load on the expandable body 316a as pressure, and adjusts the pressure by controlling the on / off of voltage application for each pump unit 315 (module).

[0061] Next, an implementation example of the HASELs 310, 310A, 310B, 310C, and 310D described above will be described. Here, the HASEL 310 to which the output unit 316A according to a modified example is connected will be illustrated as an example. Fig. 19 is a diagram showing an implementation example of the HASEL 310 according to the first embodiment.

[0062] The HASEL 310 is implemented in, for example, a soft robot. In this case, as shown in FIG. 19, the HASEL 310 is implemented as an actuator that bends the fingers or arms of the soft robot.

[0063] The soft robot has, for example, a first link L1 and a second link L2. The first link L1 is supported at a tip end of the second link L2 so as to be bendable relative to the second link L2.

[0064] The HASEL 310 is attached to, for example, the second link L2. For example, at least the pump unit 315 of the HASEL 310 may be built into the second link L2. An output unit 316A is connected to the HASEL 310. The expandable body 316a of the output unit 316A is provided to connect the first link L1 and the second link L2, and the passage unit 316b of the output unit 316A is provided to connect the expandable body 316a and the HASEL 310.

[0065] When a voltage is applied, the HASEL 310 contracts the expandable body 316a to bend the first link L1 relative to the second link L2. When a voltage is not applied, the HASEL 310 relaxes the expandable body 316a to release the bending of the first link L1 relative to the second link L2. This allows the HASEL 310 to be applied to joints of soft robots, etc.

[0066] 19 is merely an example, and HASELs 310, 310A, 310B, 310C, and 310D can be applied to various fields depending on the implementation target. For example, in the case of robots, the application is not limited to soft robots, but can be applied to various industrial robots, etc. Furthermore, in the case of non-robots, the application can be applied to medical devices such as artificial limbs and prosthetic hands.

[0067] <<3. Second Embodiment>> Next, a second embodiment will be described. Fig. 20 is a cross-sectional view of a HASEL 330 according to the second embodiment, taken along the XY plane. Fig. 21 is a schematic plan view of an electrode portion 340 of the HASEL 330 according to the second embodiment.

[0068] Also, Fig. 22 is a first cross-sectional view taken along line VI-VI in Fig. 20. Also, Fig. 23 is a second cross-sectional view taken along line VI-VI in Fig. 20. Also, Fig. 24 is a first cross-sectional view taken along line VII-VII in Fig. 20. Also, Fig. 25 is a second cross-sectional view taken along line VII-VII in Fig. 20.

[0069] 20, the HASEL 330 has a circular shape in a plan view. Although not shown, the HASEL 330 has a cylindrical shape as a whole, and has a circular top surface (first surface) and bottom surface (second surface) in a plan view, and a side surface (third surface) connecting the top surface and the bottom surface.

[0070] In the following description, the cylindrical shell 331 will be referred to as the "pump portion 335" as appropriate. The pump portion 335 has a plurality of internal spaces that are partitioned from one another. These multiple internal spaces are arranged side by side in the circumferential direction in a plan view.

[0071] Each of the plurality of internal spaces has a shape in which the width W2 in the circumferential direction increases from the center to the outer periphery of the pump section 335. That is, each of the plurality of internal spaces has a fan shape. Furthermore, each of the plurality of internal spaces is filled with the dielectric liquid 500.

[0072] 21 , electrode units 340 are disposed on the top and bottom surfaces of pump unit 335. As shown in FIG. 21 , electrode unit 340 has a plurality of first electrodes 332. The plurality of first electrodes 332 are arranged in a line in the circumferential direction corresponding to the plurality of internal spaces of pump unit 335.

[0073] 21 shows a plan view of the electrode unit 340 arranged on the top surface of the pump unit 335, but the electrode unit 340 arranged on the bottom surface of the pump unit 335 also has a similar configuration. That is, the electrode unit 340 arranged on the bottom surface of the pump unit 335 has a plurality of second electrodes 333. The plurality of second electrodes 333 are arranged side by side in the circumferential direction corresponding to the plurality of internal spaces of the pump unit 335. Furthermore, the plurality of first electrodes 332 and second electrodes 333 each have a shape (in this case, a sector shape) similar to the corresponding internal space in a plan view.

[0074] That is, the HASEL 330 has a structure in which each internal space of the pump portion 335 is sandwiched from above and below by a corresponding first electrode 332 and a corresponding second electrode 333 .

[0075] 20, a plurality of output portions 336 are arranged on the side surface of the pump portion 335. The plurality of output portions 336 are arranged in a line in the circumferential direction corresponding to the internal space of the pump portion 335.

[0076] When a voltage is applied to the HASEL 330, the internal spaces of the pump section 335 close, and the dielectric liquid 500 in each internal space moves to the corresponding output section 336 (see arrow a1 in the figure). The pressure of the dielectric liquid 500 that moves to the output section 336 causes the output section 336 to expand and deform. This allows the HASEL 330 to function as an actuator.

[0077] The HASEL 330 has a shape in which the width W2 in the circumferential direction increases from the center of the pump portion 335 toward the outer periphery, thereby making it possible to increase the volume of the dielectric liquid 500 that is enclosed.

[0078] Furthermore, the HASEL 330 partitions the internal space of the pump section 335, allowing for individual control of each partitioned internal space, resulting in high control accuracy.

[0079] As shown in FIG. 22 , the pump portion 335 has an internal space height h1 at both circumferential ends when no voltage is applied, which is smaller than the internal space height h2 at the circumferential center. This facilitates the creation of a zipper effect. To further achieve this effect, it is advisable to provide radial folds in the fan-shaped portions of the pump portion 335, the first electrode 332, and the second electrode 333. FIG. 22 shows an example in which, by providing such folds, the cross-sectional shapes of the pump portion 335, the first electrode 332, and the second electrode 333 when no voltage is applied are V-shaped.

[0080] 23, which is a modification of FIG. 22, the pump section 335 may have a configuration in which the first electrode 332 and the second electrode 333 are separated at the fold. That is, the region of the first surface extending from one end of the internal space in the circumferential direction to the center of the internal space in the circumferential direction is defined as a first region, and the region extending from the center of the internal space in the circumferential direction to the other end of the internal space in the circumferential direction is defined as a second region. In this case, the first electrode 332 includes a first regional electrode 332-1 located in the first region and a second regional electrode 332-2 located in the second region and separate from the first regional electrode 332-1.

[0081] Furthermore, the region of the second surface from one end of the internal space in the circumferential direction to the center of the internal space in the circumferential direction is defined as a third region, and the region from the center of the internal space in the circumferential direction to the other end of the internal space in the circumferential direction is defined as a fourth region. In this case, the second electrode 333 includes a third region electrode 333-1 located in the third region and a fourth region electrode 333-2 separate from the third region electrode 333-1 and located in the fourth region.

[0082] With this configuration, the zipper effect can be more easily achieved, and the controllability of the output unit 336 can be further improved by increasing the number of electrodes to be controlled.

[0083] 24, in the pump portion 335, when no voltage is applied, the height h3 of the internal space at the center of the pump portion 335 is smaller than the height h4 of the internal space at the outer periphery of the pump portion 335. This makes it easier to achieve the zipper effect when the pump portion 335 is closed by applying a voltage as shown in FIG.

[0084] Next, a HASEL 330A according to a first modified example of the second embodiment will be described. Fig. 26 is a cross-sectional view of the HASEL 330A according to the first modified example of the second embodiment. Fig. 27 is a schematic plan view of an electrode portion 340A of the HASEL 330A according to the first modified example of the second embodiment. Fig. 28 is a cross-sectional view showing the state when stacked.

[0085] The HASEL 330A has a configuration in which a plurality of units can be stacked. Specifically, as shown in Fig. 26 , the HASEL 330A has a pump section 335 including a through-hole section 337. The through-hole section 337 includes the through-hole H1 that penetrates the first surface and the second surface described above. In the example of Fig. 26 , the through-hole section 337 is provided in the center of the pump section 335.

[0086] 27, the electrode unit 340A of the HASEL 330A includes a through-hole 337. In the example of FIG. 27, the through-hole 337 of the electrode unit 340A is provided in the center where the plurality of first electrodes 332 or second electrodes 333 are arranged, corresponding to FIG. 26.

[0087] As shown in FIG. 28, a plurality of HASELs 330A configured in this manner are stacked so that the first surface (top surface) of one HASEL 330A faces the second surface (bottom surface) of another HASEL 330A, and are connected by a connecting portion 338.

[0088] The connecting portions 338 are inserted into the aforementioned through holes H1 to connect the stacked HASELs 330A. The connecting portions 338 are elastic. A sponge shaft, a wire shaft, a spring shaft, or the like can be used for the connecting portions 338. The stacked HASELs 330A connected by the connecting portions 338 correspond to an example of an "electrostatic actuator structure."

[0089] The electrostatic actuator structure shown in FIG. 28 can be operated so that the bellows bends leftward as shown in the figure, for example, by expanding the output section 336 on the right side of the figure.

[0090] Next, an example of mounting such an electrostatic actuator structure will be described. Fig. 29 is a diagram (part 1) showing an example of mounting an electrostatic actuator structure. Fig. 30 is a diagram (part 2) showing an example of mounting an electrostatic actuator structure. Fig. 31 is a diagram (part 3) showing an example of mounting an electrostatic actuator structure.

[0091] As shown in Fig. 29, an electrostatic actuator structure in which multiple HASELs 330A are stacked can be implemented as, for example, a joint of a soft robot. In this case, as shown in Fig. 30, wiring of each electrode is performed using the through-hole H1 of the HASEL 330A. Furthermore, a connection portion 338 (not shown) inserted into the through-hole H1 may be provided with a strain sensor (not shown). This makes it possible to grasp the posture of the electrostatic actuator structure.

[0092] Furthermore, a pressure sensor (not shown) may be provided inside the output section 336. This makes it possible to grasp the contact pressure from the outside and the internal pressure of the output section 336.

[0093] The electrostatic actuator structure may also be covered with, for example, a mesh member 410 whose resistance changes when pressure is applied. The change in resistance of such a member can be used to determine whether or not the electrostatic actuator structure has come into contact with an obstacle.

[0094] Furthermore, each HASEL 330A constituting the electrostatic actuator structure may be provided on its side with a camera 420. Images captured by the camera 420 can be used for, for example, image-based contact determination and joint angle control.

[0095] Furthermore, an electrostatic actuator structure in which multiple HASELs 330A are stacked can be mounted, for example, as a multi-joint section of a multi-joint endoscope, as shown in Fig. 31. In this case, the aforementioned through-hole H1 can be used for wiring for each electrode and a strain sensor, as well as wiring for a light, an insertion hole for forceps, a water pipe for discharging water, an airway tube for discharging air, wiring for a cable for transmitting images from an endoscopic camera, and the like.

[0096] Next, a HASEL 330B according to a second modification of the second embodiment will be described. Fig. 32 is a cross-sectional view of the HASEL 330B according to the second modification of the second embodiment. Fig. 33 is a schematic plan view of an electrode portion 340B of the HASEL 330B according to the second modification of the second embodiment.

[0097] 32 and 33 correspond to FIGS. 26 and 27, and therefore differences from FIGS. 26 and 27 will be mainly described here.

[0098] As shown in FIG. 32, a HASEL 330B differs from that shown in FIG. 26 in that a through-hole portion 337 and a through-hole H1 are provided at a position closer to one of the plurality of internal spaces from the center of a pump portion 335.

[0099] 33, the electrode portion 340B of the HASEL 330B differs from that of Fig. 27 in that the through-hole portion 337 and the through-hole H1 are provided at a position closer to one of the multiple internal spaces corresponding to Fig. 32. This makes it possible to pass the connection portion 338 through the optimum position according to the operation of the electrostatic actuator structure.

[0100] In this way, the through-hole portion 337 and the through-hole H1 do not necessarily have to be provided in the center of the pump portion 335. Furthermore, a plurality of the through-hole portions 337 and the through-hole H1 may be provided at positions corresponding to each other in the internal space, thereby increasing the strength of the electrostatic actuator structure.

[0101] Next, modified examples of the output section 336 in the electrostatic actuator structure will be described. Fig. 34 is a diagram (part 1) showing a modified example of the output section 336 in the electrostatic actuator structure. Also, Fig. 35 is a diagram (part 2) showing a modified example of the output section 336 in the electrostatic actuator structure. Note that Fig. 34 corresponds to the state when no voltage is applied, and Fig. 35 corresponds to the state when a voltage is applied.

[0102] As shown in FIGS. 34 and 35, the movable directions of the multiple output sections 336 in the electrostatic actuator structure may be inclined with respect to a direction parallel to the axis ax2, which is the stacking direction of the multiple HASELs 330A.

[0103] 34 and 35 show an example in which the movable direction of the output section 336 is a direction along axis ax3 that is inclined with respect to axis ax2. In this way, when the movable directions of the multiple output sections 336 are inclined with respect to the stacking direction, it is possible to rotate the electrostatic actuator structure, for example, around axis ax2. In this case, it is necessary that adjacent output sections 336 are coupled to each other and that there is only one connecting section 338.

[0104] <<4. Third Embodiment>> Next, a third embodiment will be described. Fig. 36 is a diagram showing an example of the configuration of a control device 10 according to the third embodiment. Note that Fig. 2 shows, in functional blocks, only the components necessary for explaining this embodiment, and omits descriptions of general components.

[0105] In addition, in the explanation using FIG. 36, the explanation of components that have already been explained will be appropriately simplified or omitted.

[0106] The control device 10 is a device that controls one or more modules 31 included in the electrostatic actuator structure 3 for each module. The control device 10 controls each module 31 by performing voltage on / off control for each module 31.

[0107] 36, the control device 10 includes a storage unit 11 and a control unit 12. The control device 10 is also connected to modules 31-1, 31-2, ... 31-n (n is a natural number) included in the electrostatic actuator structure 3 and an HMI (Human Machine Interface) unit 5.

[0108] The HMI unit 5 includes an output interface that presents to the user various types of information related to the control of the electrostatic actuator structure 3. The HMI unit 5 includes, for example, a display as the output interface. The display is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display.

[0109] The HMI unit 5 also includes an input interface that accepts various operations from the user. The HMI unit 5 includes, for example, a keyboard, a mouse, etc. as the input interface. The HMI unit 5 may also be configured such that the output interface and the input interface are integrated into one, for example, by a touch panel display. In this case, the input interface may include, for example, a software component such as a GUI (Graphical User Interface).

[0110] The storage unit 11 is realized by a storage device such as a random access memory (RAM), a read only memory (ROM), a flash memory, or a hard disk drive (HDD).

[0111] 36, the storage unit 11 stores operation specification information 11a and calibration information 11b. The operation specification information 11a is information related to the operation of the electrostatic actuator structure 3, such as the contact pressure and target angle specified by the user. When the electrostatic actuator structure 3 is implemented in a robot such as a soft robot, the operation specification information 11a corresponds to, for example, teaching data for the robot. The calibration information 11b is information including measurement results, etc., obtained during the manufacture of each module 31.

[0112] The control unit 12 corresponds to a so-called processor or controller. The control unit 12 is realized by, for example, a central processing unit (CPU) or a micro processing unit (MPU). The control unit 12 executes a program according to an embodiment (not shown) stored in the storage unit 11, using RAM as a work area. The control unit 12 can also be realized by, for example, an integrated circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0113] The control unit 12 realizes or executes functions and actions of information processing according to the processing procedure described below. Fig. 37 is a flowchart showing the processing procedure executed by the control device 10 according to the third embodiment.

[0114] First, the control unit 12 receives a contact pressure specification from the user via, for example, the HMI unit 5 (step S101). Subsequently, the control unit 12 similarly receives a target angle specification from the user (step S102).

[0115] Then, the control unit 12 executes a process of reading calibration information for each module 31 from the calibration information 11b (step S103). A specific example of the calibration information 11b will now be described.

[0116] Fig. 38 is a diagram (part 1) showing an example of the calibration information 11b. Fig. 39 is a diagram (part 2) showing an example of the calibration information 11b. Fig. 40 is a diagram showing other examples of the calibration information 11b.

[0117] As shown in FIG. 38, the calibration information 11b includes, for each module 31, the relationship between time T and flow rate S1 of the dielectric liquid 500 (flow rate from the pump sections 315, 335 to the output sections 316, 336), for example.

[0118] As shown in FIG. 39, the calibration information 11b also includes, for each module 31, the relationship between time T and the total volume S2 of the dielectric liquid 500 (the total volume of the dielectric liquid 500 accumulated in the output sections 316, 336), for example.

[0119] As shown in FIG. 40, the calibration information 11b includes, as information for each module, the relationship between time T and internal pressure P, the relationship between time T and displacement angle θ, and the relationship between time T and displacement amount ΔM.

[0120] Furthermore, the calibration information 11b includes information common to each module, such as the relationship with the applied voltage V, the relationship with the number of cycles N, and the relationship with the applied load G. This information is obtained, for example, by conducting a life test or a destructive test on a sample that is different from the module used in the actuator or the like.

[0121] The control unit 12 executes a process of reading the calibration information 11 b in step S103. Note that which calibration information or a combination thereof to use may be arbitrarily designated by the user, for example, or may be automatically selected in accordance with the operation designation information 11 a.

[0122] Incidentally, to explain what the various parameters included in each calibration result can be used as criteria for judgment, for example, when the applied voltage V is increased above a certain level, a zipper effect occurs. Also, for example, the applied voltage V can shorten the time T up to a certain value (non-linear). Also, for example, when the applied voltage V is increased above a certain level, dielectric breakdown occurs.

[0123] For example, when the applied voltage V is naturally discharged with a load G applied, the displacement ΔM contracts according to a first contraction pattern (nonlinear). For example, when the applied voltage is discharged at -V with a load G applied, the displacement ΔM contracts according to a second contraction pattern (nonlinear).

[0124] Furthermore, for example, when the maximum internal pressure P is maintained, the shell material will deteriorate and break down over time after the number of cycles N. Furthermore, for example, when operation is continued at the internal pressure P when the applied load G is generated, the shell material will deteriorate and break down over time after the number of cycles N.

[0125] Returning to the explanation of Fig. 37, the control unit 12 uses the read calibration information 11b as a basis for making such a decision, and then executes a voltage on / off pattern setting process for the module 31, either automatically or in response to a user instruction (step S104).

[0126] Fig. 41 is a flowchart showing the processing procedure for setting a voltage on / off pattern for the module 31. Fig. 42 is a diagram showing an example of step S205. In the voltage on / off pattern setting processing for the module 31, as shown in Fig. 41, the control unit 12 sets a voltage limiter (step S201). A maximum value and a minimum value are set for the voltage limiter. The maximum value corresponds to dielectric breakdown. The minimum value corresponds to the occurrence of the zipper effect.

[0127] Next, the control unit 12 sets a cycle limiter (step S202). The cycle corresponds to the suspension of use of the module 31. Then, it is determined whether or not to operate the electrostatic actuator structure 3 at the limit speed at which it can output power (step S203).

[0128] If the modules 31 are to be operated at the limit speed (Yes at step S203), the control unit 12 performs collective on / off setting for all the modules 31 (step S204), and ends the voltage on / off pattern setting process for the modules 31.

[0129] If the modules 31 are not to be operated at the limit speed (step S203, No), the control unit 12 sets a voltage on / off pattern (step S205) for each module 31. The control unit 12 determines the timing of voltage application for each module 31 based on, for example, information included in the calibration information 11b regarding the time from when voltage is applied to the first electrode and the second electrode to when the output unit finishes moving.

[0130] Alternatively, the control unit 12 determines the magnitude of the voltage to be applied for each module 31 based on information included in the calibration information 11b indicating the relationship between the time from when the voltage is applied to the first electrode and the second electrode until the output unit finishes moving and the magnitude of the voltage to be applied to the first electrode and the second electrode.

[0131] 42 shows an example of step S205 in which the timing of applying voltage to each module 31 is staggered for an electrostatic actuator structure 3 having five modules 31-1, 31-2, 31-3, 31-4, and 31-5. This allows the electrostatic actuator structure 3 to be displaced more gently than when operated at the limit speed. Here, by adjusting the activation time (voltage-on time) of each module 31 based on the calibration information 11b, the electrostatic actuator structure 3 can be operated in a desired manner even if there are individual differences between the modules 31.

[0132] Furthermore, the voltage on / off setting patterns are not limited to the above examples, and multiple patterns may be used. For example, while the example in FIG. 42 shows voltage being applied sequentially from module 31-1 to module 31-5, the order may be reversed, or a pattern may be used in which the start-up times of some of the modules 31 are aligned. Furthermore, a pattern in which voltage is applied only to some of the modules 31 may be used, such as applying voltage only to modules 31-1, 31-3, and 31-5, but not to modules 31-2 and 31-4. Furthermore, while the example in FIG. 42 uses the start-up time as an example, the end time (voltage-off time) may also be handled in the same way.

[0133] After executing step S205, the control unit 12 ends the voltage on / off pattern setting process for the module 31.

[0134] Returning to the description of Fig. 37, after step S104 is executed, the control unit 12 executes the operation of the electrostatic actuator structure 3 based on the set voltage on / off pattern (step S105). Then, the control unit 12 determines whether the target angle and pressure specified in steps S101 and S102 have been reached (step S106).

[0135] If it has not reached the limit (step S106, No), the control unit 12 repeats the process from step S105. If it has reached the limit (step S106, Yes), the control unit 12 ends the process.

[0136] <<5. Modifications>> It should be noted that several modifications can be made to the above-described embodiments of the present disclosure. For example, among the processes described in the above-described embodiments of the present disclosure, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using a known method. In addition, the processing procedures, specific names, and information including various data and parameters shown in the above documents and drawings can be changed as desired unless otherwise specified. For example, the various information shown in each drawing is not limited to the illustrated information.

[0137] Furthermore, the components of each device shown in the figure are conceptual functional components and do not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

[0138] The above-described embodiments of the present disclosure can be combined as appropriate within the scope of the present disclosure without causing any contradiction in the processing content. The order of the steps shown in the sequence diagrams or flowcharts of the present embodiments can be changed as appropriate.

[0139] <<6. Conclusion>> As described above, according to one embodiment of the present disclosure, the HASEL 310 (corresponding to an example of an “electrostatic actuator”) includes a flexible shell 311, a dielectric liquid 500 located inside the shell 311, and a plurality of electrodes located outside the shell 311. The shell 311 includes a central collection portion 314 and a plurality of pump portions 315 that are connected to the collection portion 314 and are arranged in a circumferential direction around the collection portion 314. The pump portion 315 has a first side surface 315a located at one end in the circumferential direction and a second side surface 315b located at the other end in the circumferential direction. The plurality of electrodes are located on the first side surface 315a and the second side surface 315b of each pump portion 315. By including the collection portion 314, the HASEL 310 can increase the volume of the dielectric liquid 500 sealed in the shell 311 by the amount of the collection portion 314. That is, the HASEL 310 allows a larger amount of the dielectric liquid 500 to be discharged.

[0140] Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, components of different embodiments and modifications may be combined as appropriate.

[0141] Furthermore, the effects of each embodiment described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0142] The present technology can be configured as follows: (1) An electrostatic actuator including: a flexible shell; a dielectric liquid located inside the shell; and a plurality of electrodes located outside the shell, wherein the shell includes: a central collection portion; and a plurality of pump portions that communicate with the collection portion and are arranged in a circumferential direction around the collection portion as a center, wherein the pump portions have a first side surface located at one end in the circumferential direction and a second side surface located at the other end in the circumferential direction, and the plurality of electrodes are located on the first side surface and the second side surface of each of the pump portions. (2) The electrostatic actuator according to (1), wherein the plurality of pump portions extend radially around the collection portion as a center. (3) The electrostatic actuator according to (2), wherein the width of the pump portions in the circumferential direction increases toward the collection portion. (4) The electrostatic actuator according to (3), wherein the plurality of electrodes include a first electrode located on the first side surface and a second electrode located on the second side surface, and wherein the first side surface and the second side surface are concavely curved toward each other at a tip end of the pump section. (5) The electrostatic actuator according to any one of (1) to (4), wherein the electrode is located across the first side surface of one of the plurality of pump sections and the second side surface of another pump section adjacent to the one pump section. (6) The electrostatic actuator according to any one of (1) to (5), wherein the plurality of pump sections are arranged at intervals in the circumferential direction, and the collection section has a connection section that is arc-shaped in a plan view between one of the plurality of pump sections and the other pump section adjacent to the one pump section. (7) The electrostatic actuator according to any one of (1) to (6), further comprising an output section connected to the collection section, wherein the collection section has an opening, and the output section is a flexible film that closes the opening.(8) The electrostatic actuator according to any one of (1) to (6), further comprising: an output section connected to the collection section; the output section comprising: an expandable body that is provided separately from the shell and expands and contracts in response to changes in internal pressure; and a passage section that has one end connected to the collection section and the other end connected to the expandable body, connecting the inside of the shell to the inside of the expandable body. (9) An electrostatic actuator comprising: a flexible pump section having a first surface that is circular in a plan view, a second surface that is circular in a plan view and is positioned opposite the first surface, and a third surface that connects the first surface and the second surface; a dielectric liquid positioned inside the pump section; a plurality of first electrodes positioned on the first surface of the pump section; a plurality of second electrodes positioned on the second surface of the pump section; and a plurality of output ports positioned on the third surface of the pump section, wherein the pump section has a plurality of internal spaces partitioned from one another, the plurality of internal spaces being arranged side by side in a circumferential direction in a plan view, and the plurality of first electrodes, the plurality of second electrodes, and the plurality of output ports being arranged side by side in the circumferential direction corresponding to the plurality of internal spaces. (10) The electrostatic actuator according to (9), wherein the width of the internal space in the circumferential direction increases from the center of the pump section toward the outer periphery. (11) The electrostatic actuator according to (9) or (10), wherein the height of the internal space at the center of the pump section is smaller than the height of the internal space at the outer periphery of the pump section. (12) The electrostatic actuator according to (9), (10), or (11), wherein the height of the internal space at both ends in the circumferential direction is smaller than the height of the internal space at the center in the circumferential direction.(13) The electrostatic actuator according to (12), wherein, when a region of the first surface from one end of the internal space in the circumferential direction to a center of the internal space in the circumferential direction is defined as a first region and a region from the center of the internal space in the circumferential direction to the other end of the internal space in the circumferential direction is defined as a second region, the first electrode includes a first regional electrode located in the first region and a second regional electrode separate from the first regional electrode and located in the second region; when a region of the second surface from one end of the internal space in the circumferential direction to the center of the internal space in the circumferential direction is defined as a third region and a region from the center of the internal space in the circumferential direction to the other end of the internal space in the circumferential direction is defined as a fourth region, the second electrode includes a third regional electrode located in the third region and a fourth regional electrode separate from the third regional electrode and located in the fourth region. (14) An electrostatic actuator structure comprising a plurality of electrostatic actuators according to any one of (9) to (13), the plurality of electrostatic actuators being stacked such that the first surface of one of the electrostatic actuators faces the second surface of another of the electrostatic actuators, and further comprising a connecting portion connecting the plurality of electrostatic actuators. (15) The electrostatic actuator structure according to (14), in which the connecting portion is elastic. (16) The electrostatic actuator structure according to (14) or (15), in which the pump portion has a through hole penetrating the first surface and the second surface, and the connecting portion is inserted into the through hole. (17) The electrostatic actuator structure according to (16), in which the through hole is provided in a center of the pump portion. (18) The electrostatic actuator structure according to (16), in which the through hole is provided at a position closer to one of the plurality of internal spaces from the center of the pump portion. (19) The electrostatic actuator structure according to any one of (14) to (18), wherein the movable direction of the plurality of output sections is inclined with respect to the stacking direction of the plurality of electrostatic actuators.(20) The electrostatic actuator structure according to any one of (14) to (19), comprising: a control unit that controls the plurality of electrostatic actuators; and a memory unit that stores, for each of the plurality of electrostatic actuators, information relating to the time from when a voltage is applied to the first electrode and the second electrode until when movement of the output unit is completed, wherein the control unit determines the timing of applying the voltage to the first electrode and the second electrode for each of the plurality of electrostatic actuators based on the information stored in the memory unit. (21) The electrostatic actuator structure according to any one of (14) to (19), comprising: a control unit that controls the plurality of electrostatic actuators; and a memory unit that stores, for each of the plurality of electrostatic actuators, information indicating the relationship between the time from when a voltage is applied to the first electrode and the second electrode until movement of the output unit is completed and the magnitude of the voltage to be applied to the first electrode and the second electrode, wherein the control unit determines the magnitude of the voltage to be applied to the first electrode and the second electrode for each of the plurality of electrostatic actuators based on the information stored in the memory unit.

[0143] 3 Electrostatic actuator structure 5 HMI section 10 Control device 11 Memory section 11a Operation designation information 11b Calibration information 12 Control section 31 Module 301 Shell 302 First electrode 303 Second electrode 310, 310A, 310B, 310C, 310D HASEL 311 Shell 312 First electrode 313 Second electrode 314 Collector section 315 Pump section 315a First side surface 315b Second side surface 316 Output section 316A Output section 316a Expandable body 316b Passage section 316c Flow meter section 316d Electromagnetic valve section 317 Connection section 318 Top cover section 319 Bottom cover section 330, 330A, 330B HASEL 331 Shell 332 First electrode 333 Second electrode 335 Pump section 336 Output section 337 Through-hole section 338 Connection section 340 Electrode section 340A Electrode section 340B Electrode section 500 Dielectric liquid H1 Through-hole

Claims

1. An electrostatic actuator comprising: a flexible shell; a dielectric liquid located inside the shell; and a plurality of electrodes located outside the shell, wherein the shell comprises: a central collection section; and a plurality of pump sections connected to the collection section and arranged in a circumferential direction around the collection section, wherein the pump sections have a first side surface located at one end in the circumferential direction and a second side surface located at the other end in the circumferential direction, and the plurality of electrodes are located on the first side surface and the second side surface of each of the pump sections.

2. The electrostatic actuator according to claim 1, wherein the plurality of pump sections extend radially from the collection section as a center.

3. The electrostatic actuator according to claim 2, wherein the width of the pump portion in the circumferential direction increases toward the collection portion.

4. An electrostatic actuator as described in claim 3, wherein the plurality of electrodes include a first electrode located on the first side surface and a second electrode located on the second side surface, and at the tip of the pump section, the first side surface and the second side surface are curved concavely in the direction approaching each other.

5. An electrostatic actuator as described in claim 1, wherein the electrode is positioned across the first side surface of one of the plurality of pump sections and the second side surface of another pump section adjacent to the one pump section.

6. An electrostatic actuator according to claim 1, wherein the plurality of pump sections are arranged at intervals in the circumferential direction, and the assembly section has a connection section that is arc-shaped in a plan view between one pump section of the plurality of pump sections and another pump section adjacent to the one pump section.

7. An electrostatic actuator according to any one of claims 1 to 6, comprising an output section connected to said collection section, said collection section having an opening, and said output section being a flexible film that closes said opening.

8. An electrostatic actuator according to any one of claims 1 to 6, comprising an output section connected to the collection section, the output section comprising: an expandable body provided separately from the shell and expanding and contracting in response to changes in internal pressure; and a passage section having one end connected to the collection section and the other end connected to the expandable body, connecting the inside of the shell with the inside of the expandable body.

Images