阅读说明：本技术 包括电极对的人造肌肉及包含人造肌肉的人造肌肉组件 (Artificial muscle including electrode pair and artificial muscle assembly including the same ) 是由 M·P·罗威 S·S·潘瓦尔 M·B·艾美特 于 2021-05-28 设计创作，主要内容包括：一种人造肌肉,包含：壳体,其具有电极区域以及可膨胀流体区域；定位于所述电极区域中的电极对,所述电极对具有固定至所述壳体的第一表面的第一电极以及固定至所述壳体的第二表面的第二电极。所述第一电极和第二电极各自具有两个或更多个接片部分以及两个或更多个桥接部分。所述两个或更多个桥接部分中的每一个使相邻的接片部分互连,并且所述第一电极和第二电极中的至少一个包含中心开口,所述中心开口定位于所述两个或更多个接片部分之间并且围绕所述可膨胀流体区域。电介质流体容纳于所述壳体内并且所述电极对可在非致动状态与致动状态之间致动,以使得从所述非致动状态至所述致动状态的致动将所述电介质流体引导至所述可膨胀流体区域中。(An artificial muscle comprising: a housing having an electrode region and an expandable fluid region; a pair of electrodes positioned in the electrode area, the pair of electrodes having a first electrode secured to a first surface of the housing and a second electrode secured to a second surface of the housing. The first and second electrodes each have two or more tab portions and two or more bridge portions. Each of the two or more bridging portions interconnects adjacent tab portions, and at least one of the first and second electrodes includes a central opening positioned between the two or more tab portions and surrounding the expandable fluid region. A dielectric fluid is contained within the housing and the electrode pairs are actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region.)

1. An artificial muscle comprising:

a housing comprising an electrode region and an expandable fluid region;

a pair of electrodes positioned in an electrode area of the housing, the pair of electrodes comprising a first electrode secured to a first surface of the housing and a second electrode secured to a second surface of the housing, wherein:

the first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions, wherein:

each of the two or more bridging portions interconnecting adjacent tab portions; and

at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and surrounding the expandable fluid region; and

a dielectric fluid contained within the housing;

wherein the electrode pair is actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region.

2. The artificial muscle according to claim 1, wherein the shell comprises a first membrane layer and a second membrane layer partially sealed to each other to define a sealed portion of the shell, the shell further comprising an unsealed portion surrounded by the sealed portion, wherein the electrode region and the expandable fluid region of the shell are disposed in the unsealed portion.

3. An artificial muscle according to claim 2, wherein the first and second membrane layers are each a biaxially oriented polypropylene membrane.

4. The artificial muscle of claim 1, further comprising a first electrical insulator layer secured to an inner surface of the first electrode opposite the first surface of the housing and a second electrical insulator layer secured to an inner surface of the second electrode opposite the second surface of the housing, wherein the first and second electrical insulator layers each include an adhesive surface and an opposing non-sealable surface.

5. The artificial muscle according to claim 1, wherein the first electrode and the second electrode are each aluminum-coated polyester electrodes.

6. The artificial muscle according to claim 1, wherein the first electrode and the second electrode each comprise two pairs of tab portions and two pairs of bridge portions, each bridge portion adjacently interconnecting a pair of adjacent tab portions, each tab portion diametrically opposed to an opposite tab portion.

7. The artificial muscle according to claim 1, wherein the two or more tab portions each have a tab length and the two or more bridge portions each have a bridge length extending radially from the central opening, the bridge length being 20% to 50% of the tab length.

8. The artificial muscle according to claim 1, wherein each of the first and second electrodes comprises a central opening positioned between the two or more tab portions and surrounding the expandable fluid region, the central openings being coaxially aligned with each other.

9. The artificial muscle according to claim 1, wherein:

the first and second electrodes are non-parallel to each other when the electrode pair is in the non-actuated state; and

the first and second electrodes are parallel to each other when the electrode pair is in the actuated state such that the first and second electrodes are configured to zip toward each other and toward the central opening when actuated from the non-actuated state to the actuated state.

10. An artificial muscle assembly comprising:

a plurality of artificial muscles, each artificial muscle comprising:

a housing comprising an electrode region and an expandable fluid region;

a pair of electrodes positioned in an electrode area of the housing, the pair of electrodes comprising a first electrode secured to a first surface of the housing and a second electrode secured to a second surface of the housing, wherein:

the first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions, wherein:

each of the two or more bridging portions interconnecting adjacent tab portions; and

at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and surrounding the expandable fluid region; and

a dielectric fluid contained within the housing;

wherein the plurality of artificial muscles are arranged in a stack such that the inflatable fluid regions of each artificial muscle are coaxially aligned with each other; and

wherein the electrode pair is actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region.

11. The artificial muscle assembly according to claim 10, wherein the plurality of artificial muscles are electrically coupled to each other and configured to be actuated simultaneously between the non-actuated state and the actuated state.

12. The artificial muscle assembly according to claim 10, further comprising:

a first electrical insulator layer secured to an inner surface of the first electrode opposite the first surface of the housing and a second electrical insulator layer secured to an inner surface of the second electrode opposite the second surface of the housing,

wherein the first electrical insulator layer and the second electrical insulator layer each comprise an adhesive surface and an opposing non-sealable surface.

13. The artificial muscle assembly according to claim 10, wherein the first and second electrodes each comprise two pairs of tab portions and two pairs of bridge portions, each bridge portion interconnecting a pair of adjacent tab portions, each tab portion being diametrically opposed to an opposing tab portion.

14. The artificial muscle assembly according to claim 10, wherein each of the first and second electrodes includes the central opening positioned between the two or more tab portions and surrounding the expandable fluid region, the central openings being coaxially aligned with each other.

15. The artificial muscle assembly according to claim 10, wherein:

the first and second electrodes are non-parallel to each other when the electrode pair is in the non-actuated state; and

the first and second electrodes are parallel to each other when the electrode pair is in the actuated state such that the first and second electrodes are configured to zip toward each other and toward the central opening when actuated from the non-actuated state to the actuated state.

16. A method for actuating an artificial muscle assembly, the method comprising:

generating a voltage using a power source electrically coupled to a pair of electrodes of an artificial muscle comprising a housing having an electrode region and an expandable fluid region, wherein:

the electrode pair is positioned in an electrode region of the housing;

the electrode pair includes a first electrode fixed to a first surface of the housing and a second electrode fixed to an opposing second surface of the housing;

the first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions, wherein:

each of the two or more bridging portions interconnecting adjacent tab portions; and

at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and surrounding the expandable fluid region; and

a dielectric fluid contained within the housing, an

Applying the voltage to the pair of electrodes of the artificial muscle, thereby actuating the pair of electrodes from a non-actuated state and an actuated state such that the electrical fluid is directed into and expands the expandable fluid region of the housing.

17. The method of claim 16, wherein the casing comprises a first film layer and a second film layer, and the first film layer and the second film layer are partially heat sealed to each other to define a sealed portion of the casing, the casing further comprising an unsealed portion surrounded by the sealed portion, wherein the electrode region and the expandable fluid region of the casing are disposed in the unsealed portion.

18. The method of claim 16, wherein a controller is communicatively coupled to the pair of electrodes, and the controller directs a voltage from the power source across the first and second electrodes to actuate the artificial muscle from the unactuated state to the actuated state.

19. The method of claim 16, wherein the artificial muscle is one of a plurality of artificial muscles arranged in a stack such that the inflatable fluid regions of each artificial muscle are coaxially aligned with each other.

20. The method of claim 16, wherein inflating the inflatable fluid region generates a force greater than 4n.mm per cubic centimeter of actuator volume.

Technical Field

The present description relates generally to apparatus and methods for focused dilation on at least one surface of a device, and more particularly, to apparatus and methods for directing a fluid with an electrode pair to dilate a device.

Background

Current robotics typically relies on rigid members such as servo motors to perform tasks in a structured environment. This rigidity has limitations in many robotic applications caused at least in part by the weight-to-power ratio of servo motors and other rigid robotic devices. The field of soft robots ameliorates these limitations by using artificial muscles and other soft actuators. Artificial muscles attempt to mimic the versatility, performance, and reliability of biological muscles. Some artificial muscles rely on fluid actuators, but fluid actuators require a supply of pressurized gas or liquid, and fluid transport must be performed through channels and tubing, thereby limiting the speed and efficiency of the artificial muscle. Other artificial muscles use heat activated polymer fibers, but these polymer fibers are difficult to control and operate less efficiently.

A particular artificial muscle design is described in the article entitled "Hydraulically amplified self-healing electrostatic actuators with muscle-like properties" (Science 05Jan 2018: vol.359, Issue 6371, pp.61-65) by e.acome, s.k.mitchell, t.g.morrissey, m.b.emmett, c.benjamin, m.king, m.radakovitz and c.keplinger. These hydraulically amplified self-healing electrostatic (HASEL) actuators use electrostatic and hydraulic forces to achieve multiple actuation modes. However, hydraulically amplified self-healing electrostatic (HASEL) actuator artificial muscles have limited actuator power per unit volume.

Accordingly, there is a need for an improved artificial muscle having increased actuator power per unit volume.

Disclosure of Invention

In one embodiment, an artificial muscle, comprising: a housing having an electrode region and an expandable fluid region; and an electrode pair positioned in an electrode area of the housing, the electrode pair having a first electrode secured to a first surface of the housing and a second electrode secured to a second surface of the housing. The first electrode and the second electrode each have two or more tab portions and two or more bridge portions. Each of the two or more bridging portions interconnecting adjacent tab portions; and at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and surrounding the expandable fluid region. A dielectric fluid is contained within the housing and the electrode pairs are actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region.

In another embodiment, an artificial muscle component comprises: a plurality of artificial muscles, each artificial muscle having a housing with an electrode area and an expandable fluid area, and a pair of electrodes positioned in the electrode area of the housing, the pair of electrodes comprising a first electrode secured to a first surface of the housing and a second electrode secured to a second surface of the housing. The first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions. Each of the two or more bridging portions interconnects adjacent tab portions and at least one of the first and second electrodes includes a central opening positioned between the two or more tab portions and surrounding the expandable fluid region. A dielectric fluid contained within the housing, the plurality of artificial muscles arranged in a stack such that the inflatable fluid regions of each artificial muscle are coaxially aligned with each other; and the electrode pair is actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region.

In yet another embodiment, a method for actuating an artificial muscle assembly, comprises: a voltage is generated using a power source electrically coupled to a pair of electrodes of an artificial muscle having a housing with an electrode region and an expandable fluid region. The electrode pair is positioned in an electrode region of the housing. The electrode pair includes a first electrode secured to a first surface of the housing and a second electrode secured to an opposing second surface of the housing. The first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions. Each of the two or more bridging portions interconnects adjacent tab portions, and at least one of the first and second electrodes has a central opening positioned between the two or more tab portions and surrounding the expandable fluid region. A dielectric fluid is contained within the housing. The method further includes applying the voltage to an electrode pair of the artificial muscle, thereby actuating the electrode pair from a non-actuated state and an actuated state such that the electro-fluidic fluid is directed into and expands an expandable fluidic region of the housing.

These and additional features provided by the embodiments described herein will be more fully understood from the following detailed description, taken together with the accompanying drawings.

Drawings

The embodiments set forth in the drawings are illustrative and exemplary in nature and are not intended to limit the subject matter defined by the claims. The following detailed description of exemplary illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

fig. 1 schematically depicts an exploded view of an example illustrative artificial muscle, according to one or more embodiments shown and described herein;

fig. 2 schematically depicts a top view of the artificial muscle of fig. 1, according to one or more embodiments shown and described herein;

fig. 3 schematically depicts a cross-sectional view of the artificial muscle of fig. 1 in a non-actuated state, taken along line 3-3 in fig. 2, according to one or more embodiments shown and described herein;

fig. 4 schematically depicts the cross-sectional view of the artificial muscle of fig. 3 in an actuated state according to one or more embodiments shown and described herein;

fig. 5 schematically depicts a cross-sectional view of an example illustrative artificial muscle in a non-actuated state, according to one or more embodiments shown and described herein;

fig. 6 schematically depicts the cross-sectional view of the artificial muscle of fig. 5 in an actuated state according to one or more embodiments shown and described herein;

fig. 7 schematically depicts an artificial muscle assembly including a plurality of artificial muscles of fig. 1, according to one or more embodiments shown and described herein; and

fig. 8 schematically depicts an actuation system for operating the artificial muscle of fig. 1, according to one or more embodiments shown and described herein.

Detailed Description

Embodiments described herein relate to artificial muscles and artificial muscle assemblies including a plurality of artificial muscles. The artificial muscles described herein are actuatable to selectively raise and lower an area of the artificial muscle to provide a selective, on-demand distendable fluid region. The artificial muscle includes a housing and a pair of electrodes. A dielectric fluid is contained within the housing, and the housing contains an electrode region and an expandable fluid region, wherein the electrode pair is positioned in the electrode region. The electrode pair includes a first electrode fixed to a first surface of the housing and a second electrode fixed to a second surface of the housing. The electrode pair is actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region. This expands the expandable fluid region, thereby raising a portion of the artificial muscle as desired. Further, the first and second electrodes each include two or more tab portions and two or more bridging portions interconnecting adjacent tab portions, and at least one of the first and second electrodes includes a central opening positioned between the tab portions and surrounding the expandable fluid region. The design of the tab portion and the bridging portion of the electrode pair facilitates a zip-like connection actuation motion to increase the force per unit volume obtainable by actuation of the artificial muscle. Various embodiments of artificial muscles and the operation of artificial muscles are described in more detail herein. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Referring now to fig. 1 and 2, an artificial muscle 100 is shown. The artificial muscle 100 includes: a housing 102; an electrode pair 104 affixed to opposing surfaces of the housing 102, the electrode pair 104 comprising a first electrode 106 and a second electrode 108; a first electrical insulator layer 110 secured to the first electrode 106; and a second electrical insulator layer 112 secured to the second electrode 108. In certain embodiments, the housing 102 is a one-piece monolithic layer comprising a pair of opposing inner surfaces, such as a first inner surface 114 and a second inner surface 116, and a pair of opposing outer surfaces, such as a first outer surface 118 and a second outer surface 120. In certain embodiments, the first and second inner surfaces 114, 116 of the housing 102 are heat sealable. In other embodiments, the housing 102 may be a pair of separately manufactured film layers, such as a first film layer 122 and a second film layer 124. Thus, the first film layer 122 includes the first inner surface 114 and the first outer surface 118, and the second film layer 124 includes the second inner surface 116 and the second outer surface 120.

Throughout the following description, reference may be made to the housing 102 containing the first membrane layer 122 and the second membrane layer 124, as opposed to a unitary housing. It should be understood that any arrangement is contemplated. In certain embodiments, the first film layer 122 and the second film layer 124 generally comprise the same structure and composition. For example, in certain embodiments, the first film layer 122 and the second film layer 124 each comprise biaxially oriented polypropylene.

The first electrode 106 and the second electrode 108 are each positioned between the first membrane layer 122 and the second membrane layer 124. In certain embodiments, the first electrode 106 and the second electrode 108 are each aluminum-coated polyester, for example,in addition, one of the first electrode 106 and the second electrode 108 is a negatively charged electrode, and the other of the first electrode 106 and the second electrode 108 is a positively charged electrode. For purposes discussed herein, either of the first and second electrodes 106, 108 may be positively charged, so long as the other of the first and second electrodes 106, 108 of the artificial muscle 100 is negatively charged.

The first electrode 106 has a membrane facing surface 126 and an opposing inner surface 128. The first electrode 106 is positioned against the first membrane layer 122, specifically the first inner surface 114 of the first membrane layer 122. In addition, the first electrode 106 includes a first terminal 130, the first terminal 130 extending from the first electrode 106 beyond an edge of the first membrane layer 122 such that the first terminal 130 may be connected to a power source to actuate the first electrode 106. Specifically, as shown in fig. 8, the terminals are coupled directly or in series to the power source and the controller of the actuation system 400. Similarly, the second electrode 108 has a membrane-facing surface 148 and an opposing inner surface 150. The second electrode 108 is positioned against the second membrane layer 124, specifically the second inner surface 116 of the second membrane layer 124. The second electrode 108 includes a second terminal 152 that extends from the second electrode 108 beyond an edge of the second film layer 124 such that the second terminal 152 can be connected to a power source and a controller of the actuation system 400 to actuate the second electrode 108.

The first electrode 106 includes two or more tab portions 132 and two or more bridge portions 140. Each bridging portion 140 is positioned between adjacent tab portions 132, thereby interconnecting these adjacent tab portions 132. Each tab portion 132 has a first end 134 that extends radially with respect to the central axis C of the first electrode 106 to an opposite second end 136 of the tab portion 132, wherein the second end 136 defines a portion of an outer periphery 138 of the first electrode 106. Each bridge portion 140 has a first end 142 that extends radially with respect to the central axis C of the first electrode 106 to an opposite second end 144 of the bridge portion 140, thereby defining another portion of the outer periphery 138 of the first electrode 106. Each tab portion 132 has a tab length L1, and each bridge portion 140 has a bridge length L2 that extends in a radial direction relative to the central axis C of the first electrode 106. Tab length L1 is the distance from the first end 134 to the second end 136 of the tab portion 132 and the bridging length L2 is the distance from the first end 142 to the second end 144 of the bridging portion 140. The tab length L1 of each tab portion 132 is longer than the bridging length L2 of each bridging portion 140. In certain embodiments, the bridging length L2 is 20% to 50% of the tab length L1, such as 30% to 40% of the tab length L1.

In certain embodiments, two or more tab portions 132 are disposed in one or more pairs of tab portions 132. Each pair of tab portions 132 includes two tab portions 132 arranged diametrically opposite each other. In certain embodiments, the first electrode 106 may include only two tab portions 132 positioned on opposite sides or ends of the first electrode 106. In certain embodiments, as shown in fig. 1 and 2, the first electrode 106 includes four tab portions 132 and four bridge portions 140 interconnecting adjacent tab portions 132. In this embodiment, four tab portions 132 are arranged in two pairs of tab portions 132 diametrically opposite each other. Further, as shown, the first terminal 130 extends from the second end 136 of one of the tab portions 132 and is integrally formed with the second end 136.

Similar to the first electrode 106, the second electrode 108 includes at least a pair of tab portions 154 and two or more bridge portions 162. Each bridging portion 162 is positioned between adjacent tab portions 154, thereby interconnecting these adjacent tab portions 154. Each tab portion 154 has a first end 156 that extends radially with respect to the central axis C of the second electrode 108 to an opposite second end 158 of the tab portion 154, wherein the second end 158 defines a portion of an outer periphery 160 of the second electrode 108. Since the first electrode 106 and the second electrode 108 are coaxial with each other, the central axes C of the first electrode 106 and the second electrode 108 are the same. Each bridge portion 162 has a first end 164, which first end 164 extends radially with respect to the central axis C of the second electrode to an opposite second end 166 of the bridge portion 162, thereby defining another portion of the outer periphery 160 of the second electrode 108. Each tab portion 154 has a tab length L3 and each bridge portion 162 has a bridge length L4 that extends in a radial direction relative to the central axis C of the second electrode 108. Tab length L3 is the distance from first end 156 to second end 158 of tab portion 154 and bridge length L4 is the distance from first end 164 to second end 166 of bridge portion 162. The tab length L3 is longer than the bridging length L4 of each bridging portion 162. In certain embodiments, the bridging length L4 is 20% to 50% of the tab length L3, such as 30% to 40% of the tab length L3.

In certain embodiments, two or more tab portions 154 are disposed in one or more pairs of tab portions 154. Each pair of tab portions 154 includes two tab portions 154 arranged diametrically opposite each other. In certain embodiments, the second electrode 108 may include only two tab portions 154 positioned on opposite sides or ends of the first electrode 106. In certain embodiments, as shown in fig. 1 and 2, the second electrode 108 includes four tab portions 154 and four bridge portions 162 interconnecting adjacent tab portions 154. In this embodiment, four tab portions 154 are arranged in two pairs of tab portions 154 diametrically opposite each other. Further, as shown, second terminal 152 extends from second end 158 of one of tab portions 154 and is integrally formed with second end 158.

Referring now to fig. 1-6, at least one of the first electrode 106 and the second electrode 108 has a central opening formed therein between the first end 134 of the tab portion 132 and the first end 142 of the bridge portion 140. In fig. 3 and 4, the first electrode 106 has a central opening 146. However, it should be understood that when a central opening is provided within the second electrode 108, the first electrode 106 need not include the central opening 146, as shown in fig. 5 and 6. Alternatively, when the central opening 146 is provided within the first electrode 106, the second electrode 108 need not include a central opening. Still referring to fig. 1-6, first electrical insulator layer 110 and second electrical insulator layer 112 have geometries corresponding to first electrode 106 and second electrode 108, respectively. Thus, the first and second electrical insulator layers 110, 112 each have tab portions 170, 172 and bridge portions 174, 176 corresponding to similar portions on the first and second electrodes 106, 108. Further, first electrical insulator layer 110 and second electrical insulator layer 112 each have an outer perimeter 178, 180, which outer perimeters 178, 180 correspond to outer perimeter 138 of first electrode 106 and outer perimeter 160 of second electrode 108, respectively, when positioned on outer perimeter 138 of first electrode 106 and outer perimeter 160 of second electrode 108.

It should be understood that in certain embodiments, first electrical insulator layer 110 and second electrical insulator layer 112 generally comprise the same structure and composition. As such, in certain embodiments, the first electrical insulator layer 110 and the second electrical insulator layer 112 each comprise an adhesive surface 182, 184 and an opposing non-sealable surface 186, 188, respectively. Thus, in certain embodiments, the first electrical insulator layer 110 and the second electrical insulator layer 112 are each polymeric ribbons adhered to the inner surface 128 of the first electrode 106 and the inner surface 150 of the second electrode 108, respectively.

Referring now to fig. 2-6, artificial muscle 100 is shown in an assembled form, wherein first terminal 130 of first electrode 106 and second terminal 152 of second electrode 108 extend beyond the outer perimeter of housing 102, i.e., first membrane 122 and second membrane 124. As shown in fig. 2, the second electrode 108 is stacked on top of the first electrode 106, and thus, the first electrode 106, the first membrane layer 122, and the second membrane layer 124 are not shown. In its assembled form, first electrode 106, second electrode 108, first electrical insulator layer 110, and second electrical insulator layer 112 are sandwiched between first membrane layer 122 and second membrane layer 124. First film layer 122 is partially sealed to second film layer 124 at a region around outer perimeter 138 of first electrode 106 and outer perimeter 160 of second electrode 108. In certain embodiments, the first film layer 122 is heat sealed to the second film layer 124. Specifically, in certain embodiments, the first film layer 122 is sealed to the second film layer 124 to define a sealed portion 190 that surrounds the first electrode 106 and the second electrode 108. The first film layer 122 and the second film layer 124 may be sealed in any suitable manner, such as using an adhesive, heat sealing, or the like.

The first electrode 106, the second electrode 108, the first electrical insulator layer 110, and the second electrical insulator layer 112 provide a barrier that prevents the first membrane layer 122 from sealing to the second membrane layer 124, thereby forming the unsealed portion 192. Unsealed portion 192 of housing 102 includes an electrode region 194 in which electrode pair 104 is disposed and an expandable fluid region 196 surrounded by electrode region 194. The central openings 146, 168 of the first and second electrodes 106, 108 form an expandable fluid region 196 and are arranged to be axially stacked on top of each other. Although not shown, the housing 102 may be cut to conform to the geometry of the electrode pair 104 and to reduce the size of the artificial muscle 100, i.e., the size of the sealing portion 190.

A dielectric fluid 198 is provided within the unsealed portion 192 and flows freely between the first electrode 106 and the second electrode 108. As used herein, a "dielectric" fluid is a medium or material that: the medium or material transfers the electromotive force without conduction and because of this has a low electrical conductivity. Some non-limiting exemplary dielectric fluids include perfluorohydrocarbons, transformer oil, and deionized water. It should be understood that dielectric fluid 198 may be injected into unsealed portion 192 of artificial muscle 100 using a needle or other suitable injection device.

Referring now to fig. 3 and 4, the artificial muscle 100 is actuatable between an unactuated state and an actuated state. In the non-actuated state, as shown in fig. 3, the first and second electrodes 106, 108 are partially spaced from one another proximate their central openings 146, 168 and the first ends 134, 156 of the tab portions 132, 154. Since the housing 102 is sealed at the outer periphery 138 of the first electrode 106 and the outer periphery 160 of the second electrode 108, the second ends 136, 158 of the tab portions 132, 154 are held in position relative to each other. In the actuated state, as shown in fig. 4, first electrode 106 and second electrode 108 are in contact with each other and oriented parallel to each other to force dielectric fluid 198 into expandable fluid region 196. This causes dielectric fluid 198 to flow through central openings 146, 168 of first electrode 106 and second electrode 108 and expand expandable fluid region 196.

Referring now to fig. 3, the artificial muscle 100 is shown in a non-actuated state. The electrode pair 104 is disposed within an electrode region 194 of the unsealed portion 192 of the housing 102. Central opening 146 of first electrode 106 and central opening 168 of second electrode 108 are coaxially aligned within expandable fluid region 196. In the non-actuated state, the first electrode 106 and the second electrode 108 are partially spaced from each other and are non-parallel to each other. Since the first membrane layer 122 is sealed to the second membrane layer 124 around the electrode pair 104, the second ends 136, 158 of the tab portions 132, 154 contact each other. Accordingly, dielectric fluid 198 is provided between first electrode 106 and second electrode 108, thereby separating first ends 134, 156 of tab portions 132, 154 proximate expandable fluid region 196. In other words, the distance between the first end 134 of the tab portion 132 of the first electrode 106 and the first end 156 of the tab portion 154 of the second electrode 108 is greater than the distance between the second end 136 of the tab portion 132 of the first electrode 106 and the second end 158 of the tab portion 154 of the second electrode 108. This causes the electrode pairs 104 to zip toward the expandable fluid region 196 when actuated. In certain embodiments, the first electrode 106 and the second electrode 108 may be flexible. Thus, as shown in fig. 3, the first and second electrodes 106, 108 are convex so that the second ends 136, 158 of their tab portions 132, 154 may be held close to each other, but spaced apart from each other proximate the central openings 146, 168. In the unactuated state, expandable fluid region 196 has a first height H1.

When actuated, as shown in fig. 4, the first and second electrodes 106, 108 are zippered toward one another from the second ends 144, 158 of their tab portions 132, 154, thereby pushing the dielectric fluid 198 into the expandable fluid region 196. As shown, the first electrode 106 and the second electrode 108 are parallel to each other when in the actuated state. In the actuated state, dielectric fluid 198 flows into expandable fluid region 196 to expand expandable fluid region 196. As such, the first film layer 122 and the second film layer 124 expand in opposite directions. In the actuated state, expandable fluid region 196 has a second height H2, which second height H2 is greater than a first height H1 of expandable fluid region 196 when in the non-actuated state. Although not shown, it should be noted that the electrode pair 104 may be partially actuated to a position between the non-actuated state and the actuated state. This will allow the portion of expandable fluid region 196 to expand and allow adjustments to be made as necessary.

To move the first electrode 106 and the second electrode 108 towards each other, a voltage is applied by a power supply. In certain embodiments, a voltage of up to 10kV may be provided from a power supply to induce an electric field through the dielectric fluid 198. The resulting attractive force between first electrode 106 and second electrode 108 pushes dielectric fluid 198 into expandable fluid region 196. Pressure from dielectric fluid 198 within expandable fluid region 196 causes first membrane layer 122 and first electrical insulator layer 110 to deform in a first axial direction along central axis C of first electrode 106 and second membrane layer 124 and second electrical insulator layer 112 to deform in an opposite second axial direction along central axis C of second electrode 108. Once the voltage supply to the first and second electrodes 106, 108 is stopped, the first and second electrodes 106, 108 return to their original non-parallel positions in the non-actuated state.

It will be appreciated that the embodiments of the invention disclosed herein, and in particular the tab portions 132, 154 with the interconnecting bridge portions 174, 176, provide a number of improvements to actuators that do not include the tab portions 132, 154, such as HASEL actuators. In comparison to known HASEL actuators that include doughnut-shaped electrodes having uniform radially extending widths, embodiments of the artificial muscle 100 that include two pairs of tab portions 132, 154 on each of the first and second electrodes 106, 108, respectively, reduce the overall mass and thickness of the artificial muscle 100, reduce the amount of voltage required during actuation, and reduce the overall volume of the artificial muscle 100 without reducing the magnitude of the resultant force after actuation. More particularly, the tab portions 132, 154 of the artificial muscle 100 provide a zippered front that increases actuation power by providing localized and uniform hydraulic actuation of the artificial muscle 100 as compared to a HASEL actuator containing a doughnut-shaped electrode. Specifically, in comparison to a doughnut-shaped HASEL actuator, one pair of tab portions 132, 154 provides twice the amount of actuator power per unit volume as compared to a doughnut-shaped HASEL actuator, while two pairs of tab portions 132, 154 provide four times the amount of actuator power per unit volume as compared to a doughnut-shaped HASEL actuator. The bridge portions 174, 176 interconnecting the tab portions 132, 154 also limit buckling of the tab portions 132, 154 by maintaining a distance between adjacent tab portions 132, 154 during actuation. Since the bridge portions 174, 176 are integrally formed with the tab portions 132, 154, the bridge portions 174, 176 also prevent leakage between the tab portions 132, 154 by eliminating attachment locations that provide an increased risk of breakage.

In operation, when artificial muscle 100 is actuated, the expansion of expandable fluid region 196 results in a volume per cubic centimeter (cm)³) The actuator volume is 3 newton-millimeters (n.mm) or more force, such as 4n.mm or more per cubic centimeter, 5n.mm or more per cubic centimeter, 6n.mm or more per cubic centimeter, 7n.mm or more per cubic centimeter, 8n.mm or more per cubic centimeter, or the like. In one example, when the artificial muscle 100 is actuated by a voltage of 9.5 kilovolts (kV), the artificial muscle 100 provides a resultant force of 5N. In another example, when the artificial muscle 100 is actuated by a voltage of 10kV, the artificial muscle 100 provides a strain of 440% under a load of 500 grams.

Furthermore, the size of the first electrode 106 and the second electrode 108 is proportional to the amount of displacement of the dielectric fluid 198. Thus, when greater displacement within expandable fluid region 196 is desired, the size of electrode pair 104 is increased relative to the size of expandable fluid region 196. It should be appreciated that the size of expandable fluid region 196 is defined by central openings 146, 168 in first electrode 106 and second electrode 108. Accordingly, the degree of displacement within expandable fluid region 196 may alternatively or additionally be controlled by increasing or decreasing the size of central openings 146, 168.

As shown in fig. 5 and 6, another embodiment of an artificial muscle 200 is shown. Artificial muscle 200 is substantially similar to artificial muscle 100. Thus, like structures are denoted by like reference numerals. However, as shown, the first electrode 106 does not include a central opening. Thus, only the second electrode 108 includes the central opening 168 formed therein. As shown in fig. 5, the artificial muscle 200 is in a non-actuated state, in which the first electrode 106 is flat and the second electrode 108 is convex with respect to the first electrode 106. In the unactuated state, expandable fluid region 196 has a first height H3. In the actuated state, as shown in fig. 6, expandable fluid region 196 has a second height H4, which is second height H4 is greater than first height H3. It should be appreciated that by providing a central opening 168 in only second electrode 108, as opposed to providing a central opening on both first electrode 106 and second electrode 108, the total deformation may be formed on one side of artificial muscle 200. In addition, since the total deformation is formed on only one side of artificial muscle 200, second height H4 of expandable fluid region 196 of artificial muscle 200 extends further from the longitudinal axis perpendicular to central axis C of artificial muscle 200 than second height H2 of expandable fluid region 196 of artificial muscle 100 when all other dimensions, orientations, and volumes of dielectric fluid are the same.

Referring now to fig. 7, an artificial muscle assembly 300 comprising a plurality of artificial muscles, such as artificial muscle 100, is shown. However, it should be understood that a plurality of artificial muscles 200 may similarly be arranged in a stacked fashion. Each artificial muscle 100 may be structurally identical and arranged in a stack such that inflatable fluid region 196 of each artificial muscle 100 is superposed on inflatable fluid region 196 of an adjacent artificial muscle 100. The terminals 130, 152 of each artificial muscle 100 are electrically connected to each other so that the artificial muscle 100 can be actuated simultaneously between the non-actuated state and the actuated state. By arranging artificial muscles 100 in a stacked configuration, the total deformation of artificial muscle assembly 300 is the sum of the deformations within expandable fluid region 196 of each artificial muscle 100. As such, the degree of deformation caused by artificial muscle assembly 300 is greater than the degree of deformation provided by artificial muscle 100 alone.

Referring now to fig. 8, an actuation system 400 may be provided for operating an artificial muscle or artificial muscle assembly, such as artificial muscles 100, 200 or artificial muscle assembly 300, between a non-actuated state and an actuated state. Accordingly, actuation system 400 may include a controller 402, an operating device 404, a power source 406, and a communication path 408. The various components of the actuation system 400 will now be described.

The controller 402 includes a processor 410 and non-transitory electronic storage 412 communicatively coupled to various components. In certain embodiments, processor 410 and non-transitory electronic memory 412 and/or other means are contained within a single device. In other embodiments, the processor 410 and non-transitory electronic storage 412 and/or other components may be distributed among a plurality of devices communicatively coupled. The controller 402 includes non-transitory electronic memory 412 that stores a set of machine-readable instructions. The processor 410 executes machine-readable instructions stored in the non-transitory electronic memory 412. The non-transitory electronic storage 412 may include RAM, ROM, flash memory, a hard drive, or any device capable of storing machine-readable instructions such that the machine-readable instructions may be accessed by the processor 410. Accordingly, the actuation system 400 described herein may be implemented as pre-programmed hardware elements or as a combination of hardware and software components in any conventional computer programming language. The non-transitory electronic storage 412 may be implemented as one memory module or multiple memory modules.

In certain embodiments, the non-transitory electronic storage 412 contains instructions for performing the functions of the actuation system 400. For example, the instructions may comprise instructions for operating the artificial muscle 100, 200 or artificial muscle component 300 based on user commands.

Processor 410 may be any device capable of executing machine-readable instructions. For example, the processor 410 may be an integrated circuit, a microchip, a computer, or any other computing device. Non-transitory electronic storage 412 and processor 410 are coupled to communication path 408, which communication path 408 provides signal interconnectivity between the various components and/or modules of actuation system 400. Thus, the communication path 408 may communicatively couple any number of processors to one another and allow the modules coupled to the communication path 408 to run in a distributed computing environment. In particular, each module may operate as a node that may send and/or receive data. As used herein, the term "communicatively coupled" means that the coupled components are capable of exchanging data signals with each other, e.g., electrical signals via a conductive medium, electromagnetic signals via air, optical signals via an optical waveguide, and the like.

As schematically depicted in fig. 8, communication path 408 communicatively couples processor 410 and non-transitory electronic storage 412 of controller 402 with various other components of actuation system 400. For example, the actuation system 400 depicted in fig. 8 includes a processor 410 and non-transitory electronic storage 412 communicatively coupled with the operating device 404 and the power source 406.

The operation device 404 allows a user to control the operation of the artificial muscle 100, 200 or the artificial muscle assembly 300. In some embodiments, the operating device 404 may be a switch, trigger, button, or any combination of controls to provide user operation. As a non-limiting example, the user may actuate the artificial muscle 100, 200 or artificial muscle assembly 300 into the actuated state by actuating the control of the operating device 404 into the first position. When in the first position, the artificial muscle 100, 200 or artificial muscle assembly 300 will remain in the actuated state. The user can switch the artificial muscle 100, 200 or the artificial muscle assembly 300 into the non-activated state by operating the control of the operating means 404 from the first position into the second position.

Operating device 404 is coupled to communication path 408 such that communication path 408 communicatively couples operating device 404 to the other modules of actuation system 400. The operation device 404 may provide a user interface for receiving user instructions regarding a particular operational configuration of the artificial muscle 100, 200 or artificial muscle assembly 300. In addition, the user instructions may comprise instructions to operate the artificial muscle 100, 200 or the artificial muscle assembly 300 only under certain conditions.

A power source 406 (e.g., a battery) powers the artificial muscle 100, 200 or the artificial muscle component 300. In certain embodiments, the power source 406 is a rechargeable dc power source. It should be understood that the power source 406 may be a single power source or battery for powering the artificial muscle 100, 200 or artificial muscle assembly 300. A power adapter (not shown) may be provided and electrically coupled via a harness or the like to power the artificial muscle 100, 200 or artificial muscle assembly 300 by means of the power source 406.

In certain embodiments, the actuation system 400 also includes a display device 414. Display device 414 is coupled to communication path 408 such that communication path 408 communicatively couples display device 414 to the other modules of actuation system 400. The display device 414 may output a notification or indicate a change in the actuation state of the artificial muscle 100, 200 or artificial muscle assembly 300 in response to the actuation state of the artificial muscle 100, 200 or artificial muscle assembly 300. Moreover, display device 414 may be a touch screen that, in addition to providing optical information, detects the presence and location of tactile input on the surface of display device 414 or on a surface adjacent to display device 414. Thus, the display device 414 may contain the operation device 404 and receive mechanical input directly on the optical output provided by the display device 414.

In certain embodiments, the actuation system 400 includes network interface hardware 416 for communicatively coupling the actuation system 400 to a portable device 418 via a network 420. The portable device 418 may include, but is not limited to, a smart phone, a tablet computer, a personal media player, or any other electrical device that includes wireless communication functionality. It should be understood that when a portable device 418 is provided, the portable device 418 may be used to provide user commands to the controller 402 rather than to the operating device 404. In this way, the user may be able to control or set a program for controlling the artificial muscle 100, 200 or artificial muscle assembly 300 without using the controller of the operating device 404. Thus, the artificial muscle 100, 200 or artificial muscle assembly 300 may be remotely controlled via a portable device 418 that is in wireless communication with the controller 402 by means of a network 420.

From the foregoing, it will be appreciated that what is defined herein is an artificial muscle that swells or deforms the surface of an object by selectively actuating the artificial muscle to raise or lower an area thereof. This provides a low profile, expandable member that can be manipulated as desired.

It should be noted that the terms "about" and "approximately" may be used herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also used herein to denote the extent to which: quantitative representation may vary from the stated reference by degree without resulting in a change in the basic function of the subject matter at issue.

Although specific embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, these aspects need not be used in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.