Artificial muscle having vacuum-coupled electrode insulator and method for manufacturing the same

Abstract

To provide a manufacturing method for an electrode assembly.SOLUTION: The present method for manufacturing an electrode assembly comprises: arranging in a vacuum bag a layer stack comprising an electrode positioned between an electrode insulator and a supporting polymer; removing air from the vacuum bag to vacuum-bond the electrode to the electrode insulator; and removing the layer stack from the vacuum bag. The removal of the layer stack from the vacuum bag leaves the electrode vacuum-bonded to the electrode insulator, and the electrode insulator directly contacts the electrode, thereby forming an electrode assembly.SELECTED DRAWING: Figure 5A

Description

Technical Field

[0001] The present invention generally relates to artificial muscles, and particularly to an artificial muscle having vacuum coupled electrode insulators.

Background Art

[0002] Current robotic technology relies on rigid components such as servo motors that perform tasks, which are commonly found in structured environments. This rigidity creates constraints 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 robotics addresses the aforementioned constraints 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-based actuators. For example, certain types of artificial muscles can introduce and discharge a certain volume of fluid to expand / contract the artificial muscle, so as to perform mechanical work against a load. However, since these artificial muscles rely on heat sealing and adhesives, they have several material restrictions.

[0003] Therefore, there is a need for a method of manufacturing an artificial muscle that facilitates the use of materials for which heat sealing is difficult.

Summary of the Invention

[0004] In one embodiment, a method of manufacturing an electrode assembly includes placing a layer stack including an electrode disposed between an electrode insulator and a support polymer into a vacuum bag, vacuum coupling the electrode to the electrode insulator by removing air from the vacuum bag, and removing the layer stack from the vacuum bag. When the layer stack is removed from the vacuum bag, the electrode remains vacuum coupled to the electrode insulator, and the electrode insulator is in direct contact with the electrode, thereby forming the electrode assembly.

[0005] In another embodiment, a method for manufacturing an artificial muscle includes forming a first electrode assembly and a second electrode assembly. Forming each electrode assembly includes placing a layer stack containing electrodes positioned between an electrode insulator and a support polymer in a vacuum bag, vacuum coupling the electrodes to the electrode insulator by removing air from the vacuum bag, and removing the layer stack from the vacuum bag, wherein upon removal of the layer stack from the vacuum bag, the electrodes remain vacuum coupled to the electrode insulator, and the electrode insulator is in direct contact with the electrodes, thereby forming the electrode assembly. The method further includes arranging the first electrode assembly and the second electrode assembly in a laminated configuration between a first film layer and a second film layer, and sealing the first film layer to the second film layer, thereby forming an artificial muscle containing the first electrode assembly and the second electrode assembly housed in a housing formed from the first film layer and the second film layer.

[0006] In yet another embodiment, the artificial muscle includes a housing having an electrode region and an expandable fluid region. A dielectric fluid is contained within the housing. An electrode pair is positioned within the electrode region of the housing, and the electrode pair includes a first electrode and a second electrode. An electrode insulator is vacuum-coupled to the first electrode in direct contact with the first electrode. The electrode insulator comprises a high dielectric constant polymer, and the electrode pair is operable between a non-operating state and an operating state, and the operation from the non-operating state to the operating state guides the dielectric fluid into the expandable fluid region, which expands.

[0007] The above and additional features provided by the embodiments described herein will be further understood by reading the following detailed description with reference to the drawings. [Brief explanation of the drawing]

[0008] The embodiments shown in the drawings are essentially illustrative and not intended to limit the subject matter defined by the claims. The following detailed description of preferred embodiments can be understood by reading in conjunction with the following drawings, in which similar structures are indicated by the same reference numerals.

[0009] [Figure 1] This is a schematic exploded view of an exemplary artificial muscle formed by a vacuum coupling process according to one or more embodiments illustrated and described herein. [Figure 2] This is a schematic top view of the artificial muscle shown in Figure 1, according to an embodiment illustrated and described herein. [Figure 3] This is a schematic cross-sectional view of the artificial muscle of Figure 1 in a non-operating state, along line 3-3 in Figure 2, according to one or more embodiments illustrated and described herein. [Figure 4] This is a schematic cross-sectional view of the artificial muscle of Figure 1 in operation, along line 3-3 in Figure 2, according to one or more embodiments illustrated and described herein. [Figure 5A] This is a schematic cross-sectional view of a layer stack placed in a vacuum bag, including a first electrode positioned between a first electrode insulator and a first support polymer, according to one or more embodiments illustrated and described herein. [Figure 5B] This is a schematic cross-sectional view of a second layer stack placed in a vacuum bag, including a second electrode positioned between a second electrode insulator and a second support polymer, according to one or more embodiments illustrated and described herein. [Figure 6] This is a schematic diagram of the first layer stack of Figure 5A arranged in a vacuum bag according to one or more embodiments illustrated and described herein. [Figure 7] These are schematic diagrams of the first layer stack of Figures 5A and 6, which undergo a heat sealing process according to one or more embodiments illustrated and described herein. [Figure 8]These are schematic diagrams of a first electrode assembly and a second electrode assembly formed using the process shown in Figures 5A to 57, according to one or more embodiments illustrated and described herein. [Figure 9] This is a schematic cross-sectional view of a first electrode assembly and a second electrode assembly disposed between a first film layer and a second film layer according to one or more embodiments illustrated and described herein. [Figure 10] This is a schematic cross-sectional view of another exemplary artificial muscle in a non-operating state, according to one or more embodiments illustrated and described herein. [Figure 11] This is a schematic cross-sectional view of the artificial muscle shown in Figure 11 in an operating state, according to one or more embodiments illustrated and described herein. [Figure 12] This is a schematic exploded view of another exemplary artificial muscle according to one or more embodiments illustrated and described herein. [Figure 13] This is a schematic top view of the artificial muscle shown in Figure 12, according to one or more embodiments illustrated and described herein. [Figure 14] This is a schematic top view of another artificial muscle according to one or more embodiments illustrated and described herein. [Figure 15] This is a schematic diagram of an actuation system for operating an artificial muscle according to one or more embodiments illustrated and described herein. [Modes for carrying out the invention]

[0010] The embodiments described herein relate to artificial muscles and methods for manufacturing artificial muscles. The methods for manufacturing artificial muscles described herein include a vacuum sealing step, which facilitates the use of certain high-performance electrode insulators that cannot be effectively heat-sealed. In the field of dielectric elastomer actuators, although not limited by theory, increasing the dielectric constant of an electrically insulating polymer (e.g., the electrode insulator of the artificial muscle described herein) improves the performance of the actuator. However, high dielectric constant polymers such as polyvinylidene fluoride (PVDF) cannot be effectively heat-sealed to electrodes. An adhesive layer may be placed between the high dielectric constant polymer and the electrode, but the introduction of adhesive complicates the series capacitance. Therefore, forming an artificial muscle in which the electrode insulator is vacuum-coupled to the electrode facilitates the use of high dielectric constant polymers and increases the performance of the artificial muscle. Various embodiments of artificial muscles and methods for manufacturing artificial muscles are described in detail herein. Wherever possible, the same reference numerals are used throughout all drawings to refer to the same or similar parts.

[0011] Figures 1-4 show an artificial muscle 101 that can be formed using the manufacturing method shown in Figures 5A-9. In particular, the artificial muscle 101 shown in Figures 1-4 includes a housing 110 having an electrode region 194 and an expandable fluid region 196. An electrode pair 104, including a first electrode 106 and a second electrode 108, is positioned within the electrode region 194 of the housing 110, and a dielectric fluid 198 is contained within the housing 110. During operation, the electrode pair 104 is operable between a non-operating state and an operating state, and the operation from the non-operating state to the operating state guides the dielectric fluid 198 into the expandable fluid region 196, causing the expandable fluid region 196 to expand, thereby enabling the expandable fluid region 196 to provide an operating force. Furthermore, the artificial muscle 101 includes a first electrode insulator 111 that is electrically coupled to the first electrode 106 in direct contact with the first electrode 106, and a second electrode insulator 112 that is vacuum-coupled to the second electrode 108 in direct contact with the second electrode 108. However, it should be understood that an embodiment having a first electrode insulator 111 without a second electrode insulator 112 is intended. As will be described in detail below, with respect to Figures 5A to 59, by vacuum-coupling the first electrode insulator 111 to the first electrode 106 and vacuum-coupling the second electrode insulator 112 to the second electrode 108, it becomes possible to use a highly dielectric polymer material such as PDVF as an electrode insulator. Although these highly dielectric polymer materials cannot be heat-sealed, they can improve the operating performance of the artificial muscle.

[0012] Referring to Figures 1 and 2, the artificial muscle 101 includes a housing 110, an electrode pair 104 comprising a first electrode 106 and a second electrode 108 coupled to opposing surfaces of the housing 110, a first electrode insulator 111 fixed to the first electrode 106, and a second electrode insulator 112 fixed to the second electrode 108. In particular, the first electrode insulator 111 is vacuum-coupled to the first electrode 106 in direct contact with the first electrode 106, and the second electrode insulator 112 is vacuum-coupled to the second electrode 108 in direct contact with the second electrode 108. In some embodiments, the housing 110 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 another embodiment, the housing 110 may consist of a pair of individually manufactured film layers, such as a first film layer 122 and a second film layer 124. Thus, the first film layer 122 includes a first inner surface 114 and a first outer surface 118, and the second film layer 124 includes a second inner surface 116 and a second outer surface 120. The first inner surface 114 and the second inner surface 116 of the housing 110 are heat-sealable.

[0013] As shown in Figure 1, the artificial muscle 101 may further include a first support polymer 103 positioned between a first electrode 106 and a first inner surface 114 of the housing 110, and a second support polymer 105 positioned between a second electrode 108 and a second inner surface 116 of the housing 110. As described herein, the first and second support polymers 103, 105 assist in a vacuum bonding process that enables the use of high dielectric polymers as the first and second electrode insulators 111, 112. In some embodiments, the first support polymer 103 and the second support polymer 105 have substantially the same structure and composition. For example, in some embodiments, the first support polymer 103 and the second support polymer 105 each include biaxially oriented polypropylene (BOPP).

[0014] The embodiments described in the present specification basically describe housing 110 as including a first film layer 122 and a second film layer 124, as opposed to a one-piece housing, but it should be understood that any configuration is contemplated. In some embodiments, the first film layer 122 and the second film layer 124 generally comprise the same structure and composition. For example, in some embodiments, the first film layer 122 and the second film layer 124 each comprise BOPP.

[0015] The first electrode 106 and the second electrode 108 are each disposed between the first film layer 122 and the second film layer 124. In some embodiments, the first electrode 106 and the second electrode 108 are each aluminum-coated polyester such as, for example, Mylar® (biaxially oriented polyethylene terephthalate (BoPET)). However, it should be understood that the first electrode 106 and the second electrode 108 may also include an electrically conductive material such as copper, silver, titanium, platinum or the like, which can be coated with polyester such as Mylar®. The first electrode 106 and the second electrode 108 may include a flexible material or an inflexible material (e.g., a rigid material), and in some embodiments, may include a stretchable material. Furthermore, embodiments are contemplated in which the first electrode 106 and the second electrode 108 include a hydrogel material. Also, 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 the purposes described herein, either electrode 106, 108 may be positively charged as long as the other electrode 106, 108 of the artificial muscle 101 is negatively charged.

[0016] The first electrode 106 has a surface 126 facing the film, and an inner surface 128 on the opposite side. The first electrode 106 is disposed proximate to the first film layer 122, specifically the first inner surface 114 of the first film layer 122. That is, the first electrode 106 may be in contact with the first inner surface 114 of the first film layer 122, or may be in contact with the first support polymer 103 disposed between the first electrode 106 and the first inner surface 114 of the first film layer 122. Further, the first electrode 106 includes a first terminal 130 extending from the first electrode 106 beyond the edge of the first film layer 122, and the first terminal 130 can be connected to a power source to activate the first electrode 106. Specifically, the terminal is coupled to the power source and controller of the actuation system 400, either directly or in series, as shown in Figure 15. Similarly, the second electrode 108 has a surface 148 facing the film, and an inner surface 150 on the opposite side. The second electrode 108 is disposed proximate to the second film layer 124, specifically the second inner surface 116 of the second film layer 124. That is, the second electrode 108 may be in contact with the second inner surface 116 of the second film layer 124, or may be in contact with the second support polymer 105 disposed between the second electrode 108 and the second inner surface 116 of the second film layer 124. The second electrode 108 includes a second terminal 152 extending from the second electrode 108 beyond the edge of the second film layer 124, and the second terminal 152 can be connected to the power source and controller of the actuation system 400 to activate the second electrode 108.

[0017] The first electrode 106 includes two or more tab portions 132 and two or more bridge portions 140. Each bridge portion 140 is positioned between adjacent tab portions 132 and interconnects these adjacent tab portions 132. Each tab portion 132 has a first end 134 that extends radially from the central axis C of the first electrode 106 to a second end 136 on the opposite side of the tab portion 132, the second end 136 defining a portion of the outer circumference 138 of the first electrode 106. Each bridge portion 140 has a first end 142 that extends radially from the central axis C of the first electrode 106 to a second end 144 on the opposite side of the bridge portion 140, defining another portion of the outer circumference 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 radially from the central axis C of the first electrode 106. The tab length L1 is the distance from the first end 134 to the second end 136 of the tab portion 132, and the bridge length L2 is the distance from the first end 142 to the second end 144 of the bridge portion 140. The tab length L1 of each tab portion 132 is longer than the bridge length L2 of each bridge portion 140. In some embodiments, the bridge length L2 is 20% to 50% of the tab length L1, for example, 30% to 40% of the tab length L1.

[0018] In some embodiments, two or more tab portions 132 are arranged as one or more pairs of tab portions 132. Each pair of tab portions 132 includes two tab portions 132 arranged on opposite sides in the diametrical direction. In some embodiments, the first electrode 106 may include only two tab portions 132 arranged on opposite sides or ends of the first electrode 106. In some embodiments, as shown in Figure 7, the first electrode 106 includes four tab portions 132 and four bridge portions 140 interconnecting adjacent tab portions 132. In this embodiment, the four tab portions 132 are arranged as two pairs of tab portions 132 arranged on opposite sides in the diametrical direction. Furthermore, as shown, the first terminal 130 is formed integrally with the second end 136, extending from one of the second ends 136 of the tab portion 132.

[0019] Similar to the first electrode 106, the second electrode 108 includes at least one pair of tab portions 154 and two or more bridge portions 162. Each bridge portion 162 is positioned between adjacent tab portions 154 and interconnects these adjacent tab portions 154. Each tab portion 154 has a first end 156 that extends radially from the central axis C of the second electrode 108 to a second end 158 on the opposite side of the tab portion 154, the second end 158 defining a portion of the outer circumference 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 identical. Each bridge portion 162 has a first end 164 that extends radially from the central axis C of the second electrode to a second end 166 on the opposite side of the bridge portion 162, defining another portion of the outer circumference 160 of the second electrode. Each tab portion 154 has a tab length L3, and each bridge portion 162 has a bridge length L4 that extends radially from the central axis C of the second electrode 108. The tab length L3 is the distance from the first end 156 to the second end 158 of the tab portion 154, and the bridge length L4 is the distance from the first end 164 to the second end 166 of the bridge portion 162. The tab length L3 is longer than the bridge length L4 of each bridge portion 162. In some embodiments, the bridge length L4 is 20% to 50% of the tab length L3, for example, 30% to 40% of the tab length L3.

[0020] In some embodiments, two or more tab portions 154 are arranged as one or more pairs of tab portions 154. Each pair of tab portions 154 includes two tab portions 154 arranged on opposite sides in the diametrical direction. In some embodiments, the second electrode 108 may include only two tab portions 154 arranged on opposite sides or ends of the first electrode 106. In some embodiments, as shown in Figures 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, the four tab portions 154 are arranged as two pairs of tab portions 154 arranged on opposite sides in the diametrical direction. Furthermore, as shown, the second terminal 152 is formed integrally with the second end 158, extending from one of the second end 158s of the tab portion 154.

[0021] Referring to Figures 1-4, at least one of the first electrode 106 and the second electrode 108 has a central opening formed between the first end 134 of the tab portion 132 and the first end 142 of the bridge portion 140. In Figures 3 and 4, the first electrode 106 has a central opening 146. However, it should be understood that the first electrode 106 does not need to include the central opening 146 if the central opening is provided within the second electrode 108, as shown in Figures 10 and 11. Alternatively, the second electrode 108 does not need to include the central opening if the central opening 146 is provided within the first electrode 106. Furthermore, referring to Figures 1-4, the first electrode insulator 111 and the second electrode insulator 112 have geometric shapes that generally correspond to the first electrode 106 and the second electrode 108, respectively. Therefore, the first electrode insulator 111 and the second electrode insulator 112 each have tab portions 170, 172 and bridge portions 174, 176 corresponding to similar portions of the first electrode 106 and the second electrode 108. However, when placed on the first electrode 106 and the second electrode insulator 112, each has outer circumferences 178, 180 extending in the shorter direction beyond the outer circumference 138 of the first electrode 106 and the outer circumference 160 of the second electrode 108, respectively. This configuration facilitates bonding between the first electrode insulator 111 and the first support polymer 103, and between the second electrode insulator 112 and the second support polymer 105. However, it should be understood that in the embodiment where the first electrode insulator 111 and the second electrode insulator 112 are placed on the first electrode 106 and the second electrode 108, the outer circumferences 178 and 180 of the first electrode insulator 111 and the second electrode insulator 112 correspond to the outer circumference 138 of the first electrode 106 and the outer circumference 160 of the second electrode 108, respectively.

[0022] It should be understood that in some embodiments, the first electrode insulator 111 and the second electrode insulator 112 have substantially the same structure and composition. Therefore, in some embodiments, the first electrode insulator 111 and the second electrode insulator 112 each include first faces 182, 184 and opposite second faces 186, 188, respectively. In some embodiments, the first electrode insulator 111 and the second electrode insulator 112 are polymer materials vacuum-bonded to the inner surface 128 of the first electrode 106 and the inner surface 150 of the second electrode 108, respectively. For example, as detailed herein, the first electrode insulator 111 and the second electrode insulator 112 may include high dielectric constant polymers.

[0023] Next, referring to Figures 2-4, the artificial muscle 101 is shown assembled with the first terminal 130 of the first electrode 106 and the second terminal 152 of the second electrode 108 extending beyond the outer circumference of the housing 110, i.e., beyond the first film layer 122 and the second film layer 124. As shown in Figure 2, the second electrode 108 is laminated on the first electrode 106, so the first electrode 106 and the first film layer 122 are not shown. In the assembled form, the first electrode 106, the second electrode 108, the first electrode insulator 111, the second electrode insulator 112, the first support polymer 103, and the second support polymer 105 are sandwiched between the first film layer 122 and the second film layer 124. The first film layer 122 is partially sealed to the second film layer 124 in the region surrounding the outer periphery 138 of the first electrode 106 and the outer periphery 160 of the second electrode 108. In some embodiments, the first film layer 122 is heat-sealed to the second film layer 124. Specifically, in some embodiments, the first film layer 122 is sealed to the second film layer 124 to define a sealing portion 190 surrounding the first electrode 106 and the second electrode 108. The first film layer 122 and the second film layer 124 can be sealed by any preferred method, such as using an adhesive, heat seal, or the like.

[0024] The first electrode 106, the second electrode 108, the first electrode insulator 111, the second electrode insulator 112, the first support polymer 103, and the second support polymer 105 provide a barrier that prevents the first film layer 122 from sealing the second film layer 124, forming an unsealed portion 192. The sealed portion 190 surrounds the unsealed portion 192. The unsealed portion 192 of the housing 110 includes an electrode region 194 in which the electrode pair 104 is provided, and an expandable fluid region 196 surrounded by the electrode region 194. The central openings 146, 168 of the first electrode 106 and the second electrode 108 form the expandable fluid region 196 and are arranged to be stacked axially relative to each other. Although not shown, the housing 110 can be cut to fit the geometry of the electrode pair 104 to reduce the size of the artificial muscle 101, i.e., the size of the sealed portion 190.

[0025] 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 transmits power without conductivity and therefore has low electrical conductivity. Some non-limiting examples of dielectric fluids include perfluoroalkanes, transformer oil, and deionized water. It should be understood that the dielectric fluid 198 may be injected into the unsealed portion 192 of the artificial muscle 101 using a needle or other suitable injection device.

[0026] Referring next to Figures 3 and 4, the artificial muscle 101 is operable between a non-operating state and an operating state. In the non-operating state, as shown in Figure 9, the first electrode 106 and the second electrode 108 are partially separated from each other in proximity to the central openings 146, 168 of the first electrode 106 and the second electrode 108 and the first ends 134, 156 of the tab portions 132, 154. The second ends 136, 158 of the tab portions 132, 154 are in the same position relative to each other because the housing 110 is sealed to the outer circumference 138 of the first electrode 106 and the outer circumference 160 of the second electrode 108. In the operating state, as shown in Figure 10, the first electrode 106 and the second electrode 108 are in contact with each other and oriented parallel to each other, pushing the dielectric fluid 198 into an expandable fluid region 196. As a result, the dielectric fluid 198 flows through the central openings 146 and 168 of the first electrode 106 and the second electrode 108, causing the expandable fluid region 196 to expand.

[0027] Referring next to Figure 3, the artificial muscle 101 is shown in a non-operating state. The electrode pair 104 is located within the electrode region 194 of the unsealed portion 192 of the housing 110. The central opening 146 of the first electrode 106 and the central opening 168 of the second electrode 108 are coaxially aligned within the expandable fluid region 196. In the non-operating state, the first electrode 106 and the second electrode 108 are partially separated and non-parallel to each other. Because the first film layer 122 is sealed to the second film layer 124 around the electrode pair 104, the second ends 136, 158 of the tab portions 132, 154 are close to or in contact with each other. Thus, the dielectric fluid 198 is provided between the first electrode 106 and the second electrode 108, thereby separating the first ends 134, 156 of the tab portions 132, 154 in close proximity within the 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 pair 104 to zipper (close like a zipper) toward the expandable fluid region 196 when in operation. In some embodiments, the first electrode 106 and the second electrode 108 may be flexible. The first electrode 106 and the second electrode 108 may be convex such that the second ends 136 and 158 of the tab portions 132 and 154 of the first electrode 106 and the second electrode 108 remain close to each other, while they are spaced apart in proximity to the central openings 146 and 168. In the non-operating state, the expandable fluid region 196 has a first height H1.

[0028] During operation, as shown in Figure 4, the first electrode 106 and the second electrode 108 zip towards the second ends 144 and 158 of the tab portions 132 and 154 of the first electrode 106 and the second electrode 108, thereby pushing the dielectric fluid 198 into the expandable fluid region 196. As shown in the figure, in the operating state, the first electrode 106 and the second electrode 108 are parallel to each other. In the operating state, the dielectric fluid 198 flows into the expandable fluid region 196 and expands the expandable fluid region 196. Thus, the first film layer 122 and the second film layer 124 expand in opposite directions. In the operating state, the expandable fluid region 196 has a second height H2, which is greater than the first height H1 of the expandable fluid region 196 when it is in the non-operating state. Note that, although not shown, the electrode pair 104 is partially operable in a position between the non-operating and operating states. This allows the expandable fluid region 196 to be partially expanded and adjusted as needed.

[0029] A voltage is applied by a power source (such as power source 480 in Figure 15) to bring the first electrode 106 and the second electrode 108 closer together. In some embodiments, a voltage of up to 10 kV can be provided from the power source to induce an electric field through the dielectric fluid 198. The resulting attractive force between the first electrode 106 and the second electrode 108 causes the dielectric fluid 198 to flow into the expandable fluid region 196. The pressure from the dielectric fluid 198 within the expandable fluid region 196 causes the first film layer 122, the first support polymer 103, and the first electrode insulator 111 to deform in the first axial direction along the central axis C of the first electrode 106, and the second film layer 124, the second support polymer 105, and the second electrode insulator 112 to deform in the opposite second axial direction along the central axis C of the second electrode 108. When the voltage supplied to the first electrode 106 and the second electrode 108 is stopped, the first electrode 106 and the second electrode 108 return to their initial non-parallel positions in the non-operating state.

[0030] It should be understood that embodiments of the present invention of the artificial muscle 101 disclosed herein, specifically the tab portions 132, 154 comprising interconnecting bridge portions 174, 176, provide many improvements over actuators that do not include tab portions 132, 154, such as the hydraulically amplified self-healing electrostatic (HASEL) actuator described in the paper entitled "Hydraulically amplified self-healing electrostatic actuators with muscle-like performance" (Science 05 Jan 2018: Vol. 359, Issue 6371, pp. 61-65) by E. Acome, SK Mitchell, TG Morrissey, MB Emmett, C. Benjamin, M. King, M. Radakovitz, and C. Keplinger. Embodiments of the artificial muscle 101 including two pairs of tab portions 132, 154 above the first electrode 106 and the second electrode 108 respectively reduce the overall mass and thickness of the artificial muscle 101, reduce the amount of voltage required during operation, and reduce the total volume of the artificial muscle 101 without reducing the amount of force produced after operation compared to a well-known HASEL actuator including a donut-shaped electrode with a uniformly radially extending width. Specifically, the tab portions 132, 154 of the artificial muscle 101 provide a zip front that generates increased operating force by providing localized and uniform hydraulic operation of the artificial muscle 101 compared to a HASEL actuator including a donut-shaped electrode. Specifically, one pair of tab portions 132, 154 provides twice the actuator power per unit volume compared to a donut-shaped HASEL actuator, while two pairs of tab portions 132, 154 provide four times the actuator power per unit volume. The bridge sections 174 and 176, which interconnect the tab sections 132 and 154, limit buckling of the tab sections 132 and 154 by maintaining the distance between adjacent tab sections 132 and 154 during operation.Since the bridge portions 174 and 176 are integrally formed with the tab portions 132 and 154, the bridge portions 174 and 176 also prevent leakage between the tab portions 132 and 154 by eliminating mounting positions that increase the risk of breakage.

[0031] During operation, activating the artificial muscle 101 expands the expandable fluid region 196, resulting in a force of 3 Newton-millimeters (N.mm) or more per cubic centimeter of actuator volume, for example, 6 N.mm / cm². 3 More than 10N.mm / cm 3 Above, 15N.mm / cm 3 Above, 25N.mm / cm 3 More than 50N.mm / cm 3 More than 100N.mm / cm 3 A force of the above or similar magnitude is generated. In fact, although not limited by theory, increasing the dielectric constant of the first electrode insulator 111 and the second electrode insulator 112 increases the achievable working force of the artificial muscle 101 accordingly. That is, the dielectric constants of the first electrode insulator 111 and the second electrode insulator 112 have a linear relationship with the achievable working force of the artificial muscle 101, such that doubling the dielectric constants of the first electrode insulator 111 and the second electrode insulator 112 doubles the achievable working force of the artificial muscle 101.

[0032] Furthermore, the sizes of the first electrode 106 and the second electrode 108 are proportional to the displacement of the dielectric fluid 198. Therefore, if a larger displacement within the expandable fluid region 196 is desired, the size of the electrode pair 104 is increased relative to the size of the expandable fluid region 196. It should be understood that the size of the expandable fluid region 196 is defined by the central openings 146 and 168 of the first electrode 106 and the second electrode 108. Therefore, it should be understood that the degree of displacement within the expandable fluid region 196 can be controlled alternatively or additionally by increasing or decreasing the size of the central openings 146 and 168.

[0033] Next, with reference to Figures 5A-59, a method for manufacturing an artificial muscle such as the artificial muscle 101 shown in Figures 1-4 will be described, which includes a vacuum bonding step for directly bonding an electrode, such as a first electrode 106, to an electrode insulator, such as a first electrode insulator 111. Figures 5A and 5B are schematic cross-sectional views of a first layer stack 30A and a second layer stack 30B, which include layers of material that can be formed in a first electrode assembly 40A and a second electrode assembly 40B (Figures 8 and 9), respectively. The first electrode assembly 40A and the second electrode assembly 40B can be used to form the artificial muscle 101 shown in Figures 1-4, or other artificial muscles such as the artificial muscles 201, 300, 300' described below with reference to Figures 10-14. The first layer stack 30A includes a first electrode 106 positioned between a first electrode insulator 111 and a first support polymer 103, and undergoes a vacuum sealing step and a heat sealing step to form the first electrode assembly 40A. The second layer stack 30B includes a second electrode 108 positioned between a second electrode insulator 112 and a second support polymer 105, and undergoes a vacuum sealing process and a heat sealing process to form the second electrode assembly 40B.

[0034] The first electrode insulator 111 and the second electrode insulator 112 may each contain a high dielectric constant polymer. The high dielectric constant polymer used herein is a polymer having a dielectric constant of 3 or more. In some embodiments, the high dielectric constant polymer may have a dielectric constant of 6 or more. The high dielectric constant polymer may also contain halogenated polymers, such as fluoropolymer polymers such as PVDF. Although not limited by theory, polymers containing VDF (vinylidene difluoride) monomers typically have high dielectric constants. Examples of PVDF polymers include PVDF homopolymer, P(VDF-HFP)(hexafluoropropylene) copolymer, P(VDF-CTFE)(chlorotrifluoroethylene) copolymer, P(VDF-TFE)(tetrafluoroethylene) copolymer, P(TFE-HFP-VDF) terpolymer, and P(VDF-TrFE) copolymer. Additional high dielectric polymers include high dielectric constant terpolymers with dielectric constants of 20-50, such as P(VDF-TrFE-CFE) and P(VDF-TrFE-CTFE) terpolymers. Further high dielectric constant polymers include fluoropolymer thermoplastic elastomers, including physically crosslinked fluoropolymers, chemically crosslinkable fluoropolymers, and ferroelectric polymers. While the methods described herein are effective in overcoming the manufacturing difficulties of high dielectric constant polymers, it should be understood that the methods described herein can be used to form artificial muscles with various electrode insulating polymers, including polymers having dielectric constants of less than 3.

[0035] Furthermore, the first support polymer 103 and the second support polymer 105 each include overhangs 35 that extend in the shorter direction beyond the first electrode 106 and the second electrode 108, respectively. The overhangs 35 facilitate direct contact between the electrode insulators 111, 112 and the support polymers 103, 105. As a result, when the electrode insulators 111, 112 are vacuum-coupled to the first electrode 106 and the second electrode 108, respectively, the overhangs 35 of the support polymers 103, 105 are heat-sealed to the electrode insulators 111, 112.

[0036] Referring to Figure 6, the first layer stack 30A is shown positioned within the vacuum bag 10. As shown in Figure 6, the vacuum bag 10 includes a tube connector 12 having an opening for connecting a tube 14 to the vacuum bag 10. The tube 14 is also connected to a fluid pump 16. Thus, the fluid pump 16 is fluidly coupled to the vacuum bag 10 using the tube 14. When in operation, the fluid pump 16 is configured to remove air from the vacuum bag 10, thereby vacuum-couple the first electrode 106 of the first layer stack 30A to the first electrode insulator 111. Although not limited by theory, both the first electrode 106 and the first electrode insulator 111 contain several surface defects at the micron level. Once air is removed from the vacuum bag 10 and thus from the interface between the first electrode 106 and the first electrode insulator 111, a persistent vacuum is maintained in the micron-level gap at the interface between the first electrode 106 and the first electrode insulator 111, due to the presence of surface defects in both the first electrode 106 and the first electrode insulator 111. The persistent vacuum maintained between the first electrode 106 and the first electrode insulator 111 allows the first electrode 106 and the first electrode insulator 111 to remain in a vacuum-coupled state when they are removed from the vacuum bag 10.

[0037] It should be understood that the second layer stack 30B can also be vacuum-coupled to maintain a sustained vacuum between the second electrode 108 and the second electrode insulator 112 of the second layer stack 30B. In some embodiments, both the first layer stack 30A and the second layer stack 30B may be placed together in the vacuum bag 10 during the vacuum sealing operation, and in other embodiments, the first layer stack 30A and the second layer stack 30B may be vacuum-sealed separately. Furthermore, the vacuum coupling techniques described herein facilitate the use of high dielectric constant polymers as the first and second electrode insulators 111, 112, but these techniques also facilitate uniform adhesion between the first and second electrode insulators 111, 112 and between the respective first and second electrodes 106, 108, thereby further improving the performance of the artificial muscle.

[0038] Next, referring to Figure 7, a heat sealing process using a heat sealing device 18 is shown. The first and second layer stacks 30A and 30B in Figures 5A and 5B are placed in a vacuum bag 10 and can be heat-sealed with the air removed from the vacuum bag 10. In some embodiments, both the first layer stack 30A and the second layer stack 30B may be placed together in the vacuum bag 10 during the heat sealing operation, and in other embodiments, the first layer stack 30A and the second layer stack 30B may be heat-sealed separately. During operation, the first and second layer stacks 30A and 30B are heat-sealed, thereby sealing (i.e., heat-sealing) the first and second support polymers 103 and 105 to the first and second electrodes 106 and 108, respectively. Therefore, when the first and second layer stacks 30A and 30B are removed from the vacuum bag 10, the first support polymer 103 and the second support polymer 105 can be bonded to the first electrode 106 and the second electrode 108, respectively. Furthermore, the protruding portions 35 of the first and second support polymers 103 and 105 can come into direct contact with the first and second electrode insulators 111 and 112, respectively. During the heat sealing process, the protruding portion 35 of the first support polymer 103 can be heat-sealed to the first electrode insulator 111, and the protruding portion 35 of the second support polymer 105 can be heat-sealed to the second electrode insulator 112. In fact, the first and second electrode insulators 111 and 112 may contain a highly dielectric polymer that does not allow for effective heat sealing to the electrodes, but the material of the support polymers 103 and 105 (e.g., BOPP) is readily heat-sealable, and the protruding portions 35 of the first and second support polymers 103 and 105 can be easily bonded to the first and second electrode insulators 111 and 112, respectively. Thus, when the first and second layer stacks 30A and 30B are removed from the vacuum bag 10, the first and second support polymers 103 are bonded to both the first and second electrodes 106 and 108 and the first and second electrode insulators 111 and 112, respectively.

[0039] Next, referring to Figure 8, the first electrode assembly 40A and the second electrode assembly 40B are shown. The first electrode assembly 40A and the second electrode assembly 40B are formed using the vacuum sealing and heat sealing processes described in relation to Figures 5-7. For example, the first electrode assembly 40A is formed by vacuum sealing and heat sealing the first layer stack 30A, and the second electrode assembly 40B is formed by vacuum sealing and heat sealing the second layer stack 30B. In fact, when the first and second layer stacks 30A and 30B are removed from the vacuum bag 10, each electrode 106 and 108 remains vacuum-coupled to their respective electrode insulators 111 and 112, and in this state, the layer stacks 30A and 30B include the first electrode assembly 40A and the second electrode assembly 40B.

[0040] Referring again to Figures 5A and 5B, the first heat dissipation layer 50 and the second heat dissipation layer 52 may be placed inside the vacuum bag 10 during the vacuum sealing and heat sealing steps of the method described herein. In Figure 5A, the first heat dissipation layer 50 is placed between the first electrode insulator 111 and the vacuum bag 10, and the second heat dissipation layer 52 is placed between the first support polymer 103 and the vacuum bag 10. In Figure 5B, the first heat dissipation layer 50 is placed between the second electrode insulator 112 and the vacuum bag 10, and the second heat dissipation layer 52 is placed between the second support polymer 105 and the vacuum bag 10. In fact, the first and second heat dissipation layers 50 and 52 are placed on both sides of each layer stack 30A and 30B. During operation, the first heat dissipation layer 50 and the second heat dissipation layer 52 prevent the layer stacks 30A and 30B from bonding to the vacuum bag 10 during the vacuum sealing and heat sealing steps. After the heat sealing process, the first and second heat dissipation layers 50 and 52 may be removed from contact with the layer stacks 30A and 30B. The first and second heat dissipation layers 50 and 52 include a material having a limited texture, such as carbon fiber resin or paper. Furthermore, the first and second heat dissipation layers 50 and 52 may also include a porous material that allows a certain airflow to pass through.

[0041] Referring next to Figures 8 and 9, the first electrode assembly 40A and the second electrode assembly 40B can be used to form an artificial muscle such as the artificial muscle 101 shown in Figures 1-4. Figure 8 is a schematic cross-sectional view of the first electrode assembly 40A and the second electrode assembly 40B positioned between the first film layer 122 and the second film layer 124. In particular, when the first and second electrode assemblies 40A and 40B are manufactured to form the artificial muscle 101, the first electrode assembly 40A and the second electrode assembly 40B may be arranged in a laminated configuration between the first film layer 122 and the second film layer 124. In the laminated configuration, the first electrode insulator 111 of the first electrode assembly 40A faces the second electrode insulator 112 of the second electrode assembly 40B, the first support polymer 103 of the first electrode assembly 40A faces the first film layer 122, and the second support polymer 105 of the second electrode assembly 40B faces the second film layer 124.

[0042] To form an artificial muscle such as the first artificial muscle 101 shown in Figures 1-4, the first film layer 122 is sealed to the second film layer 124 to form a housing 110 that accommodates the first and second electrode assemblies 40A and 40B. By heat-sealing the first film layer 122 to the second film layer 124, the first and second film layers 122 and 124 are heat-sealed to the first and second electrode assemblies 40A and 40B, respectively, to the first and second support polymers 103 and 105. Furthermore, by sealing the first film layer 122 to the second film layer 124, the sealing portion 190 of the housing 110 is defined, enclosing the unsealed portion 192 surrounded by the sealing portion 190 of the housing 110. Once the first electrode assembly 40A is sealed to the second electrode assembly 40B to form the artificial muscle 101, the dielectric fluid 198 (Figures 1-4) can be injected into the artificial muscle between the first electrode assembly 40A and the second electrode assembly 40B.

[0043] Referring next to Figures 10 and 11, another embodiment of the artificial muscle 201 that can be formed using the method of Figures 5A to 9 is shown. The artificial muscle 201 is substantially similar to the artificial muscle 101. Therefore, similar structures are shown with similar reference numerals. However, as shown, the first electrode 106 does not include a central opening. Therefore, only the second electrode 108 includes a central opening 168 formed in the electrode. As shown in Figure 10, the artificial muscle 201 is in a non-operating state in which the first electrode 106 is planar and the second electrode 108 protrudes from the first electrode 106. In the non-operating state, the expandable fluid region 196 has a first height H3. In the operating state, as shown in Figure 11, the expandable fluid region 196 has a second height H4 which is greater than the first height H3. It should be understood that by providing the central opening 168 only within the second electrode 108, in contrast to both the first electrode 106 and the second electrode 108, total deformation can be formed on one side of the artificial muscle 201. Furthermore, because total deformation is formed on only one side of the artificial muscle 201, the second height H4 of the expandable fluid region 196 of the artificial muscle 201 extends further from the longitudinal axis perpendicular to the central axis C of the artificial muscle 201 than the second height H2 of the expandable fluid region 196 of the artificial muscle 101, assuming all other dimensions, orientation, and volume of the dielectric fluid are the same.

[0044] As shown in Figures 12-14, another embodiment of the artificial muscle 300 that can be formed using the method of Figures 5A-9 is shown. It should be understood that the artificial muscle 300 includes a structure similar to that of the artificial muscle 101 (Figure 1) and therefore operates similarly to the artificial muscle 101 (Figure 1) during operation. In particular, the artificial muscle 300 includes a fan portion 332 instead of the tab portion 132 (Figure 1) described with respect to the artificial muscle 101 (Figure 1). However, it should be understood that both the fan portion 332 and the tab portion 132 of the artificial muscle 300 are, each roughly, radially extending portions of the electrodes of the artificial muscle, positioned adjacent to the bridge portion, and providing a zipping function as previously described with respect to the artificial muscles 101 and 201 and as described below with respect to the artificial muscle 300. In fact, these radially extending portions (e.g., the tab portion and the fan portion) each increase the actuator power per unit volume while minimizing buckling and rupture during operation.

[0045] Referring to Figures 12 and 13, the artificial muscle 300 includes a housing 302, an electrode pair 304 including a first electrode 306 and a second electrode 308 fixed to the opposite side of the housing 302, a first electrode insulator 310 fixed to the first electrode 306, and a second electrode insulator 312 fixed to the second electrode 308. In some embodiments, the housing 302 is a one-piece monolithic layer including a pair of opposing inner surfaces such as a first inner surface 314 and a second inner surface 316, and a pair of opposing outer surfaces such as a first outer surface 318 and a second outer surface 320. In some embodiments, the first inner surface 314 and the second inner surface 316 of the housing 302 are heat-sealable. In another embodiment, the housing 302 may be a pair of individually manufactured film layers such as a first film layer 322 and a second film layer 324. Therefore, the first film layer 322 includes a first inner surface 314 and a first outer surface 318, and the second film layer 324 includes a second inner surface 316 and a second outer surface 320.

[0046] Through the explanation of the reasoning above, a housing 302 including a first film layer 322 and a second film layer 324 may be referred to, in contrast to a one-piece housing. It should be understood that either configuration is intended. In some embodiments, the first film layer 322 and the second film layer 324 have substantially the same structure and composition. For example, in some embodiments, the first film layer 322 and the second film layer 324 each include BOPP.

[0047] As shown in Figure 12, the artificial muscle 300 may further include a first support polymer 303 positioned between a first electrode 306 and a first inner surface 314 of the housing 302, and a second support polymer 305 positioned between a second electrode 308 and a second inner surface 316 of the housing 302. As previously mentioned, the first and second support polymers 303, 305 assist in a vacuum bonding process that enables the use of high dielectric polymers as the first and second electrode insulators 310, 312. In some embodiments, the first support polymer 303 and the second support polymer 305 have substantially the same structure and composition. For example, in some embodiments, the first support polymer 303 and the second support polymer 305 each contain BOPP.

[0048] The first electrode 306 and the second electrode 308 are each positioned between the first film layer 322 and the second film layer 324. In some embodiments, the first electrode 306 and the second electrode 308 are each aluminum-coated polyester, such as Mylar®. However, it should be understood that the first electrode 306 and the second electrode 308 may also contain an electrically bonding material of copper, silver, titanium, platinum, or the same, which can be coated with a polyester such as Mylar®. The first electrode 306 and the second electrode 308 may contain a flexible material or a non-flexible material (e.g., a rigid material), and in some embodiments, they may contain an expandable material. Furthermore, embodiments are conceivable in which the first electrode 306 and the second electrode 308 contain a hydrogel material. Also, one of the first electrode 306 and the second electrode 308 is a negatively charged electrode, and the other of the first electrode 306 and the second electrode 308 is a positively charged electrode. For the purposes described herein, either electrode 306, 308 may be positively charged, insofar as the other electrode 306, 308 of the artificial muscle 300 is negatively charged.

[0049] The first electrode 306 has a surface 326 facing the film and an inner surface 328 on the opposite side. The first electrode 306 is positioned in close proximity to the first film layer 322, specifically to the first inner surface 314 of the first film layer 322. That is, the first electrode 306 may be in contact with the first inner surface 314 of the first film layer 322, or it may be in contact with the first support polymer 303 positioned between the first electrode 306 and the first inner surface 314 of the first film layer 322. Furthermore, the first electrode 306 includes a first terminal extending from the first electrode 306 beyond the edge of the first film layer 322, and the first terminal 330 can be connected to a power source to actuate the first electrode 306. Specifically, the terminal is coupled directly or in series to the power source and controller of the actuating system 400 (Figure 15). Similarly, the second electrode 308 has a surface 348 facing the film and an inner surface 350 on the opposite side. The second electrode 308 is positioned in close proximity to the second film layer 324, specifically to the second inner surface 316 of the second film layer 324. That is, the second electrode 308 may be in contact with the second inner surface 316 of the second film layer 324, or it may be in contact with the second support polymer 305 positioned between the second electrode 308 and the second inner surface 316 of the second film layer 324. The second electrode 308 includes a second terminal 352 extending from the second electrode 308 beyond the edge of the second film layer 324, and the second terminal 352 can be connected to the power supply and controller of the actuation system 400 (Figure 15) to actuate the second electrode 308.

[0050] Next, regarding the first electrode 306, the first electrode 306 includes two or more fan portions 332 that extend radially from the central axis C of the artificial muscle 300. In some embodiments, the first electrode 306 includes only two fan portions 332 located on opposite sides or ends of the first electrode 306. In some embodiments, the first electrode 306 includes three or more fan portions 332, such as three, four, or five fan portions 332. In embodiments in which the first electrode 306 includes an even number of fan portions 332, the fan portions 332 may be arranged in two or more pairs of fan portions 332. As shown in Figure 12, the first electrode 306 includes four fan portions 332. In this embodiment, the four fan portions 332 are arranged in two pairs of fan portions 332, with the two individual fan portions 332 in each pair being diametrically opposite to each other.

[0051] Each fan portion 332 has a first edge portion 332a and a second edge portion 332b on the opposite side. As shown in the figure, the first terminal 330 is formed integrally with the second end portion 336, extending from one of the second end portions 336 of the fan portion 332. The channel 333 is at least partially defined by the opposing edges 332a, 332b of adjacent fan portions 332 and thus extends radially toward the central axis C. The channel 333 terminates at the end portion 340a of a bridge portion 340 that interconnects adjacent fan portions 332.

[0052] As shown in Figure 12, a dividing line D is included to define the boundary between the fan portion 332 and the bridge portion 340. The dividing line D extends from the edges 332a and 332b of the fan portion 332 to the first end 334 of the fan portion 332, which is collinear with the edges 332a and 332b. In Figure 13, the dividing line D is shown for clarity, so that it can be understood that the fan portion 332 is a single unit with the bridge portion 340. The first end 334 of the fan portion 332 extends between the adjacent bridge portions 340 and defines the inner length of the fan portion 332. Because the geometric shape of the fan portion 332 tapers toward the central axis C between the first edge 332a and the second edge 332b, the second end 336 of the fan portion 332 defines the outer length of the fan portion 332, which is greater than the inner length of the fan portion 332.

[0053] Furthermore, each fan portion 332 has a pair of corners 332c defined by the intersection of the second end 336 of the fan portion 332 with the first edge portion 332a and the second edge portion 332b, respectively. In one embodiment, the corners 332c are formed at an angle of 90 degrees or less. In another embodiment, the corners 332c are formed at an acute angle.

[0054] As shown in Figure 12, each fan portion 332 has a first side length defined by the distance between a first edge 332a and a dividing line D that is collinear with the first edge 332a, between the first end 334 and the second end 336 of the fan portion 332. Each fan portion 332 also has a second side length defined by the distance between a second edge 332b and a dividing line D that is collinear with the second edge 332b, between the first end 334 and the second end 336 of the fan portion 332. In this embodiment, the first side length is greater than the second side length of the fan portion 332, so that the first electrode 306 has an ellipsoidal geometric shape.

[0055] The second end 336, first edge 332a and second edge 332b of each fan portion 332, and the bridge portion 340 that interconnects the fan portions 332 define the outer circumference 338 of the first electrode 306. In this embodiment, a central opening 346 is formed within the first electrode 306 between the fan portion 332 and the bridge portion 340 and is coaxial with the central axis C. Each fan portion 332 has a fan length extending from the outer circumference 342 of the central opening 346 to the second end 336 of the fan portion 332. Each bridge portion 340 has a bridge length extending from the outer circumference 342 of the central opening 346 to the end 340a of the bridge portion 340, i.e., the channel 333. As shown in the figure, the bridge lengths of each bridge portion 340 are substantially equal to each other. Each channel 333 has a channel length defined by the distance between the end 340a of the bridge portion 340 and the second end of the fan portion 332. Since the bridge lengths of each bridge portion 340 are substantially equal to each other and the first side length of the fan portion 332 is greater than the second side length of the fan portion 332, a first pair of opposing channels 333 has a channel length greater than the channel length of a second pair of opposing channels 333. As shown in the figure, the width of the channel 333 extending between the opposing edges 332a and 332b of adjacent fan portions 332 remains substantially constant because the opposing edges 332a and 332b are substantially parallel to each other.

[0056] In the embodiment, the central opening 346 has a radius of 2 cm to 5 cm. In the embodiment, the central opening 346 has a radius of 3 cm to 4 cm. In the embodiment, the total fan area of ​​each fan section 332 is more than twice the area of ​​the central opening 346. It should be understood that the ratio of the total fan area of ​​the fan section 332 to the area of ​​the central opening 346 is directly related to the total deflection of the first film layer 322 when the artificial muscle 300 is activated. In the embodiment, the bridge length is 20% to 50% of the fan length. In the embodiment, the bridge length is 30% to 40% of the fan length. In the embodiment where the first electrode 306 does not include the central opening 346, the fan length and bridge length can be measured from the outer circumference of a virtual circle coaxial with the central axis C.

[0057] Similar to the first electrode 306, the second electrode 308 includes two or more fan sections 354 extending radially from the central axis C of the artificial muscle 300. The second electrode 308 includes substantially the same structure as the first electrode 306 and, therefore, includes the same number of fan sections 354. Specifically, the second electrode 308 is illustrated as including four fan sections 354. However, it should be understood that the second electrode 308 may include any preferred number of fan sections 354.

[0058] Each fan portion 354 of the second electrode 308 has a first edge portion 354a and a second edge portion 354b on the opposite side. As shown in the figure, the second terminal 352 is formed integrally with the second end portion 358, extending from one of the second end portions 358 of the fan portion 354. The channel 355 is at least partially defined by the opposing edges 354a, 354b of adjacent fan portions 354 and thus extends radially toward the central axis C. The channel 355 terminates at the end portion 362a of a bridge portion 362 that interconnects adjacent fan portions 354.

[0059] As shown in Figure 12, an additional dividing line D is included to depict the boundary between the fan portion 354 and the bridge portion 362. Dividing line D extends from the edges 354a, 354b of the fan portion 354 to the first end 356 of the fan portion 354, which is collinear with the edges 354a, 354b. In Figure 13, dividing line D is shown for clarity, so that it can be understood that the fan portion 354 is integrated with the bridge portion 362. The first end 356 of the fan portion 354 extends between the adjacent bridge portions 362 and defines the inner length of the fan portion 354. Because the geometric shape of the fan portion 354 tapers toward the central axis C between the first edge 354a and the second edge 354b, the second end 358 of the fan portion 354 defines the outer length of the fan portion 354, which is greater than the inner length of the fan portion 354.

[0060] Furthermore, each fan portion 354 has a pair of corners 354c defined by the second end 358 of the fan portion 354 and the intersection of the first edge 354a and the second edge 354b. In some embodiments, the corners 354c are formed at an angle of 90 degrees or less. In other embodiments, the corners 354c are formed at an acute angle. During operation of the artificial muscle 300, the corners 332c of the first electrode 306 and the corners 354c of the second electrode 308 are configured to attract each other at a lower voltage compared to the rest of the first electrode 306 and the second electrode 308. Therefore, when the artificial muscle 300 is first activated at the corners 332c and 354c, the outer circumference 338 of the first electrode 306 and the outer circumference 360 ​​of the second electrode 308 are attracted at a lower voltage, reducing the possibility of air pockets or gaps forming between the first electrode 306 and the second electrode 308 after the artificial muscle 300 is activated.

[0061] As shown in Figures 12 and 13, in the embodiment, the first edge portion 354a of each fan portion 354 has a first side length defined by the distance between the first edge portion 354a and a dividing line D that is collinear with the first edge portion 354a, between the first end portion 356 of the fan portion 354 and the second end portion 358 of the fan portion 354. In addition, each fan portion 354 has a second side length defined by the distance between the second edge portion 354b and a dividing line D that is collinear with the second edge portion 354b, between the first end portion 356 of the fan portion 354 and the second end portion 358 of the fan portion 354. In the embodiment, the first side length is greater than the second side length of the fan portion 354, such that the second electrode 308 has an ellipsoidal geometry corresponding to the geometric shape of the first electrode 306.

[0062] The second end 358, first edge 354a and second edge 354b of each fan portion 354, and the bridge portion 362 interconnecting the fan portions 354 define the outer circumference 360 ​​of the second electrode 308. In this embodiment, a central opening 368 is formed within the second electrode 308 between the fan portion 354 and the bridge portion 362 and is coaxial with the central axis C. Each fan portion 354 has a fan length extending from the outer circumference 364 of the central opening 368 to the second end 358 of the fan portion 354. Each bridge portion 362 has a bridge length extending from the central opening 368 to the end 362a of the bridge portion 362, i.e., the channel 355. As shown in the figure, the bridge lengths of each bridge portion 362 are substantially equal to each other. Each channel 355 has a channel length defined by the distance between the end 362a of the bridge portion 362 and the second end of the fan portion 354. Since the bridge lengths of each bridge portion 362 are substantially equal to each other, and the first side length of the fan portion 354 is greater than the second side length of the fan portion 354, the first pair of opposing channels 355 has a channel length greater than the channel length of the second pair of opposing channels 355. As shown in the figure, the width of the channel 355 extending between the opposing edges 354a and 354b of adjacent fan portions 354 remains substantially constant because the opposing edges 354a and 354b are substantially parallel to each other.

[0063] In the embodiment, the central opening 368 has a radius of 2 cm to 5 cm. In the embodiment, the central opening 368 has a radius of 3 cm to 4 cm. In the embodiment, the total fan area of ​​each fan section 354 is more than twice the area of ​​the central opening 368. It should be understood that the ratio of the total fan area of ​​the fan section 354 to the area of ​​the central opening 368 is directly related to the total amount of deflection of the second film layer 324 when the artificial muscle 300 is activated. In the embodiment, the bridge length is 20% to 50% of the fan length. In the embodiment, the bridge length is 30% to 40% of the fan length. In the embodiment where the second electrode 308 does not include the central opening 368, the fan length and bridge length can be measured from the outer circumference of a virtual circle coaxial with the central axis C.

[0064] As described herein, each of the first electrode 306 and the second electrode 308 has central openings 346 and 368 coaxial with the central axis C, however, it should be understood that the first electrode 306 does not need to include the central opening 346 if the central opening 368 is located within the second electrode 308. Alternatively, the second electrode 308 does not need to include the central opening 368 if the central opening 346 is located within the first electrode 306.

[0065] Referring again to Figure 12, the first electrode insulator 310 and the second electrode insulator 312 each have substantially ellipsoidal geometry that roughly corresponds to the geometry of the first electrode 306 and the second electrode 308. Thus, the first electrode insulator 310 and the second electrode insulator 312 each have fan portions 370, 372 and bridge portions 374, 376 that correspond to similar portions on the first electrode 306 and the second electrode 308. However, the first electrode insulator 310 and the second electrode insulator 312 each have outer peripheries 378, 380 that extend in the shorter direction beyond the outer periphery 338 of the first electrode 306 and the outer periphery 360 of the second electrode 308. This facilitates bonding between the first electrode insulator 310 and the first support polymer 303 and between the second electrode insulator 312 and the second support polymer 305. However, it should be understood that when the outer peripheries 378 and 380 of the first electrode insulator 310 and the second electrode insulator 312 are arranged on the first electrode 306 and the second electrode 308, embodiments corresponding to the outer periphery 338 of the first electrode 306 and the outer periphery 360 of the second electrode 308 are intended.

[0066] It should be understood that in some embodiments, the first electrode insulator 310 and the second electrode insulator 312 have substantially the same structure and composition. Therefore, in some embodiments, the first electrode insulator 310 and the second electrode insulator 312 each include first faces 382, ​​384 and opposite second faces 386, 388. In some embodiments, the first electrode insulator 310 and the second electrode insulator 312 are polymer materials vacuum-bonded to the inner surface 328 of the first electrode 306 and the inner surface 350 of the second electrode 308, respectively. For example, the first electrode insulator 310 and the second electrode insulator 312 may contain a high dielectric constant polymer.

[0067] Next, referring to Figure 13, the artificial muscle 300 is shown assembled with the first terminal 330 of the first electrode 306 and the second terminal 352 of the second electrode 308 extending beyond the outer circumference of the housing 302, i.e., beyond the first film layer 322 (Figure 12) and the second film layer 324. The first film layer 322 (Figure 12) is not shown because the second electrode 308 is laminated on the first electrode 306. Next, referring to Figures 12 and 13, in the assembled form, the first electrode 306, the second electrode 308, the first electrode insulator 310, the second electrode insulator 312, the first support polymer 303, and the second support polymer 305 are sandwiched between the first film layer 322 and the second film layer 324. The first film layer 322 is partially sealed to the second film layer 324 in the region surrounding the outer periphery 338 of the first electrode 306 and the outer periphery 360 of the second electrode 308. In some embodiments, the first film layer 322 is heat-sealed to the second film layer 324. Specifically, in some embodiments, the first film layer 322 is sealed to the second film layer 324 to define a sealing portion 390 surrounding the first electrode 306 and the second electrode 308. The first film layer 322 (Figure 12) and the second film layer 324 can be sealed by any preferred method, such as using an adhesive, heat seal, vacuum seal, or the like.

[0068] Referring further to Figures 12 and 13, the first electrode 306, the second electrode 308, the first electrode insulator 310, the second electrode insulator 312, the first support polymer 303, and the second support polymer 305 provide a barrier that prevents the first film layer 322 from being sealed to the second film layer 324, forming an unsealed portion 392. The unsealed portion 392 of the housing 302 includes an electrode region 394 in which the electrode pair 304 is provided, and an expandable fluid region 396 surrounded by the electrode region 394. The central openings 346, 368 of the first electrode 306 and the second electrode 308 define the expandable fluid region 396 and are arranged to be stacked axially relative to each other. Although not shown, the housing 302 can be cut to fit the geometry of the electrode pair 304 to reduce the size of the artificial muscle 300, i.e., the size of the sealed portion 390. A dielectric fluid is provided within the unsealed portion 392 and flows freely between the first electrode 306 and the second electrode 308.

[0069] Next, referring to Figure 14, another embodiment of the artificial muscle 300' is shown. It should be understood that the artificial muscle 300' is similar to the artificial muscle 300 described herein. Therefore, similar structures are shown with similar reference numerals. The first electrode 306 and the second electrode 308 of the artificial muscle 300' have circular geometric shapes, in contrast to the ellipsoidal geometric shapes of the first electrode 306 and the second electrode 308 of the artificial muscle 300 described herein. As shown in Figure 14, with respect to the second electrode 308, the first edge length of the first edge portion 354a is equal to the second edge length of the second edge portion 354b. Therefore, the channels 355 formed between the opposing edges 354a and 354b of the fan portion 354 each have equal lengths. In Figure 15, the first electrode 306 is hidden beneath the second electrode 308 and not visible, but please understand that the first electrode 306 also has a circular geometric shape that corresponds to the geometric shape of the second electrode 308.

[0070] Next, the operation of the artificial muscle 300 will be described with reference to Figures 12 and 13. In the non-operating state, the first electrode 306 and the second electrode 308 are partially separated from each other at close proximity to the central openings 346, 368 of the first electrode 306 and the second electrode 308 and the first ends 334, 356 of the fan portions 332, 354. The second ends 336, 358 of the fan portions 332, 354 are in the same position relative to each other because the housing 302 is sealed to the outer circumference 338 of the first electrode 306 and the outer circumference 360 ​​of the second electrode 308. This is shown in Figure 3 with respect to the artificial muscle 101 which operates similarly. In the operating state, the first electrode 306 and the second electrode 308 are in contact with each other and oriented parallel to each other, pushing the dielectric fluid 398 into the expandable fluid region 396. As a result, the dielectric fluid 398 flows through the central openings 346, 368 of the first electrode 306 and the second electrode 308, inflating the expandable fluid region 396. This is shown in Figure 4 with respect to an artificial muscle 101 that operates similarly.

[0071] In the non-operating state, the distance between the first end 334 of the fan portion 332 of the first electrode 306 and the first end 356 of the fan portion 354 of the second electrode 308 is greater than the distance between the second end 336 of the fan portion 332 of the first electrode 306 and the second end 358 of the fan portion 354 of the second electrode 308. This causes the electrode pair 304 to zipper toward the expandable fluid region 396 when activated. When activated, the first electrode 306 and the second electrode 308 zipper toward each other from the second ends 336 and 358 of the fan portions 332 and 354 of the first electrode 306 and the second electrode 308, thereby pushing the dielectric fluid 398 into the expandable fluid region 396. In the operating state, the first electrode 306 and the second electrode 308 are parallel to each other. In operation, the dielectric fluid 398 flows into the expandable fluid region 396, causing the expandable fluid region 396 to expand. Consequently, the first film layer 322 and the second film layer 324 expand in opposite directions.

[0072] Referring to Figure 15, an actuator system 400 can be provided for operating the artificial muscles 101, 201, 300, and 300'. The actuator system 400 may include a controller 500, an operating device 460, a power supply 480, a display device 420, network interface hardware 440, and a communication path 410 that connects these components communicatively. The controller 500 includes a processor 520 and a non-temporary electronic memory 540 in which various components are communicatively coupled. In some embodiments, the processor 520 and the non-temporary electronic memory 540 and / or other components are contained within a single device. In other embodiments, the processor 520 and the non-temporary electronic memory 540 and / or other components may be distributed across multiple communicatively coupled devices. The controller 500 includes a non-temporary electronic memory 540 that stores a set of machine-readable instructions. The processor 520 executes the machine-readable instructions stored in the non-temporary electronic memory 540. The non-temporary electronic memory 540 may include RAM, ROM, flash memory, a hard drive, or any device capable of storing machine-readable instructions so that machine-readable instructions can be accessed from the processor 520. Thus, the actuator system 400 described herein can be implemented in any conventional computer programming language, either as a pre-programmed hardware element or as a combination of hardware and software components. The non-temporary electronic memory 540 can be implemented as one memory module or multiple memory modules. In some embodiments, the non-temporary electronic memory 540 includes instructions for performing the functions of the actuator system 400. These instructions may include instructions for operating the artificial muscles 101, 201, 300, and 300'.

[0073] The processor 520 may be any device capable of executing machine-readable instructions. For example, the processor 520 may be an integrated circuit, a microchip, a computer, or any other computing device. The non-temporary electronic memory 540 and the processor 520 are coupled to a communication path 410 that provides signal interconnection between various components and / or modules of the operating system 400. Thus, the communication path 410 communicates with each other in any number of processors, enabling modules coupled to the communication path 410 to operate in a distributed computing environment. Specifically, each module can operate as a node capable of transmitting and / or receiving data. As used herein, the term “communicatively coupled” means that the coupled components can exchange data signals with each other, such as electrical signals over a conductive medium, electromagnetic signals over air, optical signals over an optical waveguide, and the like.

[0074] As schematically shown in Figure 15, the communication path 410 connects the non-temporary electronic memory 540 of the processor 520 and the controller 500 to several other components of the actuator system 400 in a communicative manner. For example, in the actuator system 400 shown in Figure 15, the processor 520 and the non-temporary electronic memory 540 are communicatively connected to the operating device 460 and the power supply 480.

[0075] The operating device 460 allows the user to control the operation of the artificial muscles 101, 201, 300, and 300'. In some embodiments, the operating device 460 may be a switch, toggle, button, or any combination of controls that provide user operation. The operating device 460 is coupled to a communication path 410 such that the communication path 410 connects the operating device 460 to other modules of the actuator system 400 in a communicative manner.

[0076] Power supply 480 (e.g., a battery) supplies power to the artificial muscles 101, 201, 300, and 300'. In some embodiments, power supply 480 is a rechargeable DC power supply. It should be understood that power supply 480 may be a single power supply or battery for supplying power to the artificial muscles 101, 201, 300, and 300'. A power adapter (not shown) may be provided and electrically coupled via a wire harness or similar to power supply 480 for supplying power to the artificial muscles 101, 201, 300, and 300'. In fact, power supply 480 is a device capable of receiving power at one level (e.g., one voltage, power level, or current) and outputting power at a second level (e.g., a second voltage, power level, or current).

[0077] In some embodiments, the actuation system 400 also includes a display device 420. The display device 420 is coupled to a communication path 410 such that the communication path 410 connects the display device 420 to other modules of the actuation system 400 in a communicative manner. The display device 420 may output notifications in response to the display of the operating status of the artificial muscles 101, 201, 300, 300' or changes in the operating status of the artificial muscles 101, 201, 300, 300'. Furthermore, in addition to providing optical information, the display device 420 may be a touchscreen that detects the presence and location of tactile inputs on or adjacent to the surface of the display device 420. Thus, the display device 420 includes an operating device 460 which can receive mechanical inputs directly on the optical output signals provided by the display device 420.

[0078] In some embodiments, the actuator system 400 includes network interface hardware 440 for communicatively connecting the actuator system 400 to a portable device 580 via a network 560. The portable device 580 may include, but is not limited to, a smartphone, a tablet, a personal media player, or any other electrical device including wireless communication capabilities. Where a portable device 580 is provided, it should be understood that the portable device 580 may serve the role of providing user commands to the controller 500 in place of the operating device 460. Thus, the user can use each control of the operating device 460 to control or set programs for controlling the artificial muscles 101, 201, 300, 300'. Therefore, the artificial muscles 101, 201, 300, 300' may be remotely controlled via the portable device 580, which wirelessly communicates with the controller 500 via the network 560.

[0079] Embodiments described herein relate to artificial muscles that facilitate the use of certain high-performance electrode insulators that cannot be effectively heat-sealed, and to a method for manufacturing artificial muscles using a vacuum sealing process. In particular, the vacuum sealing technique described herein facilitates the use of highly dielectric polymer materials such as PVDF as electrode materials to enhance the actuator performance of the artificial muscles.

[0080] It should be noted that the terms “substantially” and “about” may be used herein to describe the degree of inherent uncertainty that may arise from any quantitative comparison, value, measurement, or other representation. These terms are also used herein to describe the degree to which a quantitative representation may deviate from the stated standard without resulting in a change in the fundamental function of the subject matter in question.

[0081] While specific embodiments have been illustrated and described herein, it should be understood that various other changes and modifications are possible without departing from the scope of the claimed subject matter. Furthermore, while various aspects of the claimed subject matter have been described herein, it is not necessary to use such aspects in combination. Therefore, the attached claims are intended to cover all such changes and modifications that fall within the scope of the claimed subject matter. The inventions disclosed herein include the following embodiments: [Aspect 1] Placing a layer stack comprising electrodes positioned between an electrode insulator and a supporting polymer inside a vacuum bag, By removing air from the vacuum bag, the electrode is vacuum-coupled to the electrode insulator, Removing the layer stack from the vacuum bag, Includes, When the layer stack is removed from the vacuum bag, the electrode remains vacuum-coupled to the electrode insulator, and the electrode insulator comes into direct contact with the electrode, thereby forming the electrode assembly. A method for manufacturing an electrode assembly. [Aspect 2] The method according to embodiment 1, further comprising heat-sealing the support polymer to the electrode while the layer stack is positioned in the vacuum bag, such that the support polymer bonds to the electrode when the layer stack is removed from the vacuum bag. [Aspect 3] The method according to embodiment 2, wherein the support polymer has an overhang portion such that when the layer stack is removed from the vacuum bag, the support polymer is bonded to the electrode insulator. [Aspect 4] A first heat dissipation layer is placed between the electrode insulator and the vacuum bag. A second heat dissipation layer is placed between the support polymer and the vacuum bag. After the support polymer is heat-sealed to the electrode, the first and second heat dissipation layers are removed from the layer stack. The method described in Embodiment 2. [Aspect 5] The method according to embodiment 1, wherein the electrode insulator contains a high dielectric constant polymer. [Aspect 6] The method according to embodiment 5, wherein the high dielectric constant polymer includes a halogenated polymer. [Aspect 7] The method according to embodiment 6, wherein the halogenated polymer includes PVDF. [Aspect 8] The electrode comprises two or more radially extending portions and two or more bridge portions, The method according to embodiment 1, wherein each of the two or more bridge portions interconnects adjacent radially extending portions. [Aspect 9] The method according to embodiment 1, wherein the supporting polymer includes biaxially oriented polypropylene (BOPP). [Aspect 10] This includes forming a first electrode assembly and a second electrode assembly, and forming each electrode assembly is Placing a layer stack containing electrodes positioned between an electrode insulator and a supporting polymer inside a vacuum bag, By removing air from the vacuum bag, the electrode is vacuum-coupled to the electrode insulator, Removing the layer stack from the vacuum bag, wherein the electrode remains vacuum-coupled to the electrode insulator, the electrode insulator comes into direct contact with the electrode, thereby forming an electrode assembly. The first electrode assembly and the second electrode assembly are arranged in a laminated configuration between the first film layer and the second film layer, The first film layer is sealed to the second film layer, thereby forming an artificial muscle comprising the first electrode assembly and the second electrode assembly housed within a housing formed from the first film layer and the second film layer. A method for manufacturing artificial muscle, including [Aspect 11] Forming each electrode assembly further includes heat-sealing the support polymer to the electrodes and the electrode insulator while the layer stack is positioned in the vacuum bag, such that the support polymer bonds to the electrodes when the layer stack is removed from the vacuum bag. The support polymer has a protruding portion that is bonded to the electrode insulator when the layer stack is removed from the vacuum bag. The method according to embodiment 10. [Aspect 12] The method according to embodiment 10, further comprising injecting a dielectric fluid into the artificial muscle between the first electrode assembly and the second electrode assembly. [Aspect 13] The method according to embodiment 10, wherein sealing the first film layer to the second film layer defines a sealed portion of the housing of the artificial muscle, and the housing further comprises an unsealed portion surrounded by the sealed portion, and the electrode region and expandable fluid region of the housing are located in the unsealed portion. [Aspect 14] Each electrode of the first electrode assembly and the second electrode assembly comprises two or more radially extending portions and two or more bridge portions, The method according to embodiment 10, wherein each of the two or more bridge portions interconnects adjacent radially extending portions. [Aspect 15] The method according to embodiment 10, wherein sealing the first film layer to the second film layer includes heat sealing the first film layer to the second film layer. [Aspect 16] A housing comprising an electrode region and an expandable fluid region, A dielectric fluid contained within the housing, An electrode pair comprising a first electrode and a second electrode, disposed within the electrode region of the housing, The device comprises an electrode insulator that is in direct contact with the first electrode and vacuum-coupled to the first electrode, The first electrode insulator comprises a high dielectric constant polymer, The electrode pair is operable between a non-operating state and an operating state, and the operation from the non-operating state to the operating state guides the dielectric fluid into the expandable fluid region, and the expandable fluid region expands. 、 Artificial muscle. [Aspect 17] The electrode insulator is a first electrode insulator, A second electrode insulator is vacuum-coupled to the second electrode and is in direct contact with the second electrode, Equipped with, The second electrode insulator contains a high dielectric constant polymer. The artificial muscle described in embodiment 16. [Aspect 18] The artificial muscle according to embodiment 16, wherein the high dielectric constant polymer includes a halogenated polymer. 。 [Aspect 19] The artificial muscle according to embodiment 18, wherein the halogenated polymer contains PVDF. [Aspect 20] The first electrode and the second electrode each comprise two or more radially extending portions and two or more bridge portions, Each of the two or more bridge sections interconnects adjacent radially extending sections. At least one of the first electrode and the second electrode is positioned between the two or more radially extending portions and has a central opening surrounding the expandable fluid region. 、 The artificial muscle described in embodiment 16.

Claims

1. Placing a layer stack comprising electrodes positioned between an electrode insulator and a supporting polymer inside a vacuum bag, By removing air from the vacuum bag, the electrode is vacuum-coupled to the electrode insulator, Removing the layer stack from the vacuum bag, The support polymer is heat-sealed to the electrode while the layer stack is placed in the vacuum bag, such that when the layer stack is removed from the vacuum bag, the support polymer bonds to the electrode. Includes, When the layer stack is removed from the vacuum bag, the electrode remains vacuum-coupled to the electrode insulator, the electrode insulator comes into direct contact with the electrode, thereby forming the electrode assembly. A method for manufacturing an electrode assembly.

2. The method according to claim 1, wherein the support polymer has an overhang portion such that when the layer stack is removed from the vacuum bag, the support polymer is bonded to the electrode insulator.

3. A first heat dissipation layer is placed between the electrode insulator and the vacuum bag. A second heat dissipation layer is placed between the support polymer and the vacuum bag. After the support polymer is heat-sealed to the electrode, the first and second heat dissipation layers are removed from the layer stack. The method according to claim 1.

4. The method according to claim 1, wherein the electrode insulator contains a high dielectric constant polymer.

5. The method according to claim 4, wherein the high dielectric constant polymer includes a halogenated polymer.

6. The method according to claim 5, wherein the halogenated polymer contains PVDF.

7. The electrode comprises two or more radially extending portions and two or more bridge portions, The method according to claim 1, wherein each of the two or more bridge portions interconnects adjacent radially extending portions.

8. The method according to claim 1, wherein the supporting polymer comprises biaxially oriented polypropylene (BOPP).

9. This includes forming a first electrode assembly and a second electrode assembly, and forming each electrode assembly is Placing a layer stack containing electrodes positioned between an electrode insulator and a supporting polymer inside a vacuum bag, By removing air from the vacuum bag, the electrode is vacuum-coupled to the electrode insulator, The process involves removing the layer stack from the vacuum bag, wherein, upon removal of the layer stack from the vacuum bag, the electrode remains vacuum-coupled to the electrode insulator, the electrode insulator comes into direct contact with the electrode, and thereby an electrode assembly is formed. The first electrode assembly and the second electrode assembly are arranged in a laminated configuration between the first film layer and the second film layer, The first film layer is sealed to the second film layer, thereby forming an artificial muscle comprising the first electrode assembly and the second electrode assembly housed within a housing formed from the first film layer and the second film layer. Forming each electrode assembly involves heat-sealing the support polymer to the electrodes and electrode insulators while the layer stack is positioned in the vacuum bag, such that the support polymer bonds to the electrodes when the layer stack is removed from the vacuum bag. Includes, The support polymer has a protruding portion that is bonded to the electrode insulator when the layer stack is removed from the vacuum bag. A method for manufacturing artificial muscles.

10. The method according to claim 9, further comprising injecting a dielectric fluid into the artificial muscle between the first electrode assembly and the second electrode assembly.

11. The method according to claim 9, wherein sealing the first film layer to the second film layer defines a sealed portion of the housing of the artificial muscle, and the housing further comprises an unsealed portion surrounded by the sealed portion, and the electrode region and expandable fluid region of the housing are located in the unsealed portion.

12. Each electrode of the first electrode assembly and the second electrode assembly comprises two or more radially extending portions and two or more bridge portions, The method according to claim 9, wherein each of the two or more bridge portions interconnects adjacent radially extending portions.

13. The method according to claim 9, wherein sealing the first film layer to the second film layer includes heat sealing the first film layer to the second film layer.

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