Actuator with sealable edge region

Actuators having reversible seals are described herein. The actuators can move from a first position to a second position and lock in the second position using a reversible seal. The device can include a soft hydraulic actuator having a fluid-impermeable membrane. The fluid-impermeable membrane can define a compartment, the compartment having a central region, an edge region extending from and fluidly connected with the central region, a reversible seal between the central region and the edge region, and a dielectric fluid. When actuated, the actuators can force fluid through the reversible seals and into the edge region. Once in the edge region, the reversible seals be actuated and controllably sealed to prevent return flow.

TECHNICAL FIELD

The subject matter described herein generally relates to actuators and, more particularly, actuators with a sealable edge region.

BACKGROUND

Control systems employed for the actuation and positioning of a remote object or the like can include pneumatic, hydraulic and electromechanical systems. These control systems can be used to control the movement of a variety of objects, such as autonomous devices. Each of these types of systems has particular advantages under some conditions. Pneumatic systems can supply force through the delivery of a compressed gas, whereas hydraulic systems rely on minimally compressible liquids.

Furthermore, high pressures can be employed which reduces the size of the operating equipment. Electromechanical systems rely on electrically moveable components and can include combinations of the previous systems (e.g., electro pneumatic and electro hydraulic systems).

SUMMARY

Disclosed herein is an actuator capable of controllably sealing an edge region, as well as methods for the same. In one or more implementations, an actuator is disclosed. The actuator can include a fluid-impermeable membrane configured to deliver a hydraulic force and a compartment defined by the fluid-impermeable membrane. The compartment can include a central region, an edge region extending from and fluidly connected with the central region, a reversible seal between the central region and the edge region, the reversible seal comprising an interlocking element and a connecting element; and a dielectric fluid.

In another implementation, an actuator is disclosed. The actuator can include a fluid-impermeable membrane. The fluid impermeable membrane can include a first insulating portion defining an interior surface of the fluid-impermeable membrane, the first insulating portion comprising an insulating elastomer. The fluid impermeable membrane can further include one or more central conductive portions connected to an outer surface of the first insulating portion, the central conductive portions comprising a conductive material. The fluid impermeable membrane can further include one or more sealing conductive portions connected to an outer surface of the first insulating portion. The sealing conductive portion can include a conductive material. The fluid impermeable membrane can further include a second insulating portion surrounding an exterior surface of the central conductive portions and the sealing conductive portions. The fluid impermeable membrane can further define a compartment. The compartment can further include a central region. The compartment can further include an edge region extending from and fluidly connected with the central region. The compartment can further include a reversible seal between the central region and the edge region, the reversible seal comprising an interlocking element and a connecting element. The compartment can further include a dielectric fluid.

In another embodiment, an actuator is disclosed. The actuator can include a first conductive portion comprising a conductive material and configured to produce an electric field in response to a first electrical input. The actuator can further include a second conductive portion comprising a conductive material, the second conductive portion being positioned opposite the first conductive portion and configured to attract to the first conductive portion in response to the first electrical input. The actuator can further include an insulating portion comprising an elastomer configured to electrically isolate the first conductive portion from the second conductive portion. The actuator can further include a compartment defined within the insulating portion and having a dielectric fluid, the compartment being configured to deliver a hydraulic force to the insulating portion in response to adherence of the first conductive portion and the second conductive portion. The actuator can further include a reversible seal comprising an interlocking element and a connecting element, the reversible seal positioned within the compartment and configured to maintain the hydraulic force on the insulating portion and release the hydraulic force upon receiving a second electrical input.

To facilitate understanding, identical reference numerals have been used, wherever possible, to designate identical elements that are common to the figures. Additionally, elements of one or more implementations may be advantageously adapted for utilization in other implementations described herein.

DETAILED DESCRIPTION

The implementations disclosed herein generally relate to an actuator. The implementations described can enable the actuator to maintain an actuated position without further electrical input. The actuator includes a fluid-impermeable membrane defining a compartment which can contain a dielectric fluid. Within the fluid-impermeable membrane is a reversible seal. The actuator can be configured to remain in an activated position, after power to the soft hydraulic actuator is turned off, by sealing the reversible seal. The reversible seal can include one or more interlocking components that can block a fluid passage within the compartment of the fluid-impermeable membrane.

Conductive portions of the actuator can have a deactivated state, such that the electrodes do not compress the fluid-impermeable membrane. Power can be supplied to the electrodes, causing the electrodes to move toward each other, to have an activated state. As a result, the compartment of the fluid-impermeable membrane is compressed, and the dielectric fluid is squeezed to an outer edge region on the membrane, passing the reversible seal to the edge region. When the reversible seal is not activated, the fluid flows through the region freely. The flow of the dielectric fluid into the edge region of the compartment causes the edge region to bulge/stretch to accommodate the dielectric fluid. The reversible seal can then be closed through a secondary actuation or during the initial actuation, creating an interlocking seal which does not allow further fluid flow. Thus, the dielectric fluid is trapped in the edge region of the compartment until the reversible seal is opened to allow reverse flow. The implementations disclosed herein are more clearly described with reference to the figures below.

FIG. 1are sectional views of an actuator100, according to one or more implementations. The actuator100can be a hydraulic actuator. As will be described herein, the actuator100can be configured for connection with a surface and/or for moving one or more objects. The actuator100can have a pliable or semi-pliable body, or can otherwise have a soft body. The actuator100can be an electrostatic device capable of displacing and/or affecting the flow of a fluid with the application of electric charge. The application of an electric charge can be used to attract two or more conductive elements together into an actuated position. “Actuated position,” as used herein, relates to the use electrostatic attraction to bring opposing inner surfaces of the fluid-impermeable membrane toward each other. Thus, hydraulic force can be created. In one or more implementations, the actuated position can be achieved by delivering an electrical input to the conductive portions of the fluid-impermeable membrane, as described herein. “Relaxed position,” as used herein, refers to the actuator100being in a state without power input from electrostatic attraction creating a hydraulic force in the membrane. In one or more implementations, the relaxed position includes the original shape or the substantially original shape of the membrane, in response to stopping the electrical input to the conductive portions. The actuator100can be capable of changing shape in the presence of the electric charge, causing fluid pressure to be applied to the portions of the fluid-impermeable membranes110aand110b. This fluid pressure can then change the shape of the actuator100, in relation to the elasticity of the fluid-impermeable membranes110aand110b. Thus, the actuator100has a first shape which is maintained in the absence of an electrical input. The electric charge to the actuator100can then be delivered, causing the actuator100to achieve to a second state, which can include one or more activated shapes, due to hydraulic forces. When the charge is removed, the actuator100can then return to substantially the first shape.

As shown here, the actuator100can include fluid-impermeable membranes110aand110band a dielectric fluid114. The fluid-impermeable membranes110aand110bcan be composed of layers, such as external insulating portions102aand102b, conductive portions104aand104b, and internal insulating portions106aand106b. “Portion,” as used herein, relates to one or more components which form a layer, a portion of a layer, or structure in the fluid-impermeable membranes110aand110bof the actuator100. The portions can have non-uniform coverage or thickness, as desired. The portions above are described as a single, uniform element or layer for simplicity purposes. However, the portions can include one or more of any of the layers, portions of layers, or variations as disclosed herein. As such, the portions may only partially extend the dimensions of the fluid-impermeable membranes110aand110b. As well, the portions of the fluid-impermeable membranes110aand110bcan meet to form a seal, such that a chamber or compartment118is formed in the inner region of the fluid-impermeable membrane110aand110b. It should be noted that internal insulating portions106aand106bcan be the same structure, or they can be separate structures. Further, external insulating portions102aand102bcan be separate portions, or they can be the same structure.

The fluid-impermeable membranes110aand110b, or components thereof (e.g., the external insulating portions102aand102b, the conductive portions104aand104b, and/or the internal insulating portions106aand106b), can be flexible and/or elastic at one or more points and/or across one or more portions of the fluid-impermeable membranes110aand110b. In one or more implementations, the fluid-impermeable membranes110aand110b, or components thereof, are completely flexible and elastic. In another implementation, the fluid-impermeable membranes110aand110bare flexible across the entirety but only elastic across one or more strips of the fluid-impermeable membranes110aand110b. In another implementation, the fluid-impermeable membranes110aand110bare flexible and elastic at the external insulating portion102aand102band the internal insulating portions106aand106b, but neither flexible nor elastic at the conductive portions104aand104b. One skilled in the art will understand the variety of combinations of flexibility, elasticity, and positioning of the portions of the fluid-impermeable membranes110aand110b, without further explicit recitation of specific examples herein.

The external insulating portion102aand102bcan form an exterior surface108of the fluid-impermeable membranes110aand110b. In one or more implementations, the external insulating portion102aand102bcan form the entire exterior surface of the fluid-impermeable membranes110aand110b. The external insulating portion102aand102bcan be flexible and/or elastic at one or more portions. In one or more implementations, the external insulating portions102aand102bare entirely flexible and elastic. In another implementation, the external insulating portion102aand102bcan have interspersed regions of flexibility, or flexibility and elasticity. The interspersed regions can be in a pattern or random, as desired. The external insulating portion102aand102bcan form an interface with the surface of one or more inner layers, such as the internal insulating portions106aand106band/or the conductive portions104aand104b.

The external insulating portion102aand102bcan include a polymer, an elastomeric polymer (elastomer) or both. The use of a plurality of different encapsulating elastomers and/or polymers of varying degrees of softness and hardness can be employed. The polymers used in the implementations described herein can further include the addition of a plasticizer, such as phthalate esters. The polymers or elastomers may be natural or synthetic. Examples of elastomers usable as part of the external insulating portion102aand102bcan include an insulating elastomer, such as nitrile, ethylene propylene diene monomer (EPDM), fluorosilicone (FVMQ), vinylidene fluoride (VDF), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), perfluoromethylvinylether (PMVE), polydimethylsiloxane (PDMS), natural rubber, neoprene, polyurethane, silicone, silicone rubber, or combinations thereof. The external insulating portion102aand102bcan be described with regards to electrical insulation. The electrical insulation of the external insulating portion102aand102bcan be described in relation to the dielectric constant, or κvalue, of said material, such as having a higher or lower dielectric constant. The term “elastomer,” as used herein, means a material which can be stretched by an external force at room temperature to at least twice its original length, and then upon immediate release of the external force, can return to its original length. Room temperature can generally refer to a temperature in a range of from about 20° C. to about 25° C. Elastomers, as used herein, can include a thermoplastic, and may be cross-linked or thermoset.

The conductive portions104aand104bcan be largely or entirely internal elements of the fluid-impermeable membranes110aand110b. The conductive portions104aand104bcan be conductive to electrical current, such that the conductive portion creates an electric field. In one or more implementations, the conductive portions104aand104bcan be formed between the external insulating portion102aand102band the internal insulating portions106aand106b. In another implementation, the conductive portions104aand104bcan include hydrogels. The conductive portions104aand104bcan further include a polymer, an elastomeric polymer (elastomer) or both. Examples of elastomers usable as part of the conductive portions104aand104bcan include nitrile, EPDM, fluorosilicone (FVMQ), vinylidene fluoride (VDF), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), perfluoromethylvinylether (PMVE), polydimethylsiloxane (PDMS), natural rubber, neoprene, polyurethane, silicone, or combinations thereof. The conductive portions104aand104bcan be composed or further include a conductive material, such as an electrically conductive dopant. Electrically conductive dopants can include silver, gold, platinum, copper, aluminum, or others. In further implementations, the conductive portions104aand104bcan include inks and adhesives, for the purpose of flexibility and/or conductivity.

The internal insulating portions106aand106bcan form an interior surface112of the fluid-impermeable membranes110aand110b. The internal insulating portions106aand106bcan be composed of a material similar to that of the external insulating portion102aand102b. In one or more implementations, the internal insulating portions106aand106bcan include an insulating elastomer, such as nitrile, EPDM, fluorosilicone (FVMQ), vinylidene fluoride (VDF), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), perfluoromethylvinylether (PMVE), polydimethylsiloxane (PDMS), natural rubber, neoprene, polyurethane, silicone, or combinations thereof. In one or more implementations, the internal insulating portions106aand106bcan include polymers and elastomers having a high electric breakdown voltage and not electrically conductive. The internal insulating portions106aand106bcan further include a protective layer116. The protective layer116can be formed between the internal insulating portions106aand106band a dielectric fluid114. In some arrangements, the protective layer116can form a part of the interior surface112. The protective layer116can be uniform or vary in size or composition. Further, the protective layer116can be non-conductive and/or resistant to corrosion. In one or more implementations, the protective layer116is a flexible and corrosion resistant plastic, such as fluorinated ethylene propylene (FEP).

FIGS. 2A and 2Bdepict side views of a portion of the actuator200having a reversible seal220, according to one or more implementations. The side views depict the actuator200as an operating unit, according to one or more implementations. In one or more implementations, the fluid-impermeable membranes210aand210bare sealed at the edges and disposed against one another. The actuator200and/or components thereof can be substantially similar to the actuator100, described with reference toFIG. 1. The insulating portions206aand206bcan form the interior surface212of the compartment218. The dielectric fluid214can be disposed inside of the compartment218.

The fluid-impermeable membranes210aand210bcan be sealed at one or more edges, such that the fluid-impermeable membranes210aand210bcan form a fluid-impermeable compartment218. However, in some implementations, the fluid-impermeable membranes210aand210bmay not be separate structures, but instead are a unitary structure. The compartment218can hold the dielectric fluid214. The dielectric fluid214can be a fluid that is resistant to electrical breakdown and/or provides insulation. In one or more implementations, the dielectric fluid214can prevent arcing between one or more opposing layers (e.g., the opposing conductive portions204a,204b). The dielectric fluid214can be a lipid based fluid, such as a vegetable oil-based dielectric fluid. In one implementation, the dielectric fluid214can be ethylene glycol. The dielectric fluid214can have a low dielectric constant, or κvalue.

The actuator200can include one or more reversible seals220, which can include an interlocking element223and a connecting element222. The reversible seals220are capable of selectively subdividing the compartment218. The interlocking element223can be a component capable of or configured to receive and maintain contact with the connecting element222. As such, the interlocking element223can have a corresponding shape to at least a portion of the connecting element222, such that the connecting element222does not separate from the interlocking element in the absence of a secondary input. The secondary input can be an applied hydraulic force, an electroactive movement (e.g., an electroactive polymer receiving an electrical input), or others. In some implementations, the connecting element222can be positioned in alignment with the interlocking element223(e.g., forming an opening219) to form one or more reversible seals220. An example can include two (2) interlocking elements223positioned to interact with the connecting element222is shown inFIG. 2A. In further implementations, the connecting element222can be positioned in connection with an integrated interlocking element223to form one or more reversible seals220, an example of which is shown inFIG. 2B.

When engaged, the connecting element222and the interlocking element223of the reversible seals220can subdivide the compartment218into at least a central region224and an edge region226. The connecting element222can be composed of a material substantially similar to one or more materials for the fluid-impermeable membranes210aand210b. The central region224is a region of the compartment218which is in the center of the actuator200. The central region224can include the conductive portions204aand204b. The edge region226is a region of the compartment218which includes the edge of the actuator200. Further, the edge region226can include one or more edge conductive portions235aand235b.

The reversible seals220can function to control the flow of the dielectric fluid214between the central region224and the edge region226. The reversible seals220can include the interlocking element223. The interlocking element223can include one or more arms capable of connecting with the connecting element222in a grip-like fashion. The interlocking element223can include one or more flexible or semi-flexible polymers. In one or more embodiments, the interlocking element223can include an electroactive polymer. Materials suitable for use as an electroactive polymer, in the one or more implementations described herein, can include any insulating polymer or rubber (or a combination thereof) that deforms in response to an electrostatic force or whose deformation results in a change in electric field. Exemplary materials suitable for use as an electroactive polymer can include silicone elastomers, acrylic elastomers, polyurethanes, thermoplastic elastomers, copolymers comprising PVDF, pressure-sensitive adhesives, fluoroelastomers, polymers comprising silicone and acrylic moieties, and the like. Polymers, such as those including silicone and acrylic moieties, can include copolymers having silicone and acrylic moieties, polymer blends having a silicone elastomer and an acrylic elastomer, or others. Combinations of some of these materials may also be used as the interlocking element223and/or the connecting element222in the reversible seals220disclosed herein.

Materials used as an electroactive polymer for the interlocking element223can be selected based on one or more material properties. Material properties used for selection can include a high electrical breakdown strength, a low modulus of elasticity (such as for controlling the level of deformation), or others. The interlocking element223used herein can include a wide range of thicknesses to suit the fluid control requirements of the present implementations. The thickness of the interlocking element223in the reversible seal220can be reduced by stretching an existing polymer film in one or both planar directions, can be fabricated and implemented as thin films, or others.

In one or more implementations, the one or more electrodes240can positioned near, positioned on or integrated with one or more components of the actuator200. One or more electrodes240can be connected with the interlocking element223of the reversible seal220. The electrodes240can be flexible or malleable, such as being capable of deforming or deflecting without compromising mechanical or electrical performance. Generally, electrodes240as used herein can be of a shape and material such that they can supply a suitable voltage to or receive a suitable voltage from the reversible seal220. The voltage delivered through the electrodes240be either constant or varying over time. In one or more implementations, the electrodes240can adhere to a surface of the interlocking element223and/or the connecting element222. Electrodes240, which can adhere to a component of the reversible seal220, can be compliant and conform to the changing shape of the reversible seal220. In further implementations, the electrodes240can be formed in the connecting element222and/or the interlocking element223of the reversible seal220. Correspondingly, one or more implementations can include compliant electrodes that conform to the shape of the reversible seal220which they are attached to or positioned within. The electrodes240can be applied to a portion of the interlocking element223of the reversible seal220and define an active area according to their geometry.

The reversible seal220is depicted here as a unit, including a cut-away portion of a connecting element222and an interlocking element223. The connecting element222and/or the interlocking element223can be a continuous element, such as following the circumference of a circle or moving from adjoining wall to adjoining wall. As such, the connecting element222can be used in conjunction with the interlocking element223to form a continuous reversible seal220. The interlocking element223can further be associated with one or more electrodes240. When the connecting element222and the interlocking element223are not engaged, an opening219can be defined between them. The opening219can be configured to allow the dielectric fluid214to move between the central region224and an edge region226when the reversible seal220is open.

In one or more implementations, the interlocking element223can include material properties such that the interlocking element223can connect with the connecting element222to control the opening219. The material properties can include shape and dimensions, material composition, and others. The material composition can include one or more material types and/or combinations of materials. In one implementation, the interlocking element223can include polymers and electroactive polymers, each as described above.

The interlocking element223can have a variety of dimensions and form one or more shapes or combinations of shapes. Possible shapes for the interlocking element223can include all primary shapes or combinations thereof, such that the interlocking element223is capable of closing the opening219in conjunction with the connecting element222. In this example, the interlocking element223is a square-shaped with a slightly expanded head configured for interconnection with the equivalent region of the connecting element222. In further implementations, the interlocking element223can include components that are triangular, circular, hexagonal, or others.

In operation, the interlocking element223can regulate and/or control fluidic communication between the central region224and the edge region226. The interlocking element223can be connected to the connecting element222by sealing conductive portions230a,230b. The sealing conductive portions230a,230bcan receive an electric input which causes the sealing conductive portions230a,230bto attract. The force caused by the attraction of the sealing conductive portions230a,230bmoves a head region225of the connecting element222into connection with a receiving region227of the interlocking element223. Thus, the physical force locks the interlocking element223and the connecting element222together (e.g., a locked state). The connecting edge228of the interlocking element223can be separated from the connecting element222(e.g., the unlocked state) or connected to the connecting element222(e.g., the locked state). In embodiments which employ an electroactive polymer, the interlocking element223can change state to separate from the connecting element222. When the interlocking element223is in a passive unlocked state (e.g., an unlocked state while not receiving an electric current), the reversible seal220can allow the flow of the dielectric fluid214through the opening219and between the central region224and the edge region226. However, the locked state of the interlocking element223can limit or prevent the return flow of the dielectric fluid214into the central region224.

When the interlocking element223is in an active state (e.g., receiving an electric current), the interlocking element223can move to a second position which no longer maintains a connection with the connecting element222. If previously in a locked state, thus blocking fluid flow, the second position of the interlocking element223can release the connecting element222and allow a return flow of the dielectric fluid214. In one example, when the interlocking element223receives an electric charge, such as from the electrode240, the flexing edge228can move out and away from the connecting element222. This movement of the interlocking element223can allow the dielectric fluid214to flow through the opening219. In embodiments which employ other polymers, the interlocking element223can be physically separated from the connecting element222by the creation of a fluid force in the edge region226. The edge conductive portions235a,235bcan receive an electric charge, thus creating a hydraulic force in the edge region226. This hydraulic force can apply pressure on the portion of the membrane connected to the connecting element222and the interlocking element223, thus causing the elements to physically separate.

In further embodiments, the connecting element222and the interlocking element223can be physically separated by an optional electroactive bead245. The electroactive bead245can be configured to lift or expand in response to an electric input. As the electroactive bead245lifts or expands, the connecting element222and the interlocking element223can be moved apart which opens the seal. As such, the dielectric fluid214can equilibrate between the central region224and the edge region226. The properties of movement for the interlocking element223can be controlled as desired, including the range and direction of movement, the force of movement, and other facets of the change in position, in accordance with implementations described herein.

Thus, the reversible seal220can control the flow of fluids from either the edge region226or the central region224with minimal energy input. When in a passive state, the reversible seal can allow for free flow of fluid between the edge region226and the central region224. When in an active state, the reversible seal can allow free flow of fluid between the edge region226and the central region224. Thus, the actuator200can be actuated and held in an actuated position without further input from the conductive portion204aand204b.

FIGS. 3A-3Eare depictions of a series of movements from an example of an actuator300, according to one or more implementations. The actuator300can be a soft hydraulic actuator, as described above with reference toFIG. 1. The actuator300can include a fluid-impermeable membrane302, including an insulating portion303with one or more central conductive portions304a, one or more sealing conductive portions304b, and one or more edge conductive portions304cdisposed therein. The fluid-impermeable membrane302can define a compartment306. The compartment306can hold a dielectric fluid308.

Further, the compartment306can be subdivided into a central region310and an edge region312by a reversible seal314. The reversible seal314can include a connecting element316, an interlocking element318, and an opening319. The fluid-impermeable membrane302can be connected with an electrode320and/or a control unit322, such as for delivering an electrical input to one or more responsive components as described herein. The actuator300and/or components thereof can be substantially similar to the actuator100, described with reference toFIG. 1. The reversible seal314can be substantially similar to the reversible seal220, described with reference toFIGS. 2A and 2B.

The actuator300can be configured to lock the actuator300in an active state. The actuator300can have central conductive portions304acomprising a conductive material. The central conductive portions304acan be configured to produce an electric field in response to a first electrical input. The actuator300can further have sealing conductive portions304bcomprising a conductive material. The sealing conductive portions304bcan be positioned opposite each other, and the central conductive portions304acan be positioned opposite each other. The sealing conductive portions304bcan be configured to attract to each other, and the central conductive portions304acan be configured to attract to each other, in response to the first electrical input. The actuator300can further include the insulating portion303as part of the fluid-impermeable membrane302. The insulating portion303can be configured to electrically isolate the central conductive portions304afrom the sealing conductive portions304b. The actuator300can include the compartment306, as defined by the insulating portion303. The compartment306can include the dielectric fluid308and can be configured to deliver a hydraulic force of the dielectric fluid308to at least the insulating portion303in response to activation and/or adherence of the central conductive portions304aand the sealing conductive portions304b. The actuator300can further include a reversible seal314positioned within the compartment306. The reversible seal314can be configured to maintain the hydraulic force on the insulating portion303. The reversible seal314can further be configured to release the hydraulic force upon receiving an unlocking hydraulic force, such as from the electrode320and/or the control unit322at the one or more edge conductive portions304c.

FIG. 3Adepicts the actuator300in a relaxed unlocked state. The dielectric fluid308can be substantially evenly dispersed across the central region310and the edge region312. The central conductive portions304a, the sealing conductive portions304b, and the edge conductive portions304ccan be in a passive state, not receiving an electric input. As such, the hydraulic force delivered by dielectric fluid308in conjunction with the fluid-impermeable membrane302can be equal throughout the actuator300. As well, the interlocking element318of the reversible seal314can be separated from the connecting element316, allowing flow through the opening319. As shown here, the interlocking element318can allow flow through the opening319, between the central region310and the edge region312.

FIG. 3Bdepicts the actuator300with the central conductive portions304ain an active state. Here, the central conductive portions304acan receive an electric input, which transitions the central conductive portions304afrom the passive state to an active state. The dielectric fluid308can be forced by the contraction in the central region310into the edge region312through the opening319. As such, the hydraulic force delivered by dielectric fluid308in conjunction with the fluid-impermeable membrane302of the central region310can expand the fluid-impermeable membrane302in the edge region312. During this time, the interlocking element318of the reversible seal314can be in a passive state, allowing flow from the central region310into the edge region312.

When the central conductive portions304aare in the active state, fluid pressure from the dielectric fluid is higher in the central region310than the edge region312. The interlocking element318and the connecting element316of the reversible seal314allows the flow of the dielectric fluid308through the opening319from the central region310into the edge region312. The hydraulic force can continue until the pressure from the edge region312is equal to the pressure from the central region310, or until the dielectric fluid has moved entirely over into the edge region312. The fluid-impermeable membrane302in the edge region312can be expanded in relation to the elasticity of the fluid-impermeable membrane302.

FIG. 3Cdepicts the actuator300in a locked active state. Here, the electric input has been further applied to sealing conductive portions304b, which forces a head region325of connecting element316and a receiving region330of the interlocking element318together. Thus, the reversible seal314is in a locked state. The dielectric fluid308, being previously forced by the contraction of the central conductive portion304ain the central region310into the edge region312through the opening319, is maintained by the locked state of the reversible seal314. The hydraulic force delivered by dielectric fluid308in conjunction with the fluid-impermeable membrane302of the central region310can be held in place by the reversible seal314. Thus, the reversible seal314maintains the expansion of the fluid-impermeable membrane302in the edge region312.

In the locked active state, the interlocking element318of the reversible seal314is forced into the connecting element316, which blocks return flow through the opening319from the edge region312into central region310. As the reversible seal314is not permeable, the hydraulic force applies an equal force to the fluid-impermeable membrane302and the reversible seal314. The hydraulic force is insufficient to separate the reversible seal314thus creating the opening319. As such, a hydraulic force is delivered to the edge region312and sealed by the locked active state of the reversible seal314.

FIG. 3Ddepicts the actuator300in a locked passive state. Here, the electric input has been removed from the central conductive portions304aand the sealing conductive portions304b, which allows the conductive portions304to move into the passive state from the active state. The dielectric fluid308, being previously forced by the contraction in the central region310into the edge region312through the opening319, is maintained by the reversible seal314. The hydraulic force delivered by dielectric fluid308in conjunction with the fluid-impermeable membrane302of the central region310can be held in place by the reversible seal314. Thus, the interlocking element318maintains the expansion of the fluid-impermeable membrane302in the edge region312.

In the locked passive state, the receiving region330of the interlocking element318is maintained in connection with the head region325of connecting element316by the interlocking size and shape of the respective components. Thus the reversible seal314continues to block return flow through the opening319from the edge region312into central region310. The interlocking element318is shown here as two (2) strips, each attached at a first end to the fluid-impermeable membrane302. As the interlocking element318is not permeable and the receiving region330is in contact with the head region325, the hydraulic force applies an equal force to the fluid-impermeable membrane302and the interlocking element318. The hydraulic force thus compresses the interlocking element318against the connecting element316to block the opening319. As such, a hydraulic force is delivered to the edge region312and maintained indefinitely by the interlocking element318in the absence of electrical input.

FIG. 3Edepicts the actuator300in an unlocked active state. Here, the electric input has been removed from the central conductive portions304aand the sealing conductive portions304b, which as described above places those conductive portions into the passive state. The dielectric fluid308, being previously forced by the contraction in the central region310into the edge region312through the opening319, is released by actuating the edge conductive portions304c. The edge conductive portions304ccan receive an electric input from the electrode320and/or the control unit322to create a physical movement in the edge region312. Thus, the hydraulic force delivered by dielectric fluid308in conjunction with the fluid-impermeable membrane302of the edge region312can be used to release the connecting element316from the interlocking element318. Once released, the dielectric fluid308once again equilibrates between the central region310and the edge region312.

In the active state, the interlocking element318of the reversible seal314is forced away from the connecting element316, once again opening fluid communication between the edge region312and the central region310. The interlocking element318can be separated from the connecting element316by the increase in hydraulic force from the actuation of the edge conductive portions304c. The edge conductive portions304ccan respond to the electric input by closing together, as previosuly described with reference toFIG. 1. The hydraulic force thus breaks the seal between the connecting element316and the interlocking element318, allowing the dielectric fluid308to return to other regions of the actuator300.

The actuator300described herein can provide numerous benefits. By locking in an activated state, the actuator300can deliver force through hydraulic pressure without further energy input. Thus, lift moving or otherwise displacing an object can be done in a more energy efficient fashion and over a longer period of time. Further, the actuator300can deliver hydraulic force in stages, such as when using more than one pair of conductive portions for actuation.

FIGS. 4A-4Eare depictions of a series of movements from an example of an actuator400, according to one or more implementations. The actuator400can be a soft hydraulic actuator, as described above with reference toFIG. 1. The actuator400can include a fluid-impermeable membrane402, including an insulating portion403. The insulating portion403can include one or more central conductive portions404aand one or more sealing conductive portions404bdisposed therein. The fluid-impermeable membrane402can define a compartment406. The compartment406can hold a dielectric fluid408.

Further, the compartment406can be subdivided into a central region410and an edge region412by a reversible seal414. The reversible seal414can include a connecting element416, an interlocking element418, and an opening419. The interlocking element418, shown here as a single element, can be connected with an electrode420and/or a control unit422. The actuator400and/or components thereof can be substantially similar to the soft hydraulic actuator100, described with reference toFIG. 1. The reversible seal414and/or components thereof can be substantially similar to the reversible seals220described with reference toFIGS. 2A and 2B.

FIG. 4Adepicts the actuator400in a relaxed unlocked state. The dielectric fluid408can be substantially evenly dispersed across the central region410and the edge region412. The central conductive portions404aand the sealing conductive portions404bcan be in a passive state, not receiving an electric input. As such, the hydraulic force delivered by dielectric fluid408in conjunction with the fluid-impermeable membrane402can be equal throughout the actuator400. As well, the interlocking element418of the reversible seal414can be separated from the connecting element416, allowing flow through the opening419. As shown here, the interlocking element418can allow flow through the opening419, between the central region410and the edge region412.

FIG. 4Bdepicts the actuator400with the central conductive portions404ain an active state. Here, the central conductive portions404acan receive an electric input, which transitions the central conductive portions404afrom the passive state to an active state. The dielectric fluid408can be forced by the contraction in the central region410into the edge region412through the opening419. As such, the hydraulic force delivered by dielectric fluid408in conjunction with the fluid-impermeable membrane402of the central region410can expand the fluid-impermeable membrane402in the edge region412. During this time, the interlocking element418of the reversible seal414can be in a passive unlocked state, allowing flow from the central region410into the edge region412.

When the central conductive portions404aare in the active state, fluid pressure from the dielectric fluid is higher in the central region410than the edge region412. The interlocking element418and the connecting element416of the reversible seal414allows the flow of the dielectric fluid408through the opening419from the central region410into the edge region412. The hydraulic force can continue until the pressure from the edge region412is equal to the pressure from the central region410, or until the dielectric fluid has moved entirely over into the edge region412. The fluid-impermeable membrane402in the edge region412can be expanded in relation to the elasticity of the fluid-impermeable membrane402.

FIG. 4Cdepicts the actuator400in a locked active state. Here, the electric input has been further applied to sealing conductive portions404b, which forces a head region425of connecting element416and a receiving region430of the interlocking element418together. Thus, the reversible seal414is in a locked state. The dielectric fluid408, being previously forced by the contraction of the central conductive portions404ain the central region410into the edge region412through the opening419, is maintained by the locked state of the reversible seal414. The hydraulic force delivered by dielectric fluid408in conjunction with the fluid-impermeable membrane402of the central region410can be held in place by the reversible seal414. Thus, the reversible seal414maintains the expansion of the fluid-impermeable membrane402in the edge region412.

In the locked active state, the interlocking element418of the reversible seal414is forced into the connecting element416by the sealing conductive portions404b. This connection blocks flow through the opening419from the edge region412into central region410. As the reversible seal414is not permeable, the hydraulic force applies an equal force to the fluid-impermeable membrane402and the reversible seal414. The hydraulic force is insufficient to separate the reversible seal414thus creating the opening419. As such, a hydraulic force is delivered to the edge region412and maintained by the sealing conductive portions404bagainst the reversible seal414.

FIG. 4Ddepicts the actuator400in a locked passive state. Here, the electric input has been removed from the central conductive portions404aand the sealing conductive portions404b, which allows the conductive portions404a,404bto move into the passive state from the active state. The dielectric fluid408, being previously forced by the contraction in the central region410into the edge region412through the opening419, is maintained by the reversible seal414. The hydraulic force delivered by dielectric fluid408in conjunction with the fluid-impermeable membrane402of the central region410can be held in place by the reversible seal414. Thus, the interlocking element418maintains the expansion of the fluid-impermeable membrane402in the edge region412.

In the locked passive state, the receiving region430of the interlocking element418of the reversible seal414is maintained in connection with the head region425of connecting element416by the interlocking size and shape of the respective components. Thus the reversible seal414continues to block return flow through the opening419from the edge region412into central region410. The interlocking element418is shown here as a strip attached at a first end to the connecting element416and comprising an electroactive polymer. As the interlocking element418is not permeable, the hydraulic force applies an equal force to the fluid-impermeable membrane402and the interlocking element418. The hydraulic force thus compresses the interlocking element418against the opening419creating a seal. As such, a hydraulic force is delivered to the edge region412and maintained indefinitely by the interlocking element418.

FIG. 4Edepicts the actuator400in an unlocked active state. Here, the electric input has been removed from the central conductive portions404aand the sealing conductive portions404b, which, as described above, places the central conductive portions404aand the sealing conductive portions404binto the passive state. The dielectric fluid408, being previously forced by the contraction in the central region410into the edge region412through the opening419, is released by actuating the interlocking element418. The interlocking element418can receive an electric input from the electrode420and/or the control unit422to create a physical movement in the interlocking element418. The hydraulic force delivered by dielectric fluid408in conjunction with the fluid-impermeable membrane402of the edge region412can be released by the interlocking element418. Thus, the dielectric fluid408once again equilibrates between the central region410and the edge region412.

In the active state, the interlocking element418of the reversible seal414lifts away from the connecting element416, forming the opening419between the edge region412and the central region410. The interlocking element418comprising an electroactive polymer can move away from or otherwise separate from the connecting element416. The interlocking element418can respond to the electric input in a number of ways, including lifting away from, contracting/expanding, shifting upward, or otherwise separating from the connecting element416. Though shown as separating from the connecting element416bilaterally, the interlocking element418can act in a non-uniform fashion. The interlocking element418thus breaks the seal with the connecting element416to form the opening419, thus allowing the dielectric fluid408to return to other regions of the actuator400.

Thus, the actuator400can be configured to lock the actuator400in an active state. The actuator400can have a first conductive portion (e.g., the central conductive portion404aor the sealing conductive portions404bon the lower side ofFIGS. 4A-4E) comprising a conductive material. The first conductive portion can be configured to produce an electric field in response to a first electrical input. The actuator400can further have a second conductive portion (e.g., the central conductive portion404aor the sealing conductive portion404bon the upper side ofFIGS. 4A-4E) comprising a conductive material. The second conductive portion can be positioned opposite the first conductive portion. The second conductive portion can be configured to attract to the first conductive portion in response to the first electrical input. The actuator400can further include the insulating portion403as part of the fluid-impermeable membrane402. The insulating portion403can be configured to electrically isolate the first conductive portion from the second conductive portion. The actuator400can include the compartment406, as defined by the insulating portion403. The compartment406can include the dielectric fluid408and can be configured to deliver a hydraulic force of the dielectric fluid408to at least the insulating portion403in response to activation and/or adherence of the first conductive portion and the second conductive portion. The actuator400can further include a reversible seal414positioned within the compartment406. The reversible seal414can be configured to maintain the hydraulic force on the insulating portion403. The reversible seal414can further be configured to release the hydraulic force upon receiving a second electrical input, such as from the electrode420and/or the control unit422at the interlocking element418. In further embodiments, the electroactive polymer can be in the connecting element416and/or the interlocking element418. Thus, an electric input can create a conformational shift in the connecting element416and/or the interlocking element418to cause the above described separation.

The actuator400described herein can provide numerous benefits. By locking in an activated state, the actuator400can deliver force through hydraulic pressure without further energy input. Thus, lift moving or otherwise displacing an object can be done in a more energy efficient fashion and over a longer period of time. Further, the actuator400can deliver hydraulic force in stages, such as when using more than one pair of conductive portions for actuation.

In the description above, certain specific details are outlined in order to provide a thorough understanding of various implementations. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the implementations. Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is, as “including, but not limited to.” Further, headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.

Reference throughout this specification to “one or more implementations” or “an implementation” means that a particular feature, structure or characteristic described in connection with the implementation is included in at least one or more implementations. Thus, the appearances of the phrases “in one or more implementations” or “in an implementation” in various places throughout this specification are not necessarily all referring to the same implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more implementations. Also, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

The headings (such as “Background” and “Summary”) and sub-headings used herein are intended only for general organization of topics within the present disclosure and are not intended to limit the disclosure of the technology or any aspect thereof. The recitation of multiple implementations having stated features is not intended to exclude other implementations having additional features, or other implementations incorporating different combinations of the stated features. As used herein, the terms “comprise” and “include” and their variants are intended to be non-limiting, such that recitation of items in succession or a list is not to the exclusion of other like items that may also be useful in the devices and methods of this technology. Similarly, the terms “can” and “may” and their variants are intended to be non-limiting, such that recitation that an implementation can or may comprise certain elements or features does not exclude other implementations of the present technology that do not contain those elements or features.

The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the specification and the following claims. Reference herein to one aspect, or various aspects means that a particular feature, structure, or characteristic described in connection with an implementation or particular system is included in at least one or more implementations or aspect. The appearances of the phrase “in one aspect” (or variations thereof) are not necessarily referring to the same aspect or implementation. It should also be understood that the various method steps discussed herein do not have to be carried out in the same order as depicted, and not each method step is required in each aspect or implementation.

The preceding description of the implementations has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular implementation are generally not limited to that particular implementation, but, where applicable, are interchangeable and can be used in a selected implementation, even if not specifically shown or described. The same may also be varied in many ways. Such variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

While the preceding is directed to implementations of the disclosed devices, systems, and methods, other and further implementations of the disclosed devices, systems, and methods can be devised without departing from the basic scope thereof. The scope thereof is determined by the claims that follow.