A hybrid actuation device includes an artificial muscle, a first plate coupled to a second plate, and a shape memory alloy wire. The artificial muscle includes a housing, a first electrode and a second electrode, and a dielectric fluid. The housing includes a first film layer, a second film layer, an electrode region, and an expandable fluid region. The first electrode and the second electrode are each disposed in the electrode region of the housing. The dielectric fluid is disposed within the housing. The first plate and the second plate are positioned within the housing, the first plate positioned between the first film layer and the first electrode, and the second plate positioned between the second film layer and the second electrode. The shape memory alloy wire extends from the first plate to the second plate and through the dielectric fluid.

An approximation method and system are provided for more quickly controlling a prosthetic or other device by reducing computational processing time in a muscle model that can be used to control the prosthetic. For a given muscle, the approximation method can quickly compute polynomial structures for a muscle length and for each associated moment arms, which may be used to generate a torque for a joint position of a physics model. The physics model, in turn, produces a next joint position and velocity data for driving a prosthetic. The approximation method expands the polynomial structures as long as expansion is possible and sufficiently beneficial. The computations can be performed quickly by expanding the polynomial structures in a way that constrains the muscle length polynomial to the moment arm polynomial structures, and vice versa.

An artificial muscle includes a housing including an electrode region and an expandable liquid region and a dielectric liquid housed within the housing. The artificial muscle further includes an electrode pair positioned in the electrode region of the housing, the electrode pair comprising a first electrode and a second electrode, wherein the electrode pair is configured to actuate between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric liquid into the expandable liquid region, expanding the expandable liquid region. The artificial muscle also includes a composite electrical insulating layered structure in contact with at least one of the first electrode or the second electrode, wherein the composite electrical insulating layered structure that includes an electrical insulator layer surrounded by adhesive surfaces. The adhesive surfaces are located between one or more flexible electrical insulators.

A hybrid actuation device includes an artificial muscle, a first plate coupled to a second plate, and a shape memory alloy wire. The artificial muscle includes a housing, a first electrode and a second electrode, and a dielectric fluid. The housing includes a first film layer, a second film layer, an electrode region, and an expandable fluid region. The first electrode and the second electrode are each disposed in the electrode region of the housing. The dielectric fluid is disposed within the housing. The first plate and the second plate are positioned within the housing, the first plate positioned between the first film layer and the first electrode, and the second plate positioned between the second film layer and the second electrode. The shape memory alloy wire extends from the first plate to the second plate and through the dielectric fluid.

In some embodiments, the present invention is directed to an actuator which includes at least the following: a pre-stretched electro-active polymer film being pre-stretched in a single or biaxial planar directions; at least one first semi-stiff conductor attached to a first surface of the pre-stretched electro-active polymer film, wherein the first surface is parallel to the single or biaxial planar stretch directions; at least one second semi-stiff conductor attached to a second surface of the pre-stretched electro-active polymer film, wherein the second surface is opposite to the first surface; where the semi-stiff conductors are configured to: fix the pre-stretched electro-active polymer film in a pre-stretched state and allow the pre-stretched electro-active polymer film to expand; a pair of mechanical connectors coupled to each end of an active region of the pre-stretched electro-active polymer film.

In one aspect, the disclosure relates to free-standing artificial muscles having a polymeric core encased by an elastic spring. The polymeric core can be any two-way shape memory polymer including, but not limited to, a semicrystalline polymer (polybutadiene polymer, a polycaprolactone polymer, a poly(ethylene-co-vinyl acetate)), a rubber, an ionomer, an elastomer, or a gel. In some aspects, the shape memory polymers are crosslinked. In an alternative aspect, the polymeric core is a twisted and coiled polymeric fiber. In other aspects, the polymeric core is reprocessable, remoldable, and/or recyclable. In one aspect, the elastic spring is metallic, ceramic, plastic, or any combination thereof. The stiffnesses or spring rate of the elastic spring and polymeric core, the two-way shape memory effect of the polymeric core, and their geometrical dimensions can be optimized to maximize the actuation strain based on theoretical principles described herein. Also disclosed are devices incorporating the free-standing artificial muscles.

Provided is a soft actuator. The soft actuator includes a first bistable polymer layer, a second bistable polymer layer on the first bistable polymer layer, a first flexible electrode layer on an upper surface of the second bistable polymer layer, a second flexible electrode layer between the first bistable polymer layer and the second bistable polymer layer, a first light absorption heating layer disposed on the first flexible electrode layer and configured to increase a temperature when light is absorbed, and a first voltage supply unit, wherein the first voltage supply unit is electrically connected to the first flexible electrode layer and the second flexible electrode layer.

In some embodiments, the present invention is directed to an actuator which includes at least the following: a pre-stretched electro-active polymer film being pre-stretched in a single or biaxial planar directions; at least one first semi-stiff conductor attached to a first surface of the pre-stretched electro-active polymer film, wherein the first surface is parallel to the single or biaxial planar stretch directions; at least one second semi-stiff conductor attached to a second surface of the pre-stretched electro-active polymer film, wherein the second surface is opposite to the first surface; where the semi-stiff conductors are configured to: fix the pre-stretched electro-active polymer film in a pre-stretched state and allow the pre-stretched electro-active polymer film to expand; a pair of mechanical connectors coupled to each end of an active region of the pre-stretched electro-active polymer film.

A thermally responsive shape memory polymer (SMP) actuator includes a body having at least one non-linear segment arranged between first and second ends, with the body comprising a plurality of dots, rods, or layers of SMP material. The SMP material my include a linear aliphatic thermoplastic polyester and at least one other polymer. The non-linear segment may have a substantially flat zig-zag shape arranged between first and second substantially straight segments. A prosthetic device may include multiple thermally responsive shape memory actuators and a movable joint arranged between structural members having anchors associated therewith. At least one first SMP actuator provides pivotal movement in a first direction, and at least one second SMP actuator provides pivotal movement in a second direction. Methods for forming SMP actuators include body formation by additive manufacturing, heating the body to a glass transition temperature range while applying tension, and cooling the body.

The present disclosure provides for a photoredox-responsive material, processes of making the photoredox-responsive material, and methods of use thereof.