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. A first group of SMP actuators provides pivotal movement in a first direction, and a second group of SMP actuators 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.

A system and method for controlling a device, such as a virtual reality (VR) and/or a prosthetic limb are provided. A biomimetic controller of the system comprises a signal processor and a musculoskeletal model. The signal processor processes M biological signals received from a residual limb to transform the M biological signals into N activation signals, where M and N are integers and M is less than N. The musculoskeletal model transforms the N activation signals into intended motion signals. A prosthesis controller transforms the intended motion signals into three or more control signals that are outputted from an output port of the prosthesis controller. A controlled device receives the control signals and performs one or more tasks in accordance with the control signals.

In a driving device of an artificial muscle module and a driving method thereof, the driving device includes a fluid tank unit, a fluid providing line, a fluid collecting line, a circulation pump unit, a temp control unit and a fluid distributing unit. The fluid providing line includes high temp and low temp water tanks. The fluid providing line connects a first side of the artificial muscle module to the fluid tank unit. The fluid collecting line connects a second side of the artificial muscle module to the fluid tank unit. The circulation pump unit is positioned at least one of the fluid providing line and the fluid collecting line. The temp control unit controls temperature of the fluid. The fluid distributing unit is positioned at the fluid collecting line, and distributes the fluid in the fluid collecting line.

An assist wear item is worn on a portion of a living body and has an inner surface brought into contact with the portion. The assist wear item includes assisting actuators, contact sensors, and a controller. Each assisting actuator is driven to expand and contract. The assisting actuators are linearly arranged along an expansion/contraction direction of a muscle at the portion. Each contact sensor detects a contact with an outer surface of the assist wear item. The contact sensors include a first contact sensor and a second contact sensor. The controller increases or decreases a driving power of expansion/contraction driving of an assisting actuator corresponding to a region ranging from the first contact sensor to the second contact sensor if the controller continuously receives a detection result indicating a contact from at least one contact sensor between the first and second contact sensors during a certain time period.

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.

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.

Rate-dependent, elastically-deformable devices according to various embodiments can be stretched and recovered at low elongation rates. Yet they become stiff and resistive to stretching at high elongation rates. These device can be utilized in orthotics, braces, and circulation-enhancing compression garments for the prevention of injury, promotion of personal health, and/or enhancement in human performance. The rate-responsive properties of the devices are critical performance enablers, as they allow the devices to provide a unique balance of comfort and performance that cannot be achieved with conventional, passive straps, braces, and compression garments.

Variable stiffness devices and methods of their use are provided. In some embodiments, a variable stiffness device comprises an inner member defining a compartment for receiving an actuating fluid; an outer member disposed around the inner member; and a granular medium disposed between the inner member and the outer member; wherein the inner member is being moveable in a radial direction from a relaxed state to an expanded state by introducing the actuating fluid into the compartment of the inner member to compress the granular medium against the outer member to increase the stiffness of the device.

An actuator device that includes a first fiber, a conducting material, and a coating. The coating coats the first fiber or the conducting material. The coating may also provide moisture protection, UV protection, thermal insulation and thermal conductivity.

Variable stiffness devices and methods of their use are provided. In some embodiments, a variable stiffness device comprises an inner member defining a compartment for receiving an actuating fluid; an outer member disposed around the inner member; and a granular medium disposed between the inner member and the outer member; wherein the inner member is being moveable in a radial direction from a relaxed state to an expanded state by introducing the actuating fluid into the compartment of the inner member to compress the granular medium against the outer member to increase the stiffness of the device.