A torsional actuator formed of a yarn of twisted shape memory material. The yarn has multiple strands of homogeneous shape memory material that have been homochirally twisted. For torsional actuation, a fractional portion of the yarn is heated such as by Joule heating. Various Joule heating mechanisms include passing an electrical current through an unwound segment of the yarn, or by coating a fractional portion of the length of each homogeneous strand with a coating material of higher electrical conductivity than the electrical conductivity of the shape memory material an passing current through the length of the yarn. The shape memory material may be a shape memory alloy such as a NiTi alloy.

A thermobimetal heat driven turbine having a rotor, and a series of vanes extending from the rotor wherein the vanes comprise two or more separate materials laminated together, said two separate materials having different coefficients of expansion whereby exposure to a heat source causes the two separate materials to expand at different rates thereby re-shaping the vanes to drive the rotor. The rotating turbine is thus able to generate power using direct heat from an energy source. The heat source may be radiant, convection and/or conduction type heat.

An actuator device includes an actuator member, a drive subject, a drive device, and a tension applicator. The actuator member is configured to be deformed in response to application of energy to the actuator member from an outside of the actuator member. The drive subject is coupled to the actuator member. The drive device is configured to apply the energy to the actuator member and thereby displace the drive subject in a deforming direction of the actuator member. The tension applicator is configured to apply the actuator member a tension, which enables correction of a tension change generated by at least one of elongation and contraction of the actuator member that is induced by natural deformation of the actuator member.

Cooling by a twist-untwist process, by a stretch-release process for twisted, coiled, or supercoiled yarns or fibers, and methods and systems thereof. High mechanocaloric cooling results from release of inserted twist or from stretch release for twisted, coiled, or supercoiled fibers, including natural rubber fibers, NiTi wires, and polyethylene fishing line. Twist utilization can increase cooling and cooling efficiencies. A cooler using twist insertion and release can be shorter and smaller in volume than a cooler that requires a large elastomeric elongation. The cooler system can be utilized in mechanochromic textiles and remotely readable tensile and torsional sensors.

A rotary engine that generates electricity using differences in relative humidity. A water-responsive material expands and contracts as water evaporates which drives the rotation of two wheels. The rotary motion drives an electrical generator which produces electricity. In another embodiment, the water-responsive material is used to actuate an artificial muscle of a robotic device.

SMA actuators and related methods are described. One embodiment of an actuator includes a base; a plurality of buckle arms; and at least a first shape memory alloy wire coupled with a pair of buckle arms of the plurality of buckle arms. Another embodiment of an actuator includes a base and at least one bimorph actuator including a shape memory alloy material. The bimorph actuator attached to the base.

A torsional actuator formed of a yarn of twisted shape memory material. The yarn has multiple strands of homogeneous shape memory material that have been homochirally twisted. For torsional actuation, a fractional portion of the yarn is heated such as by Joule heating. Various Joule heating mechanisms include passing an electrical current through an unwound segment of the yarn, or by coating a fractional portion of the length of each homogeneous strand with a coating material of higher electrical conductivity than the electrical conductivity of the shape memory material an passing current through the length of the yarn. The shape memory material may be a shape memory alloy such as a NiTi alloy.

Methods and a device for the continuous manufacturing of artificial muscle actuator device fibers are disclosed. The method includes: threading an untwisted fiber along the axis of a tube and inside the tube that includes a heating means to raise the localized temperature of a cross-section of the tube to a predetermined temperature; providing a tension on the untwisted fiber; and twisting the untwisted fiber while the fiber is within the tube.

An actuator (18) includes a first part (3), a second part (2) and eight shape memory alloy, SMA, wires (4.sub.1, . . . , 4.sub.8) connected between the first part (3) and the second part (2) so as to enable the second part (2) to be moved relative to the first part (3) with at least two degrees of freedom. Two of the SMA wires (4.sub.1, . . . , 4.sub.8) are located on each of four sides (s.sub.1, . . . , s.sub.4). The four sides (s.sub.1, . . . , s.sub.4) extend in a loop around a primary axis (z). On contraction, a first group (4.sub.1, 4.sub.3, 4.sub.5, 4.sub.7) of four of the SMA wires each provide a force on the second part (2) with a component in a first direction along the primary axis (z), and a second group (4.sub.2, 4.sub.4, 4.sub.6, 4.sub.8) of the other four of the SMA wires each provide a force on the second part (2) with a component in a second, opposite direction along the primary axis (z). Each of the eight SMA wires (4.sub.1, . . . , 4.sub.8) is configured such that a length perpendicular to the primary axis (z) is foreshortened relative to a length (l.sub.1, . . . , l.sub.4) of a corresponding one of the four sides (s.sub.1, . . . , s.sub.4).

This device consists of a housing (1) made of electrically insulating material, in which a fuse (6) is provided with at least one main fuse wire (7) located in its cavity. The main fuse wire (7) is electrically conductively connected at one end to at least one connecting pin (2) which is led out of the housing (1) and at the other end it is electrically conductively connected to at least one terminal (3) located in at least one cavity (4) formed in the housing (1). The shape of the connecting pin (2) is adapted for connection to the protected device.