Disclosed herein is an actuator for effectuating a shape memory alloy (SMA). The actuator includes a body including shape memory alloy. The body includes a plurality of segments. The actuator also includes a plurality of heaters that are each configured to maintain a predetermined temperature based on a predetermined resistance of the heater when a voltage is applied to the heater. Each heater of the plurality of heaters is associated with a different segment of the plurality of segments. A segment of the plurality of segments is effectuated in response to increasing a temperature of the heater associated with the segment.

Aspects of the present disclosure generally relate to an SMA actuator that includes a cooling device disposed within a torque tube. In one aspect, the cooling device includes a sliding sleeve, an expandable sleeve, and plurality of cooling fins coupled to the expandable sleeve. Axial movement of the sliding sleeve relative to the expandable sleeve facilitates radial expansion of the expandable sleeve and urges the cooling fins into contact with the torque tube. The cooling fins function as heat sinks when in contact with the torque tube to facilitate the removal of heat from the torque tube to increase the cooling rate of the torque tube. During heating of the torque tube, the cooling fins may be spaced apart from the torque tube to reduce the thermal mass that is heated, thus increasing the heating rate of the torque tube.

An actuator includes a drum defining a longitudinal axis and having axially opposed first and second end portions that are rotatable relative to one another about the longitudinal axis. A shape memory element is wrapped around the drum and extends from the first end portion of the drum to the second end portion of the drum to actuate relative rotation of the first and second end portions of the drum about the longitudinal axis by activation of the shape memory element.

A system for heating a shape memory alloy (SMA) actuator may include an SMA actuator, a smart susceptor, a plurality of induction coils, and a control module. The SMA actuator may have at least one layup. The SMA actuator may be selectively heated to a transition temperature. The smart susceptor may be in thermal contact with the at least one layup of the SMA actuator. The induction heating coils may be configured to receive an alternating current and generate a magnetic field based on the alternating current. The magnetic field may create an eddy current in at least one of the SMA actuator and the smart susceptor to heat the SMA actuator to the transition temperature. The control module may be configured to drive the alternating current supplied to the induction heating coils.

An actuator includes a drum defining a longitudinal axis and having axially opposed first and second end portions that are rotatable relative to one another about the longitudinal axis. A shape memory element is wrapped around the drum and extends from the first end portion of the drum to the second end portion of the drum to actuate relative rotation of the first and second end portions of the drum about the longitudinal axis by activation of the shape memory element.

Ratcheting shape memory alloy actuators and systems and methods including the same are disclosed herein. The ratcheting shape memory alloy actuators include a ratcheting assembly that is operatively coupled to a first bracket and a shape memory alloy element that is operatively coupled to the ratcheting assembly and to a second bracket. The first bracket is configured to be operatively coupled to a first structure, while the second bracket is configured to be operatively coupled to a second structure. The shape memory alloy element is configured to apply a motive force to the ratcheting assembly upon deformation between a first conformation and a second conformation. The ratcheting assembly is configured to utilize the motive force to selectively adjust an orientation of the first structure relative to the second structure.

The present embodiments relate to shape memory alloy (SMA) haptics devices. An example device can include a fixed bow that is fixed to a base and a moving bow that is configured to move in a direction. The moving bow and fixed bow can each include a flat portion and angled portions that allow the moving bow and fixed bow to be connected at a first end and/or second end. The device can also include a SMA element that, in response to a current, is configured to actuate.