The subject matter of this specification can be embodied in, among other things, an actuator that includes a piston configured to actuate relative to a housing, a sensor rod configured to be actuated by the piston, a sensor affixed to the housing and configured to detect a piston position of the piston relative to the housing based on a sensor rod position of the sensor rod relative to the sensor, and a linkage configured to couple the sensor rod to the piston, and to offset a change to the sensor rod position due to a temperature-induced dimensional change to at least one of the housing, piston, the sensor rod, and the sensor.

An asymmetric bistable shape memory alloy inertial actuator capable of preventing accidental actuation caused by environmental temperature variations but preserving temperature-related safety features and its use in devices.

An asymmetric bistable shape memory alloy inertial actuator capable of preventing accidental actuation caused by environmental temperature variations but preserving temperature-related safety features and its use in devices.

A heat engine including at least one shape memory alloy (SMA) core that, when exposed to at least two different temperatures contracts and expands to generate mechanical motion which can then be transmitted to a generator.

A driving device is provided that can suppress power consumption, and is excellent in response characteristics, and also capable of appropriately adjusting a revolving angle of a target member. According to an exemplary design, the device includes a rotational shaft supported by a housing and is capable of revolving in each of a positive and counter rotation direction about a Z-axis. Shape memory alloys formed in a wire-like shape apply an external force acting in the positive rotation direction to the rotational shaft by heat shrinkage. A bias spring applies an external force acting in the counter rotation direction to the rotational shaft. Moreover, a wiper is displaced following the rotation of the rotational shaft. A power supply system including power supply terminals, a relay member, relay terminals, and lead wires separately supplies power to three or more mutually different positions of the shape memory alloys.

Broadly speaking, the present techniques provide specific arrangements of shape memory alloy (SMA) actuator wires in SMA actuation apparatuses. In one arrangement, a single straight shape memory alloy actuator wire may be used, which may be inclined at an acute angle greater than 0 degrees with respect to a plane normal to the movement direction. In another arrangement, two straight lengths of shape memory alloy actuator wire may be used, where the SMA wires may be inclined at an acute angle greater than 0 degrees with respect to a plane normal to the movement direction.

A spacecraft, such as a satellite, uses a shape memory polymer actuator to deploy one or more deployable parts. The shape memory polymer actuator may be formed integrally with a deployable part and/or with a fuselage or other structure of the spacecraft, with the shape memory polymer actuator being for example a relatively thin portion of the shape memory polymer material of the integral structure. The shape memory actuator allows deployment of the deployable part(s) upon heating of the shape memory polymer material of the actuator, such as after the satellite has been launched into space. The heating may be caused by a heat source that is part of the spacecraft itself, or may be merely the result of exposing the spacecraft to solar heating after launch. The deployable part of the spacecraft may include any of a wide variety of parts that are used after launch.

A mechanical driver comprising a wedge shaped member operatively coupled to a shape memory alloy such that the shape memory alloy is able to displace the wedge shaped member in an essentially linear direction. The wedge shaped member is in constant contact with a lever arranged so that it can rotate about a fixed pivot point. A piston is arranged such that it is constant contact with the lever at a point between the pivot point of the lever and the contact point between the lever and the wedge shaped member. Return springs are provided to return the piston, lever and wedge shaped member to their respective start positions. Activation of the shape memory alloy displaces the wedge shaped member along its linear direction and this causes the lever to be deflected about its pivot point and the piston to be deflected in an essentially linear direction that is perpendicular to the linear direction of travel of the wedge shaped member.