An actuator for a vehicle seat can be configured to prevent overstress of a shape memory alloy (SMA) wire. The actuator can include a first body member and a second body member pivotably connected to each other. The actuator can include an overstress post and an overstress contact plate operatively connected to the overstress post. Thus, movement of the overstress post causes movement of the overstress contact plate. The actuator can include an overstress contact pin. The actuator can include an SMA wire operatively connected to one of the body members and to the overstress post. When activated, the SMA wire can shrink, causing one of the body members to pivot relative to the other body member and causing the overstress contact plate to move toward the overstress contact pin. If the overstress contact plate contacts the overstress contact pin, the SMA wire can be deactivated.

A shape memory alloy actuator includes a bistable shape memory alloy strip having openings. The bistable shape memory alloy strip having a straight stable state and a curled stable state. The shape memory alloy actuator further includes a shape memory alloy wire located along a side of the bistable shape memory alloy strip. The shape memory alloy wire contracts from heat exposure with each end secured to one of the plurality of openings of the bistable shape memory alloy strip.

A circuit arrangement controls a system for a seat comfort function with at least one air cushion, at least one actuator with at least one adjusting element and at least one SMA element being movable between a first position and a second position. The circuit arrangement includes at least one driver unit with at least one driver to activate the actuator with the at least one SMA element; at least one temperature sensor; and a control unit to control the driver unit, the control unit being configured to generate a control signal to control the driver unit. The control signal is determined from a) at least one actual filling level parameter; b) a temperature signal from the temperature sensor; c) a system parameter; and d) at least one of a target filling level parameter and a target filling level change parameter. A related seat and method of controlling same are also disclosed.

A lens assembly for a mobile device includes an adjustable diaphragm device capable of being combined to a first lens unit, or between the first lens unit and a second lens unit. The adjustable diaphragm device includes a case having a light transmission hole being communicated with an inner space of the case, a diaphragm sheet with an aperture, and a driving mechanism disposed in the inner space of the case. The driving mechanism includes a driving member and a swing arm. One end of the swing arm is movably connected to the case and the opposite end thereof is fixedly connected to the diaphragm sheet. The driving member is movably connected to a position between two ends of the swing arm. The driving member is controlled by a control unit to move the swing arm and thus the diaphragm sheet, in order to control the amount of light.

Broadly speaking, embodiments of the present techniques provide shape memory alloy (SMA) actuation apparatus for moving a moveable component relative to a static component or support structure and along a notional primary axis. The SMA actuation apparatus may comprise a biasing element to resist motion of the moveable component in particular directions relative to the primary axis, or may comprise an arrangement of SMA actuator wires that provides the biasing function.

Actuation systems and methods are disclosed. An apparatus includes a system including a flow cell receptacle and a valve drive assembly including a shape memory alloy actuator including a pair of shape memory alloy wires and a flow cell disposable within the flow cell receptacle and having a membrane valve. The system actuates the membrane valve, via the shape memory alloy actuator, by causing a voltage to be applied to a first one of the shape memory alloy wires and the system not applying the voltage to a second one of the shape memory alloy wires.

A driving device includes a first driving element and a first flexible structure. The first driving element includes a first wire extending in a first direction and includes a shape memory alloy. The first flexible structure has a certain width in a second direction perpendicular to the first direction, and when the first wire contracts in the first direction, the first flexible structure has a height increasing in a third direction perpendicular to both the first direction and the second direction. The driving device further includes a second driving element including a second wire and a second flexible structure, the second wire extending in the first direction and including a shape memory alloy. The second flexible structure has a certain width in the second direction, and when the second wire contracts in the first direction, the second flexible structure has a height increasing in the third direction.

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.

Apparatus and method for supporting an elongated slender member having a high axial compression stress state during a change in length of the member.

Broadly speaking, embodiments of the present techniques provide techniques for delivering, when required, higher powers to SMA actuator wires by using a single controller/control circuit that implements pulse width modulation (PWM). Typically, when PWM is used to deliver power, the PWM frequency may be fixed, and power may be applied to each SMA actuator wire during each PWM cycle/period. The present techniques provide a method for delivering higher powers to SMA actuator wires (i.e. increasing the length of individual PWM pulses) without changing the duration of the PWM cycle/period. The present techniques also provide techniques for making accurate resistance measurements to determine position of a moveable component that is moved by the SMA actuator wires.