Abstract: An SMA actuator is arranged to tilt the mirror in a zoom camera to effect optical image stabilization. The actuator may comprise four angled-V SMA wires. The actuator may alternatively comprise a gimbal flexure and SMA wires. In this case there may be four SMA wires or two SMA wires and two springs. The SMA wires may be straight wires or wires hooked in a V shape.

Abstract: An SMA actuation apparatus (1) comprises a support structure (2) and a movable element (3) supported thereon by a suspension system (8, 10) that supports the movable element on the support structure and guides movement of the movable element along a movement axis. Two closely spaced lengths of SMA wire (4) that are close to parallel and inclined at the same acute angle with respect to a plane normal to the movement axis are connected to the support structure and to the movable element so as to apply respective forces to the movable element with respective components parallel to the movement axis that are in opposite directions. The two lengths of shape memory alloy wire apply a couple to the movable element perpendicular to the movement axis and the suspension system includes a pair of flexures or bearings that resist the resultant couple applied to the movable element by the lengths of SMA wire.

Abstract: There is provided a method of driving a shape memory alloy haptic assembly comprising an actuator comprising shape memory alloy that is arranged on actuation to provide a haptic effect, the method comprising supplying drive current to the actuator successively during a pre-heating period in which the temperature of the shape memory alloy is raised without causing the shape memory alloy to provide the haptic effect and during an actuation period in which the temperature of the shape memory alloy is raised so as to cause the shape memory alloy to provide the haptic effect. A shape memory alloy haptic assembly is also provided.

Abstract: A shape memory alloy actuator assembly comprises a first part, including a surface, a second part which moves relative to the first part across the surface and a resilient biasing element that biases the second part into contact with the first part so as to generate frictional forces therebetween for retaining the second part on the surface. At least one shape memory alloy actuator wire is connected between the first part and the second part and arranged to, on contraction thereof, apply a force to the second part with a component parallel to the surface that drives movement of the second part relative to the first part across the surface. Thus, the second part is retained on the surface when no power is applied to the shape memory alloy wire, and movement is achieved when power is applied.

Abstract: 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.

Abstract: Embodiments of the present techniques provide methods for assembling and manufacturing shape memory alloy (SMA) actuator assemblies, which may also advantageously simplify the process of, speed-up the process of and/or reduce the cost of manufacturing SMA actuator assemblies.

Abstract: Broadly speaking, embodiments of the present techniques provide an actuator that comprises segments of shape memory alloy (SMA) actuator wire that can be used to deliver a relatively large output stroke. In particular, two segments of SMA actuator wire may be mechanically coupled together around a corner of a static component of the actuator such that a displacement (e.g. contraction) of one segment causes a displacement (e.g. contraction) of the other segment. In this way, the displacement of each segment combines in an additive manner to generate a large output stroke that is able to move a moveable component of the actuator.

Abstract: A shape memory alloy actuator assembly (2) is disclosed. The actuator assembly comprises a support (21), a first stage (22) moveable in at least two different non-parallel directions in a first plane relative to the support, a first set of at least two shape memory alloy wires (271) configured to move the first stage in the first plane, a second stage (23) moveable in at least two different non-parallel in a second plane parallel to or coplanar with the first plane relative to the first stage, and a second set of at least two shape memory alloy wires (272) configured to move the second stage in the second plane. The first stage is coupled to the support via the first set of shape memory alloy wires and the second stage is coupled to the first stage via the second set of shape memory alloy wires such that movement of the second stage in the second plane with respect to the support is a combination of movement of the first stage relative to support and the second stage relative to the first stage.

Abstract: Broadly speaking, embodiments of the present techniques provide methods for driving shape memory alloy (SMA) actuator wires in a more power-efficient manner.

Abstract: Broadly speaking, embodiments of the present techniques provide haptic button assemblies in which the haptic button has a low profile while still providing a satisfying tactile response or sensation to a user. Advantageously, the haptic button assemblies may have a profile that, for example, enables the assembly to be incorporated into the free space along an edge of a portable computing device. The haptic assemblies may, for example, be arranged to move the button perpendicularly with respect to the edge of the device.

Abstract: Broadly speaking, embodiments of the present techniques provide mechanisms for electrically connecting shape memory alloy (SMA) actuator wires of an actuation device to a power or current source via at least one connection element.

Abstract: Broadly speaking, embodiments of the present techniques provide apparatus and methods for providing haptic feedback, and in particular to user-operated buttons for electrical and electronic products that provide haptic feedback to the user when operated.

Abstract: 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.

Abstract: A camera assembly comprises a lens assembly supported on a support structure, wherein the lens assembly includes an autofocus actuator arrangement and the camera assembly includes an optical image stabilization assembly arranged to move the lens assembly in a plane perpendicular to the optical axis. A flexible printed circuit tape connected between the support structure and the lens assembly and providing an electrical connection to the auto-focus actuator arrangement is bent around a corner, thereby allowing the flexible printed circuit tape to accommodate the motion of the lens assembly perpendicular to the optical axis. A crimp plate connected to the lens assembly which crimps shape memory alloy wires has features extending out of the plane of the crimp plate for reducing flexibility. At least part of the optical image stabilization assembly overlaps the lens assembly in the direction along the optical axis, thereby reducing the height of the camera assembly.

Abstract: An apparatus is disclosed for measuring the resistance of a shape memory alloy, SMA, wire. The apparatus comprises: an SMA wire; a sense resistor connected in series with the SMA wire; a measurement circuit configured to perform a measurement indicative of the potential difference across at least the SMA wire; and a measurement switch between the SMA wire and the sense resistor. The measurement switch is configured to connect either to the measurement circuit such that the measurement circuit can perform the measurement or to a circuit that bypasses the sense resistor.

Abstract: Broadly speaking, embodiments of the present techniques provide methods for driving shape memory alloy (SMA) actuator wires in a more power-efficient manner.

Abstract: 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.

Abstract: Broadly speaking, embodiments of the present techniques provide an actuator that comprises segments of shape memory alloy (SMA) actuator wire that can be used to deliver a relatively large output stroke. In particular, two segments of SMA actuator wire may be mechanically coupled together around a corner of a static component of the actuator such that a displacement (e.g. contraction) of one segment causes a displacement (e.g. contraction) of the other segment. In this way, the displacement of each segment combines in an additive manner to generate a large output stroke that is able to move a moveable component of the actuator.

Abstract: A shape memory alloy actuator assembly comprises a first part, including a surface, a second part which moves relative to the first part across the surface and a resilient biasing element that biases the second part into contact with the first part so as to generate frictional forces therebetween for retaining the second part on the surface. At least one shape memory alloy actuator wire is connected between the first part and the second part and arranged to, on contraction thereof, apply a force to the second part with a component parallel to the surface that drives movement of the second part relative to the first part across the surface. Thus, the second part is retained on the surface when no power is applied to the shape memory alloy wire, and movement is achieved when power is applied.

Abstract: 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.