Shape memory alloy actuation apparatus

摘要

An SMA actuation apparatus comprises a support structure, a movable element movably supported on the support structure and an arrangement of three or more SMA actuator wires mechanically connected between the support structure and the movable element. The SMA actuator wires have an interconnection at the movable element that electrically connects the group of SMA actuator wires together. This avoids the need to make a separate electrical connection to the movable element.

主权项

1. An SMA actuation apparatus comprising:
a support structure; a movable element movably supported on the support structure; an arrangement of eight SMA actuator wires mechanically connected between the support structure and the movable element, the SMA actuator wires being arranged on contraction thereof to drive displacement of the movable element relative to the support structure, the SMA actuator wires being inclined with respect to a notional primary axis with two SMA actuator wires on each of four sides around the primary axis, the SMA actuator wires being mechanically connected between the movable element and the support structure so that on contraction two groups of four SMA actuator wires provide a force on the movable element with a component in opposite directions along the primary axis, the SMA actuator wires of each group being arranged with 2-fold rotational symmetry about the primary axis, the SMA actuator wires having an interconnection at the movable element that electrically connects the SMA actuator wires together; and a control circuit electrically connected to the of SMA actuator wires at the support structure, without the control circuit being electrically connected to the SMA actuator wires at the movable element, for supplying drive signals to the SMA actuator wires.