SHAPE MEMORY ALLOY ACTUATION APPARATUS

摘要

A shape memory alloy actuation apparatus comprises a movable element (6) suspended on a support structure (2) by a plurality of flexures (13) which are non- uniformly configured to apply forces having differing components perpendicular to the movement axis generating a net moment around the centre of mass of the movable element in an opposite sense from the moment generated by the actuation force. A shape memory alloy wire (31) is coupled between the support structure (2) and an intermediate body (25) engaging the movable element through a pivotal contact to avoid lateral force transfer. Also coupled between the support structure (2) and the intermediate body (25) is a resilient biassing flexure (23) plastically deformed in a partial region thereof. The shape memory alloy wire is crimped by a crimping member (32) fixed to the support structure holding the shape memory alloy wire against a curved surface (34) from which the shape alloy memory wire extends to the movabIe element.