Shape memory alloy actuation apparatus

A shape memory alloy actuation apparatus comprising:

• a support structure;
• a movable element;
• a suspension system supporting the movable element on the support structure and guiding movement of the movable element relative to the support structure in a movement direction, the suspension system comprising plural resilient flexures connected between the movable element and the support structure in compression and arranged with the compressional forces generated in the resilient flexures balancing in a direction perpendicular to the movement direction, the plural resilient flexures being capable of supporting the movable element in two stable positions along the movement direction;
• and
• two shape memory alloy actuators each arranged on contraction thereof to drive movement of the movable element in respective, opposite directions between the two stable positions.