Patent ID: 7117673

Claim:
An apparatus for positioning a moveable structure relative to a support structure, comprising: a moveable structure; a support structure; a compliant support disposed between the moveable structure and the support structure, the compliant support including a socket on the moveable structure, a ball moveably attached to the support structure via an integral stem, and a spring disposed about the stem for urging the ball away from the support structure, the stem extending through an opening in the support structure, the compliant support biasing the moveable structure away from the support structure; and only three shape memory alloy actuators, the three shape memory alloy actuators symmetrically arranged about the compliant support wherein each shape memory alloy actuator is attached to the moveable structure and the support structure whereby selectively activating the three shape memory alloy actuators provides two degrees of freedom of movement for the moveable structure relative to the support structure.