Contractile wire biomechanical actuators

Several metal alloys have been discovered which, when fabricated into wire, contract strongly when heated and relax with cooling. The contractile force can be modulated under microcomputer control to produce a compact, powerful and durable mechanical actuator. This technique has a number of advantages over motor-driven servos in robotics and medicine. This paper reviews previous applications of contractile wire, then presents two types of biomechanical actuators built by the author.