A variable impedance actuator using shape memory alloy

摘要

Surgical robotic design is challenging mostly because of the restricted working space of the platform necessitating miniaturized actuators and sensors. Compliance is a fundamental requirement of an actuator design for safe atraumatic clinical interactions of the robot with organs and tissues. In the present paper, the authors describe a variable impedance miniaturised rotary actuator (VIMRA) using shape memory alloy (SMA) wires in antagonist configuration, to achieve a high force to weight ration. The two SMA wires are connected to a pulley providing two forces, which can be independently controlled to adjust the joint stiffness.