Shape memory alloy bending actuator for catheter with movable link and guide wires

This paper proposes two kinds of novel bending actuator using three links, two shape memory alloy coil-type springs and guide wires. One is a macro model for one directional bending actuator, the other is a micro model for two directional bending actuator. By heating the two shape memory alloy coil-type springs sequentially, bending and stretching motion of the actuator is possible. The performance of the actuator has been characterized for the possible application to catheters.