Fabrication of an Integrated Structure of Shape Memory Alloy Wires by Stringing Process

Abstract

Shape memory alloy (SMA) wires, which contract by heating, are lightweight and flexible actuators. In general, the generated force of SMA is proportional to the cross-sectional area, therefore realization of high force brings high rigidity. In this study, two types of actuators were fabricated by braiding multiple SMA wires into round and flat strings using a braiding machine to enhance the generated force. The structural advantages of the fabricated actuators were demonstrated by calculating their cross-sectional secondary moments, and the characteristics of each actuator were measured. The fabricated actuators implied higher flexibility than a single SMA wire with the same cross-sectional area. Flexible structure can be achieved by weaving into a string.