SMA Artificial Muscle Actuator protected by Rolled Film Tube (Coil Spring made of SMA Wire with Rectangular Cross Section)

Abstract

In this study we aim to realize an actuator that is comparable with a natural muscle from a viewpoint of flexibility, the output force and the responses. We constructed the Shape Memory Alloy (SMA) actuator protected by“a Rolled Film Tube”with the high heat resistance and the high flexibility. In this report we made a coil spring made of SMA wire with rectangular cross section. The characteristics are investigated by the experiments of the load/displacement measurement, the step response and the pulse response. The results of the load/displacement tests are investigated by the theoretical analysis and got two equations of low and high temperature. The results of the step response tests show that a coil spring made of SMA wire with rectangular cross section has time constants of output force shorter than a coil spring made of SMA wire with circler cross section. The results of pulse response testes show that a coil spring made of SMA wire with rectangular cross section has characteristics of nearly equivalent to a natural muscle.