Shape memory alloy hysteresis

Abstract Shape memory alloy (SMA) has interesting properties which can be applied to microminiature actuators. In order to reduce the bulk and to make strain control possible, the internal electrical resistance variation may be used as the feedback variable. The strain has the disadvantage of having a large hysteresis, especially for copper alloys. We describe in this paper some methods for removing the hysteresis and some cases where controlled SMA may be used.