“Monolithic Shape Memory Alloy Actuators”: A New Concept for Developing Smart Micro-Devices

In micro-robotics and for micro-systems, one cannot simply scale down conventional actuators. Specific difficulties like friction forces between parts and the assembly have to be considered carefully and need a special design strategy adapted to this “micro-world”. Shape Memory Alloys (SMA) have strong potential in micro actuators. So far, most of SMA devices used the SMA material as a part of a mechanical system, which raised several problems when scaling down. In this paper, a concept of monolithic SMA micro-devices, which consists in considering the SMA as a mechanical system by itself, is presented. Several applications are shown to illustrate this concept.