Progress in thin-film shape-memory-alloy actuators

This paper reviews the development and current status of thin-film shape-memory-alloy (SMA) actuators and relevant technologies. The mechanical properties of sputter-deposited SMA thin films are described and actuators using SMA thin films are discussed. Some examples of micro devises with thin-film SMA actuators are presented along with their microfabrication. As the recent development of materials, Ti-Ni-Cu thin films are introduced and, additionally, a new type actuator composed of polymer and SMA films is demonstrated. Finally, this paper concludes with future perspectives.