Size dependence of characteristics of Ti-Ni SMA thin film microactuators

Abstract

Diaphragm type microactuators were fabricated utilizing a Ti-Ni thin film sputter-deposited on a Si wafer by etching the Si. The shape of the diaphragms is a square with the dimensions ranging from 1,200 to 200mm. The microactuators were subjected to cooling and heating to expand and flatten due to the martensitic transformation and its reversion, respectively, under various constant gas pressures. The shapes of the microactuators were measured at various temperatures by laser beam measurement method. The actuator characteristics such as the actuation distance and work output were measured as a function of actuator size and gas pressure.