Microactuation Utilizing Wafer-Level Integrated SMA Wires

This paper reports on the wafer-scale integration of pre-strained SMA wires to microstructured silicon devices and the performance of the microactuator prototypes. The overall goal is to obtain low cost microactuators having high work densities and a mass production compatible manufacturing, without having to deal with the inherently high costs of a pick-and-place approach or with the complex composition control and annealing process of sputtered NiTi films. Testing above the SMA transformation temperature shows repeatability in actuation of the fabricated structures, with net strokes of 170 mum for the double cantilever actuators.