Micro NiTi-Si cantilever with three stable positions

It is well known that position control is difficult with shape memory alloys (SMAs), as the thermomechanical behavior of them is nonlinear, with hysteresis and history dependent. Hence, most of SMA devices are designed for two positions only, i.e. a high temperature (austenite phase) position and a low temperature (martensite phase) position. In this paper, we present an NiTi-Si shape memory thin film-based microcantilever, which has three stable positions, depending on how the electrical current is applied through the shape memory thin film. It demonstrates a way to have multiple stable positions in an SMA device, which can have some significant advantages in many real engineering applications. (C) 2004 Elsevier B.V. All rights reserved.