An integrated shape memory alloy micro-actuator controlled by thermoelectric effect

The integrated shape memory alloy (SMA) micro-actuator, which is presented here, has millimetre length size. The originality is the use of a thermoelectric phenomenon (i.e. the Peltier effect) to control the temperature of the SMA, A SMA thin blade, working in flexure, is connected with a thermoelectric material, bismuth telluride (N an P doped Bi2Te3). To our knowledge, it is one of the first investigation with a real measurement of the motion of the SMA actuator using a built-in thermoelectric system. Using this system, we are able to control the temperature of the SMA blade in a range of - 10 to 90 degreesC. Thermal simulations have shown that the time response, of a similar system heated by Joule effect, is about five times greater than the time response of the Peltier actuator. Moreover, this system is able to work in a confined environment. The actuator will be described and the experimental results will be given. (C) 2002 Published by Elsevier Science B.V.