Thermoelectric SMA actuator: preliminary prototype testing

In this work, preliminary analysis and testing of a thermoelectric compact shape memory alloy (TEC-SMA) actuator prototype will be presented. The prototype testing process will result in detailed feasibility assessment and quantification of the operational specification ranges for the TEC-SMA actuator. The actuators' potential for compactness and miniaturization will be assessed and quantified, however for the initial work presented in this paper, the prototype will not be optimally compact. The presented actuator prototype is a solid-state, thermoelectric SMA actuator that utilizes directly the thermoelectric effect for cooling an SMA element. The preliminary experimental setup consists of an SMA strip in close contact with Thermoelectric Modules (TEM)s for cooling, coupled with an LVDT, a load cell, and thermocouples to characterize and optimize the actuator bandwidth, stroke, length, output power and energy density based on SMA actuation cycles. Preliminary experimental results are presented based on the described setup for 0.5 Hz and 1.0 Hz actuation frequencies. A significant conclusion form this study is the need for power modulation for TEMs and SMA actuators for optimal performance of the TEC-SMA actuator.