A direct comparison of shape memory alloy and electromechanical actuation for wing twist applications

Shape Memory Alloy (SMA) actuation is often cited as significantly lighter weight and more compact than conventional actuation methods such as electromechanical (EM) or hydraulic motors. Yet there few studies directly comparing and demonstrating a SMA actuation design to a conventional design for a specific application. In this paper a complete system level design, build, and test using both SMA and EM actuation are described. Adaptive spars for a medium sized UAV wing twist application are demonstrated and a detailed comparison of size, weight, power, and performance clearly demonstrates the advantages of SMA actuation.