Enhanced Bi-Directional SMA Actuation of Origami-Inspired Microstructures

Inhalt:
We present the design, fabrication and characterization of novel shape memory alloy (SMA) bridge actuators for bi-directional self-folding of origami-inspired microstructures. In order to enhance the folding angle, a cascaded actuator design is considered that requires selective heat treatment of each cascade for local shape setting after fabrication. We demonstrate this concept for a cascade of two SMA bridge actuators that can be folded sequentially up to 180 deg. Antago-nistic systems consisting of two cascades of counteracting SMA bridge actuators enable bi-directional folding up to ±105 deg.