Bi-Directional Origami-Inspired SMA Folding Microactuator

We present the design, fabrication, and characterization of single antagonistic SMA microactuators allowing for uni- bi-directional self-folding origami-inspired devices, respectively. Test devices consist two triangular tiles that are interconnected by double-beam-shaped fabricated from thin foils 20 µm thickness with memory shapes set to a 180° folding angle. Bi-directional is achieved combining counteracting microactuators. macromodel describe engineering stress–strain characteristics foil perform FEM simulations on corresponding local evolution phase transformation. Experiments single-SMA demonstrate uni-directional tunability bending angles up 180°. The finite element qualitatively main features observed torque-folding angle provide further insights into angular dependence profiles stress martensite fraction. first reveal in range −44° +40°, which remains well below predicted limit ±100°.