Elastically and Plastically Foldable Electrothermal Micro-Origami for Controllable and Rapid Shape Morphing

摘要

Integrating origami principles within traditional microfabrication methods can produce shape morphing microscale metamaterials and 3D systems with complex geometries and programmable mechanical properties. However, available micro-origami systems usually have slow folding speeds, provide few active degrees of freedom, rely on environmental stimuli for actuation, and allow for either elastic or plastic folding but not both. This work introduces an integrated fabrication-design-actuation methodology of an electrothermal micro-origami system that addresses the above-mentioned challenges. Controllable and localized Joule heating from electrothermal actuator arrays enables rapid, large-angle, and reversible elastic folding, while overheating can achieve plastic folding to reprogram the static 3D geometry. Because the proposed micro-origami do not rely on an environmental stimulus for actuation, they can function in different atmospheric environments and perform controllable multi-degrees-of-freedom shape morphing, allowing them to achieve complex motions and advanced functions. Combining the elastic and plastic folding enables these micro-origami to first fold plastically into a desired geometry and then fold elastically to perform a function or for enhanced shape morphing. The proposed origami systems are suitable for creating medical devices, metamaterials, and microrobots, where rapid folding and enhanced control are desired.