Nanomembrane folding origami: Geometry control and micro-machine applications

Abstract

Three-dimensional (3D) microstructures have important applications in a wide range of engineering fields. A strategy of nanomembrane folding origami with microdroplet-guided intercalation and strain engineering to construct complex 3D microstructures for micro-machine applications is proposed in the present investigation. The results showed that nanomembranes were released by the microdroplet intercalation and subsequently fold up as creases, or remain flat as facets, depending on the strain design configurations. The 3D geometry can be controlled by the crease design and by an externally applied magnetic field. Moreover, this folding strategy is used to construct magnetic micro-mirror arrays, magnetic micro-robots, and a twin-jet motor platform, showing potential micro-machine applications in optical micro-devices and robotics. This strategy offers a simple, precise, and designable method of folding 3D microstructures for fundamental research and practical applications.