Incompatible Geometry Regulation of Nanowire Assemblies Enabled Light-Driven Shape Morphing and Motions

Abstract

Photoresponsive shape-changing materials have significant applications in miniaturized smart robotics and biomedicine powered in a remote and wireless manner. Existing light-fuelled soft materials suffer from limited continuous shape manipulation and constrained mobility and locomotive modes. One promising solution is developing a hierarchical structure design approach to integrate rapid, reversible photoactive molecular alignment and mechanically incompatible geometry in a macroscopic system. Here, a nanowire assemblies-induced geometry engineering method is reported for the fabrication of silver nanowire-incorporated nematic liquid crystalline elastomers with prominent anisotropic structures at multi-length scales and incompatible elasticity that show sharp morphological transitions among the rings, helicoids, and spirals with diverse helical configurations. The engineered composite films can realize complex light-driven motions including rotating, rolling, and jumping with the controlled directionality and magnitude that are pre-encoded in their both molecular and macroscopic configurations. Owing to the great controllability of multimodal locomotion, a spiral robot can undertake task-specific configuration to climb up complex terrains. The complete regulatory relationship among molecular orientation, shape geometry, and light-driven motions is also established. This study may open an avenue for elaborate design and precise fabrication of novel shape-morphing materials for future applications in intelligent robotic systems.