Programmable and Reprocessable Multifunctional Elastomeric Sheets for Soft Origami Robots

Smart, soft, multifunctional robots that are tunable are contributing to remarkable advances in various fields such as medical and rehabilitative robots, human-machine interaction and intelligent homes. One of key factors in soft robot fabrication is to find flexible and efficient schemes to seamlessly introduce configurable structures, programmable actuations and various functions such as electrical and optical ones simultaneously upon implementation. In this study, we selectively modified elastomeric surface and subsequently penetrated those surfaces with an active particle infused solvent following with instantaneous drying. This allowed us to develop a novel method to program a proper design by employing origami strategies and to memorize locally heterogeneous swollen (deformation/folding) effects using the agglomeration of active nanoparticles on the surface. Moreover, such automatic folding can be erased by solvent retreatment and reprogrammed by repeating the above processes. Based on these findings, we established a platform technique to fabricate programmable and reprocessable/reconfigurable elastomeric sheets by varying detailed morphology patterns and active particles; in this way, we produced functional soft origami robots with a seamlessly integrated structure. The new technique makes it possible to achieve soft origami ferromagnetic robots with various active functions, for example, robots mimicking flowers that have petals bent in different angles and curvatures, low friction swimming robots, multimode locomotion carriers with gradient stiffness claws for protecting and delivering objects, and frog-like robots with adaptive switchable coloration responding to external thermal and optical stimuli.