Self-rolling up micro assembly using temperature — Responsive hydrogel sheet with rigid plate array

We propose a design method of a micro self-rolling up structure using a temperature-responsive hydrogel sheet with rigid plate array. Our self-rolling up is a method for developing a micro three-dimensional (3D) structure performed by rolling up a two-dimensional (2D) flat sheet, like making a croissant, through a continuous self-folding. The local curvature of the self-rolled up structure could be controlled by the length of rigid plates. By controlling the local curvature, we designed and developed self-rolled up structures with or without gaps between the self-rolled up layers, such as cylindrical and croissant-like ellipsoidal structures. In addition, all the structures demonstrated repetitive deformation of forward and backward rolling up by changing a temperature of water.