Stress Communication between the Chain Movement and the Shape Transformation from 2D to 3D.

Shape memory polymers can change their initial shape under the stimulation of the external environment, but most of the stimulations require not only an external force but also a high temperature, which limits their application to a certain extent. Inspired by the unmatched elongation of cells on both sides of the mimosa petiole in nature, which leads to leaf closure, we designed a new type of shape transformation polymer, which can transform between 2D and 3D by simple stretching and releasing steps at room temperature. Surface patterning on one side of the sample film was realized via a coordination network of Fe 3+ -COOH to achieve different coordination gradients along its thickness. By this way, different movements of polymer chains along the thickness would lead to 2D-3D transformation upon releasing the stretched sample. Using this method, we obtained a series of transformations from customized 2D materials to complex 3D shapes and explored their potential application in information encryption transmission.