A Versatile Approach for Preparing Shape-Morphing Bilayer Films by Simply Adhering Two SEBS/Paraffin Films with Different Deformability and Melting Temperatures

Shape-morphing materials that can exhibit various shape deformations are highly desirable. In this work, shape-morphing materials with diverse deformation modes are prepared via a facile approach of constructing bilayer structures of SEBS/paraffin blends with different melting temperatures. The bilayer films are prepared using a simple solvent-coating adhesion method, either by adhering two single-layers together and stretching or by adhering two pre-stretched single-layers. These bilayer films show strong interfacial adhesion due to the similar chemical composition of the two layers. By adjusting the programming method, stretching strain, and thickness ratio, the shape deformation behaviors of the resultant bilayer films can be flexibly tuned. To demonstrate the wide applicability of this approach, several 2D sheets with hinge structures as well as a smart dressing are prepared, in which the former can be transformed into 3D configurations and the latter can automatically fit to the human body and peel off. Owing to the advantages of low cost, easy and large-scale preparation, recyclability, and high designability, the approach for preparing shape-morphing bilayer films proposed by this work is versatile and the obtained bilayer films have the potential to satisfy the demands of divergent application fields.

Automated summary

This study presents a facile approach to prepare shape-morphing materials with diverse deformation modes by constructing bilayer structures of SEBS/paraffin blends with different melting temperatures. The shape deformation behaviors of the resultant bilayer films can be flexibly tuned by adjusting the programming method, stretching strain, and thickness ratio. The approach offers the advantages of low cost, easy preparation, recyclability, and high designability, making it versatile for various applications.