Fast digital patterning of surface topography toward three-dimensional shape changing structures.

Exiting strategies for 3D shape changing structures are constrained by either the complicated fabrication process or the harsh demands of active materials. Facile preparation of 3D shape changing structures with an extremely simple approach based on the elastomeric polymer still remains a challenging topic. Here, we report a fast digital patterning of surface topography of a single-layer elastomeric polymer toward 3D shape changing structures. The surface topography features digitally engraved grooves by a laser engraver on a poly(dimethylsiloxane) (PDMS) sheet, which is surface oxidized by the UV-ozone treatment. The resulting engraved PDMS sheets exhibit programmable shape changing behaviors to form various 3D structures under the action of organic solvent. Experimental and numerical studies reveal the fundamental aspects of surface topography guided 3D shape changing structures. Demonstrations of this concept in developing various complex 3D shape changing structures illustrate the simplicity and effectiveness of our approach, thereby creating engineering opportunities in a wide range of applications such as actuators and soft robots.