Photo switchable 4D printing remotely controlled responsive and mechanically robust shape memory polymer nanocomposites

Abstract

Photo-triggered shape morphing structures can be found in myriads of areas. Utilizing light as a switch can effectively control and regulate the precise deformation of structures. However, the integration of photo switching functions in shape morphing structures with complex geometries remains a challenge. Here, we report photo switchable digital light processing based 4D printing high-resolution and highly complex geometries, based on UV curable WO2.9 nanoparticle doped shape memory polymer nanocomposites, which are highly deformable (stretchability up to ~1000% at rubbery state) and fatigue resistant (repeatedly loaded > 1200 times at ambient temperature). The presence of just trace WO2.9 nanoparticles (< 0.20 wt.‰) contributes to the controlled photothermal property of nanocomposite via selective absorption of light, which enables reversibly photo switchable (＞50 times), spatial and remote control of 4D printing shape morphing structures. These findings offer a promising approach to expanding the applications of photo-triggered shape morphing structures.