Preparation and assembly of five photoresponsive polymers to achieve complex light-induced shape deformations

Five photoresponsive polymers towards ultraviolet (UV), visible, and near-infrared (NIR) light were prepared and assembled to achieve complicated light-induced shape deformation. The UV light responsive polymer was contributed by a synthesized linear polyurethane elastomer (azo-PU) containing azobenzene groups in the main chains, which presented both shape-memory effect and UV light-induced shape deformation behavior . The other four polymers that were sensitive to visible or NIR light consisted of crosslinked poly(ethylene-co-vinyl acetate) (EVA) composites mixing with gold nanoparticles (AuNPs), Nd(TTA) 3 Phen, Yb(TTA) 3 Phen, and Sm(TTA) 3 Phen as photothermal fillers, respectively. The results showed that the shape recoveries of these EVA composites were triggered merely by visible and/or NIR light with suitable wavelengths. Moreover, the assembly of the prepared five light-induced polymers in three different manners improved the spatiotemporal control of complicated shape deformations upon different light illumination sequences. Benefiting from the creation and assembly of five photoresponsive polymers with high wavelength selectivities, complex shapes of polymer specimens can be achieved in a remote and non-contact manner via simply tuning irradiation sequences. The reported materials here and their assembly manners provide a strategy to expand the applications of photoresponsive polymers.