writer：Yu Li Jia Yang,* Xianqiang Yu, Xiangbin Sun, Feng Chen, Ziqing Tang, Lin Zhu, Gang Qin,Qiang Chen*
keywords：Controlled Shape Deformation, Bilayer Film, Tough Adhesion
source：期刊
specific source：J Mater Chem B
Issue time：2018年

Shape-shifting materials have received increasing attentions owing to their promising applications in soft robotics, biomedical devices, actuator, morphing aircrafts and so on. However, their practical application is limited because of weak mechanical strength, low interfacial adhesion as well as complex preparation method. In the paper, the bilayer film was synthesized by in situ one-step free radical polymerization of soft and water-swellable nanocomposite hydrogel on the surface of the rigid and nonresponsive poly(ethylene terephthalate) (PET) film without any surface modification. The strong interfacial toughness between the hydrogel layer and the PET layer, high swelling of the soft hydrogel layer as well as high strength of the rigid PET film endowed the bilayer film with excellent self-bending behavior. The shape deformation of bilayer films can be controlled by adjusting the geometry parameters of the bilayer film, such as the hydrogel thickness, the aspect ratio and the width of the bilayer film. Moreover, the bilayer film exhibited the excellent reversible bidirectional self-bending behaviors. In addition, the mechanisms of the driving shape transformation were discussed. We believe this work will provide a promising and simple strategy to develop novel responsive materials with controlled shape deformation.