Nanofiber-based flexible actuator with high transparency and large-scale deformation for biomimetic and intelligent control

In this study, a novel flexible PVP/PVA-co-PE composite film with excellent transparency and large-scale bending deformation capability was prepared by a simple impregnation process. Due to the similar refractive index between the filling phase of PVP and PVA-co-PE nanofibers, the pore layer of the nanofibrous was replaced by PVP after impregnation, thus endowing the composite film with excellent optical transparency. In addition, the excellent hygroscopic response of PVP promoted the rapid hygroscopic swelling behavior in response to external moisture, and thus achieved complex bending deformation of the PVP/PVA-co-PE composite film. Experimental results show that the optimum optical transparency of the composite film can reach 82.53%, and the maximum bending angle of the composite film can reach 180° within 1.2 s of contact with moisture stimulation. Based on the excellent optical transparency and actuation performance, the PVP/PVA-co-PE composite film was prepared into smart windows, Venus flytrap and bionic reptiles, which promoted its application and development in the field of intelligent bionic and smart control systems.