Homogeneous Chitosan/Graphene Oxide Nanocomposite Hydrogel-Based Actuator Driven by Efficient Photothermally Induced Water Gradients

Various kinds of photoresponsive hydrogels have been developed for years; however, the complex synthesis method and high cost limit their broad application. In the current work, a facile strategy for the light-stimuli actuator was proposed based on a homogeneous chitosan (CS)/graphene oxide (GO) nanocomposite hydrogel. Controllable actuation of the CS/GO hydrogel film has been realized as a result of the water gratitude induced by the near-IR (NIR)-light illumination. The contraction and swelling behavior of the hydrogel actuator were completely reversible, which endowed the actuator with repetitive application. Moreover, the NIR-light-induced actuation speed could be adjusted by varying the GO content in the CS/GO hydrogel. The homogeneous structure enabled the hydrogel actuator to more easily realize mass production at low cost. The demo applications of the CS/GO hydrogel actuator as a remote-control device and smart curtain were achieved under both NIR light and sunlight, which confirm the extensive application potential of this material.