▎ 摘　　要

Although Janus films of different compositions have been commonly utilized to develop moisture actuators due to the different capabilities of swelling in materials, a sole material with a distinct structural design is also able to provide moisture-actuation. In this study, we simply used graphene oxide (GO) to fabricate a sole GO film with an asymmetric structure which consisted of a wavy layer and a smooth layer. Due to the asymmetric structure and excellent hygroscopicity of the GO material, the asymmetric graphene oxide (AGO) film (2.5 x 0.5 cm(2)) was responsive to moisture and showed a maximum bending angle change of approximate to 1800 degrees as the relative humidity (RH) changed. Compared with other reports about moisture actuators, the AGO film exhibited a superior bending capability. Furthermore, we propose a novel mechanism for moisture actuation of the AGO film based on our detailed observations, and a wavy structure has been introduced for showing great potential in bending deformation. Finally, the AGO film was used as a grabber to grab a leaf and it exhibited good capability to twine around a plastic rod. This work provides a novel pathway for the development of moisture-responsive materials for potential applications in robotics, artificial muscles and switches.