Facile fabrication of moisture responsive graphene actuators by moderate flash reduction of graphene oxides films；Yu-Qing Liu, Jia-Nan Ma, Yan Liu, Dong-Dong Han, Hao-Bo Jiang, Jiang-Wei Mao, Chang-Hao Han, Zhi-Zhen Jiao, and Yong-Lai Zhang；Optical Materials Express Vol. 7, Issue 7, pp. 2617-2625 (2017) •https://doi.org/10.1364/OME.7.002617
We reported here a facile, green, and simple method to fabricate moisture-responsive graphene actuators by moderate flash reduction of graphene oxides (GO) films. Due to the limited light transparency and thermal relaxation, the oxygen containing groups (OCGs) on the GO sheets could be selectively removed from the radiation side, forming a photoreduction gradient along the lateral direction of the GO film. In this manner, we obtained a reduced GO (RGO)/GO bilayer film. The RGO/GO film can bend to the RGO side when exposed to moisture because RGO and GO layers show different absorption capabilities of water molecules（湿度应激性原理）.Taking advantage of this controllable deformation, we fabricated moisture-responsive actuators including a crawler and claw robots.