[Adv. Mater. Interfaces] Highly Efficient Actuator of Graphene/Polydopamine Uniform Composite Thin Film Driven by Moisture Gradients
writer：Jiang He, Peng Xiao, Jiawei Zhang, Zhenzhong Liu, Wenqin Wang, Liangti Qu, Yousi Chen*, Tao Chen
keywords：Graphene, Poly(dopamine), Composite thin film, actuator, Water gradients responsiveness
source：期刊
specific source：Adv. Mater. Interfaces, 2016, 3, 1600169-1600176
Issue time：2016年
Bilayer materials with different swelling behavior are usually used as actuator, yet still suffer from limitations such as poor
interlayer adhesion during frequent bending, and the complex multistep fabrication process. Here, we present a new
strategy that a structure of reduced graphene oxide/polydopamine (RGO-PDA) uniform
composite thin film can serve as highly efficient actuator driven by moisture gradients. During the trigger
by moisture from one side of the film, hydrophilic PDA can absorb water on the
surface layers of RGO-PDA film to activate the swelling behavior, while
the relatively hydrophobic RGO with ordered two dimensional lamellar structure hinders the diffusion of
water molecules across the composite film. A unique bilayer structure
in swelling difference along the lateral uniform composite thin film has thus
been successfully in situ prepared upon the exposure to
moisture gradient. This highly sensitive actuator has a very fast
moisture gradient responsiveness with bending speed about 1000°/s and can serve as a "loader
machine" with the ability to transport cargo 42 times heavier than itself.