Graphene oxide/polymer actuator driven by acetone vapor enabling an ultra-large bending angle and fast response

Abstract

A simple approach to fabricating smart actuators with large directional bending actuation and fast response has yet to be developed. Herein, a self-standing actuator is fabricated through layer-by-layer assembly of a graphene oxide (GO) film on a flexible commercial cellulose acetate (CA) polymer membrane. The GO/CA actuator responds to acetone vapor and the bending angle depends on the strip length and the thickness of GO film. Bending greater than 720° is achieved within 19 s in acetone vapor at a fixed strip length of 30 mm and a GO film thickness of 29 μm, and recovery within 38 s in air. A bending mechanism of GO/CA bilayer actuator is proposed based on the swelling effect of the CA polymer membrane in alcohol vapor. The GO film plays an important role as the barrier layer to avoid over-swelling of the CA polymer, induced by the organic vapor, and to create tension in the recovery process. The new driven system is used in example applications for designing various devices to demonstrate the dynamic process.