Multi-Wavelength Light Drivable Oscillatory Actuator on Graphene-Based Bilayer Film

A multi-wavelength light drivable bilayer actuator is fabricated by depositing a thin layer of reduced graphene oxide (RGO) onto a flexible poly(dimethyl siloxane) (PDMS) substrate. The RGO/PDMS bilayer film shows fast and reversible bending/unbending motions upon exposure to UV light, visible light, or near-infrared light (NIR). The photo-thermal effect of the pump lights is studied by measuring and comparing the light induced temperature rises on RGO/PDMS film. The results demonstrate that the RGO absorbs and converts the light into heat. Thus the bilayer film undergoes thermal expansion under light irradiation. The calculated thermal expansion of the RGO thin layer is smaller than that of the PDMS layer, which results in the bilayer actuator bending towards the layer on the RGO side. Oscillational motion on the bilayer film is successfully achieved using continuous light irradiation on an offset sandwiched RGO/PDMS bilayer cantilever. Light induced motion on the RGO based film provides a new strategy for absorbing light energy and outputting photomechanical work.