Transparent Reduced Graphene Oxide Films for Strain Sensing

Abstract

We fabricated and characterized transparent reduced graphene oxide (rGO) films that can be potentially used as wide-area strain sensors. rGO/SU-8 bilayer structures were produced through combinations of spin coating and reduction processes. Both chemical reduction - Assisted by hydrazine - And thermal reduction were explored. Also, the areal coverage of rGO was varied by controlling the concentration of GO suspension. The piezoresistivity of rGO films was characterized to investigate the in situ strain sensing behavior of rGO films undergoing tension. It was discovered that chemically reduced rGO films provide stronger rGO-substrate adhesion, which leads to higher strain sensitivity. Also, sensitivity increases as the rGO areal coverage decreases, as the conductive network formed by rGO becomes sparse. Reduction method and rGO areal coverage can serve as effective parameters for controlling the strain sensing performance of transparent rGO films, which are likely to find numerous lightweight, smart applications.