Graphene film development on flexible substrate using a new technique: temperature dependency of gauge factor for graphene-based strain sensors

Purpose - The purpose of this paper is to develop a new simple technique to synthesize graphene film on a flexible polyethylene terephthalate (PET) substrate and applied as a strain sensor. Design/methodology/approach - Graphene film was synthesized using laser treatment of graphene oxide (GO) film deposited on PET substrate. A universal laser system was used to simultaneously reduce and pattern the GO film into laser reduced graphene oxide (LRGO) film. Findings - The laser treatment synthesizes a multilayer graphene film with overlapped flakes, which shows structure integrity, mechanical flexibility and electrical conductivity of 1,330 S/m. The developed LRGO/PET film was used to fabricate a high sensitivity strain sensor. The sensitivity and temperature dependency of its gauge factor (GF) was examined at applied strains up to 0.25 per cent and operating temperatures up to 80 degrees C. The fabricated sensor shows stable GF of approximately 78 up to 60 degrees C with standard error of the mean not exceeding approximately +/- 0.2. Originality/value - The proposed method offers a new simple and productive technique of fabricating large-scale graphene-based flexible devices at a low cost.