Strain based electrical resistance behaviour of graphene-coated elastomeric yarns

Graphene-based sensing materials are promising for creating wearable sensors. Traditional electro-conductive textile strain sensors made with metallic materials produce electrical signals that are linearly changing with the strain. However, this was not the case when graphene flakes are coated onto a yarn surface. In this contribution, in situ scanning electron microscopy reveals that once the graphene coated yarn is elongated, graphene flakes move as clusters rather than equally distributed individual flakes. The nonlinear variation in distances between those clusters is more analogous to the resistance variation. Thus, typical non-linear resistance variation seen in graphene coated yarns is suggested to underpin by the predictable behaviour of the cluster like segmentation of the graphene flakes in the yarn surface.