Piezoresistive sensing mechanism of graphene-based electronic skin

Graphene-based sensing electronic skin has a broad application prospect, but its piezoresistive sensing mechanism still needs to be further studied. In this work, according to the microscopic characteristics of graphene electronic skin, the Monte Carlo stochastic algorithm is used to generate randomly distributed graphene sheets, and then the piezoresistive sensor model of graphene electronic skin is established. The relative resistance and gauge factor of the model are calculated by finite element method. Meanwhile, the current density and potential contour under different graphene morphology are obtained. The results show that the graphene sensor with high area fraction has a higher sensing range, and the graphene sensor with low area fraction has a higher gauge factor. The piezoresistive effect of the model depends mainly on the change of graphene sheet density. With the change of strain, the variation of overlap area and overlap number between graphene sheets will cause the change of graphene density and electron migration path. The separation between graphene sheets can lead to a reduction in electron migration paths, resulting in nonlinear changes in the relative resistance of the model. The present work can provide technical support for the design and preparation of graphene-based electronic skin.