Bio-inspired mechanics of highly sensitive stretchable graphene strain sensors

Graphene woven fabrics (GWFs) can sense large strain up to 10% with the highest gauge factors (10(5)) thus far reported. This result promises key applications particularly in sensing strains of soft materials such as biological tissues, but the mechanism of such super gauge factor (SGF) property was not very clear. Through a bio-inspired Voronoi polycrystalline micromechanics model together with experimental validations, we show that the successive cracking, the fish-scale like network structure of GWFs, and the superlubricity between overlapped graphene flakes play crucial roles resulting in the SGF property. We also reveal the influences of overlapping width, graphene strip size, Poisson's ratio of the substrate material, size effect, interfacial resistance, and network size to the SGF property. These results can guide the design of GWFs with desired sensing performance. (C) 2015 AIP Publishing LLC.