Figure 1
From: Stretchable and highly sensitive graphene-on-polymer strain sensors

GWF-on-PDMS structure for tensile test.
(a) Schematic of the GWF-on-PDMS structure. (b) Macroscopic optical image of a wired sample. (c) A series of optical images showing the formation of crack and their evolution in GWF under different strain and corresponding schematics. (d) Optical images of the GWF under large strains (20% and 50%).