Fig. 2: Restorable and stable VGS-V behavior.
From: Vertical graphene on flexible substrate, overcoming limits of crack-based resistive strain sensors
a Illustration of VGS when the elongated direction is perpendicular to the cracks on the BFG. b Enlarged SEM image of surface on BFG, clearly showing well-aligned cracks on the BFG. Scale bar, 50 μm. c Resistance as a function of time with applied stepwise strain. Approaching 2.5% strain, the resistance reaches in unmeasurable range, namely, the current path is broken, which the corresponded in situ SEM image is shown in the inset (Scale bar, 500 μm). However, the resistance is restored after the strain is released, and the post-overloaded resistance is almost the same to the pre-overloaded resistance at each strain. d In situ SEM images of VGS during stretching (I (0%), green box and II (2%), yellow box)/releasing (III (1%), purple box and IV (0%), blue box), which are corresponded to those boxes in (c). Scale bar, 200 μm.
