Stretchable and Calibratable Graphene Sensors for Accurate Strain Measurement

Stretchable nanomaterial-based strain sensors are essential to soft electronics and robotics and wearable devices, but it is a challenge to calibrate those sensors having multiple constant gauge factors. We herein prepared stretchable elastomer/graphene composite sensors, and at the interface some graphene sheets were infiltrated within elastomer macromolecules. The infiltration facilitated strain transfer from the elastomer to the graphene film, thus both cyclic stability and high linearity were obtained for accurate strain measurement. Depending on the strain level, the dominant sensing mechanism switched between the sliding of graphene sheets, the tunnelling effect and the propagation of cracks on the graphene film as well as the evolutionary changes at the interface between the film and the substrate. Our stretchable graphene sensors can be readily calibrated to be proper gauges without pursuing constant gauge factors. The sensors can provide strain measurement with high accuracy of over 99.7% and resolution up to 0.089%.