A graphene force sensor with pressure-amplifying structure

We present a sensor of vertical forces based on single-layer graphene, with a working range that corresponds to the pressure of a gentle touch that can be perceived by humans. Polydimethylsiloxane (PDMS) is employed for the supporting material of the graphene layer and also works as a force absorber of the sensor. In spite of the low gauge factor that arises from the intrinsic electromechanical character of single-layer graphene, we achieve a resistance variation of about 17 +/- 7% in response to an applied vertical pressure of 10 kPa by introducing a pressure-amplifying structure of patterned lines that induces additional structural deformation of the graphene layer for the applied vertical force. In addition, we demonstrate a method to enhance the sensitivity of the sensor by applying resistive single-layer graphene. (C) 2014 Elsevier Ltd. All rights reserved.