Piezoresistive\nGraphene/P(VDF-TrFE) Heterostructure\nBased Highly Sensitive and Flexible Pressure Sensor

Abstract

We\nreport on a novel graphene/P­(VDF-TrFE) heterostructure based\nhighly sensitive, flexible, and biocompatible pressure/strain sensor\ndeveloped through a facile and low-cost fabrication technique. The\nhigh piezoelectric coefficient of P­(VDF-TrFE) coupled with outstanding\nelectrical properties of graphene makes the sensor device highly sensitive,\nwith an average sensitivity of 0.76 kPa^–1, a gauge\nfactor of 445, and signal-to-noise ratio of 60.8 dB in the range of\npressure up to 45 mmHg. A model was proposed to explain the sensor\noperation, based on carrier density and mobility changes induced by\nthe piezoelectric charge generated in response to strain, which was\nsupported by Hall measurements and Raman spectroscopy. Potential applications\nin wearable sensing for human activity monitoring were also demonstrated.