Fabrication of a Cost-effective Piezoresistive Pressure Sensor Based on PVC/Reduced Graphene Oxide (rGO) Composite

A cost-effective piezoresistive sensor based on PVC/Reduced graphene oxide (rGO) was fabricated and its performance was investigated. The weight percent range from 0.1 to 30% of rGO in PVC matrix was studied. Composite parts were prepared by using the solution casting method from tetrahydrofurane (THF) solvent followed by solvent evaporation. The plot of electrical conduction versus rGO percentage was constructed to obtain the percolation threshold concentration. It was found that the percolation threshold of rGO leading to a continuous stable electrical conductivity in PVC matrix is about 25% beyond which electrical resistance was reduced from about 800 GΩ to lower than 100 KΩ range. The relative changes in electrical resistance of prepared polymer parts as a result of impact (stress), stretch and bending deformation were studied. The results showed that the fabricated composite can be used for sensing and/or monitoring and measurement of any mechanical displacement with high sensitivity, promising reproducibility and satisfactory durability. It must be mentioned that, during impact tests of polymer composites, a small piezoelectric effect was also observed for which further complimentary studies are being planned to be performed in near future in order to better understand this effect and its underlining molecular basis.