Electrical response, elastic property, and pressure sensing under bending of hybrid graphene/CNT/elastomer nanocomposites

The hybrid graphene/carbon nanotube (CNT)/elastomer nanocomposite is studied as a pressure sensor under bending. The main idea is that, due to the uneven elastic deformation between the softer elastomer matrix and the stiffer nanofillers, the volume fractions of graphene and CNTs both increase as a result of bending, and this in turn triggers higher electrical conductivity and superb sensing performance of the nanocomposite. This effect is analyzed through a three-phase composite model that contains graphene nanoplatelets (GNPs) and CNTs in a fluorinated elastomer matrix. We also show how the elastic and electrical properties of the hybrid nanocomposite depend on the graphene and CNT volume fractions. It is demonstrated that, with the increase of bending pressure from 0 to 1 KPa, the sensor resistance reduced by several orders of magnitude, which makes the hybrid sensor conductive from an insulator and an ideal pressure sensor.