Development of conductive thin films as piezoresistive strain sensor

Abstract Carbon nanocomposites are looked as the future smart materials for the applications of sensor transducers, actuators and soft electronic devices. In the present work, we have developed conductive nanocomposite thin films CNTFs using polyvinylidene fluoride (PVDF) dielectric polymer and vapour grown carbon nanofibers (VGCNF) conductive filler in varying 5, 10, 15 wt% concentration after optimization using solvent casting technique. VGCNF played a crucial role in developing conducting network as well as in enhancing the mechanical performance. The conducting behaviour was used for strain sensing and the mechanical behaviour helped in providing the flexibility for strain sensing application. The sample with 10 wt% of VGCNF showed best results for high conductivity 1.3 × 10−3 s/m and elongation of 5.8 × 10−3 mm. Moreover, the developed CNTFs showed a gauge factor around 2.88 which is higher to metal-based piezoresistive strain sensors and showed high flexibility. The developed thin films can be looked for the application of human health and structural health monitoring for determining the change in electrical signals with respect to deformation.