Piezoresistive sensitivity tuning using polyelectrolyte as interface linker in carbon based polymer composites

Abstract

Poly (4-styrenesulfonic acid) (PSSA) solution with Carbon nanofiber (CNF) were mixed in polyvinylidene fluoride (PVDF) polymer matrix to prepare series of PVDF/PSSA/CNF blend membrane. The results demonstrate improvement in the gauge factor and piezoresistive sensitivity, with increasing concentration of CNF, in presence of PSSA. The morphology of the composite membranes was examined by scanning electron microscopy. The phase shift from α to β was observed by the XRD patterns and DSC curves confirmed no change in the crystallinity of the membranes. The elasticity was observed to be increased in thin membranes of ∼0.2 mm thickness, with increase in PSSA content. The detailed investigation revealed that, the tuning of PSSA in carbon-based polymer composite achieved significant increase in gauge factor up to 5.07, attributed to good interfacial linking characteristic of PSSA. The developed CPNC membranes may find their applications in prosthetic limbs, biomedical instruments and other wearable devices as pressure sensors.