Flexible KNN-BT-Poly(vinylidene fluoride) Composites: Synergistic Effect on Ferroelectric Properties and Capacitive Pressure Sensing Response

Abstract

Multifunctional ferroelectric composites are increasingly regarded as promising sustainable energy solutions in modern industry. Lead-free ferroelectric perovskite ceramics are gaining attention as potential ceramic materials for electronic applications. In this paper, promising lead-free ferroelectric ceramic materials are considered as fillers in a polymer matrix to prepare flexible composites for sensing applications. This study reports the development of a lead-free ceramic system incorporated into a PVDF polymer matrix to fabricate flexible KNN-BT/PVDF composite films. The incorporation of nanofiller into the PVDF polymer matrix resulted in an enhancement of interfacial polarisation, which subsequently improved the dielectric, ferroelectric and sensing properties of the composite ceramic-polymer samples compared to the PVDF film. The permittivity of the ceramic-polymer composite sample (ε = 15.2) was enhanced significantly compared to PVDF (ε = 9.6), and the sensing value increased by a factor of 1.3 with respect to the pristine PVDF film. The activation energy for the composite film (Eact=0.36 eV) is found to be higher than PVDF (Eact=0.28 eV).