Piezoelectric Elements with PVDF–TrFE/MWCNT-Aligned Composite Nanowires for Energy Harvesting Applications

Abstract

A self-sustainable power supply function with flexibility, mechanical stability, and lightweight quality is among the required properties for pressure sensors and other low-power-consuming electronics and wearable devices. In this work, a poly(vinylidene fluoride-trifluoroethylene)/multi-walled carbon nanotube (P(VDF–TrFE)/MWCNT) composite was prepared to increase the electrical conductivity of the piezoelectric polymer and, thus, improve its electrical power generation capabilities. It was soaked by injection molding through an anodic aluminum oxide membrane to align vertically with the dipoles and exclude the possibility of dipole moment quenching. The composite membrane-type element exhibited an excellent piezoelectric coefficient d33 of 42 pC/N at a frequency of 50 Hz and an applied force intensity of 10 N, while the sensitivity was ~375 µV/g, which is favorable for self-powered pressure sensor application. The resulting composite element was utilized to generate the piezoelectric signal and to investigate the dependence of the electromechanical behavior on the surface roughness, morphology, and contact interface resistance.