Designing of pressure sensor with polyvinylidene fluoride composite films embedded with nickel oxide for energy harvesting

Abstract

This paper describes the successful fabrication of specially designed piezoelectric pressure sensor by using poly-vinylidene-fluoride (PVDF) films embedded with nickel oxide (NiO). This PVDF-NiO composite film is prepared using the solvent casting method to improve the electro-active β-phase and enhance crystallinity for various sensing and energy harvesting applications. Various tools were used to analyze changes in the crystalline structure, morphology, and dielectric behavior of PVDF-NiO composite films. Structural characterization and Infrared Spectroscopy affirmed the predominance of electro-active β-phase in the PVDF matrix by adding NiO loadings. XRD studies show that the addition of NiO enhances the crystallinity from 45.62 (for pure PVDF) to 59.01 (1 wt% NiO). FTIR analysis shows that the β-phase fraction for PVDF-NiO film reaches to optimum value from 54% (pure PVDF) to 72% (1 wt% NiO). Micrographs from FESEM illustrates the uniform dispersion of NiO particles within the polymer with little agglomeration at the bottom. The I-V characteristic curves investigate the carrier transport mechanism in the composite films which is predominantly governed by Richardson-Schottky in addition to Poole-Frenkel. The maximum dielectric obtained is 25 with relatively low losses which are thrice than pure PVDF. The increase in AC conductivity at higher frequencies makes this novel composite material suitable for various electronic applications.