Development and Optimization of Highly Piezoelectric BTO/PVDF-TrFE Nanocomposite Film for Energy Harvesting Application

The interest in flexible vibrational energy harvesters is continuously increasing due to their low cost, biocompatibility, and environmental friendliness. This paper presents the optimization of PVDF-TrFE nanocomposite thin film in which barium titanate (BTO) is added as a functional material for the transformation of inherent α to highly piezoelectric β phase. The PVDF-TrFE and BTO are dispersed in dimethyl sulfoxide (DMSO) and spin-coated on a Molybdenum/polyethylene terephthalate sheet (Mo/PET). The composition and crystallinity are varied to optimize the growth of PVDF-TrFE and BTO/PVDF-TrFE films. X-ray diffraction (XRD) is used to characterize the spin-coated films' β phase. The field emission scanning electron microscope (FE-SEM) is utilized to characterize the film's uniformity. The Fourier Fourier-transform infrared spectroscopy (FTIR) is used to detect the transmittance in the wavenumber range from 400 to 1500 cm-1 of spin-coated BTO/PVDF-TrFE thin films. The piezo response force microscopy (PFM) measurement of films with different weight % and compositions is performed to identify the energy harvesting ability. It is found that the film deposited with 15% BTO in 15% PVDF-TrFE shows the best piezoelectric response. The piezoelectricity coefficient (d31) is found to be 1.29 nm/V, showing the excellent ability of polymer film to harvest vibrational energy available in the environment.