Polymeric PVDF Fibers for Piezoelectric Applications in Energy Harvesting

This work focuses on developing and characterizing the piezoelectric response of Cerium doped Polyvinylidene Fluoride (PVDF) fine fibers and the effects of dopants and alignment on the formation of the β-phase and consequently on the piezoelectric performance. Six sets of fiber mats were prepared varying the concentration (2.5–7.5wt%) of Cerium (III) Nitrate-Hexahydrate and Ammonium-Cerium (IV) Sulfate-Dihydrate. Fiber mats were developed using the Forcespinning® technique and the angular velocity and dopant concentration were adjusted to obtain a synergy between fiber yield and fiber diameter. Fourier Transform Infrared Spectroscopy showed a significant enhancement in the PVDF β-phase and inhibition of the non-polar α-phase. The doping effect of the cerium complexes shows a small effect on the piezoelectric response, with the PVDF Cerium-Sulfate fibers producing 7 to 8V; whereas the pure PVDF fibers’ response ranged between 5 to 7V. Fibers doped with 5wt% Cerium-Sulfate showed the best fiber morphology and had the highest yield of production. Addition of graphene demonstrated increased in sensitivity for the fibers, while the addition of PPy helped in increasing the charge/discharge rate for the fibers’ voltage response. The effect of fiber alignment proved beneficial by increasing the β-phase formation of the fibers, reducing fiber diameter, and thus producing higher voltage response, 9.20–11 V for 5wt% Cerium-Sulfate