A flexible piezoelectric pressure sensor based on PVDF nanocomposite fibers doped with PZT particles for energy harvesting applications

Flexible piezoelectric energy harvesters are a suitable choice for scavenging wasted mechanical energy because of the high demand for sustainable power sources. Flexible pressure sensors based on PVDF-PZT nanocomposite with different PZT volume fractions (0.011, 0.041, 0.096, 0.17, 0.3, and 0.37) were prepared in the form of fibers through an electrospinning method for piezoelectric energy harvesting application. According to the results, dielectric constant and piezoelectric coefficients (e.g. piezoelectric coefficient, and figure of merit) gradually increased with the doping of PZT particles into PVDF fibers. Dielectric constant (ϵ), piezoelectric coefficient (d), and figure of merit (d × g) for PVDF-PZT nanocomposite with 0.011 PZT volume fraction were 37.29, 10.51 pCN−1, and 33.46 × 10−16 m2/N, respectively, and increased to 104.81, 22.93 pCN−1, and 56.68 × 10−16 m2/N for PVDF-PZT nanocomposite fibers with a volume fraction of 0.37. As piezoelectric energy harvesters, piezoelectric sensitivity of PVDF-PZT nanocomposite fibers rose with increasing the PZT volume fraction. The generated output voltage was 184 mV under an applied force of 2.125 N with the piezoelectric sensitivity calculated as 173.507mV/Nμm for PVDF-PZT nanocomposite fibers with 0.37 PZT volume fractions which increased compared to pristine PVDF fibers (generated output voltage = 22 mV under applied force 2.4 N, piezoelectric sensitivity = 29.49 mV/Nμm). The achieved output power density of PVDF-PZT nanocomposite fibers with 0.37 PZT volume fractions was obtained 30.69μW cm−2 higher than PVDF-PZT nanocomposite fibers with 0.011 PZT volume fractions (18.44μW cm−2).