Flexible lead-free piezoelectric nanofiber composites based on BNT-ST and PVDF for frequency sensor applications

Flexible lead-free piezoelectric nanofibers composites of BNT-ST (0.78Bi0.5Na0.5TiO3-0.22SrTiO3) ceramic and polyvinylidenefluoride (PVDF) polymer were synthesized by an electrospinning method. The as-prepared BNT-ST/PVDF nanofibers composite with different BNT-ST concentrations from 0 wt% to 80 wt% were characterized by XRD, FE-SEM and EDS to investigate the crystal structure, microstructure and morphology. The piezoelectric characteristics were analyzed by the polarization-electric field (P-E) loops, and the results demonstrated that a BNT-ST content of 60 wt% had enhanced piezoelectric characteristics. The possibility of frequency sensor application was confirmed by measuring the output voltage as a function of the frequency of the BNT-ST/PVDF nanofiber composite with a BNT-ST content of 60 wt%.