Electrospun Polyvinylidene Fluoride-Polyoctafluoropentyl Acrylate-Hydroxyapatite Blend Based Piezoelectric Pressure Sensors

In this study, neat polyvinylidene fluoride (PVDF), PVDF/polyoctafluoropentyl acrylate (PFA, 90/10 w/w) and PVDF-PFA/hydroxyapatite (HAP, 0 to 20 wt% HAP w.r.t. PVDF-PFA content) were electrospun under controlled conditions, and studied for their piezo-responsive behaviours as a function of nanoweb stacking arrangement (constructive and destructive) and folding architectures (simple, series and parallel connection of electrodes between each folding). Influence of varying HAP content (0, 3, 7, 10, and 20 wt%) on the molecular orientation of CH2-CF2 dipoles in PVDF-PFA/HAP blends were investigated using FTIR, XRD and SEM analysis. Quantitative analysis showed increased beta-crystalline content for the 7 wt% HAP sample. From the peak-to-peak output voltage, 7 wt% HAP sample exhibited significantly higher output voltage (Vp-p = 1.21 V) compared to neat PVDF-PFA sample (Vp-p = 0.46 V). Overall, the combinative effect of HAP addition and folding played a vital role in improving the piezoelectric output signals of PVDF-PFA/HAP, which signifies the importance of this study.