Enhanced Piezoelectric Performance of PVDF Nanofibers through Negative-Polarity Electrospinning and Grid-Controlled Corona Poling

Poly(vinylidene fluoride) (PVDF) nanofibers hold great promise for self-powered sensing and energy harvesting. However, simultaneously achieving high piezoelectric charge and voltage coefficients and a high electromechanical figure of merit remains challenging because charge generation, voltage output, and dielectric response are intrinsically coupled. Herein, we report a synergistic strategy that integrates negative-polarity electrospinning with grid-controlled corona poling to jointly amplify charge and voltage responses in PVDF nanofibrous membranes. Negative-polarity electrospinning was associated with a higher relative β-phase fraction of 96.28% without markedly changing the overall crystallinity, together with polarity-dependent differences in the near-surface chemical environment. Combined structural, surface-chemical, dielectric, ferroelectric, and piezoelectric analyses suggest that these pre-existing features may influence the subsequent corona-poling response. The enhanced response is discussed within a proposed preconstruction–activation framework, in which corona poling may further align polar domains and introduce charge-related polarization states. Consistent with the proposed coupling between crystal polarization and near-surface charge-related effects, the optimized PVDF(−15) membrane delivers an ultrahigh apparent d 33,eff of 264.4 ± 7.9 pC/N, a calculated effective g 33 of 7.337 V·m/N, and a calculated effective FOM of 1.9399 × 10 –9 m 2 /N. The resulting device further exhibits high voltage sensitivity to subtle dynamic mechanical stimuli and excellent long-term fatigue resistance, highlighting its potential for diverse self-powered sensing applications. This work identifies electrospinning polarity as a useful processing variable for tuning the device-level electromechanical response of PVDF nanofibrous membranes.