Biogenic SiO₂-induced β-phase engineering in electrospun PVDF nanofibers for self-powered, sub-millisecond impact...

Flexible piezoelectric materials capable of resolving transient mechanical events are essential for emerging sensing systems. In this work, electrospun PVDF nanofibers incorporating biogenic SiO₂ nanoparticles derived from rice husk were developed to investigate the relationship between structural evolution and dynamic electromechanical response. Structural analyses confirmed that SiO₂ incorporation promotes β-phase formation, increasing its fraction from 53.03% to 69.71%. The fabricated device exhibited stable output under periodic excitation (5, 8, and 11 Hz), with an average peak voltage of 659.04 ± 14 mV, corresponding to an ∼13.6% enhancement compared to pristine PVDF. Under dynamic impact conditions (1.7-13.7 mJ), the device generated well-defined voltage transients with a strong linear dependence on impact energy (R² = 0.958). Time-resolved analysis revealed a rapid electromechanical response, with a rise time of 0.46 ms, a peak-to-peak interval of 0.14 ms, and a recovery time of ∼1 ms. These results indicate efficient stress-to-charge conversion and fast signal stabilization within the nanofibrous architecture. The combined effects of enhanced electroactive phase content, low inertial mass, and effective stress transfer enable reliable time-resolved sensing, highlighting the potential of the PVDF-SiO₂ system for self-powered detection of dynamic mechanical stimuli.