Eco-Friendly Copper Oxide Nanoparticles Incorporated Polyvinylidene Difluoride Electrospun Nanofibers as Wearable Piezoelectric Nanogenerator

This study focuses on enhancing the performance of piezoelectric nanogenerators (PENGs) fabricated by electrospinning (ES) of polyvinylidene fluoride (PVDF) infused with varying concentrations (0, 1, 3, 5, and 7 wt.-%) of copper oxide (CuO) nanoparticles. Structural changes and the <i>β</i>-phase proportion in nanofibers (NFs) were examined using XRD and FTIR-ATR. Surface morphology and roughness were characterized using FE-SEM and AFM, respectively. The water-repellent characteristics of the NFs were assessed through WCA measurements. Electrical output (voltage and current) was evaluated under mechanical pressure using a customized setup that applied 1.0 kgf at 1.0 Hz. The pristine PVDF-based PENG generated an output of 1.7 V and 0.53 μA, while the composite NF with 5 wt.-% CuO (5PCu) delivered a significantly enhanced output of 13.7 V and 1.6 μA. The 5PCu device was further tested for detecting human activities, including tapping, wrist movements, walking, and jumping, thereby demonstrating its potential for self-powered wearable electronics.