Next-gen wearable energy harvester using PVDF-doped CuO composite nanofiber-based piezoelectric nanogenerators

Flexible piezoelectric nanogenerators (PENGs) based on electrospun (ES) nanofibers (NFs) have gained significant attention for their ability to convert mechanical energy into electrical power. This study focuses on enhancing the piezoelectric performance of PENG devices fabricated from polyvinylidene fluoride (PVDF) ES NFs infused with varying concentrations (0, 1, 3, 5, and 7 wt%) of copper oxide (CuO) nanoparticles. Structural changes and the proportion of β -phase within the fibers were examined by FTIR and XRD measurements. Surface morphology and roughness were observed from FE-SEM and AFM analyses, respectively. Electrical output, including voltage and current was evaluated under mechanical pressure using a customized setup applying 1.0 kgf at 1.0 Hz. Pristine PVDF-based PENG generated a modest output of 1.7 V and 0.53 µA, while the composite fiber 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 wearable applications, successfully detecting human activities such as tapping, wrist movements, walking, and jumping, demonstrating its potential in self-powered wearable electronics.