Flexible PVDF‐HFP/Single‐Walled Carbon Nanotubes Nanocomposite Films With Enhanced β‐Phase for High‐Performance Piezoelectric Energy Harvesting and Self‐Powered Sensing

Flexible piezoelectric nanogenerators (PENGs) are potential solutions for harvesting and sensing energy. The PVDF‐HFP/SWCNT nanocomposite films with SWCNT contents of 0.1, 0.25, and 0.5 wt% were prepared using a simple solution casting technique. The uniform dispersion of CNT and improved electroactive β‐phase formation were confirmed by the structural characterization performed by FESEM, XRD, Raman spectroscopy, and FTIR. The nucleating effect of SWCNTs is shown by the increase in the β‐phase fraction from 36.5% for pristine PVDF‐HFP to 70.4% for the 0.5 wt% SWCNT composite. The optimized PVDF‐HFP/0.5 wt% SWCNT nanogenerator demonstrated improved piezoelectric performance with an open‐circuit voltage of up to 6.39 V and a short‐circuit current of up to 8.34 μA under a 5 N applied force and a stable performance over 1000 loading cycles. Moreover, the successful demonstrations of energy harvesting and self‐powered sensing using the finger tapping and keyboard operation identify the device’s potential in wearable energy harvesting and self‐powered sensing applications.