MWCNTs/PVDF Nanofiber Array Films With Enhanced Piezoelectric Performance for Effective Mechanical Energy Harvesting

ABSTRACT Piezoelectric nanogenerators (PENGs) with high strength and low internal resistance are essential for self‐supply as well as energy harvesting. This study proposes a new type of PENG, which is a stacked structure composed of top and bottom electrodes, and a MWCNTs/PVDF nanofiber array prepared by a combination of electrospinning and cutting techniques. Each nanofiber in the array is an independent PENG exhibiting identical piezoelectric properties, thereby enhancing the output performance of PENGs. The addition of MWCNTs promoted the formation of β crystals and reduced the internal resistance of PENGs (2 MΩ), which increased the piezoelectric response and extended the load matching conditions, thus enhancing the practicability of the PENGs. The PENG (1.4 × 1.4 cm 2 ) can directly light up three LEDs under a single impact without storage equipment, with an instantaneous peak power surface density of 2.3 μW cm −2 . The dense vertical array structure enables the PENG to have excellent stability and durability. Furthermore, the nanofiber array film PENG also has a good characteristic response to small mechanical forces with different characteristics (such as finger and finger joint tapping). This study shows that the MWCNTs/PVDF nanofiber array films have broad application prospects in energy harvesting devices, self‐powered devices, and mechanical action feature detection devices.