Neodymium doped zinc oxide based advanced flexible piezoelectric energy harvester and self-powered biomotion sensor

Flexible piezoelectric devices have garnered a lot of attention for their potential as energy harvesters and transducers. In this work, Neodymium (Nd) doped Zinc Oxide (ZnO) based flexible piezoelectric energy harvester and sensory device has been developed. Nd-doped ZnO has been synthesized using wet chemical co-precipitation and incorporated in Polyvinylidene Difluoride (PVDF) polymer matrix along with Multiwalled Carbon Nanotubes (MWCNT) to produce flexible piezoelectric films. The piezoelectric output of the device is tested at variable tapping frequency (60 to 240 BPM) and pressure (10 to 40 psi). The device has also been tested with conventional electronics like bridge rectifiers, capacitors, resistors, LEDs to show its potential as an energy harvester. Compared to other modified ZnO-PVDF based unpoled piezoelectric energy harvesters, this device has shown the most open-circuit output voltage of 75.8 V and short circuit current of 28.8 µA. It has shown an optimum power density of 12.55 μwcm^-2 at 1 MΩ load impedance. Energy harvesting capacity has been further tested by placing the device between the shoe soles during running and jogging. This study endorses the potential of Nd-ZnO/PVDF/MWCNT based piezoelectric energy harvester as the most efficient Piezoelectric Nanogenerator (PENG) which shows superior power generation along with self-powered sensory applications.