Flexible Tribo-Enhanced Piezoelectric Nanogenerator Based on Aluminium Ferrite Electrospun Hybrid Nanofibers for Energy Harvesting and Patient Rehabilitation Application

Abstract

Mechanical energy harvesters have recently emerged as promising options for self-powering sensors and small electronic devices. In this work, aluminum ferrite (AlFeO₃)/PVDF hybrid perovskite electrospun nanofiber-based tribo-enhanced piezoelectric nanogenerators (TPENGs) are developed for energy harvesting. The as-fabricated TPENG achieves an average voltage output of 52.3 V and an average current output of 1.23 µA. Additionally, the power density of the TPENG is calculated to be 0.085 W.m⁻² at an 80 MΩ external resistance load. A 3D-printed device is fabricated, containing nylon fabric (tribo-positive) as a rotor attached to printed fins, while six (AlFeO₃)/PVDF hybrid perovskite electrospun nanofiber piezoelectric nanogenerators (PENGs) wrapped with Kapton tape (tribo-negative) serve as the stator. The three printed fins of the device are moved by a string-based pulley, generating an open circuit voltage of 200 V and a short circuit current of 4.5 µA. The as-fabricated 3D-printed device with TPENGs is used to power small electronics (e.g., LEDs and watch) and an exercise setup, allowing patients to generate power by pulling the attached string, thereby estimating the level of impairment. Integrating energy harvesting into rehabilitation motivates patients to move impaired body parts, enhancing TPENG's application in healthcare as a practical and engaging tool for patient rehabilitation.