High Output, Biocompatible, Fully Flexible Fiber-Based Magneto-Mechano-Electric Generator for Standalone-Powered Electronics

Abstract

Harvesting magnetic noise fields around power cables emerges as an attractive approach due to its potential as a renewable and ubiquitous energy source for powering wireless sensor networks (WSNs) in IoT applications, miniature electronics, and implantable medical devices. Flexible polymer-based magneto-mechano-electric (MME) generators gain attention for their effectiveness in magnetic energy harvesting owing to their durability and flexibility. In this study, a lead-free, flexible MME generator is developed by using Polyvinylidene fluoride (PVDF)-Aluminium nitride (AlN)-nanofiber composites fabricated via electrospinning with different AlN compositions and integrated with a magnetostrictive Metglas layer that offers self-bias characteristics. The MME generator is modeled using COMSOL Multiphysics to analyze the magnetic flux density distribution over the Metglas surface and the piezoelectric effect of the nanofiber composites, with the simulation results aligning well with the experimental data. The optimized, flexible MME generator, incorporating 15 wt.% of AlN in the PVDF/Metglas composite, achieves an open-circuit voltage of 18.5 V and a power density of 0.93 mW-cm⁻³ when exposed to an Alternating Current (AC) magnetic noise field of 6 Oe at a resonance frequency of 50 Hz. The generated power is sufficient to operate LEDs and sensor. This newly developed lead-free, flexible MME generator shows significant promise for advanced applications in self-powered WSNs.