Enhancing Stray Magnetic Energy Harvesting with Flexible PVDF/CoFe2O4 Electrospun Fiber Composite Magneto-Mechano-Electric Generators

This study introduces a highly flexible, vertically installed electrospun PVDF/CoFe₂O₄ composite-based Magneto-Mechano-Electric (MME) generator designed to capture and utilize environmental stray magnetic noise, a prevalent form of waste energy from electrical power transmission systems. We fabricated highly flexible, freestanding magnetoelectric composite electrospun fibers by combining piezoelectric PVDF polymer and magnetostrictive CoFe₂O₄. XRD and FTIR analyses confirmed a significant enhancement in the ferroelectric β-phase content, reaching 86% with the incorporation of CoFe₂O₄. The electrostatic interaction mechanism between PVDF and CoFe₂O₄ was explained and validated through Zeta potential and XPS analyses. The developed MME generator demonstrated a high output voltage and power density of 12.1 V and 174 μW/m², respectively, under a low AC magnetic field of 6 Oe. The detailed mechanism of energy generation in the MME device has been explained. The fabricated MME device also demonstrated the highest magnetoelectric voltage coefficient (α_MME) value of 224 V cm^–1 Oe^–1, even in the absence of a magnetic bias DC field. The MME generator has demonstrated stable output harvesting performance across 50,000 testing cycles. This MME generator efficiently harvested low and weak parasitic magnetic noise from various electrical appliances, such as dryers, kettles, and iron boxes, thereby enabling a remote power supply to consumer electronics.