A self-powered and stretchable magnetic film for human–machine interface applications

Abstract

Developing stretchable, self-powered electronic interfaces for ambient energy harvesting is crucial for next-generation wearable electronics and human–machine interface applications. We present a stretchable magnetoelectric composite film comprising Ni_0.5Co_0.5Fe₂O₄ magnetic nanoparticles embedded in an Ecoflex matrix. The nanoparticles, synthesized via co-precipitation, exhibit a strong magnetic response, while Ecoflex ensures high stretchability and skin-mountable adaptability. The comprehensive structural, morphological, and magnetic analyses confirm the formation of a uniform and multifunctional film. The optimized device delivers a peak output voltage of ∼8.3 V and a power density of 3.16 mW cm⁻³ under ambient magnetic fields, outperforming conventional soft nanogenerators. The films demonstrate excellent durability under repeated deformation and maintain stable performance at tensile strains up to ∼315%. Integration into a soft wearable platform enables real-time gesture recognition, with distinct voltage signals for finger bends and gestures under low-intensity magnetic fields. This work highlights the potential of magnetic/Ecoflex-based nanogenerators in self-powered, wearable, stretchable electronics, smart prosthetics, and intelligent human–machine interfaces.