A Soft Magnetoelastic Generator for Wind‐Energy Harvesting

The current energy crises and imminent danger of global warming severely limit the ability to scale societal development sustainably. As such, there is a pressing need for utilizing renewable, green energy sources, such as wind energy, which is ubiquitously available on Earth. In this work, a fundamentally new wind-energy-harvesting technology is reported, which is based on the giant magnetoelastic effect in a soft composite system, namely, magnetoelastic generators. Its working principle is based on wind-induced mechanical deformation, which alters the magnetic field in a soft system converting the wind energy into electricity via electromagnetic induction from arbitrary directions. The wind-energy-harvesting system features a low internal impedance of 68 Ω, a high current density of 1.17 mA cm^-2 , and a power density of 0.82 mW cm^-2 under ambient natural wind. The system is capable of sustainably driving small electronics and electrolytically splitting water. The system can generate hydrogen at a rate of 7.5 × 10^-2 mL h^-1 with a wind speed of 20 m s^-1 . Additionally, since magnetic fields can penetrate water molecules, the magnetoelastic generators are intrinsically waterproof and work stably in harsh environments. This work paves a new way for wind-energy harvesting with compelling features, which can contribute largely to the hydrogen economy and the sustainability of human civilization.