Human walking generates renewable and accessible energy with a potential output of up to 67 W. However, effectively harnessing this energy is significantly impeded by the high humidity within the shoe, stemming from both the human body and the surrounding environment. In response to this challenge, we introduce an intrinsically waterproof and biocompatible magnetoelastic smart insole engineered to generate electricity during walking by utilizing the giant magnetoelastic effect. The smart insole features an ultralow internal impedance of ∼80 Ω, a substantial current output up to 59.9 mA, and a peak power output of 1.04 mW, performance characteristics that enable the sustainable powering of running lights as well as provide personalized thermoregulation. Furthermore, the insole demonstrates exceptional durability, consistently maintaining peak performance, even with prolonged use and immersion in water. With these extensive advantages, the smart magnetoelastic insole serves as a sustainable, efficient, and robust power source for the Internet of Things, providing a pervasive, decentralized, and mobile energy solution that overcomes the inherent limitations of traditionally centralized and rigidly structured power grids.
Fan et al. (Mon,) studied this question.