1 Optimizing the Output of a Human-Powered Energy Harvesting System with Miniaturization and Integrated Control

Abstract

Abstract—We propose a novel harvesting technology to inconspicuously transduce mechanical energy from human foot-strikes and explore its configuration and control towards optimized energy output. Dielectric Elastomers (DEs) are high-energy density, soft, rubber-like material that electrostatically transduce mechanical energy. These properties enables increased energy-transduction efficiency without sacrificing on user comfort, if configured and controlled properly. We expose key statistical properties of human gait which show that an array of miniaturized harvesters across the foot-sole will improve energy output. Further, the gait properties naturally yield a closed-loop control strategy to individually control harvesters in the array in a manner that maximizes net energy output. We propose statistical techniques that guide the configuration and control of the harvester array, and evaluate system behavior from detailed analytical and empirical models of DE behavior. System evaluations based on experimentally collected foot pressure datasets from multiple subjects show that the proposed system can achieve up to 120mJ per foot-strike, enough to power a variety of low-power wearable devices and systems. I