Body motion for powering biomedical devices

TLDR

Kinetic energy harvesting from body motion can power small biomedical devices, recharging or replacing batteries. The study investigates generating energy from human activities. An axial‑flux generator with a gear‑shaped planar coil, multipole NdFeB magnet ring, and eccentric weight produces power through electromagnetic induction as body motion alters the magnetic flux. A 1.5 cm³ prototype delivered 3.9 µW while walking with the generator mounted laterally on the ankle.

Abstract

Kinetic energy harvesting has been demonstrated as a useful technique for powering portable electronic devices. Body motion can be used to generate energy to power small electronic devices for biomedical applications. These scavengers can recharge batteries, extending their operation lifetime or even replace them. This paper addresses the generation of energy from human activities. An axial flux generator is presented using body motion for powering miniature biomedical devices. This generator presents a gear-shaped planar coil and a multipole NdFeB permanent magnet (PM) ring with an attached eccentric weight. The device generates energy by electromagnetic induction on the planar coil when subject to a changing magnetic flux due to the generator oscillations produced by body motion. A 1.5 cm(3) prototype has generated 3.9 microW of power while walking with the generator placed laterally on the ankle.