Abstract : The development of energy harvesters for smart wearables is a challenging topic, with a difficult combination of ergonomics constraints, lifetime and electrical requirements. In this work, we focus on an inertial inductive structure, composed of a magnetic ball circulating inside a closed-loop guide and converting the kinetic energy of the user's limbs into electricity during the run. A specific induction issue related to the free self-rotation of the ball is underlined and addressed using a ferromagnetic 'rail' component. From a 2 g moving ball, a 5 cm-diameter 21 cm(3) prototype generated up to 4.8 mW of average power when worn by someone running at 8 km h(-1). This device is demonstrated to charge a 2.4 V NiMH battery and supply an acceleration and temperature Wireless Sensor Node at 20 Hz.
https://hal-cea.archives-ouvertes.fr/cea-02202411
Contributor : Marianne Leriche <>
Submitted on : Wednesday, July 31, 2019 - 4:33:34 PM Last modification on : Friday, November 6, 2020 - 3:33:23 AM
M. Geisler, S. Boisseau, P. Gasnier, J. Willemin, C. Gobbo, et al.. Looped energy harvester for human motion. Smart Materials and Structures, IOP Publishing, 2017, 26 (10), ⟨10.1088/1361-665X/aa8918⟩. ⟨cea-02202411⟩