Looped energy harvester for human motion

M. Geisler (1) , S. Boisseau (1) , P. Gasnier (1) , J. Willemin (1) , C. Gobbo (1) , G. Despesse (1) , I. Ait-Ali , S. Perraud (2)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux

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.

Keywords: energy harvesting; human motion; low-frequency vibrations; body area sensor nodes

Domains: Engineering Sciences [physics]

M. Geisler, S. Boisseau, P. Gasnier, J. Willemin, C. Gobbo, et al.. Looped energy harvester for human motion. Smart Materials and Structures, 2017, 26 (10), ⟨10.1088/1361-665X/aa8918⟩. ⟨cea-02202411⟩