Analysis of thermal energy harvesting using ferromagnetic materials

M. Lallart (1) , L. Wang (1) , G. Sebald (1) , L. Petit (1) , D. Guyomar (1)

1 LGEF - Laboratoire de Génie Electrique et Ferroélectricité

This Letter aims at giving a preliminary investigation of the thermal energy harvesting capabilities of a technique using the temperature-dependent permeability of ferromagnetic materials. The principles lie in the modification of the magnetic field caused by the variation of the permeability due to the temperature change, hence generating a voltage across a coil surrounding the circuit. The technique can be made truly passive by the use of magnets for applying bias magnetic field. Theoretical results, validated by experimental measurements, show a voltage output of 1.2 mV at optimal load of 2 Ω under 60 K temperature variation in 5 s (with a maximum slope of 25 Ks-1). Further improvements, such as the use of low resistivity coil and magnet with high remnant magnetic field, indicate that it is possible to convert up to 7.35 μJcm-3K-2cycle-1. © 2014 Elsevier B.V. All rights reserved.

Domaines: Sciences de l'ingénieur [physics]

M. Lallart, L. Wang, G. Sebald, L. Petit, D. Guyomar. Analysis of thermal energy harvesting using ferromagnetic materials. Physics Letters A, 2014, 378 (43), pp.3151-3154. ⟨10.1016/j.physleta.2014.09.016⟩. ⟨hal-01770273⟩