Thermomagnetic motors (also known as Curie wheels,[1] Curie-motors[2][3] and pyromagnetic motors[4]) convert heat into kinetic energy using the thermomagnetic effect,[5] i.e., the influence of temperature on the magnetic material magnetization.[6]
This technology dates back to 19th century, when a number of scientists submitted patents on the so-called "pyro-magnetic generators".[7] These systems operate in a magnetic Brayton cycle, in a reverse way of the magnetocaloric refrigerators.[8] Experiments have produced only extremely inefficient working prototypes,[9][10][11] however, thermodynamic analysis indicate that thermomagnetic motors present high efficiency related to Carnot efficiency for small temperature differences around the magnetic material Curie temperature.[8][5][12] The thermomagnetic motor principle has been studied as a possible actuator in smart materials,[13] being successful in the generation of electric energy from ultra-low temperature gradients.[14]
Alves, C.S.; Colman, F.C.; Foleiss, G.L.; Vieira, G.T.F.; Szpak, W. (November 2013). "Numerical simulation and design of a thermomagnetic motor". Applied Thermal Engineering. 61 (2): 616–622. doi:10.1016/j.applthermaleng.2013.07.053.
Karle, Anton (October 2001). "The thermomagnetic Curie-motor for the conversion of heat into mechanical energy". International Journal of Thermal Sciences. 40 (9): 834–842. doi:10.1016/S1290-0729(01)01270-4.
Edison, T. A., "Pyromagnetic Motor", US Patent No. 380,100; Patented March 27, 1888.
Bessa, C.V.X.; Ferreira, L.D.R.; Horikawa, O.; Gama, S. (December 2018). "On the relevance of temperature, applied magnetic field and demagnetizing factor on the performance of thermomagnetic motors". Applied Thermal Engineering. 145: 245–250. doi:10.1016/j.applthermaleng.2018.09.061. S2CID 117682356.
Gama, Sergio; Ferreira, Lucas D. R.; Bessa, Carlos V. X.; Horikawa, Oswaldo; Coelho, Adelino A.; Gandra, Flavio C.; Araujo, Raul; Egolf, Peter W. (2016). "Analytic and Experimental Analysis of Magnetic Force Equations". IEEE Transactions on Magnetics. 52 (7): 1–4. doi:10.1109/tmag.2016.2517127. S2CID 21094593.
Bessa, C. V. X.; Ferreira, L. D. R.; Horikawa, O.; Monteiro, J. C. B.; Gandra, F. G.; Gama, S. (2017). "On the influence of thermal hysteresis on the performance of thermomagnetic motors". Journal of Applied Physics. 122 (24): 244502. Bibcode:2017JAP...122x4502B. doi:10.1063/1.5010356.
Egolf, Peter W.; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier (2009). "Magnetic power conversion with machines containing full or porous wheel heat exchangers". Journal of Magnetism and Magnetic Materials. 321 (7): 758–762. Bibcode:2009JMMM..321..758E. doi:10.1016/j.jmmm.2008.11.044.
Smart Materials Structures of Systems, Allied Publishers, ISBN 8170239583, pages 23–25.
Kishore, Ravi Anant; Davis, Brenton; Greathouse, Jake; Hannon, Austin; Emery Kennedy, David; Millar, Alec; Mittel, Daniel; Nozariasbmarz, Amin; Kang, Min Gyu (2019). "Energy scavenging from ultra-low temperature gradients". Energy & Environmental Science. 12 (3): 1008–1018. doi:10.1039/C8EE03084G. ISSN 1754-5692. S2CID 104331548.