Scientists find new way to capture heat that otherwise would have been lost
An international team of scientists has figured out how to capture heat and turn it into electricity.
The discovery, published last week in the journal Science Advances, could create more efficient energy generation from heat in things like car exhaust, interplanetary space probes and industrial processes.
“Because of this discovery, we should be able to make more electrical energy out of heat than we do today,” said study co-author Joseph Heremans, professor of mechanical and aerospace engineering and Ohio Eminent Scholar in Nanotechnology at The Ohio State University. “It’s something that, until now, nobody thought was possible.”
The discovery is based on tiny particles called paramagnons—bits that are not quite magnets, but that carry some magnetic flux. This is important, because magnets, when heated, lose their magnetic force and become what is called paramagnetic. A flux of magnetism—what scientists call “spins”—creates a type of energy called magnon-drag thermoelectricity, something that, until this discovery, could not be used to collect energy at room temperature.
“The conventional wisdom was once that, if you have a paramagnet and you heat it up, nothing happens,” Heremans said. “And we found that that is not true. What we found is a new way of designing thermoelectric semiconductors—materials that convert heat to electricity. Conventional thermoelectrics that we’ve had over the last 20 years or so are too inefficient and give us too little energy, so they are not really in widespread use. This changes that understanding.”
Laura Arenschield, arenschield.2@osu.edu