06/01/2025
Researchers made a device that can generate electricity from heat radiated as infrared light.
Using a specialized semiconductor device called a thermoradiative diode, a team at the University of New South Wales (UNSW) made a major breakthrough. The thermoradiative diode, made from materials found in night-vision goggles, produces power by exploiting the temperature difference between a warm surface and the cooler environment around it.
What does this mean?
During the day, solar cells generate electricity by absorbing sunlight. Similarly, the thermoradiative diode generates electricity at night by releasing infrared radiation into the cold of space. This process mimics the way the Earth cools at night, emitting heat absorbed during the day as infrared radiation into space.
While the initial amount of electricity generated was small — about 100,000 times less than a traditional solar panel—the demonstration was a significant step in proving the technology’s potential.
Since their initial breakthrough, the team has started working with more easily manufacturable materials, opening up a range of possible uses. For instance, the technology could harness body heat to power wearable devices, potentially eliminating the need for batteries in gadgets like wristwatches or enabling them to recharge themselves.
“In principle, we can generate power from body heat,” said Professor Ned Ekins-Daukes, the team’s lead. “This could eventually lead to battery-free or self-recharging devices—something conventional solar power can’t achieve.”
In space, the technology could have transformative applications. Satellites and spacecraft in low Earth orbit experience 90-minute cycles of daylight and darkness. While solar cells power these crafts during daylight, they rely on batteries during darkness. The thermoradiative diode could generate power during these eclipse periods, reducing dependence on batteries.
