Researchers from the Karlsruhe Institute of Technology and the University of Tsukuba have created a cooling system that works without an electric motor: it is driven by ordinary heat — from sunlight, industrial equipment, or other sources.
The secret lies in two ultra-thin films made of a nickel-titanium alloy. The first contracts when heated and pulls on the second. That second film, when stretched and then released, cools rapidly — much like a rubber band changes temperature when stretched. In an experiment, heating to 86°C made it possible to achieve almost 13°C of cooling inside the material.
In the future, the technology could be used to cool electronics and reuse energy released by machines and industrial equipment.
