Researchers have developed the world’s first heat-driven elastocaloric cooling system, using waste heat and solar energy to support sustainable cooling.

A cooling system powered directly by heat rather than an electric motor has worked in laboratory tests, offering a possible way to turn waste heat or solar energy into cooling. The prototype, developed by researchers at Karlsruhe Institute of Technology (KIT) and the University of Tsukuba, uses two ultrathin nickel-titanium films that convert heat first into mechanical motion and then into cold.

The concept addresses a limitation of elastocaloric cooling, an emerging solid-state alternative to conventional refrigeration. Shape-memory alloys cool when a mechanical load applied to them is released, but existing elastocaloric systems still need electrically powered actuators to supply that force. The new design instead uses heat itself to drive the process.