Publication Yi-Ting Hsiau
Yi-Ting Hsiau, a young researcher of the Hector Fellow Academy, is the first author of the publication "Heat-driven elastocaloric cooling with shape memory films," published in Nature Energy in 2026. His work was conducted at the Institute of Microstructure Technology (IMT) at the Karlsruhe Institute of Technology (KIT) in collaboration with the University of Tsukuba, Japan. The study presents a novel cooling system that can be powered directly by heat instead of electricity, for example using waste heat or solar thermal energy.
At the heart of the work are two ultrathin films made of nickel-titanium-based shape-memory alloys. An actuator film is heated and contracts as a result, mechanically loading a second film known as the refrigerant film. This film exploits the elastocaloric effect, in which materials alternately heat up and cool down as they are stretched and relaxed. The team demonstrated that the prototype achieves a temperature span of 4.0 kelvin at the device level and also operates reliably when driven by an external heat source instead of electrical heating. This is an important proof that cooling can indeed be powered directly by heat.
The results mark a step toward cooling technologies that require significantly less electricity than today's systems based on compressors or thermoelectrics. Since the shape-memory films also operate entirely without climate-damaging refrigerants, the approach opens up prospects for electronics cooling, for example in computer processors, or in automotive engineering, where waste heat from the drivetrain could in the future be used directly for cooling sensitive components.