German and Japanese researchers develop electricity-free cooling tech

Researchers in Germany and Japan have demonstrated a radically different approach to keeping computer hardware cool: use the heat itself to generate cooling, without electricity. The technology is still a laboratory prototype, but researchers say it could eventually cool computer processors and other electronics using waste heat that would otherwise be discarded.

Turning Waste Heat Into Cold

The system uses two incredibly thin nickel-titanium foils with different jobs. The first acts as a heat-powered actuator. When heated, the shape-memory alloy changes shape and generates mechanical movement. That movement is transferred to a second foil, which functions as the refrigerant.

Loading and unloading that second foil triggers a phase transition known as the elastocaloric effect, causing it to absorb and release heat and ultimately produce a cooling effect.

The key breakthrough is that the actuator normally requiring an electric motor can instead be powered by heat.

That means waste heat from something like a computer processor could potentially help power the mechanism that cools it. Solar thermal energy or other external heat sources could also drive the system.

Proof of concept

The researchers demonstrated a temperature span of 12.9 Kelvin at the refrigerant film level and 4.0 Kelvin at the device level when they electrically heated the actuator to 86°C. More importantly, they tested the system using an external heat source rather than electricity. At a heating temperature of 130°C, the prototype still achieved a 2.2 Kelvin temperature span at the device level.

Those numbers are modest, and the researchers aren't suggesting that data centers can rip out their existing cooling infrastructure tomorrow. The current device was built as a feasibility demonstration, not as a high-capacity cooling system.

Data Centers Are the Big Opportunity

Data-center cooling is becoming a major energy problem. AI workloads are driving demand for increasingly powerful processors, while those chips generate enormous amounts of heat. Traditional cooling systems can consume significant amounts of electricity and, depending on the design, substantial quantities of water.

An electricity-free cooling technology could therefore reduce the energy overhead associated with running AI infrastructure.

The researchers are now working on scaling the concept by connecting multiple films in parallel to increase its cooling capacity.