Evaporative cooling tech could curb data centers’ rising energy demands

Engineers at the University of California San Diego have developed a new cooling technology that could significantly improve the energy efficiency of data centers and high-powered electronics. The technology features a specially engineered fiber membrane that passively removes heat through evaporation. It offers a promising alternative to traditional cooling systems like fans, heat sinks and liquid pumps. It could also reduce the water use associated with many current cooling systems.

The advance is detailed in a paper published on June 13 in the journal Joule.

As artificial intelligence (AI) and cloud computing continue to expand, the demand for data processing—and the heat it generates—is skyrocketing. Currently, cooling accounts for up to 40% of a data center’s total energy use. If trends continue, global energy use for cooling could more than double by 2030.

The new evaporative cooling technology could help curb that trend. It uses a low-cost fiber membrane with a network of tiny, interconnected pores that draw cooling liquid across its surface using capillary action. As the liquid evaporates, it efficiently removes heat from the electronics underneath—no extra energy required. The membrane sits on top of microchannels above the electronics, pulling in liquid that flows through the channels and efficiently dissipating heat.

“Compared to traditional air or liquid cooling, evaporation can dissipate higher heat flux while using less energy,” said Renkun Chen, professor in the Department of Mechanical and Aerospace Engineering at the UC San Diego Jacobs School of Engineering, who co-led the project with professors Shengqiang Cai and Abhishek Saha, both from the same department. Mechanical and aerospace engineering Ph.D. student Tianshi Feng and postdoctoral researcher Yu Pei, both members of Chen’s research group, are co-first authors on the study.

Many applications currently rely on evaporation for cooling. Heat pipes in laptops and evaporators in air conditioners are some examples, explained Chen. But applying it effectively to high-power electronics has been a challenge.

Previous attempts using porous membranes—which have high surface areas that are ideal for evaporation—have been unsuccessful because their pores were either too small so they would clog or too large and they would trigger unwanted boiling.

“Here, we use porous fiber membranes with interconnected pores with the right size,” said Chen. This design achieves efficient evaporation without those downsides.

When tested across variable heat fluxes, the membrane achieved record-breaking performance. It managed heat fluxes exceeding 800 watts of heat per square centimeter—one of the highest levels ever recorded for this kind of cooling system. It also proved stable over multiple hours of operation.

“This success showcases the potential of reimagining materials for entirely new applications,” said Chen. “These fiber membranes were originally designed for filtration, and no one had previously explored their use in evaporation.

“We recognized that their unique structural characteristics—interconnected pores and just the right pore size—could make them ideal for efficient evaporative cooling. What surprised us was that, with the right mechanical reinforcement, they not only withstood the high heat flux–they performed extremely well under it.”

While the current results are promising, Chen says the technology is still operating well below its theoretical limit. The team is now working to refine the membrane and optimize performance. Next steps include integrating it into prototypes of cold plates, which are flat components that attach to chips like CPUs and GPUs to dissipate heat. The team is also launching a startup company to commercialize the technology.