Miljkovic research group exhibits a strong showing at ARPA-E Summit

MechSE Professor Nenad Miljkovic and his research group recently showcased some of their cutting-edge work at the 2024 ARPA-E Energy Innovation Summit, held last month in Dallas, Texas.

The Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) supports transformational and impactful energy technologies that are, by design, too early for private-sector investment. The program focuses on disruptive energy projects that can be meaningfully advanced with a small amount of funding over a defined period of time.

The ARPA-E Summit is an annual conference and technology showcase that brings together thousands of experts from government, academia, and industry to collaborate and advance cutting-edge energy technologies. The three-day agenda featured keynotes, breakout panels, networking opportunities.

The event’s popular Technology Showcase featured nearly 400 exhibitors – including Miljkovic and his Illinois colleagues, who have three current projects funded under the ARPA-E COOLERCHIPS program (Cooling Operations Optimized for Leaps in Energy, Reliability, and Carbon Hyperefficiency for Information Processing Systems), which aims to develop high-performance, energy-efficient cooling solutions for data centers.

One of Miljkovic’s projects, “Holistic Rack-to-Processor Power and Thermal Co-Design for Future Servers,” with co-PI and MechSE Professor Bill King, won the Best Booth Award at the Summit, and their booth was one of just two visited by ARPA-E Director Evelyn Wang to discuss their work. The vision of this project is to build an energy-efficient, reliable, single-phase water-cooling system for highly power-dense datacenters. Many datacenters in the near future will have high-performance IT components to satisfy the demand of AI-based services. However, these IT components need an advanced cooling solution for full-time operation without frequent maintenance and replacement.

At the component level, the multi-university team has developed a solution that integrates high-performance thermal interface materials, reliable silicon carbide coolers that are made using topology optimization and additive manufacturing, robust and cost-effective single-phase water cooling, and high heat capture temperatures to enable efficient heat dissipation to the ambient without the use of air conditioning. They also developed and conducted thermal aging and cycling tests to prove the system’s reliability.

Now, the team aims to build this energy-efficient architecture at the system level – utilizing their own CDU (coolant distribution unit) design to minimize system TUE (total-power usage effectiveness) and maximize power density. Use of water as a coolant enables a global warming potential (GWP) that is lower than that of any other liquid cooled systems, and the high heat capture temperature enables potential for heat reuse. Graduate students Woo Young Park and Ilan Pinkus, along with postdocs Dr. Vish Ganesan and Dr. Ronnie Xu, represented the booth showcasing this research.

Miljkovic was also at the Summit representing a second COOLERCHIPS-funded project, led by researchers at University of Texas at Arlington, to develop a hybrid cooling technology that will aid high-power data centers and server farms. Miljkovic’s team aims to develop novel thermal interface materials with ultra-low thermal resistance and high re-workability. Illinois graduate students Arielle Gamboa and Angkan Haider attended the summit to represent this project.

Miljkovic is also co-PI on a third COOLERCHIPS project, with Nokia Bell Labs. The team’s vision is to develop a fully passive two-phase liquid-cooling architecture that tackles the concerns regarding rising rack power density, stalled efficiency, and an increased trend toward urbanized data centers. The high coolant temperature targeted in this program can offer opportunities for waste heat reuse or simplification of heat rejection infrastructure. Miljkovic’s team aims to develop novel wick structures for chip-level cooling as well as design passive cooling strategies for secondary components. As the program enters its third year, researchers in his Energy Transport Research Laboratory (ETRL) and Bell Labs are collaborating to deploy the developed technologies for rack-level integrations. Graduate students Aaron Qiu, Pouya Kabirzadeh and Vivek Garimella represented the Nokia project at the summit.

The team also exhibited a booth showcasing a fourth research project, PULSE – this one unrelated to data cooling – that shows promising findings for the future of electrified aircraft capability. Snow and ice removal is crucial for maintaining aerodynamic lift and energy efficiency, but electrified aircraft do not have the kind of onboard ice accumulation mitigation methods that are typical in internal combustion engine aircraft. Miljkovic’s team has been pursuing one deicing method called pulse interfacial deicing (PID) that involves a localized “pulse” of thermal heat applied directly to the interfacial layer adhering to the ice and frost. In concert with this, they have also developed a coating that combines PID with surface wettability to accelerate ice, frost and snow removal.

Their PULSE booth welcomed a visit not only by Wang but also by celebrity Jonathan Scott of HGTV’s Property Brothers. Graduate student Alex Solecki and postdoc Dr. Jahid Hoque work on PULSE and attended the summit to represent the research.

A fifth project, called CRUISE, has been funded by the ARPA-E OPEN FOA program, which supports the development of potentially disruptive new technologies across the full spectrum of energy applications. CRUISE, led by PI Kiruba Haran, Professor of Electrical and Computer Engineering and Director of the POETS Center at Illinois, aims to construct a cryogen-free superconducting electric motor for aircraft propulsion. Compared to past superconducting motors, the CRUISE motor features a closed-loop cryogenic cooling system that does not consume liquid cryogen. This feature improves motor reliability with a compact and simple package and enables 40 kW/kg motor specific power. Several of Miljkovic’s researchers are involved in this project: Dr. Jahid Hoque, Saptarshi Joshi, Yashraj Gurumukhi, and Shayan Aflatounian.