Electric power creates heat. It’s a fundamental truth of electric technology from handheld electronics to large computer centers to electric motors. Unless a system properly manages and dissipates heat, it degrades the system, resulting in inefficiency, shortened operating lifespans, and, in extreme cases, hazards such as fire and explosion.

The electrification of transportation brings new urgency to the problem. Propulsion and energy storage for electric cars, marine craft and aircraft demands lighter, more compact and more efficient systems than have ever been made, and conventional design approaches have been pushed to their limits. To build a sustainable future in transportation, we need to completely rethink the way electrical systems dissipate heat.

Founded by the National Science Foundation (NSF) in 2014 as a collaboration between the University of Illinois Urbana-Champaign, the University of Arkansas, Howard University and Stanford University, the Center for Power Optimization of Electro-Thermal Systems (POETS) works to completely integrate thermal management with electrical design. By considering both problems simultaneously and giving them equal weight, new tools, designs and products have emerged with unprecedented efficiency, power density and compactness.

POETS Director Kiruba Haran, a Grainger Distinguished Chair in Engineering in the Department of Electrical and Computer Engineering at Illinois Grainger Engineering, said, “The philosophy of POETS, electro-thermal codesign, has empowered us to engineer some of the most powerful and efficient propulsion systems ever made. But more importantly, we are arming engineers – students, academic researchers and industry professionals alike – with the mentality and skillset to solve the most challenging problems in electrification.”

Now, after over 10 years, POETS is entering a new era. Originally funded by the NSF to conduct use-inspired research in power optimization, it will transition to a self-sustained center to continue its work while fostering further collaboration with industry and translating technologies from research settings to working solutions.

A new toolkit

At present, electric propulsion systems are limited by the problems of battery storage and motor and power conversion efficiency. To realize the full potential of electric transportation, it is necessary to construct systems that store and convert more energy in smaller, lighter packages and utilize that energy more efficiently. 

The catch is that storing and converting energy in smaller spaces means that the excess heat generated is confined to a smaller space, and its effects are amplified. This poses a new challenge for thermal management because heat dissipation mechanisms must also shrink.

“Traditionally, power systems are designed for optimal electrical performance, then thermal management is built around it,” Haran explained. “As we move towards smaller devices delivering higher powers, this approach fails. To design systems for large-scale transportation propulsion, you need to consider both from the earliest stages. You need to approach it as a codesign problem.”

Electro-thermal codesign rethinks the way technology is made, so it needs new tools. POETS researchers have developed software packages and simulation techniques that present holistic system overviews, allowing designers to see how electrical and thermal effects influence each other. 

Design problems are then approached from three directions: system design and operation, in which the physical architecture is studied along with the best mode of operation; packaging and integration, in which new design topologies for individual components are considered; and component fabrication, in which the new materials with desired electro-thermal properties are studied.

POETS-affiliated research teams from Illinois and Arkansas partnered with the electric aviation startup Ampaire in 2024 to fly a demonstration hybrid-electric aircraft. A Cessna 337 was modified to use one gasoline-powered engine and one electric engine. The Arkansas team designed a 250-kilowatt motor, and the Illinois team brought expertise in thermal management for a device with completely integrated mechanical, electrical and thermal control. The project was supported by the U.S. Department of Energy Advanced Research Projects Agency-Energy. Ampaire is continuing to refine and commercialize the technology.

University-industry partnership: electric aviation and beyond

As POETS transitions to a new sustainable phase, it will continue fundamental research into electro-thermal codesign, and it will also continue to foster technology translation from academic research to commercial applications. The center’s 12 industry partners include Caterpillar, the Ford Motor Company, John Deere, Rolls Royce, and the RTX Corporation.

Kiruba said, “POETS is more than a research center. We have worked hard to make it an ecosystem in which students, academic researchers and industry professionals come together, exchange ideas, and use the cutting edge of scientific research to build disruptive technologies.”

A defining feature of the center is its network of testbeds featuring major sites at Illinois and Arkansas. They currently allow for model and prototype validation through drivetrain testing from 10 to 300 kilowatts. In addition to academic research, the testbeds support product development from industrial partners with its unique equipment and facilities.

Sherry Yu, an Illinois research engineer and the POETS testbed manager, said, “Our industry partners come to the testbeds for everything from cars and trucks to marine and aviation applications. There is even synergy across different industries with one of our partners studying turbines for wind power generation. We’re a close-knit group, and we work together to solve real-world problems.”

The excellence of POETS’s testing and research capabilities was recognized by the Federal Aviation Administration when it awarded the center $2.7 million to develop a site for electric aircraft motor demonstration and pre-certification testing, a necessary step before commercial flight. As the first such university in the United States, it positions POETS as a focal point of the aviation industry as it electrifies. 

With the updates managed by Yu, the new testbed will have an extended powertrain capacity of 1 megawatt; furnace and cryogenic systems to study performance in extreme heat and cold; and tools for assessing reliability of insulation, ability of components and subsystems to endure vibrations and shocks, and tolerance of electromagnetic interference.

 “It’s a fitting cap to what POETS has achieved these past 10 years,” Haran said. “Our work is not just recognized by our peers, but it is also seen and valued in the transportation industry. We have always approached our work with the mentality of building practical technologies that solve real-world problems, and we intend to keep doing just that.”