Clemson University electrical engineer takes on moon’s extreme cold

A Clemson University electrical engineer is launching research to help characterize and apply a new breed of transistor that can withstand the extreme cold of lunar night, as NASA moves closer to sending astronauts back to the moon for the first time since 1972.

Zheyu Zhang, the Warren H. Owen – Duke Energy Assistant Professor of Electrical and Computer Engineering, is receiving $600,000 from NASA’s Early Career Faculty Award to fund the research.

Zhang will be focusing on gallium-nitride transistors that would be used in solar-powered systems on the moon and eventually on Mars. NASA has set its sights on landing astronauts at the moon’s South Pole, where temperatures reach as low as -414 degrees Fahrenheit.

Previous research by Zhang and others has shown that gallium-nitride transistors withstand extreme cold and radiation better than traditional silicon counterparts.

Over the next three years, Zhang and his team will characterize gallium-nitride transistors in a wide temperature range. They plan to then use those transistors in the development of a high-performance power regulator and a solid-state circuit breaker with the goal of showing they can work.

“This is just step one,” he said. “This is an early career award, so we are getting started and establishing our path. The idea that this could help with the future of space exploration is exciting.”

Hai Xiao, chair of the Holcombe Department of Electrical and Computer Engineering, congratulated Zhang, who is among seven faculty members nationwide to receive a 2022 NASA Early Career Award.

“This award solidifies Zheyu’s position as one of the nation’s most outstanding faculty researchers early in their careers,” Xiao said. “He is well-positioned to help make space travel more effective, affordable, and sustainable, while inspiring the next generation of electrical and computer engineers.”

In his research, Zhang will be helping develop highly advanced versions of power electronics using emerging devices that are also commonly used on Earth.

Power regulators maintain a constant voltage regardless of changes to input voltage or load conditions. Circuit breakers interrupt electrical circuits as a safety measure.

Zhang and his team will be using two power sources in their study. One is solar energy directly from the sun. They will also be experimenting with lithium-ion batteries so that power and energy systems for the lunar mission would be able to run on stored electricity when the sun isn’t shining.

Two graduate students and several undergraduate interns will assist in the research, Zhang said. While the research is focused on developing technology for lunar missions, the fundamentals could be used in more Earthly applications, including electric vehicles, renewable energy, and large data centers, he said.

Zhang is based in North Charleston, home to the Dominion Energy Innovation Center and the Zucker Family Graduate Education Center. The setting is perfect for his research, he said.

“That is a beautiful marriage between graduate education and an industry-scale lab facility,” Zhang said. “It is the dream place to be.”