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from his ‘Star Trek’ beginning, Dr. Xu sees big potential in plasma research

dr. gabe xu
The results of experiments in which turmeric yield doubled after rhizomes were treated with plasma are “semi-miraculous and wild,” says UAH’s Dr. Gabe Xu. Photo by Michael Mercier / UAH

Captain Jean Luc Picard and his crew played leading roles in getting Future Technologies & enabling Plasma Processes (FTPP) lead researcher Dr. Gabe Xu engaged with plasma physics.

“I’ve always been interested in space and space exploration. I blame it on watching reruns of ‘Star Trek: The Next Generation’ as a kid,” says Dr. Xu, an associate professor of mechanical and aerospace engineering at The University of Alabama in Huntsville (UAH) who is doing FTPP-backed research into atmospheric pressure plasmas for material and biological applications and diagnostics, as well as laser-produced plasmas.

“On the crew of the Enterprise, I identified more with Lt. Commander Geordi La Forge, the chief engineer who could fix anything and knew everything about the ship,” Dr. Xu says. “That may also have somewhat steered me towards plasma propulsion in graduate school, since it was the closest working propulsion system to a warp drive I knew about at the time.”

FTPP is an Alabama coalition of nine universities and a research corporation that’s managed at UAH and is supported by a $20 million grant from the National Science Foundation and aims to transition plasma research into agricultural, manufacturing, space science, space weather prediction and other applications, establishing Alabama as a Southeastern regional hub for plasma science expertise and creating thousands of high-paying technical careers in the state and region.

“I went to college for aerospace engineering because I wanted to design things that fly. I ended up gravitating towards propulsion, since engines are cool and are needed to get anywhere,” says Dr. Xu, who was born in China and immigrated to the U.S. as a young child, growing up mostly in the Midwest and attending college and graduate school at Georgia Tech in Atlanta.

“I originally started with undergraduate research in combustion, and then moved to plasma propulsion, which I continued through graduate school for my PhD,” he says. “My real exploration of the plasma side came once I became a faculty member, as I wanted to expand my research beyond just thrusters, at which point I discovered there’s a wealth of cool science, engineering and applications for plasma science, from fusion to astrophysics to bacterial sterilization.”

interesting results

The most interesting results so far have come from atmospheric pressure plasma treatment of turmeric rhizomes, says Dr. Xu, who has been at UAH for 11 years.

“I think some of the agricultural applications of atmospheric pressure plasmas could be very beneficial for the state,” Dr. Xu says.

In FTPP-sponsored collaborative efforts between UAH’s Dr. Xu and Alabama A&M University professor of biological and environmental sciences Dr. Rao Mentreddy, early efforts involved testing some turmeric rhizomes by exposing them to plasma gases for 60-120 seconds.

“Then the rhizomes went into the greenhouse and then the field to grow,” Dr. Xu says. “All the samples were watered and fertilized the same.”

Two surprising results may hold promise for agriculture on a broader scale, he says. First, the plasma treatment resulted in a significant improvement in the size of the plant and the resulting yield once harvested. Second, there was a clear peak at 90 seconds of treatment.

“The best case we obtained was a doubling of the yield at harvest compared to an untreated rhizome,” says Dr. Xu. “So, for little more than a minute of plasma treatment, we got double the food. That’s semi-miraculous and wild, and suggests a way to solve food problems. It also raises a lot of scientific questions as to how the plasma did this and why is there a best treatment time.”

Further research is needed, but the results are tantalizing, he says.

“If the turmeric results are portable to other food crops, it could change farming a lot.”

FTPP support has been very helpful for his research, Dr. Xu says, as it provides financial support to allow his research group to do experiments, but it also provides a large group of other researchers with different backgrounds and expertise to develop new ideas and collaborate.

“My plasma research is very multi-disciplinary these days,” he says, “and it requires other expertise in areas like chemistry, biology, materials, etc., to understand what’s happening.”