Alum finds laser parameters for fence that kills mosquitoes, not honeybees
An attempt to poison Zika-carrying mosquitoes in South Carolina made headlines earlier this month when it killed millions of honeybees, too.
That’s the perpetual issue in pest control: How do you make it deadly enough to take out the bugs you want without harming the ones you don’t – or harming the environment in general?
Biomedical engineer Matt Keller (BE’03, MS’06, PhD’09) helped find the answer in laser beams that would feel like a pinprick to humans but kill mosquitoes, protecting populations from Zika, malaria, West Nile and a host of other diseases. The Photonic Fence, developed at Intellectual Ventures Laboratory in Bellevue, Wash., tracks all insects that enter its coverage area but uses a cross-sectional profile to differentiate mosquitoes.
The Vanderbilt University engineering alumnus worked for more than two years on the fence’s laser dosing, optimal wavelength, power, pulse duration and beam diameter.
“That’s basically taking all the biomedical optics knowledge from working in the lab with Duco Jansen and Anita Mahadevan-Jansen,” said Keller, referring to his Vanderbilt biomedical engineering advisers. “I took all the things they taught me for doing medical photonics on people and applied it to mosquitoes, and it turned out that’s a valid thing to do.”
The greatest challenge, he said, was the vast combinations of laser parameters to test and developing a systematic way to pare those down and still reach valid conclusions. Again, Keller thought back to his time in the Jansens’ lab and, given the way lasers interact with biological tissues, the fundamental combinations that made the most sense.
Keller is the first author on a paper about the fence that appeared recently in the journal Scientific Reports.
He grew up in Bettendorf, Iowa, and selected Vanderbilt because it was the best university that also offered him a full-ride scholarship. His interest in biophotonics dates back to a senior design project with Mahadevan-Jansen. Keller had considered pursuing tissue engineering and molecular biology in graduate school, but a biomedical optics project convinced him to try a different field.
“There are a lot of interesting applications for biophotonics,” he said. “It became clear that Vanderbilt was a strong institution for the field, and I’d enjoyed my undergraduate experience, so I knew I would be happy staying.”
Because senior design swayed his future so dramatically, Keller advises young engineers to get as much hands-on experience as early as possible. “You can take classes in something all you want, but if you don’t have the patience to do years-long studies to get an answer to something, that’s not the field for you.”
Jansen, who is also associate dean for graduate education, said his former PhD student’s talk on the laser fence at a recent biophotonics meeting was one of the most impressive.
“His team did some really good engineering, figuring out the necessary laser dose to blow up or incapacitate the bug,” he said. “They had to determine whether the bug being filled with blood made a difference in how to keep a lock on it with the laser – it does — and how to keep the intensity high enough in the optical far field. Those are all great challenges in a very interesting field.”
Much of Intellectual Ventures Laboratory’s work is funded by Bill Gates, via the Global Good Fund, for use in developing nations. Keller’s new project is coming up with low-cost optical spectroscopy, which offers another opportunity to use his Vanderbilt research.
“My work there had been on using Raman spectroscopy to help guide breast tumor removal, so I’m now coming back to that general field,” Keller said.
He is married to Kelly Robert Keller (BS’05), and the couple have two young daughters.
Heidi Hall, 615-322-6614
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