Making big strides in microengineering

I really believe that a significant part of biomedical engineering in the future is going to involve microengineering," says David Beebe.

Formerly a professor of electrical engineering at the University of Illinois Champaign-Urbana (UIUC), Beebe is the department's newest faculty member, and a big presence in his tiny world of microdevices. Department Chair Robert Radwin encouraged him to consider coming back to Wisconsin, where he'd earned his BS, MS and PhD in electrical engineering. "Over the course of six months or so I really decided it was the best place to do the type of research I wanted to do in the future," says Beebe, "so I'm happy to be back and it's exciting to be part of a new department."

He began his professional career in industry when, undergraduate degree in hand, he took a job at Kimberly-Clark in Neenah, Wisconsin. "I made diaper machines go really fast," he laughs. "It was really high-tech, but after about 18 months I was already not doing any real engineering—it was management."

To make a change, he entered graduate school. "Over that period of time I decided I really wanted to get into semiconductors and biomedical engineering … and at that time I was thinking about doing some of the things I'm finally getting to do now," Beebe says. "At that time it was a very new field, so people were just starting to talk about microdevices and there was just very preliminary work in those areas."

His most current work deals with cells and embryos in micro-environments. To advance the state-of-the-art technologies available for assisted reproduction and biotechnology, he and his Illinois colleagues formed Micro Agri Systems, Inc. (MAS), a spin-off company. It commercializes handling and manipulating embryos in microchannels and microdevices. "The premise here is that by going into microdevices and microchannels, you can make a more in-vivolike environment for cells and embryos and do things that just aren't possible otherwise," he says.

Beebe has built his career around doing things that don't seem possible. In collaboration with UW-Madison Rehabilitation Medicine Professor Paul Bach-y-Rita and Associate Scientist Kurt Kaczmarek, his group just debuted to the military a method that allows soldiers to communicate silently using tactile sensors. "Most recently we're developing a mouth-based system, a retainer," he says. "We actually have a prototype working now of a retainerlike device that does allow someone to communicate—very crudely at this point, but completely within their mouth. They receive information on the roof of their mouth and they use their tongues to output information."

It's an offshoot of his PhD work, through which he tried to develop systems to help people with visual impairments "see" images through touch. "You can take images off a computer screen and display them on this tactile screen, so someone who's visually impaired can then feel a photograph, for example," he says. "For a visually impaired student who wants to study science and engineering, its very difficult to convey graphical information in words—like a linear regression plot, for example—but if you can put a bar graph or linear regression plot and let them feel it, that's a much more effective way of conveying information."

Funded by a three-year, $3.5 million DARPA grant, Beebe's group also is collaborating with Professor Jeff Moore at UIUC to develop microfluidic devices and devise ways to quantify microfluidic flow. "The way people had made devices in the past was sort of macro-scale engineering, where you make pumps and valves and sensors and then you assemble them—or sort of the microelectronics paradigm, where you sort of build up different layers and try to make it that way," he says. "Ours is more similar to building a ship in a bottle. We start with this generic cavity and then we build everything inside of it. There's no assembly required ... the components, the valves, pumps and sensors are made out of hydrogels, so they require no power to run and they respond to the local environment, where in a traditional system you would need a sensor and an actuator and electronics."

Ultimately Beebe hopes to build a new class of biosensors and systems that have applications in chemical and biological protection, but also in environmental protection, health and diagnostics. A paper that describes the group's research appeared in the April 13, 2000, Nature: International weekly journal of science. Beebe counts its publication as one of his biggest academic achievements.

A father of two who likes to camp and bikes to work each day, Beebe has been a member of the department since January.

"It turned out to be a great move personally and professionally," he says.