Dr. Jayne Wu holds a wafer substrate used to build electrical circuits that manipulate tiny amounts of fluid for particle detection.

By Coleman Cornelius

There’s a problem when fluid is tested for the presence of a particle, whether it’s a protein in blood or a pathogen in water: samples must be sent to a chemical laboratory, where trained technicians physically manipulate and screen the fluid. The detection process can take days, even weeks.

Dr. Jayne Wu, an electrical engineer at the University of Tennessee, Knoxville, is working to simplify the process. She is developing a miniature chemical laboratory—a “lab on a chip”—that might be used for quick and accurate particle detection in a field setting, much as diabetes test kits are used to instantly detect glucose levels in blood droplets.

Wu, an assistant professor in the Department of Electrical Engineering and Computer Science, is developing novel technologies to test particles, including proteins, bacteria, viruses, and cells, within tiny amounts of fluid. These technologies may ultimately be used for on-the-spot detection of infectious disease or pathogens used as agents of bioterrorism.

“Saving a few days could save a lot of lives,” says Wu, who came to UT from the University of Notre Dame. “This micro-technology is at the forefront of the times.”

Electrical engineering graduate students Kai Yang and Meng Lian collaborate with Dr. Wu on her microfluidics research.

To support her promising research in the field of electrokinetics, Wu earned a coveted National Science Foundation Early Career Development (CAREER) Award in 2005, as well as a Professional Promise in Research and Creative Achievement award from UT Knoxville, among other honors.

Wu’s work involves the use of AC electrical circuits built on chips of polymer, glass, or silicon substrate. The researcher and her graduate students use the micro-electromechanical devices to manipulate very small amounts of fluid, and to focus particles toward sensors for detection.

“It’s like looking at a ping-pong ball bouncing around the classroom, and the sensor is a podium in the front,” Wu says. “The chance of the ping-pong ball moving towards the podium is equal in all directions, and if it gets to the podium there’s no guarantee it will stay there to be recognized. Probably the podium needs a bunch of ping-pong balls to know they’re there. Our inventions use electric fields to draw the particles towards the sensor.”

Wu and her students are experimenting with ways to shrink but retain the basic functions of a chemical laboratory—including fluid mixing, pumping, and particle concentration to assist detection—even as they find that fluid properties unexpectedly change in miniscule volumes.

A regional editor for the Journal of Mechanics in Medicine and Biology, Wu holds several pending patents for microfluidic devices and anticipates their application in biomedical and other fields.

She recently sat down with Brad Fenwick, vice chancellor for research and engagement at UT Knoxville, to discuss her electrokinetic research.

Q: What led you to become a university professor engaged in research?

A: I’m naturally curious about how things happen, and how things can be improved, so that led my interest into science and engineering.

Q: What are some of the questions you’re seeking to answer?

A: We are looking at handling particles in fluid at a micro-scale and sometimes nano-scale. At the nano-scale, a lot of the dominance of various mechanisms changes. So we’re looking at very newly recognized phenomena, and experiments actually lead us to theoretical work. Specifically, we’re looking at the interaction between electric fields, the fluid, and the substance within it. The benefit of such research is that we can use it to expand knowledge, to build miniaturized chemical laboratories on a chip, which can be used as portable diagnostic kits.

Q: What do you find most exciting about being a scientist doing discovery-level research?

A: The joy you get from making discoveries is thrilling. I enjoy training students because they always have to look at something that hasn’t been reported. They’re getting the chance to develop their own theories and also to challenge authorities in the field. That greatly enhances their confidence.

Q: How does your research benefit and interact with your responsibilities in teaching students?

A: I like to think the work I do provides a window through which students see the advances in technology and relate that progress to their daily lives.

Q: Your research is often interdisciplinary. What is the significance of that?

A: One of the reasons we pursue interdisciplinary research is to introduce new and different perspectives, so we can solve problems with new tools. We attack a problem from different angles, and that’s a real benefit. I work with colleagues in other engineering departments, and in chemistry and physics. That naturally creates uncharted territory.