Natural Selection

Nagel Gets National Recognition For Biomimetic Research
By Eric Gorton 

During photosynthesis, tiny cells on plant leaves — called guard cells — swell and shrink to control a plant's carbon dioxide intake. In human beings, the protein tropomyosin interacts with other substances to regulate cardiac and skeletal muscle contraction.

So why would any of this be of interest to someone with an electrical and mechanical engineering background?

To improve on man-made technology, of course.

Dr. Jacquelyn Nagel, assistant professor of engineering, has some innovative ideas on how mimicking nature could advance technology; and she will be recognized for her research in that area this week as one of the National Engineer's Week Foundation's 2012 New Faces of Engineering.

Steve. E. Watkins, a professor at Missouri University of Science and Technology, nominated Nagel for the recognition and stated, "she is doing pioneering work in using biological systems as models for sensors, instrumentation and processes. In particular, she developed comprehensive approaches and design tools for biomimetic inspiration in engineering."

Nagel said natural sensing systems perform up-front processing that vastly reduces data streams and increases efficiency. In the natural world, sensors such as guard cells and tropomyosin, don't go into action until a chemical threshold has been met, reducing the amount of data the organism has to deal with. "Traditionally, engineered systems are the opposite," she said. "We are collecting so much data that we don't know what to do with it all and a lot of times it's overwhelming and it causes problems."

Nagel has researched sensor designs that could be used in anything from detecting problems in electric power transmission to aiding medical diagnosis and law enforcement practices. One of Nagel's proposed designs is for a chemical sensor that could be used as a breathalyzer, either by law enforcement or medical personnel.

"What I was designing (while working on her doctorate at Oregon State) was an indirect mechanism where the stimulus would interact with the sensor surface and then an internal signal would happen to cause a second sensing that would correlate to the output," she said.

The design draws on the functionality of both guard cells and tropomyosin. Nagel envisions a device that would have spiral-shaped wires, similar to muscle fibers, coated with a chemomechanical substance. When the coating on the spiraled wires is exposed to a critical level of a target substance, the coating on the spiraled wires would expand, like guard cells, causing the spiral to grow — or to get smaller if the level of the target substance decreased. The change in shape of the spiraled wires would change the resistance in the wires, which would be the indirect reaction.

"I was thinking it could be used for breath analysis," she said. "It would be on the nanoscale. You could have a whole array of them. Let's say you have a 100x100 array of these, little blocks of 10 could be looking for different chemicals. So in breath analysis, you could determine if there's blood on the breath, or alcohol, or sugars or a whole number of things."

Research on the sensor continues and Nagel said she would like to build a prototype at JMU. This spring, she plans to work with Anthony Tongen, associate professor of mathematics and statistics, and have his mathematical modeling class model the twisting of muscle proteins and the expansion and contraction of guard cells. With those results, she said, she can begin to determine the feasibility of her sensor design.