Sniffing Out Trouble

U.S. News & World Report profiles Tufts scientists' effort to build an electronic nose that can detect land mines.

Boston [10.01.02] --- Scattered among past and present war zones, 100 million land mines lay waiting to explode. Removing these mines--which kill or maim as many as 24,000 people per year--is a difficult, expensive, and dangerous endeavor. But scientists at Tufts' School of Medicine are working on an innovative device-an electronic nose-- that will be able to sniff out unexploded mines.

According to a report on the work of Tufts neuroscientists John Kauer and Joel White in this week's US News and World Report, the artificial nose represents an innovative new approach to detecting land mines. If successful, it will be a vast improvement over current methods of identification--dog sniffing, metal detectors, and even men in Kevlar suits feeling around with 18-inch sticks- all of which are both labor intensive and inaccurate.

Kauer and White's high-tech device works by electronically detecting chemical particles used to make explosives.

"The Tufts artificial nose has 16 fluorescent sensor strips, each sensitive to different ranges of molecules," reported U.S. News. "A computer interprets their response pattern to determine whether or not they have sniffed a mine."This unique approach is different from others detectors under development. While other detectors merely test for DNT and TNT in the ground, the Tufts nose works more like a dog's nose. Using its array of sensors, the Tufts nose actually "smells" for chemical particles in the soil and air.

When the device breaks down different smells, say the Tufts scientists, they appear on the computer interface like topographical maps.

"It's a little like watching the Rockies appear and subside," White said in this week's issue of The Scientist, which reported on the pair's work.

Kauer and White hope their innovative approach will "reduce false alarms by mimicking the biological sense of smell more closely," reported U.S. News.

Feedback on the advanced technology--which is funded by grants from the National Institutes of Health, the Office of Naval Research and the Defense Advanced Research Projects--has been promising.

"In recent tests the Tufts artificial nose detected explosives residues at concentrations of around 500 parts per trillion, about 10 times better than the average dog," reported U.S. News.

But there is still a lot of work to be done before the technology can be used extensively in the field.

"We're a long way from being able to walk across a minefield blindfolded," White told the newsmagazine, which is read by more than 2.2 million people every week.

Since Kauer and White began their research, much attention has been given to the nose. In 2001 the television program "PBS Scientific American Frontiers" profiled the Tufts scientists' efforts. During the hour-long program detailing Kauer and White's work, host Alan Alda said he hoped the Tufts research "will one day save thousands of lives."

Beyond mine detection, the artificial nose may play a number of important roles.

"The technology may soon find a host of uses," reported Discover Magazine in 2001. "Diagnosing disease, improving airport security, monitoring food safety, even enhancing your own sense of smell."

Ultimately, the Tufts scientists hope to create a device that replicates the process already used by the human brain.

"With a number of different sensors arranged in an array, more like the scent receptors in a biological nose, a system could combine the varying signals and match the patterns they produce against a database of known scents, much like the brain does," reported The Scientist.

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