Research team developing electronic nose to detect explosives

A team of researchers headed by a UConn engineering professor is working to develop an electronic nose system to detect explosives.

With a three-year grant of almost $800,000 from the National Science Foundation, a team headed by Yu Lei, an assistant professor of chemical, materials, and biomolecular engineering, hopes to develop real-time arrays of ultra-sensitive sensors that can sniff out even trace quantities of explosives.

The team includes UConn colleagues Christian Brückner, an associate professor of chemistry, and Ali Gokirmak, an assistant professor of electrical and computer engineering, and University of California-Riverside professor Yushan Yan.

UConn’s Krishna Pattipati, a professor of electrical and computer engineering, will assist the team with aspects of the research that involve pattern recognition.

The team is focusing on developing the science behind a miniaturized sensing device capable of detecting potential explosives with greater speed, selectivity, and accuracy than ever before, using simple instrumentation.

Lei and his colleagues hope this will lay the groundwork for a hand-held unit that could be used by officials to inspect the luggage of passengers boarding a plane, for example, or mounted on a small robotic vehicle to ‘sniff out’ land mines.

The team envisions a unit that will combine the ability to capture and concentrate airborne explosive molecules, and the real-time capacity to distinguish and identify compounds commonly found in explosives.

A real-time system requires that the operation be performed not only correctly but also within a specified time.

Lei says the complexity of the animal scent detection/recognition “system” illustrates the challenge of designing an electronic sensor.

Animal noses – including those of humans – detect and process scents with an array of sensors that respond to all gaseous components of a scent, although each sensor type responds to a differing degree. The brain collects the output from these sensors and memorizes the pattern of responses for roses, apples, or carrion, for example.

The next time the animal brain detects this pattern, the animal recognizes the scent as corresponding to a rose or an apple – even if the apple aroma comes mingled with all the other scents of a supermarket or the apple is of a type that’s different from those smelled previously.

Many bombs use nitrated compounds – such as TNT or dynamite – with volatile components that emit scent molecules which can be detected by trained animals, such as dogs or rats.