Mechanical engineers get explosive inspiration from a dog's nose

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November 27, 2012

Researchers at the University of California, Santa Barbara, have developed a portable vapor detecting device that mirrors the sensitivity of a dogs nose, with scientists believing that it could be used to sniff out explosives or other substances.

Using microfluidic nano-technology to imitate canine scent receptors, the device is highly sensitive to trace elements of certain molecules and engineers at the university believe that it could soon become as common a sight as a smoke detector. The engineering research is being published in Analytical Chemistry, a peer-reviewed academic journal, and has concentrated primarily on the airborne molecules produced by the vapor produced from TNT-based explosives.

The gold standard in sniffing
While the device is primarily an engineering research project funded in part by the Army Research Office, it was developed as part of a university collaboration between professors Carl Meinhart of mechanical engineering and Martin Moskovits of chemistry.

"Dogs are still the gold standard for scent detection of explosives," said Meinhart, a member of the mechanical engineering department at UCSB. "But like a person, a dog can have a good day or a bad day, get tired or distracted. We have developed a device with the same or better sensitivity as a dog’s nose that feeds into a computer to report exactly what kind of molecule it’s detecting. The key to the technology is in the merging of principles from mechanical engineering and chemistry."

The vapor detector is no larger than the size of a silicon microchip, and was produced under laboratory conditions at the university. It uses free-surface microfluidics and enhanced spectroscopy to capture and identify molecules, with six levels of magnitude assessed by a microchannel of liquid, that is twenty times smaller than the thickness of a human hair. While the focus was explosives, the team also feels that it could indicate disease on an individual's breath or spoiled food.

Capturing the vapor data
A computer database then identifies what type of molecule has been captured, with the device capable of real-time identification of any airborne vapor. Human noses are incapable of detecting such minute traces of smell, but the team believe that the "specificity and sensitivity are unparalleled" in the design and size of the canine olfactory mucus layer, the inspiration for the device.

"The technology could be used to detect a very wide variety of molecules," said Meinhart. "The applications could extend to certain disease diagnosis or narcotics detection, to name a few."