Artificial dog noses make explosives detectors more effective

Devices fitted with a 3D-printed nose that allows them to sniff like a dog worked nearly 16 times better than traditional detectors.

Whether explosives, drugs, or the scent of a missing person, dogs still outperform manmade devices as chemical trace detectors. In newly published research, making a commercially available explosives detector work more like a dog’s nose considerably improved its performance. We spoke with lead author Matthew Staymates to learn more.

ResearchGate: Why does the way a dog smells work so well?

Matthew Staymates: It’s all about what we call sampling. Any chemical detection system can be broken down into two basic components: the sampling component (how you collect the sample) and the analyzer (how you chemically analyze the sample). The way the dog samples for odors is one reason it is an amazing chemical detection system. The geometry of the nose and nostrils, coupled with the directionality of air when the dog exhales, allows the dog to “reach out” and grab odors from fairly large distances. We call this the “aerodynamic reach” for vapor sampling. Most commercially available chemical vapor detectors don’t work this way – they simply inhale air at a continuous rate, which limits their aerodynamic reach.

RG: How did you apply these principles to the explosives detector?

Staymates: Once we learned how the dog was sampling air during sniffing, we designed and 3D-printed nostril-like features that mimic the sniffing pattern of a real dog. We then attached it to the inlet of a commercially available explosive vapor detector, essentially making the instrument sniff like a real dog rather than use continuous inhalation. Then we made measurements with the instrument in standard operating mode and in sniffing mode to determine if this actually improved the sampling performance of the detector.

RG: What were the results?

Staymates: The results showed that, under certain experimental conditions, sniffing outperformed constant inhale by almost a factor of 16. We performed similar measurements with an artificial 3D-printed dog nose connected to a mass spectrometer and found comparable improvements when the nose was sniffing vs. constantly inhaling.

RG: What applications do you foresee?

Staymates: This concept of increasing the aerodynamic reach of a sampling system has applications for any trace vapor detection system. Using pulsed air jets to direct air towards a chemical detector is one way of increasing aerodynamic reach, and we suspect this concept will be integrated into the next generation of vapor sampling technology at least to some degree.

RG: Could it one day replace bomb- and drug-sniffing dogs?

Staymates: Maybe one day, but for now dogs remain the gold standard for trace chemical detection.

RG: What are the next steps in this research?

Staymates: We plan on using our artificial dog’s nose to study stereo-olfaction, the use of both nostrils to figure out where a smell is coming from. We will do this by connecting a separate mass spectrometer to each nasal airway to better understand how dogs track odor trails and pinpoint an odorant source. We may also explore the role of the dog’s exhaled air jets on how a dog’s nose removes and collects microparticles when smelling.

Featured image courtesy of Liz West.