By Tushna Commissariat
After a long trip in the US – attending the APS March meeting and visiting both the Maryland campus of the National Institute for Standards and Technology, as well as the Brookhaven National Laboratory in New York – I finally made my way back home yesterday. As I flew out of New York, I was reminded of my visit to NIST’s Surface and Trace Chemical Analysis Group, where researchers develop a variety of ways to detect contraband substances at airports and other public locations. While the team looks into a variety of ways to detect trace residues of banned substances such as drugs or explosives that may be found on people or objects – from mass spectroscopy to thermal desorption to vapour-sampling – my favourite was their canine research that led them to create a 3D-printed dog’s nose!
It is a well-known fact that dogs possess a highly advanced olfactory system, making them the “gold standard” in trace chemical sampling. While the sensitivity with which a dog can make a detection is comparable to that of a special instrument, they can actually “collect” a sample (i.e. breathe in) and process and analyse it within seconds, making them an “active aerodynamic sampling system”. This is what makes dogs so good at doing everything from tracking people to detecting contraband to even picking up signs of certain cancers or epileptic fits.
Matthew Staymates and colleagues at the Surface and Trace Chemical Analysis Group wanted to see if there was anything special about the actual physical shape and structure of a dog’s nose. To do this, they turned to biomimicry – using detailed MRI images, the team 3D-printed an anatomically correct nose of a female Labrador that can realistically sniff vapours. They then studied the flow rates and were able to visualize how a dog takes in a breath to attract and sample a vapour.
They found that when a dog exhales, a turbulent air jet emanates from each nostril and this can pull in other particles in the air (that can be as far away as 10 cm) for the dog to detect. Staymates mentioned that this inhale/exhale cycle can happen at nearly 5 Hz – a breathing rate at which a human being would faint! Watch the video above to see the nose as it inhales some vapours and to find out about an instrumental application that came out of this research.