This work presents fluid flow visualization studies and chemical detection experiments using an 3D printed anatomically-correct biomimetic canine nose from a female Labrador retriever. Schlieren imaging, high-speed videography, along with flow visualization using lasers and theatrical fog, demonstrate the dogs remarkable ability to employ expired air jets as a means to increase the aerodynamic reach of odorants to tens of centimeters ahead of itself. Experiments aimed at quantifying the apparent increase in sampling efficiency utilizing air jet assisted sniffing versus an inhale-only approach were conducted with the artificial dogs nose using a polyurethane foam vapor collection system and 2,4-Dinitrotoluene. Results show that, under a controlled set of experimental conditions, actively sniffing for vapor increases the amount of sampled vapor by almost a factor of nine from the same distance compared to the opposing, yet biologically impossible, case of constant inhalation. Additional experiments that coupled the dogs nose to a mass spectrometer resulted in data that corroborate the concept of jet-assisted fluid entrainment for improved vapor sampling. Finally, as an example of biomimicry, a commercially-available vapor detection system was outfitted with a pair of nostril-like features, enabling the system to sniff like a dog rather than continuously inhale. The results demonstrate an improvement in vapor sampling for trinitrotoluene, sometimes by a factor of four to five, by taking advantage of lessons learned from the dog. Building upon a limited knowledge-base of the external aerodynamics of the canine, this work provides additional insight into the fluid dynamics of canine olfaction and possible applications for biomimicry.
Citation: Nature - Scientific Reports
Pub Type: Journals
olfaction, 3D printing, explosives, detection, vapor, sampling