CSIRO News: Fly VS Robot – the smell-off!
Vince thought the wine smelled like a fresh Spring morning, while the E-Nose6000 thought it just smelled like springs.
Illustrated by Mike McRae
It’s not all that difficult to tell when your milk has gone off – just take a whiff! But how many people would enjoy smelling off food every day? Or using their nose to test air pollution? Sounds like a job for a robot nose.
In some ways, electronic odorant receptors – or ‘e-noses’ – work a little like our own sense of smell by detecting different chemicals wafting through the air. Yet that’s where the similarities end. The e-noses being researched by the CSIRO rely on the odour’s chemicals reacting with oxygen in a strip of metal oxide, while an animal’s smell receptors use a range of nerves to do the job.
As handy as they are, the ability for e-noses to tell some smells apart can’t match biology where the fruit fly is concerned. To improve the technology, CSIRO’s Food Future’s Flagship compared the two and came up with some interesting answers.
The olfactory receptors in fruit flies aren’t very specific, each detecting a number of different chemicals as they sniff the air. Nor are they more sensitive than the e-nose. Yet the variety of e-nose smell receptors, each working on its own, produces a broad range of sensitivities, which may give it an edge in describing complicated fragrances. For instance, the overall aroma produced by wine as it ferments can reveal a lot about how it will taste, allowing the wine maker to make improvements. Telling the difference between each chemical within a smell would require a discriminating nose but the e-nose makes this separation.
However, replicating the fly’s talent for smelling could prove tricky for engineers, who aren’t sure how the fly’s receptors work together to distinguish different smells. Learning how this happens could lead to significant improvements in the e-nose.
At least now we know the answer to one question. How do fruit flies smell? Quite well, actually.