The Electronic Nose

Counterpart of the Human Nose

7350121010_da8fbe1c5a_z © Tony Alter

The electronic tongue has already demonstrated how every now and then research into the development of new technologies manipulates human capabilities. Tasting, however, is not the only thing machines have learned from us. The human nose, without which we wouldn’t taste anything, has a synthetic counterpart: the electronic nose.

From an evolutionary perspective, the human sense of smell was indispensable for the survival and continued existence of the species. It helped in searching for food and communicating what was edible and what wasn’t. Our nose reacts very sensitively to food aromas. Although we fall far behind other mammals with our organ of smell, we are able, according to estimates, to distinguish among 1 billion different olfactory compounds. These are often emotionally coded. A certain dish can evoke childhood, a certain perfume a loved one.


The electronic nose approaches its task without emotion. What olfactory cells are in us are receptive gas sensors in the e-version. They cover the majority of gaseous compounds found in the air. Yet instead of analyzing individual components the sensors create a kind of cross-section of the air sample taken. As various kinds of sensors react with varying intensity to certain gases, a unique model emerges every time, which can then be assigned a certain olfactory compound. Still far inferior to biological receptor molecules, the e-noses are able register scentless gases we would never notice.

This last feature could come in handy in certain situations: recognizing spoiled food, for instance, that isn’t emitting any recognizable smell. The designer, Hee Tae Yang, looked into this issue and developed the “Smeller.” If you’re not sure if you can still trust what’s in the fridge, you can just hold the device over the food, and pressing a button displays its degree of freshness. The Smeller takes an air sample and translates the collected data into concepts such as “very fresh” or “a bit rotten.” If and when this everyday helper goes into production is not yet in the cards. Regardless of home use, electronic noses could also be useful in the quality control of industrially produced foodstuffs. Challenged to bring new products onto the market without scaring customers away with unpleasant scents, many companies are marshaling electronic noses for smell tests.


Little by little it seems that humans, in line with the principle of biomimicry, are creating a sensory copy of themselves. Of course we are still miles away from engineering robots that eat. Yet the more we stretch our natural limits the more imminent that moment becomes. Smelling, tasting, hearing, seeing, touching: good food can appeal to all of our senses. And who knows? In the remote future this privilege may not be reserved just for us.


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