Biology Reference
In-Depth Information
the
Review
urged, was more development money; otherwise, Japan might win the electronic-
nose race.
We've lived with the term “electronic nose” for nearly three decades, and despite some very
different mash-ups using gas chromatography, grids of nanoparticles, or polymer sensors, any
artificial nose needs to do three things: take in a vapor, show it on an array, and identify it to
the machine's operator. The dog's nose does something similar: It takes in a smell and sends
a signal to the dog's brain. The dog sits: I smell dope. The handler sees the dog sitting and
knows she's just smelled dope.
One cannot patent the dog. So “a truly biomimetic olfactory microsystem”—that is, a fake
nose—became a goal for bioengineers. Despite its lack of a mammalian reproductive system,
the fake nose is a gift that keeps on giving. In early theoretical stages, it helps get papers pub-
lished. In experimental stages, it helps buy lab space and equipment and pay for postdoctoral
lab workers. If the nose ever goes into production, even more people get involved. Most of
the current fake noses are expensive but not too expensive, especially in these days of downs-
izing public infrastructure. Law enforcement, the military, health care, and other industries,
such as food production facilities, will buy it. Developers admit that the fake nose will require
some maintenance and training. That admission just brings in additional funding.
As each new nose is trotted out to the media and public, the same claims are made: This
nose is the nose to end all noses. It will keep working in heat and cold, never false alert, never
get tired, never require dog chow. It won't have to retire at the age of eight or nine with hip
dysplasia.
Mechanical noses have flourished under scientific competition. But like a bad reality show,
So You Think You Can Make a Better Nose
, the competition can be a polyphony, or even a
cacophony, of competing tunes and dueling harmonies: Anything a dog can do, a machine
or a mash-up can do better. Your fake nose is good, my fake nose is better. Anything a Ge-
orgia Tech chemical engineer can do, an MIT researcher can do better. “There's no further
improvement in the sensor part you can get,” an MIT chemical engineer told
Wired
magazine
about his e-nose creation in 2010. “It's the last word in sensors.”
It may be the latest word in sensors. I doubt it's the last. Call me unsentimental, but I can't
decide which I prefer: having an airport security employee thrust an electronic nose into my
crotch, or having a TSA handler do the same thing with a bomb dog. If my civil rights are
going to be violated every time I fly, I do prefer that the search be effective and low on the
false positives. And that I not get cancer or get bitten.
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