John Kauer and Joel White fit Alan with the electronic
canine nose is a remarkable organ. About one hundred times
more sensitive than a human nose, it can sniff out illegal
drugs, track fugitives - even find rot spots in wooden structures.
But to bring out a dog's natural smelling ability requires
a talented human trainer, like former Secret Service agent
Ed Hawkinson who used explosive-sniffing dogs to guard the
President. Today, he trains Labradors to detect weapons in
"The Dog Nose Knows," Alan meets John
Kauer and Joel White,
both neuroscientists at Tufts University in Massachusetts.
Kauer and White have built a sniffing device modeled on a
dog's nose that they hope will help safely detect the estimated
50 to 100 million landmines buried around the world. Real
dogs have had some success finding landmines, but it's not
clear how they do it, and, of course, even a single error
could be deadly.
"nose" uses chemical sensors to identify the DNT in this
new device consists of a computer, a battery-pack and a hose-like
"sniffer" that draws in odor molecules. When the inhaled molecules
combine with chemical sensors inside the contraption, the
sensors change colors, creating a signature visual pattern
for each aroma. Light sensors "read" this pattern to determine
the identity of the odor.
a test run with Alan, the virtual nose easily detects the
difference between plain air, non-explosive DNT and methanol.
The machine can smell odors at concentrations as low as 10-20
parts per billion, but the scientists hope to get it down
to one part per billion. Then it would rival a real dog's
nose, and help authorities find those millions of unexploded
more on this topic, see the web feature:
Real Price of Landmines
the Nose Knows
What's New with the Artificial