[Tyler]

Electronic Nose Update
     

An IEEE Spectrum
article summarizes recent developments in the electronic noses. The
latest variety sensors to give machines a sense of smell are based on
conducting polymers that produce electrical signals in response to
certain chemicals. The human nose, which is not particularly capable, as
noses go, can detect about 10,000 different chemicals, known as volatile
organic compounds (VOCs). Often, a single unique scent is the
combination of hundreds of different VOCs. Early electronic sensors
could only detect single chemicals. The most recent polymer noses are
printable organic semiconductors that can "differentiate between
basic classes of odors, such as acids, alcohols, amines, and thiols"
allowing them easily sniff out the difference between wine and
vinegar. There are still some bugs to work out before this technology
becomes commercially available. For more, see our older articles on the
NASA ENose, the NIST optical nose, and
the nanobiosensor nose.
   

http://robots.net/article/2486.html