In this project, undergraduates are working together with graduate students
and faculty to develop an artificial "nose" that can detect and classify
odors. Since odorant compounds are detected in the gas phase, it is
necessary to use gas sensors that can distinguish between different
compounds. In this project we are using commercially available sensors
which contain specially prepared tin-oxide elements. These sensor elements
are heated by an applied voltage during normal operation. No one sensor
can usefully distinguish among the thousands of odors of possible interest,
but by using an array of various kinds of sensors operating at different
heater voltages, it is possible to associate a given odor with a specific
response pattern.