Group Leader

Gilberto Contreras

Group Members

John Avor
Yi-Chen Lo


Classification of odors through the use of an array of chemical sensors interlinked with a fuzzy/neuro-fuzzy computational architecture is not a new idea; however the utilization of these elements in harmony to detect and distinguish between very similar odors is perhaps a novelty in the field of artificial noses and tongues. The sensor array aforementioned consists of 8 quartz-crystal microbalance (QCM) chemical sensors. QCM chemical sensors are based on gravimetric measurement principles, or simply, they detect small mass changes. Each quartz-crystal and electrode assembly is coated with a different thin-layer of polymeric material which has partial selectivity to an odor molecule of interest. This provides the variation needed to establish a pattern for odor classification.

QCM chemical sensors
QCM chemical sensors


The main motivation for electronic noses is the development of quantitative, low-cost, real-time, and portable method to perform reliable and objective measures of volatile compounds and odors. In late 1994 and early 1995 commercial electronic noses began appearing on the market based largely on university developed prototypes. It is a fairly immature but evolving technology.

Motivation Table



Food industry


Safety and security