........ published in NEWSLETTER # 47
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........ published in NEWSLETTER # 47
SENSORS AND SENSORY SYSTEMS FOR AN ELECTRONIC NOSE
by Dr. J. Gardner, University of Warwick, Coventry (U.K.)
The material presented at the NATO Advanced Research Workshop in Reykjavik, Iceland in August 1991 reviews the current state of progress towards the development of an electronic instrument, euphemistically called an `Electronic Nose', that is capable of mimicking olfaction or the sense of smell. The emphasis is deliberately placed upon an electronic rather than a biological system. (The biological aspects of olfaction are discussed in Chemosensory Information Processing, ed: D. Schild, 1990, NATO ASI Series H39). The material broadly follows the path along which information is processed in such an instrument, the interaction of odours with the sensing materials through to the data processing techiques required to classify or identify simple and complex odours.
The first part of the book (NATO ASI SERIES E212) reviews the principles of operation of chemical sensors and describes devices on inorganic (e.g. metal oxide semiconductors, MOSFETs, electrochemical cells) and organic materials (e.g. conducting polymers, lipid_coated SAW devices). Various methods are discussed of analysing the signals coming from arrays of solid_state chemical sensors. These include conventional chemometric techniques, such as principle component analysis and Euclidean cluster analysis, through non_ linear chemometric techniques to novel neural paradigms, such as the back_propagation multilayer perceptron model, Kohonen's feature maps and fuzzy classification. The meeting focused on several application areas that may be of interest to readers, these were the measurement of beverage, coffee and tobacco odours. Some discussion was also held on the use of an electronic nose to measure the freshness of fish and wheat, and for applications in environmental monitoring of air quality. The book will be of interest to anyone working in the field of olfactory or flavour sensory analysis.
Reference books: A18, E212, F43, F52, F63, H39