Design strategies for gas and odour sensors

The authors have analysed physiological and biochemical processes that occur in vertebrate olfactory transduction in order to determine the specifications necessary for electronic gas or odour sensors which may approach some of the performance characteristics of the biological system. In the design of a multi-sensor system for gas and odour discrimination, they have aimed at a flexible apparatus that can adapt to changing circumstances and needs of the users. The gas sensing elements are deliberately not specific to individual chemicals but respond with varying degrees to different chemical classes. However, each sensor has a different degree of specificity although this may be very broad. As such, they resemble in concept the olfactory receptors found in the biological system. The degree of pattern discrimination possible is dependent on the number of polymers of differing characteristics incorporated in the array