INTEGRATED SEMICONDUCTOR TECHNOLOGY FOR AN ELECTRONIC NOSE

Over the past ten years there has been significant interest in the application of sensor arrays to discriminate between odorous mixtures. Such a system could have numerous uses in fields as diverse as agriculture, foodstuffs, brewing, perfumery and air quality measurement. At present, progress is limited by the sensor technology. To date, most of the research undertaken has been centred around the commercially available Taguchi Gas Sensor (TGS) range. These devices consist of a thick‐film tin oxide layer, the conductance of which is modulated upon exposure to a range of flammable materials. This can only occur when the sensor is operated at temperatures in the region 300–700°C. These devices are also bulky and have high power consumptions (0.9W at 300°C). This makes them unsuitable for remote field applications requiring battery supplies, particularly when there are a large number of sensors in the array.