Multisensor microsystem for contaminants in air

A novel multisensor microsystem for gas sensing, containing 39 metal oxide detectors, 2 temperature sensors and 4 heaters on an area of 8 x 9 mm(2), is described including design, fabrication process and example application to a mixture of organic gases in air. Recognition of different air contaminants is achieved by pattern recognition of the signals obtained, using temperature gradients and inhomogeneous ceramic membranes to tune the selectivity of the sensor elements. A gas sensor chip equipped with tin dioxide exhibits detection limits well below 1 ppm for most organic vapors. The overall analysis time, including measurement of all signals and pattern evaluation, is about 100 s.