Tungsten trioxide gas sensor array constructed from partitioned layers of the metal oxide

Summary form only given. A very cheap and simple but nevertheless analytically powerful gas sensor microstructure has been developed to be used in all kinds of consumer products. In order to realise a gas sensor system sensitive to air pollution caused by automobile traffic, layers of tungsten trioxide coated with silicon dioxide were tried for the first time and tested for their performance. The sensor array is based on a monolithic tungsten trioxide (WO/sub 3/) layer of rectangular shape and about 500 nm thickness. The WO/sub 3/ layer was deposited by rf sputtering and subsequently annealed to 600 /spl deg/C for 20 hours. The surface is partitioned by 41 parallel platinum strips into 40 gas sensitive segments. This patented design allows a significant reduction of the mutual drift between sensor elements and hence stabilizes the ability of gas recognition by signal pattern evaluation.