A microsensor array with porous tin oxide thin films and microhotplate dangled by wires in air

A microsensor array with the highly sensitive porous tin oxide thin films employing the noble metal catalysts of Pt and Au on a new microhotplate, dangled in air by Pt bonding wires, has been designed and fabricated. The microhot plate was made of N/O/N Si diaphragm with area of 1.9 mm×2.1 mm. Power consumption was reduced by decreasing the thickness of substrate. The sensor array was applied to recognizing the explosive gases within the range of threshold limit values (TLVs), employing principal component analysis. The result showed that the micro sensor array was qualified for classifying obviously the kinds and quantities of the explosive gases.