WHY BOTHER ABOUT GAS-SENSITIVE FIELD-EFFECT DEVICES

Gas-sensitive field-effect devices have been studied for more than 20 years. Commercial uses of such devices exist, but in special applicati ons and in small volumes. The purpose of the present contribution is t o point out several ongoing and possible developments, which make the prospects for gas-sensitive field-effect devices quite good. These are related to the fabrication of large sensing surfaces and sensor array s, the combination of sensors and catalytic combustion and the use of semiconductor substrates other than silicon to allow operation at temp eratures above 200-250 degrees C. More specifically, we discuss combus tion monitoring with field-effect devices, sensors operating with time constants close to fundamental limits, distributed chemical sensing, and combinatorial chemistry for sensor arrays. Some of the remaining m ore fundamental research problems regarding gas-sensitive field-effect devices are also touched upon.