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 applications and in small volumes. The purpose of the present contribution is to 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 arrays, the combination of sensors and catalytic combustion and the use of semiconductor substrates other than silicon to allow operation at temperatures above 200-250 degrees C. More specifically, we discuss combustion 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 more fundamental research problems regarding gas-sensitive field-effect devices are also touched upon.