OPTIMIZED TEMPERATURE-PULSE SEQUENCES FOR THE ENHANCEMENT OF CHEMICALLY SPECIFIC RESPONSE PATTERNS FROM MICRO-HOTPLATE GAS SENSORS

Microfabricated solid-state gas sensors have been of continuing intere st because of the potential for arrays of devices with low power consu mption. Devices based on a micromachined 'hotplate' offer the addition al advantage of a wide operating temperature range with a rapid therma l time constant of order 1 ms. By operating the device in a temperatur e-programmed mode, reaction kinetics on the sensing film surface are a ltered, producing a time-varying response signature that is characteri stic of the gas being sensed. Approaches to optimizing such temperatur e programs to maximize the differences in response signatures for gase s of interest or to enhance the sensitivity of the device are discusse d.