Thermal characterization of a microheater for micromachined gas sensors

In this paper, a new four-point probe, double spiral heating element configuration for micromachined gas sensors is proposed and a simple analytical model of the steady-state thermal behavior of the microheater is presented. A testing procedure is suggested, based on simple two-wire and four-wire resistance versus power measurements, together with an iterative extraction procedure for the parameters of the thermal model. This allowed us to accurately extract the sensor active area temperature as a function of the total power dissipated on the microheater.