THERMAL AND MECHANICAL ASPECTS FOR DESIGNING MICROMACHINED LOW-POWER GAS SENSORS

摘要

Metal oxide gas sensors have to be heated during operation. Idealy they should have low power consumption and a uniform temperature distribution over the sensitive area. Thermal isolation is achieved by locating the sensitive element on thin free-standing membranes fabricated by means of micromachining of silicon. Uniformity of the temperature is helpful for discriminating different gases and, thus, increasing the selectivity. This can be achieved by careful design of the heater or by additional structures. Micromachined test structures have been fabricated, their mechanical strength and thermal behaviour have been determined and the results have been correlated with extensive FEM studies. [References: 4]