ABSTRACT
In all those applications, the thermal properties of the sensing elements determine the functional operation. In order to operate thermal sensors and actuators efficiently, it is necessary to produce maximum temperature changes from a minimum amount of input energy. It should be noted that minimizing power consumption is one of the main requirements for sensor technology, especially when the devices are intended for use in portable systems. For example,
conventional combustive and semiconductive oxide gas sensors, which operate at elevated temperatures between 300 and 600°C, typically consume 0.2-1.0 W, while the single sensing element aimed for application in portable devices must have a power dissipation of less than 10-50 mW. The use of thermal microstructures having small heat capacitance with a high degree of thermal insulation gives the possibility to resolve this problem. Therefore, incorporation of thermally isolated micro hotplates in the construction of the indicated devices allows reducing considerably both the power consumption and the thermal transient time.
