Based On Mems Technology Sno < Sub > 2 < / Sub > Hydrogen Sensor And Circuit Design

The hydrogen sensor is already widely used in many areas of family life, health,energy and environmental testing. SnO₂as an application of the most widely usedsensitive material, as a hot spot for hydrogen sensors, SnO₂materials that is a widebandgap semiconductor materials, chemical, physical stability is particularly good, andstrong corrosion resistance, for many sensitivity characteristics of reducing gas is verygood, reversible, response and recovery time is short, high reliability and lowconcentrations of gas sensitivity advantages. But pure SnO₂material sensitive to avariety of reducing gases, so the less selective. This project is completed on the basis ofthe results of domestic and foreign many SnO₂hydrogen sensor. The first innovativeMEMS technology is to produce silicon cup, and the PN junction is a sensor structure,modulation doped nanocrystalline SnO₂thin films as sensitive material, interdigitalplatinum electrodes as a heating source, in which nano-SnO₂thin films by sol-gelmethod preparation, the above may be reduced to nano-SnO₂thin film resistors toincrease the sensitivity of the sensor, and the thin films were characterized by thedoping type of sensor test system, the annealing temperature, the operating temperatureis analyzed, given the sensitivity, the corresponding recovery time the final design of thesensor peripheral circuits, constant current source as a power source, which usingAD623differential amplifier for the sensor signal processing by the microcontroller, theADC0804as the D/A converter, displayed on the LCD screen in LCD12864.