Papers by Author: Yeong Soo Choi

Abstract: To integrate the ceramic Pt/alumina catalyst on micro-hotplate of micro-thermoelectric hydrogen sensor (micro-THS), a dispenser technique was used in this study. This micro-THS with the Pt/alumina catalyst is capable of sensing wide range hydrogen concentration of 50 ppm to 3 % at room temperature. For hydrogen/air mixture gas of 50 ppm, voltage signal is measured to be 0.03 mV at room temperature.

Abstract: Micromachined sensors are a new generation of sensor technology combining existing integrated circuit fabrication technology with novel deposition and etching processing. In the viewpoint of low-power operation, high sensitivity and fast response speed of thermoelectric hydrogen sensor (THS), we prepared the micromachined thermoelectric hydrogen sensor (micro-THS) with the combination of the thermoelectric effect of SiGe thin film and the Pt-catalyzed exothermic reaction of hydrogen oxidation. The power consumption of the micro-THS was greatly reduced to be 50 mW for 100 °C operating, by the Pt-micro-heater on single membrane. The micro-THS with 40 wt.% Pt/alumina catalyst showed voltage signal of 10 mV for 1 % H2 in air.