Micro-thermoelectric devices with ceramic combustors

A combustor of Pt/alumina catalyst was developed for the integration on micro-thermoelectric hydrogen sensor (μ-THS) with a dispenser method. The Pt/alumina catalyst was deposited on Si substrate and the hydrogen/air mixture gas was flowed to test the combustion performance. The effect of the catalyst size was investigated with respect to the thermoelectric voltage (ΔV_s) and the temperature difference developed by the heat generated from the hydrogen oxidation on the catalyst. The temperature difference between the catalyst surface and the Si substrate was maximum for the device with the catalyst size of φ{symbol} = 0.8 mm. For that temperature, the catalyst with a size smaller than the membrane, has developed the highest ΔV_s because of its good thermal insulation and high combustion performance. For the gas mixture of hydrogen/air, the μ-THS showed wide range hydrogen detection, 5 ppm -3%, with the ΔV_s of 0.007-34 mV.