I. Matsubara

Micro thermoelectric device with ceramic combustor

A combustor of Pt/alumina catalyst was developed for the integration on micro-thermoelectric hydrogen sensor (/spl mu/-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 temperature difference, developed by the heat generated from hydrogen oxidation on the catalyst, between catalyst surface and Si substrate showed its maximum at the Pt content of 40 wt% in the catalyst. The effect of the catalyst size on the thermoelectric voltage (/spl Delta/Vs) of /spl mu/-THS was investigated. The catalyst (/spl Phi/ = 0.8 mm) smaller than the membrane developed the highest /spl Delta/Vs because of its good thermal insulation and high combustion performance. For the gas mixture of hydrogen/air, the /spl mu/-THS showed wide range hydrogen detection, 5 ppm

Safe membrane-releasing process for thermoelectric hydrogen gas sensor

3%, with the /spl Delta/Vs of 0.007 mV-34 mV.

Robust hydrogen detection system with a thermoelectric hydrogen sensor for hydrogen station application

We present here a safe membrane-releasing process in KOH for the fabrication of a high performance freestanding device and the mass production of a single membrane device for the hydrogen gas sensing application. The fabricated devices are thermoelectric hydrogen gas sensors based on the thermoelectric detection of the catalytic hydrogen combustion. The free-standing device has a voltage response 2.7 times higher than the single membrane device. The proposed membrane-releasing process, which combines black wax and a KOH protective polymer coat, shows fabrication yields of 31%, 50% for the free-standing device and 47% for the single-membrane device produced in mass.