Micromachined catalytic combustible hydrogen gas sensor

An integrated catalytic combustion H2 sensor has been fabricated by using MEMS technology. Both the sensing elements and the reference elements could be integrated into the suspended micro heaters connected in a suitable circuit such as a Wheatstone configuration with low power consumption. Two sensitive elements and two reference sensors were integrated together onto a single chip. The size of chip was 5.76 mm2 and the catalytic combustion sensor showed high response to H2 at operating voltage of 1 V. The response and recovery times to 1000 ppm H2 were 0.36 s and 1.29 s, respectively.