A new SiC/HfB2 based low power gas sensor

A new SiC-based heated micro gas sensor with a 100 mum x 100 mum heated mem brane and excellent heater long-term stability is presented. Combining a pr eviously presented micro hotplate with new gas sensitive (2 1 1) oriented I n2O3 thin film layers yields a very stable low power NO2 gas sensor. The mo dular design allows its operation at operating voltages of either 1-2 or 12 -24 V for battery and grid powered automotive applications. A total of 20 m W of power is sufficient for the operation at 250 degreesC. The sensitivity and signal reproducibility in the MAK-range (5 ppm, maximum workplace conc entration according to German federal law) is good. The response time tau ( 50) = 50 s needs improvement. (C) 2001 Elsevier Science B.V. All rights res erved.