Development of micromachined nanocrystalline mesoporous SnO2 gas sensor for electronic nose

MEMS based sol gel synthesized mesoporous nanocrystalline SnO₂ gas sensor has been developed. The SnO₂ nano film is fabricated with the combination of polymeric sol gel chemistry with block copolymers used as structure directing agents. The novel hydrogen sensor has a fast response time (1s) and quick recovery time (3s), as well as good sensitivity (up to 90), comparing to other hydrogen sensors developed. The working temperature of the new sensor can be reduced as low as 100°C. The low working temperature poses advantages such as lower power consumption; lower thermal induced signal shift as well as safe detection in certain environments where temperature is strictly limited. The developed sensor cell will be used to develop a high sensitivity and high selectivity electronic nose for harmful gas detection by combining different catalysts doped SnO₂ gas sensor array with fuzzy neural network.