Sensor system for vapor trace detection of explosives

This article presents miniature detection system, which is able to detect and selectively recognize different vapor traces of explosives. It is based on surface-functionalized MEMS-COMB capacitive sensors and extremely low noise integrated circuit. The instrument is sensitive and selective, consumes a minimum amount of energy, is very small and cheap to produce in large quantities, and is insensitive to mechanical influences. It is possible to detect less than 3ppt of TNT molecules in the atmosphere (3 TNT molecules in 10¹² molecules of the air) at 25 °C in 1 Hz bandwidth using very small volume and only approx. 10 mA current from a 5 V supply voltage.