Explosives: A microsensor for trinitrotoluene vapour

Sensing devices designed to detect explosive vapours are bulky, expensive and in need of technological improvement — dogs remain the most effective detectors1 in the fight against terrorism and in the removal of land-mines2,3. Here we demonstrate the deflagration of trinitrotoluene (TNT) in a small localized explosion on an uncoated piezoresistive microcantilever. This explosive-vapour sensor, which has a detection capability that is comparable to that of a dog, should enable extremely sensitive, miniature detection devices to be used on a large scale.