Vapour detection

Researchers in North America and Denmark are developing a prototype device that is capable of detecting explosives based on the physical properties of their vapours.

‘Certain classes of explosives have unique thermal characteristics that help to identify explosive vapours in the presence of other vapours,’ said Thomas Thundat, a researcher at Oak Ridge National Laboratory (ORNL) and at the University of Tennessee who conducted the research with his colleagues at ORNL and the Technical University of Denmark.

The scientists have shown that their technology is capable of the trace detection of explosives. They have also shown that it is capable of distinguishing between explosive and non-explosive chemicals and of differentiating between individual explosives, including TNT, PETN and RDX.

Typical sensors use ion mobility spectrometers, which ionise tiny amounts of chemicals and measure how fast they move through an electric field. While these instruments are reliable, they are also expensive and cumbersome, leading many researchers to try to find a cheaper, more portable device for detecting explosives.