New precise and compact explosive detector created at MEPhI

Russian scientists have developed a new type of TNT detector and explosives similar to it. These devices are at the same time very sensitive, compact, and relatively inexpensive, but they cannot work in continuous mode.

“Our detector still needs to be further developed. First of all, it is necessary to speed up cleaning. We can quickly determine the concentration of the substance, but then we have to wait for recharging for the next sampling. Such devices need to be within the standards of security services, about 3-4 seconds, ”said Nikolai Samotaev, associate professor at MEPhI.

Now, as scientists note, there are two key types of detectors of explosives and other dangerous compounds. The first one is more expensive, bulky and universal; it determines if there are any traces of them in the air, sorting various ions by mass. Such installations, due to their size and cost, are almost impossible to use in crowded places.

There are also more compact and cheap systems for the detection of TNT and similar compounds. Air is passed through such devices; the system determines the volatile traces of explosives by how the nature of the glow of certain fluorescent compounds changes. These detectors are significantly less sensitive than the first ones, and less stable.

Electronic nose

Samotaev and his colleagues solved this problem: they found that a peculiar “sandwich” —  a conductor, insulator and semiconductor, similar in structure to a capacitor — can cope with the task of detecting traces of explosives in the air. As scientists explain, If traces of explosives fall into its metal part, then its electric capacity noticeably changes.

Modern detector prototypes based on similar structures are almost inferior in sensitivity to ion spectrometers. At the same time, they are much more compact. In the future, this device will fit in a box measuring 30 by 30 by 30 centimeters.

On the other hand, the use of new detectors in practice is still hindered by the fact that it takes about three to four minutes to clear them from explosive traces. Because of this, with their help it is impossible to constantly monitor the situation and instantly monitor the appearance of new accumulations of TNT and other explosives. As scientists hope, in the near future they will be able to eliminate this defect.

Source: ТАSS