Researchers at the University of California (Berkeley) have created a new technique that has improved sensitivity miniature laser sensor for the determination of explosives.
In the tests, the researchers used a new device to detect several types of explosives: dinitrotoluen (DNT), ammonium nitrate and nitrobenzene. The device was able to successfully detect the concentration of hazardous elements in the air, in extremely small doses: 0,67 per billion, 0.4 billion and 7.2 million, respectively. According to developers, the much higher sensitivity of existing methods of definition.
The author of the new research and development Xiang Zhang: "Optical sensors for explosive detection are very sensitive and compact. They have the possibility to increase the minimum traces of explosives and are one of the most powerful tools we have." The researchers say that the sensor can be applied to detect unexploded landmines.
When designing the device, the researchers used the chemical composition of the explosives, particularly nitro-compounds such as DNT and TNT. In the analysis of the interaction of the molecules with natural surface defects on the semiconductor. The device works by detecting the increase in intensity in the light signal that occurs as a result of this interaction. Co-author Ren-Min MA: "PETN has more nitro functional groups and more electrondeficient than DNT, so the sensitivity of our device should be even higher than with DNT. Our technology could lead to portable devices that can detect tiny trace vapor in the air molecules of explosive compounds."