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| Ammonia sensors |
Now the bomb diffusers are not required to carry big instruments to detect explosives as the futede advancing technology has given rise to a thin paper like sensor which would be helpful in wars for detecting the landmines. So lets see what can it be use of and how is it made.
Researchers at the Georgia Institute of Technology have developed a prototype wireless sensor capable of detecting trace amounts of a key ingredient found in many explosives.
The device, which employs carbon nanotubes and is printed on paper or paper-like material using standard inkjet technology, could be deployed in large numbers to alert authorities to the presence of explosives, such as improvised explosive devices (IEDs). A resonant lightweight antenna, which is used as the wireless component for communicating the sensor information, was printed on photographic paper using inkjet techniques developed by Professor Manos Tentzeris of Georgia Tech’s School of Electrical and Computer Engineering. The same inkjet techniques used to produce RF components, circuits and antennas can also be used to deposit the functionalized carbon nanotubes used for sensing. Beside using of heavy photographic paper or plastics to make these components more water resistant, the inkjet component printing can also use flexible organic materials. For example, liquid crystal polymer (LCP) can be used to increase robustness and weather resistance. The resulting components are similar in size to conventional components but can conform and adhere to nearly any surface. The process of creating the sensor involves printing carbon nanotubes on paper or "paper-like" materials, such as the plastic polyethylene terephthalate. The ink consists of silver nanoparticles held in an emulsion that can be passed through an ink-jet printer at a temperature of only 212 F (100 C). This ink is treated with ultrasonic waves in a process known as sonification, which alters the viscosity and makes the ink more homogeneous for greater effectiveness. As it sets, the ink forms into nanoscale cylinders called nanotubes. These are only one-billionth of a meter in diameter-about 1/50,000th the width of a human hair. When these nanotubes are coated with a conductive polymer that attracts ammonia it becomes an effective explosives sensor capable of detecting trace amounts of ammonia as low as five parts per million. With different coatings, the nanotubes can detect other gases.
The resulting integrated sensing package can potentially detect the presence of trace explosive materials at a distance, without endangering human lives. This approach, called standoff detection, involves the use of RF technology to identify explosive materials at a relatively safe distance. The GTRI team has designed the device to send an alert to nearby personnel when it detects ammonia.The sensor can be printed with a built-in communications device already installed to transmit data. These components can be printed on a suitable plastic and be formed out of flexible organic materials, such as liquid crystal polymer to make them more robust and water resistant. The device also uses very little power, which makes it suitable for running off of thin-film batteries or solar cells. And, being printed, the device can be stuck on any surface where it might be required. The GTRI team is also working to make the device capable of operating passively without an internal power source-something like RFID tags used in shops that get their power from the shop's scanning devices.This makes for a very flexible little package. The GTRI team designed the detector to act as an integrated detection/transmission system that provides stand-off explosives detection that allows personnel to remain at a safe distance while the detector transmits the results back to the operators.
So lets see what can give it to the armies and the technological world.
[via:gizmag]
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