Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UF researchers shine light on new explosives detection method

07.10.2004


A team of University of Florida researchers has invented a way to rapidly detect traces of TNT or other hidden explosives simply by shining a light on any potentially contaminated object, from a speck of dust in the air to the surface of a suitcase. "We have to find explosives quickly, inexpensively and, particularly, reliably," said Rolf Hummel, a UF professor emeritus of materials science and engineering who heads the lab where the method was invented.



The development provides instantaneous results, gives no false positives, can be used remotely and is portable -- attributes he says will make it indispensable at all levels of law enforcement, from local police to homeland security.

The method uses photoluminescence spectroscopy, a technique that casts light on a material and measures the range and intensity of the wavelengths of light the material produces in response. The wavelength of the emitted light varies depending on the chemical structure of the material.


Using photoluminescence to reveal the presence of TNT is similar to how "black light" uses ultraviolet radiation to make white clothes glow, but in this case the black light is a laser, Hummel said. "Once you shine a laser at the sample, the laser then re-emits (it) at specific wavelengths that are different for each material -- it’s a kind of a fingerprint."

TNT’s fingerprint is a sharp, distinct photoluminescent peak at a specific wavelength within the electromagnetic spectrum, the researchers discovered. The electromagnetic spectrum encompasses the entire range of light and sound waves, from long-wavelength radio waves to short-wavelength gamma rays. The peak occurs just outside the longer-wavelength, or red, portion of the spectrum that includes visible light. TNT shares this characteristic peak with other explosive materials, such as plastic explosives and nitroglycerin, but not with safe materials.

The key to this common attribute, Hummel said, lies in the explosives’ chemical makeup -- they all contain at least two "nitro groups," molecules made up of one nitrogen atom bound to two oxygen atoms. The peak is a narrow spectral line and would be easy to miss if you don’t know where in the spectrum to search, Hummel said.

The UF discovery of TNT’s signal was prompted by a request from the U.S. Army Research Office that challenged universities to find a way to make inexpensive, quick and reliable explosive-detection systems. Out of curiosity, one of Hummel’s graduate students tested TNT in the lab’s photoluminescence spectrometer. With its high resolution, the machine scanned across the entire light spectrum and caught the explosive’s elusive signal. "That’s why we detected it the first time," Hummel said.

"This is a very complex phenomenon," said Chuck Schau, a scientist at Raytheon Missile System’s Radiation Technology Laboratory who also was conducting experiments on explosive detection using photoluminescence but initially did not observe the TNT peak discovered by the UF team. Raytheon is now interested in following up on this discovery, he said. That development may include a future for this detection technology that goes beyond airport lines and into uncovering dangerous materials on a much larger scale -- though that technology may be years away.

"If I see a ship approaching, I’d like to know if it’s packed with explosives," Schau said. It’s in the field of remote detection that this is exciting. This really looks like it may give us a leg up on that."

Sample collection for explosives is familiar to anyone who has recently passed through an airport: a swab brushed across an object, such as a suitcase, clothing or even a person, or puffs of air blasted across a filter that can trap tiny amounts of airborne explosives. The advantage of photoluminescence-based explosive detection is that it can be remotely applied, and requires neither time-consuming and expensive machines nor trained dogs, said Hummel, who has applied for a patent on the technique.

"My major aim is that I would like to help and make a contribution towards secure life, airports and transportation," he said. "Just shine a laser on a car, ship or person and see if that specific wavelength comes back -- that’s my goal."

Rolf Hummel | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Process Engineering:

nachricht CeGlaFlex project: wafer-thin, unbreakable and flexible ceramic and glass
25.04.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Additive manufacturing, from macro to nano
11.04.2017 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>