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 Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>