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 No compromises: Combining the benefits of 3D printing and casting
23.03.2018 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>