Navigation Links
New method for detecting explosives
Date:3/13/2009

COLLEGE PARK, MD (Mar 12, 2009) -- A group of researchers in Tennessee and Denmark has discovered a way to sensitively detect explosives based on the physical properties of their vapors. Their technology, which is currently being developed into prototype devices for field testing, is described in the latest issue of the journal Review of Scientific Instruments, which is published by the American Institute of Physics (AIP).

"Certain classes of explosives have unique thermal characteristics that help to identify explosive vapors in presence of other vapors," says Thomas Thundat, a researcher at Oak Ridge National Laboratory (ORNL) and the University of Tennessee who conducted the research with his colleagues at ORNL and the Technical University of Denmark.

In their paper, the scientists show that their technology is capable of trace detection of explosives. They also show that it is capable of distinguishing between explosive and non-explosive chemicals and of differentiating between individual explosives, such as TNT, PETN, and RDX.

Thundat and others have been working on explosive sensors for years. Typical sensors use ion mobility spectrometers, which ionize tiny amounts of chemicals and measure how fast they move through an electric field. While these instruments are fast, sensitive, and reliable, they are also expensive and bulky, leading many researchers in the last few years to try to find a cheaper, more portable device for detecting explosives.

Much of this research focuses on "micromechanical" devices -- tiny sensors that have microscopic probes on which airborne chemical vapors deposit. When the right chemicals find the surface of the sensors, they induce tiny mechanical motions, and those motions create electronic signals that can be measured.

These devices are relatively inexpensive to make and can sensitively detect explosives, but they often have the drawback that they cannot discriminate between similar chemicals -- the dangerous and the benign. They may detect a trace amount of TNT, for instance, but they may not be able to distinguish that from a trace amount of gasoline.

Seeking to make a better micromechanical sensor, Thundat and his colleagues realized they could detect explosives selectively and with extremely high sensitivity by building sensors that probed the thermal signatures of chemical vapors.

They started with standard micromechanical sensors -- devices with microscopic cantilevers beams supported at one end. They modified the cantilevers so that they could be electronically heated by passing a current through them. Next they allowed air to flow over the sensors. If explosive vapors were present in the air, they could be detected when molecules in the vapor clung to the cantilevers.

Then by heating the cantilevers in a fraction of a second, they could discriminate between explosives and non-explosives. All the explosives they tested responded with unique and reproducible thermal response patterns within a split second of heating. In their paper, Thundat and his colleagues demonstrate that they could detect very small amounts of adsorbed explosives -- with a limit of 600 picograms (a picogram is a trillionth of a gram). They are now improving the sensitivity and making a prototype device, which they expect to be ready for field testing later this year.


'/>"/>

Contact: Jason Bardi
jbardi@aip.org
301-209-3091
American Institute of Physics
Source:Eurekalert

Related biology news :

1. Safe water: simpler method for analyzing radium in water samples cuts testing time
2. Researchers develop simple method to create natural drug products
3. New method reveals substances on surfaces of any kind
4. Alternative methods proposed to detect pesticides and antibiotics in water and natural food
5. 454 Sequencing: Science paper describes a novel, highly efficient method of sequencing ancient DNA
6. Contraception: progress brings hope for new methods for men
7. From brains to behavior: Cold Spring Harbor Protocols features methods for neuroscience research
8. Cold Spring Harbor Protocols highlights a method that captures cell growth and activity
9. Team of scientists develops non-invasive method to track nerve-cell development in live human brain
10. New book presents methods to poke and prod individual molecules
11. Feinstein researchers develop new genetic method and identify novel genes for schizophrenia
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/15/2016)... York , March 15, 2016 ... market report published by Transparency Market Research "Digital Door Lock ... and Forecast 2015 - 2023," the global digital door lock ... 731.9 Mn in 2014 and is forecast to grow at ... Growth of micro, small and medium enterprises (MSMEs) across the ...
(Date:3/11/2016)... 2016 --> ... "Image Recognition Market by Technology (Pattern Recognition), by Component ... Deployment Type (On-Premises and Cloud), by Industry Vertical and ... MarketsandMarkets, the global market is expected to grow from ... by 2020, at a CAGR of 19.1%. ...
(Date:3/9/2016)... , March 9, 2016  Crossmatch ® ... and enrollment solutions, today announced the addition of ... Altus multi-factor authentication platform. New contextual ... managers to step-up security where it,s needed most ... Washington, DC . --> ...
Breaking Biology News(10 mins):
(Date:5/23/2016)... ... 23, 2016 , ... PrecisionAg® Media has released its latest ... The paper outlines the key trends that are creating both opportunities and challenges ... lot of highs and lows as the precision agriculture market has grown and ...
(Date:5/23/2016)... 2016 Oxitec CEO Hadyn Parry ... 10:15 a.m. ET before the United States House Committee on ... can play in controlling the spread of the Aedes ...      (Logo: http://photos.prnewswire.com/prnh/20150630/227348 ) ... self-limiting gene. Trials in Brazil , ...
(Date:5/23/2016)... North Carolina (PRWEB) , ... May 23, 2016 ... ... automation and building management solutions and services based in Aurora, Ohio, has broken ... of established business in the Research Triangle Park area, this new location solidifies ...
(Date:5/22/2016)... (PRWEB) , ... May 22, 2016 , ... Doctors in ... in combating the asbestos cancer, malignant mesothelioma. Surviving Mesothelioma has just posted an article ... in the University of Rome’s Department of Clinical Sciences and Translational Medicine evaluated more ...
Breaking Biology Technology: