ECBC, UMBC Use Lasers to Detect Industrial Compounds
A new partnership between the U.S. Army Edgewood Chemical Biological Center and the University of Maryland, Baltimore County will advance research efforts for nonlinear Raman spectroscopic techniques used for the detection and identification of chemical, biological and toxic industrial compounds located on surfaces.
For the first effort of this collaboration, ECBC’s Laser Spectroscopy Branch will work with the chemistry department at UMBC on a joint research project that will combine a technique known as spatial heterodyning with Raman spectroscopy. This Spatial Heterodyne Raman Spectrometer will have a higher light throughput, allowing for more sensitive measurements. Additionally, the SHRS can simultaneously collect multiple spectra from a wider surface area, as compared to traditional Raman instruments, which normally only examine a single point. The specific design for this SHRS will utilize an ultraviolet laser, which has been shown to be more sensitive in detecting specific chemical compounds of interest for defense and security applications. The SHRS design has no moving parts and significant potential for miniaturization into a small handheld unit. This project will design and build an SHRS system to demonstrate the technology and study the tradeoffs for potential detection scenarios.
“The final end goal is to develop a surface or bulk detection system for solid and liquid chemicals and explosives,” says Darren Emge, ECBC engineer. “It could be a stand-alone system that scans surfaces in a room or on a road, or it could be part of a larger suite of detection equipment that could be used by the Warfighter or first responders.”
The project was born out of a Joint Work Statement that was signed on June 6, solidifying a mutually beneficial partnership between government and academia within the state of Maryland. The JWS falls under a master Cooperative Research and Development Agreement between UMBC and the U.S. Army Research, Development and Engineering Command, ECBC’s higher headquarters. RDECOM anticipates a changeover in workforce in the next decade or so, and welcomes new partnerships that can facilitate the next generation of world-class scientists and engineers.
“The Joint Work Statement allows us to leverage the knowledge that UMBC provides with [Dr.] Bradley Arnold and his students. He is an expert in Raman technology who has extensive experience building and designing novel systems, and that’s something we’re trying to accomplish with this project. We can use his team as a resource anytime we come to a cross-road in our research,” says Emge, who is also a UMBC alumnus.
At the same time, this partnership gives UMBC students and faculty the opportunity for a hands-on experience with the nation’s premier subject matter experts and access to some of ECBC’s unique facilities. ECBC is known for its collaboration with other government agencies, industry partners and academic institutions within the state and across the country, and the partnership with UMBC offers both entities an opportunity to work together on a next generation detection system that will improve Warfighter safety on the battlefield.
Phillip Wilcox, an ECBC engineer specializing in optics and photonics, is the principal investigator on the three-year basic research project, which is funded by the Defense Threat Reduction Agency, and stressed the importance of having a good design at the beginning of any scientific research.
“We need to first have a good understanding of the design to determine what changes we need to make along the way. It helps to understand the tradeoffs. If a component gets smaller or we lose a signal, are those things important to what we’re trying to achieve?” Wilcox says. “Ideally, at the end of our three-year effort, we want to have a prototype system that can accurately detect threats from 10 meters away and has been tested against live agents in the lab as well as simulants outside.”
The UV capability and ICCD camera used in heterodyne Raman spectroscopy would allow the team to work in daylight operations, a major benefit of the project, he says. Raman instruments can have difficulty operating in bright daylight because the sunlight can saturate the instrument detectors. Additionally, existing systems do not offer wide area proximity detection, most are limited to scanning only a few millimeters of space at a time, and then only at a very short ranges.
“Every chemical has a spectral fingerprint; think of the ridges on a human fingerprint. These are spectral bands that identify what chemicals are present, and each one of the band spikes in the spectrum corresponds to a specific chemical bond, which is unique,” Emge says. “When light comes in, it hits a grating that scatters the light using a dispersive technique. By studying the spectral peaks and how strong they are, you basically can read the entire chemical composition.”
Once the principle of the research has been proven, Emge and Wilcox hope to attract organizations in need of advanced proximity detection. Together, ECBC and UMBC will work together to develop high-sensitivity detection technologies that can be used for dual-use applications in the military and civilian sectors. I95
Nonlinear Raman technology uses spectral bands to identify what chemicals are present on a given surface. The grating of light enables scientists to study the strength of wavelengths to read a specific chemical composition. I95