Chemical analysis from the military

US Army researchers, working with small business, are developing a chemical analysis technology that should prove to be a valuable tool in military and civilian environmental cleanup efforts and in other chemical sensing applications.

ADA Technologies, of Littleton, CO, has developed two prototypes of portable instruments that use a technology called Laser Induced Breakdown Spectroscopy (LIBS) to perform chemical analysis in the field. The prototypes were developed with the sponsorship of the Army’s Small Business Innovation Research (SBIR) program coordinated through the Army Research Laboratory.

Dr. Andrzej W. Miziolek, Weapons and Materials Research Directorate, at Aberdeen Proving Ground, Md. and Dr. Russell S. Harmon, Army Research Office, Research Triangle Park, N.C., are the project managers. Other members of the team from ARL are Drs. Kevin L. McNesby, Richard T. Wainner and Robert G. Daniel.

LIBS is an analytical technique in which a solid-state, pulsed laser is focused on a sample to form high-temperature plasma. The elemental composition of the sample can be identified by the characteristics of the light emissions from the atoms, ions and molecular fragments generated in the plasma. The work by ADA has brought the LIBS technique from a theoretical lab-based analytical capability to a field-portable, real-time tool for surveying trace metals in the environment, according to Harmon.

The portable LIBS system enables this to be done without having to drill for samples or using a conventional laboratory analysis. It’s faster, less costly and virtually non-destructive. It can detect multi-metals not only in soil, but also on surfaces and from samples taken using a swipe. It’s a technology that could also lend itself to sciences like forensics, Miziolek says.

“However, I want to stress that LIBS is primarily a field screening tool, generally not a replacement for analytical laboratories,” he points out.

Originally developed as a trace metal detector, ARL is “pursuing other uses, particularly for molecular detection” Miziolek says.

Other military uses for LIBS might include, for example, detection of chemical warfare agents and energetic materials in the field.  A possibility being considered is the inclusion of a LIBS sensor on future military robotic vehicles that go into hazardous and contaminated areas.

Novel applications of LIBS continue to come up.  Recently Miziolek has had discussions with Drs. William Bruchey and Lee Magness, also of WMRD, concerning the possible use of LIBS for detection of metals such as uranium, beryllium, nickel, and cobalt in aerosols generated in ballistic impacts by kinetic energy penetrators.

Miziolek points out that there has also been some interest from NASA in including a LIBS instrument from Los Alamos National Laboratory on some of their space probes to do chemical analysis. “It’s reliable and very compact which is important in space vehicle applications.”

ARL isn’t the only laboratory looking into LIBS technology, he adds.

“There’s a large international community working with LIBS,” he points out. LIBS-based technology has been under development in the scientific community since the mid-80s. Miziolek understands its appeal.

“It’s basically a very straightforward technique.  It doesn’t require a big laser or a big computer, both keep getting smaller and cheaper.  You can get a lot of analysis done. We, at ARL, want to focus on the military applications,” he says.