Physics Today magazine is drawing attention to a recent discovery by an interdisciplinary team of scientists that includes Dr. Aaron Slepkov, Trent University’s Canada Research Chair in Physics of Biomaterials. The group demonstrated that a technique entrenched in the biomedical imaging industry can be used by geologists to analyze pockets of fluid trapped in rock. The article appears in the November 2012 issue of the magazine.

“It’s very significant that Physics Today has picked up on this,” said Professor Slepkov, who pointed out that the original research will be published in the December 2012 issue of Geology, a journal for geoscientists. “Being highlighted in a two-page article by Physics Today is huge, because it confirms that the physics community believes this is something that every physicist should know about. It’s not just of interest to geoscientists.”

Prof. Slepkov, who is a professor in Trent’s Department of Physics and Astronomy, was integral to the project – helping to develop the methodology, design the experiment, collect and analyze the data and write the report. The team included researchers from Canada’s National Research Council and the US Geological Survey.

The team used a technique known as coherent anti-Stokes Raman scattering (CARS) microscopy that has been gaining popularity in the biomedical sciences. CARS microscopy creates high-resolution, chemically-specific images, based on bond-vibration frequencies. The technique can be used to build up three-dimensional images even in relatively turbid samples.

The breakthrough came when Prof. Slepkov and his fellow researchers saw the potential application in other disciplines. “We wanted to broaden the utility of CARS microscopy, beyond biomedical imaging,” said Prof. Slepkov. “Seeing it as a tool for geologists is an idea that came right out of left field, when Bob Burruss of the US Geological Survey came to the National Research Council for a CARS microscopy workshop.”

The researchers demonstrated that the CARS microscopy tool could be used to examine rock samples for pockets of methane gas and other organic matter, without destroying the samples. Previously, one had to crush the samples to examine its contents in this way. “This is just the beginning,” said Prof. Slepkov. “We are trying to show a range of potential applications that may be of interest to a wide swath of scientists, including mineralogists, archeologists, crystallographers, petroleum chemists, and fluid inclusion researchers.”

Prof. Slepkov sees this discovery as the first step towards creating demand for the technique in the geosciences. But he also thinks there are commercial applications. “This technique allows the petrochemical industry to develop new ideas of what they might be able to do. In the long term, it’s going to assist in surveying and in determining in situ ratios of methane to crude oil content and various other chemical contents of crude oil.”

Now that the door has been opened to other disciplines, Prof. Slepkov wants to consider collaborative projects for other fields ranging from paleontology and paleobiology to mineralogy, while continuing to push the boundaries on how the technique can be used for geochemistry. “The sky’s the limit, if you know how the tool works and what kinds of problems it can solve,” said Prof. Slepkov. “We have an opportunity to expand the horizon of this unique tool and bring it to other disciplines that would never dream of using something like this.”

While the technique was developed in Dr. Albert Stolow’s lab at the National Research Council in Ottawa, Prof. Slepkov sees Trent playing a strong role in future research. He is currently working to build up research capabilities at Trent, including a laser microscopy lab to investigate biomaterials. Prof. Slepkov plans to continue working with his colleagues at the National Research Council and the US Geological Survey on this work, but he also hopes to collaborate with researchers in other disciplines at Trent.

 “We’ve only just scratched the surface on how the tool can be applied to geochemistry and solving some long-standing geochemistry questions about the origins of some of these geofluids,” said Prof. Slepkov. “But I’m eager to strike new collaborations that are unique to Trent and Canada and move forward in developing this technique. Hopefully, this will inspire researchers in other disciplines at Trent to dream up new applications for nonlinear microscopy.”

Posted on Wednesday, November 14, 2012.