The Invisible World
Jim Schiffbauer acts like a kid in a candy store when demonstrating the capabilities of the new equipment his lab has acquired at the Department of Geological Sciences. “We’re doing really cool work here,” he says, while showing observers the lab’s new X-ray microscope (also known as microcomputed X-ray tomography, or micro-CT) and a customized scanning electron microscope (SEM). Schiffbauer’s X-ray microanalysis lab is a Zeiss microscopy facility with two primary instruments available to researchers across campus: a Sigma 500 VP scanning electron microscope and an Xradia Versa 510 X-ray microscope.
Schiffbauer, an assistant professor of geology, says the scanning electron microscope was fully funded through a National Science Foundation Early Career Instrumentation & Facilities proposal, and the X-ray microscope was acquired through in-house fundraising, with significant contributions from the Office of Research, Graduate Studies and Economic Development, Mizzou Advantage, several departmental units, and the College of Arts and Science dean’s office. A portion of the NSF funding pays the salary of Schiffbauer’s graduate assistant and now lab manager, Tara Selly.
With a suite of high-resolution imaging detectors and analytical spectrometers, the customization of the SEM makes it very powerful for analysis of geological materials, first and foremost, but with applications across a wide range of material types. Schiffbauer says the SEM produces crisp high-definition images and provides detailed compositional analyses of the surface of the samples he and his colleagues examine.
“We are able to look at both the composition of the material and the topography of the material all at once and at ultra-high magnification—to a magnification of about a million X with resolvability of about 0.7 nanometers” he says. Although Schiffbauer says he doesn’t typically look at samples with features that small, he says it would be great for researchers in engineering, for example, who need to examine nanoscale materials. The real strength of this SEM for Schiffbauer’s work is that it has dual, co-planar energy dispersive X-ray spectrometers for compositional analyses with little affect from sample roughness, a capability that is unique to this configuration. In addition, it has automated functionalities for acquiring multiple images of the sample and then stitching them together into gigapixel-scale high-resolution image mosaics—a process that he used to perform manually and took days to complete at his former labs.
The First Micro-CT on Campus
The other piece of equipment Schiffbauer is eager to show visitors is a behemoth: a several ton lead box with a massive granite slab for stability. The Xradia Versa 510 X-ray microscope produces three-dimensional volume images without destroying the sample.
Xradia Versa 510 X-ray microscope
“What happens here is the 160,000 volt x-ray source and the detectors fixed in-plane, so the sample is what rotates, as opposed to what you may think of with medical CAT scanning” he says. “If you think about an elliptical CAT scan, you lie flat and the x-ray source and detector spin around you in a giant doughnut configuration. We don’t have that luxury, but we can move the sample around.”
External (surface) and an internal slice through a juvenile alligator
Schiffbauer says the sample moves at several thousand increments through 360 degrees with an x-ray projection collected at each increment, which the powerful software system then uses to interpolate a three-dimensional volume image of the sample. A huge benefit of this technique is the ability to examine each individual slice, at any orientation, through the reconstructed volume image. Researchers are currently examining a wide range of materials, from the volume of seeds to determine how drought might have impacted their development, to the serrated edges and wear marks on the tooth of a Tyrannosaurus rex, to the jaw musculature of various reptiles and birds.
External (surface) rendering of a small T. rex tooth
Drumming Up Business
Schiffbauer says his new lab is part of MU Core Facilities, so it is accessible to researchers across campus and around the globe. Researchers on campus will be charged an internal rate, and there are external academic and external business rates as well. He already has received samples to examine from places like Siberia, Canada, and China, but he’s trying to get the word out on campus that his lab is open for business.
“We hope it will be used by everybody—CAFNR, engineering, the Bond Life Sciences Center, the School of Medicine” he says. “We need business; we’d love to have the x-ray scanner going 24 hours a day, and we’re happy to talk about your projects to see what we can do for you. You can reach us at email@example.com”
Editor's note: On April 16, University of Missouri System President Mun Choi awarded Schiffbauer the President’s Early Career Award for Faculty Excellence. Read more here: Asst. Prof. Jim Schiffbauer Wins President’s Award for Early Career Excellence.