CLARKSVILLE, TN – When Dr. Amanda Stadermann loads a meteorite sample into the Department of Earth and Environmental Science’s new scanning electron microscope (SEM), the ancient rock reveals secrets that have been locked away for billions of years.
The desktop-sized instrument significantly advances research capabilities for Austin Peay State University’s College of STEM, offering students publication-quality imaging and analysis previously accessible only at major research institutions.
From Light to Electrons: A New Way of Seeing
Traditional light microscopy requires a sample to be sliced thin enough for light to pass through and has limits on the size of features that can be observed. The SEM takes a different approach entirely.
“Instead of using a beam of light, you’re using a beam of electrons to look at a sample,” said Stadermann, an assistant professor in the Department of Earth and Environmental Sciences. “Because of the way atoms are structured, with a nucleus and electrons around it, using a beam of electrons allows us to see things that are much smaller.”
The technology reveals not just what samples look like, but their actual chemical composition. When the electron beam strikes the sample surface, it generates unique X-rays for each element present—creating what Stadermann calls “the real power of this instrument.”
“Every single ray that you get is specific to the element that it came from,” she said. “Students can poke around at different areas and see these different peaks shift in heights or see different elements, and that tells us about how the rock formed.”
Meteorites Meet the Classroom
Stadermann’s research focuses on meteorites—samples that provide direct evidence of processes elsewhere in the solar system. Her specimens come from meteorite dealers working with nomadic peoples in the Sahara Desert, where the continuous landscape makes space rocks easy to spot against the sand.
Many of her samples were donated specifically for educational purposes, allowing undergraduates to examine materials that traveled millions of miles to reach Earth.
“This lets our students look at these meteorites and understand not just rocks on Earth, but rocks from space, which I think is very exciting,” she said.
Before joining the faculty at Austin Peay, Stadermann worked with some of the most precious geological samples on Earth: Apollo mission rocks brought back from the moon in the 1960s and ‘70s. Her postdoctoral work at NASA’s Johnson Space Center in Houston involved characterizing these irreplaceable specimens housed in facilities similar to the lunar sample repositories.
Accessibility Across Disciplines
While large floor-model SEMs exist at major universities, they are often difficult to maintain and intimidating for beginners. Austin Peay’s tabletop model changes that dynamic entirely.
“I think having something like this accessible and on campus is going to be great not just for myself and Dr. [Daniel] Frederick, but for faculty across the college who maybe have an interest but aren’t necessarily sure how to apply it to their own research,” Stadermann said.
Early demonstrations proved the instrument’s versatility to other CoSTEM faculty. Dr. Stefan Woltmann from field biology examined feather structure and spacing measurements. Physics professor Dr. Eugene Donev tested the instrument’s limits with his own samples. Agriculture professor Dr. Niranga Wickramarathne looked at soil particles, microfossils, and other specimens that revealed new details under electron microscopy.