For a place that takes pictures with what amounts to controlled bursts of lightning, the lab is quiet, almost hushed. Standing in the entrance to Oregon State University’s Electron Microscopy Facility (EMF), you might hear researchers’ soft voices as they discuss the best way to see pollen on a bee’s tongue or to look at a layer of molecules on a silicon wafer. You might be struck by the images on the walls and display screens — disc-shaped blood cells, elegant ocean plankton, flower-shaped nanocrystals.
The EMF is home to machines with names like Titan, Nova and Quanta, all built by FEI, a global scientific instrument company headquartered in Hillsboro, Oregon. In essence, this lab is the Hubble Telescope of the nanorealm. It reveals microorganisms associated with disease, biodiversity and pollination. It demonstrates human innovation at the molecular scale, the architecture of materials designed for industries that are just a gleam in a researcher’s eye.
The technology is a far cry from what you might have used in your high school biology lab. Researchers don’t peer at a sample through a microscope lens. They place it in a sealed chamber and sit at a computer. They direct the machine to shoot an electron beam at the sample through a tube that guides and focuses the beam with magnetic “lenses.” As the subatomic particles strike the sample, they knock other electrons off its surface. A detector captures these “secondary electrons,” and an image appears on a display screen in front of the scientist.
The EMF’s two staff members — Pete Eschbach, director, and Teresa Sawyer, instrument manager — assist scientists and train students to prepare their samples. Over the last four years, Eshbach says, the EMF has provided direct support for more than $100 million in Oregon State research projects. Its images and data underlie advances in solar energy, crop science, archaeology and human and animal health. Businesses use the facility to assure the quality of their products, and lawyers use it in disputes over pollution and patent rights.
Engineers bring in fiberglass strands, semiconductors layered with titanium-coated diatoms and piezoelectric materials, substances that change shape under the influence of an electric current. A researcher in OSU’s J.L. Fryer Salmon Disease Lab brings in a Willamette River carp that is covered in tumors, from skin to gills to throat. (The lab’s images identified the cause: an infectious parasite.)
The EMF’s two workhorses — the scanning electron microscope (SEM) and the transmission electron microscope (TEM) — differ in the power of their sample penetration. Both record the interaction of electrons with molecules, but the SEM looks at the surface, capturing images of shape and structure. The TEM dives deep for a look inside. Working with the TEM takes longer, says Eschbach, but can generate more information about composition and chemistry.
For Sawyer, the ability to generate an intimate view of materials and living things still inspires her. “It’s pretty amazing that you can get a picture with electrons,” she says. “When you hit something with electrons, they excite other electrons and you get an image. I think that’s absolutely cool.”
See examples of the images captured by Oregon State scientists.