The micro-world echoes the human-scale world in strange ways. In a microscope image, purple orbs cluster at the end of a stem like ripe grapes. Yet this "fruit" is actually a tiny fungus. Three of the orbs stacked side-by-side would fit inside the diameter of a human hair. Another image looks like it depicts the blue grottos, crevasses and columns of an underwater cave, but actually shows the structures inside a tiny crack through a tungsten-copper alloy.

Both are part of a traveling exhibition showcasing the art that arises out of scientific research at the Department of Energy's Pacific Northwest National Laboratory, in Richland, Washington. The dozen images in the exhibit represent work on nuclear energy, carbon sequestration, battery development, fisheries biology and more.

"I always really like science as art because it lets you show something in a way that is more universally relatable," says Nicole Overman, a materials engineer who captured the tungsten-copper alloy's close-up. "You don't have to have a technical background to be interested."

The power of an image to make a viewer lean closer and wonder is well recognized at the lab. Since 2010, research groups from all over the PNNL have selected, colored and submitted images related to their work to an annual "Science as Art" contest. The tradition began as an effort to update older photos of buildings and scientists in lab coats used for display around campus with something more interesting, explains John LaFemina, the lab’s director of planning and performance.

After that first contest, "we had all these images that were too interesting and too beautiful to hide in a drawer somewhere," LaFemina says. Now, every year he gathers a group of people to pour over approximately 100 to 150 submissions and choose a few that represent the lab's many facilities, projects and sponsors. (The DOE provides most of the lab's funding, but other federal agencies such as the National Institutes of Health and the Department of Defense also contribute.)

"But ultimately, they have got to be beautiful images," LaFemina says.

The winning dozen take their places in an annual calendar the lab offers in print and digital. Every few years, some of the best of the best join a traveling exhibition. This year's exhibition of 12 large-scale (36-by-48-inch) prints are currently hanging in the Washington State Legislative Building in Olympia. Next, they will visit the Pacific Science Center in Seattle.

1 of 12 Copper In the Gap Holding Strong The challenge is to make tungsten—a tough metal—even tougher, for heavy-duty applications. Researchers at PNNL have been exploring the question, trying to gain a better understanding of the properties that emerge when tungsten is united with copper in a model composite. In the image, which reflects this union of metals, the small connecting object is copper, between two sections of tungsten. Researchers believe that in tungsten-copper composites, copper takes on the role of helping to hold tungsten together, reduce cracking, and subsequently make the composite material tougher. PNNL’s research has been funded by the U.S. Department of Energy’s Office of Fusion Energy Sciences, which is advancing research in support of international efforts to develop fusion reactors for production of clean energy. 1 of 12

"I want [viewers] to be a little awed and a little inspired. The images should evoke an emotional response, the way great art does," LaFemina says. "But then when they read the captions, they also appreciate that these are stunning scientific images that represent work on important national problems."

Overman's blue, cave-like image comes from a project to engineer tougher, more resilient materials that could be used in nuclear fusion reactors. Such reactors are still very much in the development stage but experts hope they could provide abundant, sustainable energy. Tungsten's high melting point makes it a great candidate for containing fusion reactors' fuel—super-hot plasma like that found inside stars.

However, tungsten is also very brittle. "If it were to fail, it would fail catastrophically all over and all at once," Overman says. To understand how that happens, the team uses a scanning electron microscope that can peer down to the micro- and even nano-scale. "It's kind of like forensics on a really small scale," she says. She looks for clues as to where the failure started and where the cracks through the material go. "Once you know how it is cracking, you can figure out how to divert it or slow it down and give people more time in a real-world situation."

By adding flexible copper to the tungsten, the research group is trying to create an alloy that holds together better. The copper acts as tiny bridges: In her image, the pillar in the center is one of those bridges.

Scanning electron microscopy (SEM) is the technology behind many of the images in the lab's calendars and exhibits. Instead of bouncing light off a sample, the way light microscopes do, a scanning electron microscope focuses a beam of electrons on the surface to reveal the topography and the composition of a sample.

Bruce Arey, an analytical electron microscopist, is an expert on SEM. Now, he does research on national security issues at the lab, but prior to that he spent a dozen years working at the Environmental Molecular Sciences Laboratory, a PNNL facility that offers its experts and instruments to help researchers around the world. "We get involved in everything from material science issues to biological sciences where we see bacteria and fungi to geological sciences," he says. "We take a lot of images."

Most images are to understand the science, but occasionally Arey would see something striking. He'd take the time to reorient the sample and snap a more "spectacular image," he explains. The grape-like fungi was one such image, but another step was needed to enhance its viniferous qualities.

SEM images are only in grayscale, so for the covers of scientific journals and for art exhibits, researchers like to add some color. Arey chose the purple to make the grape resemblance more obvious and intriguing. "Just adding a little color can help people understand what they are looking at or attract them to read the captions" he says. While the fungi isn’t purple in real life, some of Arey’s color choices do reflect reality. The orange in an image he captured of a mineral that may be created during carbon storage would be orange if one could see it. However the purple-blue he added to the same shot was from his imagination.

"This [colorization] is the art part," says Alice Dohnalkova, who uses electron microscopy in her work investigating soil bacteria, fungi and their symbiotic relationships with plant roots. Investigating how the microbes make minerals and other nutrients available to the plants and how this changes depending on weathering and soil chemistry can provide insights for agricultural productivity and even how the planet's soil may respond to climate change.

Some bacteria are easy to color because they contain chlorophyll, making them green. But most bacteria she works with are more of a beige color. "Then, it is up to you to choose. My aesthetic is not primary colors—more like nicely coordinated shades of earth tones. But there is no rule."

Even Dohnalkova strays from her own stated preference. One of the images she colored shows a tiny soil bacterium suspended in a diamond-shaped space between plant roots. The golden-colored roots are earthy, but the bacterium itself is a purple-violet.

She laughs when asked about it.

"Scientists love beautiful things as much as people in other professions," she says.

The “Science as Art” exhibit is at the Washington State Legislative Building in Olympia until March 3. From March 6 to April 8 it will be at Seattle’s Pacific Science Center. Images from this and previous years’ calendars can be perused on the Pacific Northwest National Laboratory’s Flickr page.