Exploring the Science of Ice
With all her accomplishments, you might think that Kristen Scotti’s career in science has spanned a decade. But it’s only since the 36-year-old decided to go back to school for a bachelor’s degree that her extraordinary talents have flourished.
The gifted young scientist, who earned her degree in biology from SPS in June 2017, was named regional winner in the 2016 Undergraduate Awards—known as the junior Nobel Prize. Her paper on microgravity freeze casting was chosen as the highest-performing paper in the United States and Canada in the mathematics and physics category.
“She is my best undergraduate student in my 30 years working with students at MIT and Northwestern,” says Scotti’s adviser, materials science and engineering professor David Dunand. “And I’ve had some very good ones.”
Slowly but surely
When family circumstances dictated that Scotti get a job after graduating from high school in 1999, college wasn’t part of the picture. “I wanted to go, but I had to support myself,” says Scotti, who worked a series of jobs, from circuit court clerk to paralegal to credit manager, earning promotions along the way.
But without a college degree, she was concerned about job security, so in 2011, Scotti started night classes at Harper College in Palatine, Illinois. She hadn’t planned to study science, but after enrolling in astronomy, she was hooked.
“I wasn’t exposed to science a whole lot growing up,” admits Scotti, who had taken a single science class—biology—at West Chicago Community High School. “I was pigeonholed because I was female and because I was an art student and played piano.”
After entering a NASA Community College Aerospace Scholars competition in 2012, she emerged as one of 50 winners and spent four days at the Marshall Space Flight Center in Huntsville, Alabama. Later that year, she was awarded a Jack Kent Cooke Scholarship that allowed her to transfer to a four-year university, all expenses paid.
Still, Scotti was reluctant to begin a new life as a full-time student. “Even though I had the scholarship, I wasn’t completely convinced I could quit my job and start over in a totally different field,” she says. “It was scary, plus it would be a huge pay cut. And I had a child”—her daughter is now 14—“so it was taking a risk.”
Scotti entered SPS in the fall of 2014 as a sophomore transfer student, focusing on chemistry and biology. Three nights a week and every Saturday, she drove 90 minutes from North Aurora to school; after six months, she moved to Evanston. “The more research I did, the more I realized I didn’t want to do science and school on the side,” she says. “I wanted to spend my time in the lab.” Scotti quit her job and continued at SPS, working in a lab during the day, while her daughter was at school, and taking classes at night.
Defying gravity
As an SPS undergraduate, Scotti had the opportunity to conduct freeze-casting experiments for three years on NASA’s zero-gravity flights based in Houston. A simple, low-cost method of creating novel porous materials, freeze casting has uses as diverse as new batteries, solar cells, advanced filters, and biomedical implants.
In freeze casting, solid particles are dispersed in water that, when frozen, rejects them because they are not soluble. Gradually, as the ice grows, the particles bond and ultimately become locked in an irreversible solid structure. Once the mold is dried and the ice melts, the solid structure is retained.
Because porous materials are less dense and thus lighter (which is why evolution gave us porous bones), freeze casting extends to applications where weight is important, such as transportation. The technology might even be used to create lightweight building materials for an eventual outpost on the moon or Mars.
NASA uses a modified Boeing 727 to fly parabolic routes at high altitudes, creating short periods of zero gravity that simulate the weightlessness of space. Scotti led three flight teams over four days, experiencing 40 parabolas a day with 25 seconds of weightlessness during each maneuver. She also collaborated with University of Illinois at Urbana-Champaign engineers to put a satellite into orbit to run freeze-casting experiments. “If we understand how gravity affects the process of freeze casting,” she explains, “then we can understand how to better control what we’re creating on Earth and in space.”
One of Scotti’s strengths as a scientist is her “amazing capacity to synthesize a wide range of knowledge into a whole that is easy to understand and grasp,” Dunand says. “She has put hundreds of articles on freeze casting into a searchable, interactive website that users can query to achieve an overall understanding of a field that before was quite scattered.”
Her hard work has paid off. Scotti is now continuing her studies at Northwestern, working toward a PhD in materials science and engineering at the McCormick School of Engineering and Applied Science.
—Anne Stein