Looking Beyond the Surface
Some engineering problems are easy to see. Others remain hidden deep within rocket engines, medical devices, and components so small that conventional tools cannot physically reach them. Those invisible challenges are exactly what fascinates Hitomi Yamaguchi Greenslet, Ph.D.
“If I ask you to put your finger inside a hypodermic needle, you can’t because the needle is so tiny,” she explained. “But I can use a magnetic field to manipulate the tool to guide through the needle or even complex geometry.”
For decades, Greenslet has built her career around solving manufacturing challenges that exist beyond the reach of conventional processes. Her research in advanced manufacturing and precision surface engineering uses magnetic fields to guide miniature finishing tools through narrow channels and hidden spaces inaccessible to traditional machining techniques. The result is technology capable of refining internal surfaces in components once considered impossible to finish. By reaching areas that conventional tools cannot access, her work is helping engineers rethink what is possible in manufacturing while improving the quality, performance, and longevity of some of the world’s most advanced technologies.
Finding Harmony in Engineering
Yet engineering was not always the future she envisioned. Growing up in Japan, Greenslet spent much of her childhood studying classical piano and fully expected that music would become her career. Hours of practice taught her discipline, patience, and attention to detail long before she ever stepped into an engineering laboratory.
Instead, a love of mathematics and an interest in emerging technologies gradually pulled her in another direction. She discovered that engineering offered a similar blend of creativity and precision that had drawn her to music, while also giving her the opportunity to solve real-world problems with lasting impact.
Manufacturing From the Inside Out
Today, Greenslet’s research spans applications in aerospace, biomedical engineering, and advanced manufacturing, where improving a surface by only a few microns can make a significant difference in performance. While being nearly invisible to the naked eye, these enhancements have a profound effect on the safety, efficiency, and reliability of critical components.
In medical devices such as needles and implants, smoother internal surfaces can reduce contamination and limit the buildup of bacteria, helping improve patient safety. In aerospace applications, her work focuses on improving the finish of internal cooling channels used in rocket engines, allowing coolant to move more efficiently through systems exposed to extreme temperatures.
As additive manufacturing continues to revolutionize engineering design, engineers are able to create increasingly intricate components with internal passages and geometries that simply cannot be reached using conventional polishing methods. Finishing those hidden surfaces remains one of the field’s greatest challenges. Greenslet’s research seeks to bridge that gap by creating methods to improve these inaccessible surfaces after they have been manufactured, ensuring that the performance of a component matches the promise of its design.
“NASA has this technology, but it is difficult to polish inside,” she said. “So, we are doing some of that.”
A Place to Build and Discover
That focus on solving real-world problems is, in part, what drew Greenslet to the University of Florida’s Department of Mechanical and Aerospace Engineering. She found a community that shares her belief that engineering advances come not only from ideas, but from building, testing, and refining them. Working alongside colleagues across a range of disciplines has allowed her to pursue collaborative research while helping students gain experience tackling complex challenges.
“There is a culture here,” she said. “We really feel hands-on work is important, not just textbooks and lectures.”
Supporting Every Student’s Journey
Beyond research, Greenslet has dedicated herself to mentoring students and helping shape the next generation of engineers. When asked what is most important in her laboratory, her answer had little to do with equipment, funding, or technology. “Meeting my students,” she said immediately.
For Greenslet, mentorship begins with connection. She believes the most effective mentoring happens through regular interactions, where small conversations can reveal challenges that might never appear in a progress report. Her goal is for every student who walks into her laboratory to feel supported, not only as a researcher, but as a person. Whether discussing an experiment, celebrating a breakthrough, or navigating a difficult semester, she sees helping students grow as one of the most meaningful parts of her career.
Strengthening the MAE Community
Her mentorship commitment now extends well beyond her own research group and into her role as Associate Chair for Faculty and Staff Development, where she hopes to strengthen collaboration, mentorship, and community throughout the department. She sees the position as an opportunity to help create an environment where faculty, staff, and students feel connected, valued, and supported as they work toward common goals.
“I want to improve our department’s culture, I want staff, students, and faculty to feel at least we are working together.” – Hitomi Greenslet, Ph.D.
Somewhere between a piano bench in Japan and a manufacturing laboratory in Florida, Greenslet discovered that the skills she developed as a musician– discipline, precision, patience, and creativity– had never disappeared; they had simply found a new instrument.