Callie Zheng, a junior in chemical and biological engineering, won first prize in the 2023 APS poster session on polymer physics, a competition usually won by graduate students. Photo by Shawn Maguire
Callie Zheng didn’t take long to make an impact in polymer science. Her first research project kicked off last summer, as a rising junior, working with her adviser Emily Davidson on chemically recyclable materials. Nine months later, at the March meeting of the American Physical Society, she presented findings from her second project — on solid-state refrigeration materials — and won first prize in the Division of Polymer Physics’ poster competition.
Zheng was one of 129 presenters in the category. Most of the others were graduate students, including the two runners up.
“I normally wouldn’t send an undergraduate [to this competition], especially someone who hadn’t worked in my lab for very long,” said Davidson, assistant professor of chemical and biological engineering. “But Callie had just done so much work in such a short time. And the depth of her thought — she was absolutely working at a grad student caliber in terms of how she approached her work and communicated about it.”
Zheng worked on chemically recyclable polymers over the summer between her sophomore and junior years. She then worked on materials for solid-state refrigeration for independent work during the fall 2022 semester. Photo by Sameer A. Khan/Fotobuddy
The project involved studying liquid crystalline elastomers (LCEs), a promising class of materials for a wide range of applications from soft robotics and artificial muscles to environmentally sustainable replacements for vapor-based cooling systems. LCEs combine long strands of polymers into crosslinked networks, like a 3D structure made of al dente spaghetti. Where the strands meet, a small helper molecule joins the ends together. Davidson and Zheng wanted to understand what happens when the ratio of strands to joints changes. In the end, they found a way to optimize these material systems based on desired outcomes. They plan to build on the findings and submit a paper on the subject later this year.
This research became the centerpiece of Zheng’s junior independent work last fall, as she worked closely with Clement Chan, a postdoc in Davidson’s group who guided the project. Earlier work from a senior thesis had helped define the project’s goals and techniques.
Zheng also works with Sujit Datta, assistant professor of chemical and biological engineering, on a project that is collaborating with Davidson’s group. She plays a key role in the Princeton Mentoring Program, designed to assist first-year students of color in their academic, cultural, and social acclimation to Princeton, and is mentoring two first-year students this year. She also serves multiple roles with theater organizations on campus, and works as the front of house manager at the Lewis Center for the Arts.
