Research on ‘Active’ Fluids Led by Undergraduates Yen-Chen Chen and Brock Jolicoeur is Published in Scientific Reports



Two undergraduate students working with Kun-Ta Wu, assistant professor in the Department of Physics, are the lead authors of a new report on how “active” fluids develop circulatory flows within a millimeter–scale droplet.

Yen-Chen Chen ‘22 and Brock Jolicoeur ’23 designed active fluid droplet experiments and investigated fluid dynamics of active fluid droplet systems, which included the development of a COMSOL-based active fluid simulation platform and two novel microfluidic devices (Device 1, Device 2). The article “Flow coupling between active and passive fluids across water–oil interfaces” was published on July 7, 2021, in Scientific Reports.

Active fluids are soft materials containing molecules, cells, or other components that consume fuel, such as adenosine triphosphate, to spontaneously generate chaotic mixing flows without external intervention. Greater control and understanding of active fluids could have implications for the miniaturization of industrial micro-mixing processes. Wu’s group researches the mixing and vorticity dynamics of active fluids and their potential applications in boosting mixing efficiency in conventional microfluidic mixing devices. (NSF-CBET-2045621)

“This was a phenomenal achievement by Yen-Chen and Brock. First, from the perspective of intellectual merit, it demonstrates how a fluid spontaneously mixes within a millimeter-scale droplet,” said Wu, who supervised the research. “Mixing is ubiquitous in everyday life, like blending dough for a birthday cake, but mixing fluids in millimeter scale remains a challenging task. Second, this work was accomplished by two undergraduate students with no background in soft matter and biophysics. Yen-Chen also demonstrated outstanding perseverance: when most campus operations closed in early 2020 because of the pandemic, Yen-Chen went home to Taiwan and connected with Dr. Chih-Che Chueh of National Cheng-Kung University, who advised him to develop a simulation platform to model his active droplet system. The model was not only consistent with the experimental observation, it also provided deeper insight into the fluid dynamics of active droplet systems.”

Chen is pursuing a BS/MS degree in the Department of Mechanical Engineering and Jolicoeur is pursuing a bachelor’s degree in the Department of Physics. Both students presented their research at the March Meeting of the American Physical Society (Video 1 [B05.00008], Video 2 [F06.00003]).