MAE 298 Seminar: Microscopic Thermal-Fluids Measurements for Next-generation Energy Systems and Manufacturing

Abstract: Effective management of heat has become a critical challenge in many energy, water and advanced manufacturing systems. In this talk, I will discuss microscopic measurement and manipulation tools to provide new insight into phase-change heat transfer, and thermal effects in lithium-based batteries and metal additive manufacturing. I will first discuss the dynamic manipulation of multi-phase fluid systems using photo-sensitive surfactants, which switch their molecular conformation upon irradiation of light. By tuning the interfacial tension using these surfactants, we demonstrate programmable bubble departure and droplet movement on solid and liquid-infused surfaces. I will then discuss the application of microscopic thermal engineering and measurements for efficient solar thermal desalination, and to understand temperature’s effect on lithium-ion batteries and metal additive manufacturing. For batteries, we show that temperature heterogeneity can cause Li leaching due to the shift of the equilibrium potential due to a temperature change. At extremely low temperatures, Li salt can redistribute during a freeze-thaw cycle in a non-eutectic electrolyte system which may negatively impact the subsequent battery performance. These examples demonstrate the potential of combining fundamental thermo-fluid science and advanced micro/nano engineering approaches to address many of the pressing thermal challenges in next-generation energy and manufacturing systems.  

Bio: Yangying Zhu is an assistant professor in the Mechanical Engineering department at UC Santa Barbara. Her work focuses on fundamental understanding of the thermofluids process for energy and water sustainability and advanced manufacturing. She obtained her Ph.D. from MIT, advised by Professor Evelyn Wang, where she developed microsystems for aggressive cooling of electronics. During her postdoc with Professor Yi Cui at Stanford University, she investigated thermal effects in lithium-based batteries. She received early career awards from NSF, NASA and ONR and the ASME Pi Tau Sigma Gold Medal.