Lim and Moy receive Rackham Predoctoral Fellowships

The fellowship supports doctoral candidates working on dissertations that are unusually creative, ambitious, and impactful.
Lim and Moy receive Rackham Predoctoral Fellowships

PhD candidates Ju Won Lim and Alex Moy

MSE is proud to announce that two Ph.D. candidates, Juwon Lim and Alexandra (Alex) Moy, are recipients of the Rackham Predoctoral Fellowship for 2023-24. The prestigious fellowship supports outstanding doctoral students working on dissertations that are unusually creative, ambitious, and impactful. The award includes a stipend, and covers tuition and required fees for twelve months.

A member of the Reddy group, Juwon Lim's research focuses on the manipulation and harvesting of thermal energy, which is playing an important role as the demand for non-carbon energy resources has increased. Recent experimental work has verified that the total radiative thermal transfer between two objects can exceed the black body limit when one or more dimensions of the objects are smaller than the dominant thermal wavelength, even in the far-field. He is developing a far-field thermal transistor consisting of two coplanar SiN nano-membranes combined with a phase transition material-coated modulator as a third body to manipulate the radiative thermal energy. By only adjusting the modulator (gate) temperature, we are able to modulate heat energy between the emitter (source) and the receiver (drain) by factors of three in the far field. In addition, the device performed an extremely rapid time-response within hundreds of milliseconds, the fastest response time of a thermal transistor to date to our best knowledge. The mechanism of thermal modulation due to the phase transition of the material is verified by numerical simulations.

"Our new design of the thermal transistor will pave the way for a wide range of applications, such as thermal management, energy harvesting, and related thermal energy industries," concluded Lim.

Addressing the pressing need for improved battery performance, Alex Moy's research with the Sakamoto group is focused on replacing state-of-the-art carbon-based anodes with Li metal. However, it is generally known that Li metal anodes cannot cycle with state-of-the-art liquid electrolytes. Owing to its high conductivity, Li metal stability, wide electrochemical window, and stiffness, lithium lanthanum zirconium oxide (LLZO) is considered a promising next generation solid-state electrolyte for Li metal batteries. However, its interfaces, especially internal and cathodic, are not well understood and, thus, is the basis of her dissertation research, specifically: the effects of doping on the microstructure, structure, and electrochemical behavior of LLZO, characterization of the cathode/LLZO interface, and characterization of the sulfide electrolyte (catholyte)/LLZO interface.

"My research will provide a greater understanding into these crucial but under-investigated areas of solid-state battery research, contributing to solid electrolyte and solid-state battery advancement," Moy stated.

Congratulations to both Juwon and Alex!