기계공학부 구성원들의 많은 관심과 참여 부탁드립니다.

▣ 주   제: Nanoscale Insights into Bone Mineralization and Battery Materials: Unveiling Multi-Physical Characteristics through Advanced Atomic Force Microscop

▣ 연   사: 조한나 교수

▣ 소   속: Ohio State University

▣ 일   시: 2023. 11. 10.(Fri) 10:30

▣ 장   소: 제4공학관 D503호

▣ 초   청: 조형희 교수

▣ 초   록

Since its development in the early 1980s, atomic force microscopy (AFM) has emerged as an invaluable tool in the field of nano- and bio-science, offering nanometer-scale imaging and characterization capabilities in various environmental conditions. Leveraging our understanding of cantilever dynamics, our research group has made significant advancements in AFM technology, including the development of a novel cantilever system for enhanced material property analysis and the refinement of advanced techniques for multiphysical property quantification, such as piezoelectricity. These advancements have been instrumental in driving our material characterization endeavors across the domains of energy, bio, and environment.

This seminar will showcase our research group's work in AFM, with a specific focus on two compelling areas: bone mechanics and battery electrode materials. In the realm of bone research, we explore the intricate role of collagen piezoelectricity in modulating bone stiffness. Through the utilization of Piezoresponse Force Microscopy (PFM), we delve into the piezoelectric properties of collagen fibrils, unraveling their inherent heterogeneity and periodicity. This discovery unravels the underlying mechanism of mineralization and its intricate correlation with local piezoelectric responses, providing insights into the intrafibrillar mineralization process and its direct influence on bone stiffness modulation.

In the realm of battery electrode materials, we delve into the electro-chemo-mechanical (E-C-M) behavior of Si-based electrodes in high-energy Li-ion batteries. Through the development of in-situ AFM, we uncover the unique mechanical phenomena associated with charging and discharging cycles, including initial pulverization, irreversible volume expansion, and crack generation. These findings guide the optimization of operating conditions to mitigate mechanical failure and enhance the performance of Si-anode Li-ion batteries.