Unveiling Multi-Physical Characteristics through Advanced Atomic Force Microscopy: Nanoscale Insights into Bone Mineralization and Battery Materials

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. 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.

Dr. Hanna Cho is an Associate Professor in the Department of Mechanical and Aerospace Engineering at The Ohio State University. Dr. Cho earned her BS and MS degrees in Mechanical Engineering from Yonsei University, South Korea in 2002 and 2004, and a PhD at the University of Illinois at Urbana-Champaign (UIUC) in 2012. Dr. Cho's Micro/Nano Multiphysical Dynamics Lab explores nonlinear dynamics in micro/nanomechanical systems for MEMS, with applications in sensing, imaging, and energy harvesting. The lab also delves into the exploration of multi-physical dynamics that emerge in atomic force microscopy (AFM), with the aim of pushing the boundaries of AFM technology. Furthermore, her research extends to the application of microsystems and AFM in various material research areas, particularly in the fields of bio (bone mechanics) and energy (Li-ion batteries). She has received the Young Faculty Award and Director’s Fellowship from the Defense Advanced Research Project Agency (DARPA), along with the American Society of Mechanical Engineers (ASME) C.D. Mote Jr. Early Career Award, the OSU COE Lumley Research Award, and the Emerging Leader Award 2023 from Journal of Micromechanics and Microengineering. In 2023, Hanna Cho was elected as a fellow of the ASME. Currently, she serves as an associate editor for the ASME Journal of Computational and Nonlinear Dynamics and as a subject editor for Nonlinear Dynamics.