Staff Directory

Young Jae is a undergraduate student planning to major in Mechanical Engineering at Columbia University. He is originally from Seoul, South Korea, and grew up in Los Angeles.  As a recipient of cochlear implant technology, Young Jae was able to witness the power of technology upon the living quality of deaf people. Ever since, he has fostered a passion for the engineering. While pursuing a Mechanical Engineering major, he aims to learn more about how technology can resolve hearing issues and improve the lives of deaf children. His hobbies includes running, visiting museums, and cooking! 

Wenbin is in his fourth year as a Ph.D. student. Before coming to Columbia University, he obtained his bachelor and master degree from Xi’an Jiaotong University, China.

Wenbin is currently working on characterizing the mechanical properties of round window membrane (RWM), which is a part of cochlea. The target is to fully understand the mechanical responses of RWM under loading and to build up a constitutive model to benefit future researches.

I am a PhD candidate in the Mechanical Engineering Department at Columbia University. Since joining the Small Scale Mechanics lab, I have been working on the fabrication and mechanical testing of graphene-metal composites. Over the years I have developed proficiency in Nanoindentation, Electron Microscopy (TEM,SEM EBSD), various material characterization techniques, CVD graphene Growth and 3D printing using Nanoscribe. Further details can be found on my LinkedIn. 

Richard is a Ph.D. candidate in the Small Scale Mechanics Lab. He received his M.S. degree in Civil Engineering and Engineering Mechanics from Columbia University and B.S.E. degree in Civil Engineering from Princeton University. Prior to entering graduate school, he was a Civil Engineer Corps (Seabee) officer in the U.S. Navy and also worked briefly as a structural engineer in New York City.

Since joining the lab, he has worked on two projects: developing graphene-based composite materials and developing growth-accommodating heart valves for pediatric patients.

His research interests include the mechanics and fabrication of graphene and of polymeric heart valve prostheses.

Jeffrey W. Kysar is a professor of mechanical engineering at Columbia University. His current research interests include understanding the fracture process from the atomic length scale to the macroscopic length scale, especially in materials that exhibit an elastic-plastic constitutive behavior such as ductile metals.

I am a final-year PhD student co-advised by Professors Jeffrey Kysar and James Hone. My research interests pertain to exploring the mechanics of materials of small scale systems through both experiments and computations. My PhD research has focused on the mechanical properties of two-dimensional materials. In particular, we are interested in understanding and measuring the mechanical properties of grain boundaries in polycrystalline graphene synthesized via Chemical Vapor Deposition (CVD). My research can be broken into three interrelated projects: (1) the optimization of graphene synthesis through CVD , (2) the measurement of the critical failure load of suspended circular graphene membranes through nanoindentation, and (3) the construction of a multiscale model to analyze and predict the failure modes of polycrystalline graphene, as well as the statistics of failure. 

We designed and constructed an Ultra-High Purity (UHP) automated CVD system in order to minimize uncertainty and oxidizing impurities. This yields (1) repeatability, (2) well-stitched grain boundaries, and (3) the ability to grow graphene at lower temperatures. Combined with electropolishing, we produce very flat, clean, and mechanically robust large-area monolayer polycrystalline graphene films. The monolayer films are in turn transferred through electrochemical delamination to a holey silicon nitride substrate for mechanical testing. Lastly, we subject the suspended circular membranes to a near-point load through nanoindentation and measure the statistical distribution of the mechanical stiffness, the pre-stress, and the critical failure load based on the local distribution of grain boundaries. 

In parallel, we constructed a multiscale model using the Finite Element Method (FEM) to explore the failure modes of polycrystalline graphene within the context of the nanoindentation experiments. We model the grain boundary with a Cohesive Zone Model (CZM) whose properties are determined from Molecular Dynamics (MD) simulations. To connect to experiments, we formulated a Probability Density Function (PDF) that is informed by the multiscale model to provide a statistical distribution of the breaking load based on an idealized two-dimensional grain structure. This PDF provides the means to (1) experimentally validate our CZM properties of the grain boundary and (2) perform an inverse analysis to back-out the grain boundary strength from experimental data. 

Chaoqun is currently a master student in Kysar lab, working on pyrolysis of 3D printed micro-needles for inner-ear drug delivery. She received her Bachelor degree in Mechanical Engineering in 2018 from University of Illinois at Urbana-Champaign.

Her research interests include micro/nano fabrication, medical devices and Microelectromechanical systems.

Aykut is a Mechanical Engineering Ph.D. student in the Small Scale Mechanics Laboratory. He is interested in solving problems in the body using microengineering. He received his M.S. in Mechanical Engineering from Columbia University in 2016.

Aykut's research lies on the intersection of Mechanical Engineering, Chemical Engineering and Medicine. He is currently working to invent and make precision microneedles to better diagnose and treat inner ear disorders. He is co-advised by Prof. Jeffrey Kysar, Prof. Alan West and Dr. Anil Lalwani.