MAE Seminar (ZOOM): Mechanically Coupled Properties in Two-dimensional Van der Waals Materials

Abstract: Many mechanical deformations, such as buckling, crumpling, wrinkling, collapsing and delamination, are usually considered as threats to mechanical integrity and are avoided or reduced in the traditional design of materials and structures. My work goes against these conventions by tailoring such mechanical instabilities to create new functional morphologies. We use ultralow bending stiffness and semiconducting properties of atomically thin van der Waals (vdW) materials to enable emerging mechanically coupled properties and device-level multi-functionalities that extend beyond those of bulk material systems.

In this talk, I will present our research on controlled deformation and interfacial control of two-dimensional (2D) vdW materials, and the new and reconfigurable materials' properties exhibited in such deformed and heterogeneously layered materials. First, I will introduce controlled mechanical deformation of 2D materials, and the wide range of new properties engendered by these deformed materials, such as strain-induced exciton transport. Furthermore, I will present our work on interfacial control using vdW materials to modulate fracture modes of thinfilms to enable a new phenomenon of electrical ductility. These mechanical instability induced modulations of materials at the atomic level will open the door to new phases of matter with unconventional and reconfigurable properties for applications in next-generation deformable electronics and quantum devices.

Bio: SungWoo Nam is an associate professor and Anderson Faculty Scholar in the Department of Mechanical Science and Engineering at University of Illinois at Urbana-Champaign (UIUC). He received a bachelor's degree in materials science and engineering from Seoul National University, where he graduated in first place from the College of Engineering. Following three years of industry experience in carbon nanotube synthesis/processing, he obtained his master's degree in physics (2007) and a doctorate in applied physics (2011) from Harvard University. After his doctorate, he worked as a postdoctoral research associate at UC Berkeley. Nam is the recipient of the Minerals, Metals and Materials Society Early Career Faculty Fellow Award, NSF CAREER Award, two DoD (AFOSR and ONR) Young Investigator Program Awards, NASA Early Career Faculty Award, UIUC Center for Advanced Study Fellowship, UIUC Campus Distinguished Promotion Award, UIUC Engineering Dean's Award for Excellence in Research, UIUC Engineering Rose Award for Teaching Excellence, and UIUC Engineering Council Award for Excellence in Advising.