Special HEMI Seminar: In-Suk Choi (Seoul National University)

Formability Beyond Materiality
In-Suk Choi
Associate Professor
Department of Materials Science and Engineering, Seoul National University

How can we overcome the formability of materials beyond original materiality ? This talk will present two unique strategies from our group that can dramatically enhance the conventional limit of material formability.

In the first part of this talk, we will utilize “electron-beam irradiation” to make brittle nanomaterials mechanically formable. When electrons are injected into materials, electronic kinetic energy is transferred to the materials by electron scattering, which can break or recombine atomic bonds in the materials and generate secondary electrons in the materials. Here, guided by Monte Carlo simulations, we systematically modulate the electron-beam (e-beam) energy at which electrons can adequately interact with nanomaterials resulting in superior formability of amorphous silica.

In the second part, we introduced “simple geometric design concepts” that significantly enhance flexibility and stretchability of brittle structural materials. Geometrical design such as origami and kirigami provides us many examples of the formation of delicate and, detailed patterns leading to the effective distribution of stresses. Instead of process control and complex structure design, the simple juxtaposition of unit design can lead to simple, cheap and easily processed flexible, stretchable and deployable structures. In addition, newly developed computational approach expands our design dimension to the next level. We believe that geometrical modulation by controlled size, shape, and symmetry adds another dimension unleashing the limitation of conventional design space of structure materials.

Dr. Choi is an associate professor in the department of materials science and engineering at Seoul National University. He earned his BS degree from Seoul National University, MS degree from Stanford University and Ph.D. degree from MIT in Materials Science and Engineering. He conducted his postdoctoral research at Karlsruhe Institute of Technology in Germany and then worked as a principal research scientist at Korea Institute of Science and Technology (KIST) before joining the Seoul National University. He is currently serving as editorial board members in several domestic and international journals. At present, his work focuses on developing advanced structure materials for extreme condition.