To unveil the physical properties of functional materials, it requires a detailed understanding of materials from the electronic structural level (the orbital) to microstructural level (grain growth). Choi’s lab utilizes TEM and STEM techniques to visualize the materials with atomic level precision. His researches focus on the application of aberration-corrected STEM with emphasis on the unprecedented atomic scale imaging techniques aimed at unraveling and understanding the various material property-dependent properties and their performances.