Hyun-Joong Chung, PhD
Department of Chemical and Materials Engineering
University of Alberta
Hard / Soft Material Integration for Microstructured Coatings and Bioelectronics
Integrating materials with complimentary properties have been creating new opportunities for structural and functional materials towards unprecedented applications. For example, one can enjoy the sturdy performance of inorganic devices with the mechanical flexibility of polymeric materials by the smart blending of micro- or nano-sized hard material components in soft material matrix. This talk describes how materials science is employed to solve fundamental and practical problems (i) in the morphology control and the film stabilization of multi-component polymeric coatings and (ii) in the intimate integration of the state-of-art inorganic devices onto living organs in biomedical research. In the first part of this talk, underlying mechanisms of morphological evolution in polymer blend films are elucidated by understanding the interplay of phase separation, wetting, and dewetting. In particular, jamming of the nanoparticles at the interface between immiscible phases produces a stable bicontinuous morphology and prevents film rupture. In the second part of this talk, it is shown that smart hard/soft material integration materializes devices with the performance of conventional wafer-based systems, but with the mechanics that is compatible with soft, wrinkled, and moving biological systems. As specific examples, I will demonstrate fully-formed silicon electronic devices that can be fabricated onto nearly any surface and skin-like biochemical sensors that can wrap on the surface of a fully functioning heart. It will be emphasized that fundamental understanding of broad aspects of science, ranging from properties of materials, to mechanics of materials and integrated systems, to device physics, and to chemistry that governs microfabrication process and physiological sensing, is indeed the key for successful device integration.
Dr. Chung received B.S. from Korea Advanced Institute of Science and Technology (KAIST) in 2000 and Ph.D. from the University of Pennsylvania in 2005 under the guidance of Prof. Russell J. Composto. His thesis is about phase separation and wetting/dewetting of polymer blend coatings and on the effect of nanoparticles. Following his graduation, he worked at Samsung Mobile Display in Korea as a senior engineer. He contributed in developing prototype large-area OLED TVs, while he developed expertise in thin film transistors from ZnO-based oxide semiconductors. From 2009 to 2012, he performed researches on unconventional chemical biosensors and silicon electronics under the mentorship of Prof. John A. Rogers at the University of Illinois at Urbana-Champaign. Since January 2013, he has been an assistant professor at the University of Alberta. The current research interests are (i) hard/soft integrated materials for biomedical and industrial applications, (ii) sciences at the interface between hard and soft materials, and (iii) biomedical electronics with novel materials and fabrication strategies.
Invited by Professor Karim Karim