Woonbong Hwang, Ph.D.
Professor, Department of Mechanical Engineering
Pohang University of Science and Engineering
whwang@postech.ac.kr
Biography:
Woonbong Hwang received the B.S. degree in precision mechanical engineering from Hanyang University, Seoul, Korea in 1982 and the M.S. and Ph. D. degrees in mechanical engineering from SUNY at Buffalo, Buffalo, NY in 1985 and 1988, respectively. In 1988, he joined the Department of Mechanical Engineering at Pohang University of Science and Technology (POSTECH), Korea where he is currently a full professor and head of the department. He also leads the NSCS Research Group. In 2012 he was invited by Chinese Government as an expert of ‘1000 Plan’ and is director of Micro-Nano Technology Laboratory at China Academy of machinery Science and Technology (CAM), China. From 2000 to 2001, he was a Visiting Scholar at the Digital Appliance Research Lab. in LG Electronics Inc. From 2009 to 2010, he was a Visiting Professor at the Mechanical Engineering Department of Drexel University, USA. Since 2002, he has helped academic programs in creative engineering including axiomatic design and TRIZ. He has published more than 200 papers in internationally renowned journals and conference proceedings. His research interests include composite materials, RF-integrated mechanical structures and nanomechanics.
Topic title： Recent Advances in Nanoengineered Functional Structures
Abstract：Wettability control has been a very interesting concept because of its various practical applications such as self-cleaning, anti-frosting, and antifouling. Special surfaces inspired from lotus leaves, desert beetles, and other living things show very high contact angle (larger than 150 degree) and very low slide angle (less than 10 degree), or nearly zero contact angle. People called them superhydrophilic surface and superhydrophobic surface respectively and have developed many fabrication methods in their researches.
We have developed various fabrication processes for superhydrophilic and superhydrophobic surfaces, and now we expand and evolve them for more various, industrially compatible applications. We already developed fabrication methods for superhydrophilic and superhydrophobic surface applying nanohoneycomb, nanofiber, and nanoflake structures. Then, we tested characteristics of superhydrophobic surface; self-cleaning, drag reduction, and anti-biofouling effect. Moreover, these various characteristics have been applied to other materials: copper, titanium, stainless steel, and polymer.
Superhydrophilic or superhydrophobic filter can be used as a liquid selective gate. When superhydrophilic filter is covered by water, the filter can allow only water to penetrate and vice versa. While selectively filtering water or oil from mixture has been a problem for a long period of time, we have been recently discovering the possibility of effective oil/water separation through superhydrophilic/superhydrophobic filters. Furthermore, we have developed various systems for continuous and high speed oil/water separation. Since our surface treatment technologies are based on cost-effectiveness, simple and short time process, the success of oil/water separation would have a huge potential of industrialization. On the other hand, the filter with selective liquid repellency enabled multiphase liquid separation and implied the possibility of multiphase liquid separation system. Besides, this unconstrained control in wide wettability range and diversification of materials have been investigated to apply the special surfaces to various fields such as heat exchanger and energy harvesting using nanogenerator.
