Seminar: Immobilized ZnO Nanowire Array for Photodegradation and Multifunctional Soft Micromotors

Photocatalytic degradation is a promising approach to removing organic contaminants in water. Despite numerous efforts, traditional nanoparticle-based photocatalysts are still in a research domain and need to overcome the major technical challenges including the limited light absorption, slow overall kinetics, and poor recyclability. Recently, multifunctional photocatalytic system attracts an increasing interest because the additional functionality may address the abovementioned issues. In this talk, I will present a novel photodegradation platform based on a vertically-aligned zinc oxide nanowire (ZnO NW) array on an ultrathin, transparent and flexible film. The ZnO NW array provides a high surface area for the photodegrading reactions, and since those NWs are immobilized on the surface, the propose platform significantly improves recyclability. We then utilize a strain engineering to fabricate pollutant-degrading, self-propelled, soft micromotors from the NW-loaded film. Locomotion of the soft micromotors and their photodegradability will be presented along with an approach to enhance the visible light harvesting. If time permits, I will present another project that my group recently got involved in, which is the development of a post-processing protocol to control the physical properties of the 3D printed metal parts. The majority of the metal 3D printing research has been focused on the improving the mechanical properties of the printed parts, but here I will introduce an interesting method to alter the part’s electrical and thermal properties over many orders of magnitude. Potential applications of the 3D-printed metal parts with the modified electrical property will be discussed with the outlook on the emerging areas of metal additive manufacturing.

About the Speaker

Dr. Junghoon Yeom is an assistant professor in the Department of Mechanical Engineering at Michigan State University. He received his B.S. in Mechanical Design and Production Engineering from Yonsei University, Seoul, Korea. He completed his Ph.D. in Mechanical Engineering at the University of Illinois, Urbana-Champaign in 2007. His dissertation was focused on designing, fabricating, and characterizing micro chemical systems including micro fuel cells and micro gas chromatography. Prior to joining in Michigan State University in fall 2013, he was a NRC research associate at US Naval Research Laboratory working on Si nanowire-based chemical sensors and solar cells. Dr. Yeom was a research scientist at Cbana Labs Inc. and served as a principle investigator for NASA lunar surface analysis project. He was also a visiting scholar affiliated with the nano-CEMMS center at UIUC to develop unconventional nanomanufacturing technologies. Yeom holds two patents and has co-authored one graduate-level textbook, Nanofluidics and microfluidics: systems and applications, two book chapters, 28 peer-viewed journal papers, and numerous conference proceeding papers and invited talks in the areas of MEMS, microfluidics, nanomaterials and nanopatterning.

Hosted by Professor Shaurya Prakash