Seong Kim
Assistant Professor of Chemical Engineering Seong Kim has made a big impact in the two years he has been at Penn State. He is principal investigator of a highly competitive NSF Nanoscale Interdisciplinary Research Team (NIRT) and he is Co-PI of a pending 5-year NSF Nanoscale Science and Engineering Center. In addition he has ongoing projects in conducting polymers and nanoscale tribology. The central theme of all his research is to apply the fundamental knowledge gained from traditional UHV surface science techniques to understand and manipulate engineering problems important to polymer science.
For instance, Kim's part of the NIRT team on "Nanoreactor Processes for Manufacturing Oriented Materials" involves developing methods for depositing and anchoring catalyst materials inside tiny nanofabricated channels. The team has proposed a unique method of producing highly oriented conducting polymer wires by feeding precursor gases through nanoscale channels and having them polymerize with the aid of Kim's catalysts (similar to the way a spider produces silk). Their ultimate goal is to be able to tailor the electrical properties of individual wires by delivering precise amounts of dopants at specific locations along the length of a wire.
Top: FESEM cross-section picture showing five 20 nm wide, 20 nm high nanochannel templates, which are spaced 200 nm apart.Bottom: FESEM picture of a twisted polymer nanofilament having 170 nm width and 20 nm height.
A second research project involves using photochemistry and low energy electron bombardment to grow oriented conducting polymer thin films. While several different conducting polymers exist that can be fabricated using traditional dissolution, spin coat and lithography technologies there are problems with solubility and producing well aligned polymer chains. One approach is to synthesize a conducting polymer backbone with a soluble side chains, but, in Kim's opinion, this unnecessarily increases the size of the polymer and results in poorly oriented films. Kim's graduate students are trying to perfect the deposition of polythiophene from di-iodothiophene using a combination of photons and low energy (1-10 eV) electrons. Longterm, they foresee a method of modifying standard lithography techniques by placing a mask within the near field regime (20-100 nm) of a photomask to produce a highly oriented conducting polymer pattern on a wafer.
A final area of active research for Prof. Kim is to develop effective lubricants for micro electromechanical systems (MEMS). Solid state low friction coefficient materials such as diamond and SiC can be worn away and are difficult to place inside the intricate features that engineers produce. Traditional liquid lubricants dissipate too much power in the tiny moving parts of MEMS. Using his surface chemistry background Kim recognized that he could piggyback on the existing several monolayers of water that are present on most material surfaces. He has used vapor delivery of simple alcohols like methanol and ethanol, which are soluble in water, to demonstrate dramatically improve the lubrication at surfaces with atomic force microscopy.
Seong Kim received a Ph.D. in chemical engineering from Northwestern University after emigrating from his native Korea. He did post doctoral work in Gabor Somarjai's group at UC-Berkeley before coming to Penn State in 2001. His personal webpage is http://fenske.che.psu.edu/faculty/kim/.
