Dr. Suh earned his BS from the School of Chemical and Biological Engineering (2005) and PhD from the Interdisciplinary Program of Nano Science and Technology (2011) at Seoul National University under the direction of Professor Kookheon Char, where he investigated the tunability of surface energy using thermally cured organosilicates. He first began working as a postdoc for Paul Nealey in the Department of Chemical and Biological Engineering at the University of Wisconsin-Madison, and later moved to the Pritzker School of Molecular Engineering at the University of Chicago.
The directed self-assembly (DSA) process, which integrates self-assembling block copolymer (BCP) films with lithographically pre-defined templates, has been extensively researched as an alternative patterning technique to enhance the resolution beyond the limitation of current technology. This approach, already demonstrated with experiments at the laboratory scale, has now started to move to the line in the commercial manufacturing process. In spite of the significant progress to date in DSA technology, there are still several challenges remaining.
The more well-established BCP DSA process was developed around the principle of thermal annealing, which is the most reliable pathway to induce the self-assembly of block copolymers. Unfortunately, this method only works for the special case where the surface energies of each block are similar at the annealing temperature so both blocks are exposed on the free surface during assembly. Poly(styrene-b-methyl methacrylate), or PS-b-PMMA, meets this criterion but is restricted in its use because the smallest feature size realized by PS-b-PMMA is known as the neighborhood of 20 nm.
Seeking block copolymer systems other than PS-b-PMMA is therefore one of the key issues in further reducing the feature size down to the sub-10 nm scale. However, most other block copolymers exhibit a sizeable difference in surface energy between the blocks, especially for those materials with the properties allowing for formation of smaller features. In this case, the block with the lower surface energy tends to segregate to the free surface of films and precludes the assembly of the desired through-film perpendicularly oriented structures. Dr. Suh is actively investigating many different techniques to identify feasible solutions for realization of sub-10 nm scale features, based on his knowledge of polymer physics and interfaces.
The Role of Water Volume Fraction on Water Adsorption in Anion Exchange Membranes
Gervasio Zaldivar, Ruilin Dong, Joan M Montes de Oca, Ge Sun, Riccardo Alessandri, Christopher G Arges, Shrayesh N Patel, Paul F Nealey, Juan J de Pablo, Macromolecules, 2025
Role of Crosslinking and Backbone Segmental Dynamics on Ion Transport in Hydrated Anion-Conducting Polyelectrolytes
Zhongyang Wang, Kai Wang, Christopher Eom, Yuxi Chen, Ge Sun, Mincheol Kim, Joan M Montes de Oca, Dongyue Liang, Kushal Bagchi, Shrayesh N Patel, Juan J de Pablo, Paul F Nealey, Advanced Functional Materials, 2025
IEC-Independent Coupling between Water Uptake and Ionic Conductivity in Anion-Conducting Polymer Films
Joan M Montes de Oca, Ruilin Dong, Gervasio Zaldivar, Ge Sun, Zhongyang Wang, Shrayesh N Patel, Paul F Nealey, Juan J de Pablo, Macromolecules, 2025
Water-mediated ion transport in an anion exchange membrane
Zhongyang Wang, Ge Sun, Nicholas HC Lewis, Mrinmay Mandal, Abhishek Sharma, Mincheol Kim, Joan M Montes de Oca, Kai Wang, Aaron Taggart, Alex B Martinson, Paul A Kohl, Andrei Tokmakoff, Shrayesh N Patel, Paul F Nealey, Juan J de Pablo. Nature Communications. 2025.
Directed self-assembly of block copolymer films on atomically-thin graphene chemical patterns
Chang, TH; Xiong, SS; Jacobberger, RM; Mikael, S; Suh, HS; Liu, CC; Geng, DL; Wang, XD; Arnold, MS; Ma, ZQ; Nealey, PF. Directed self-assembly of block copolymer films on atomically-thin graphene chemical patterns. Scientific Reports. 2016. Vol. 6, Pg. 31407.
Directed self-assembly of high-chi block copolymer for nano fabrication of bit patterned media via s
Xiong, S. S. Chapuis, Y. A. Wan, L. Gao, H. Li, X. Ruiz, R. Nealey, P. F.. Directed self-assembly of high-chi block copolymer for nano fabrication of bit patterned media via s. Nanotechnology. 2016. Vol. 27, Pg. 415601.
Directed Self-Assembly of Triblock Copolymer on Chemical Patterns for Sub-10-nm Nanofabrication via
Xiong, SS; Wan, L; Ishida, Y; Chapuis, YA; Craig, GSW; Ruiz, R; Nealey, PF. Directed Self-Assembly of Triblock Copolymer on Chemical Patterns for Sub-10-nm Nanofabrication via. ACS Nano. 2016. Vol. 10, Pg. 7855–7865.
Roadmap on optical metamaterials
Urbas, A. M. Jacob, Z. Dal Negro, L. Engheta, N. Boardman, A. D. Egan, P. Khanikaev, A. B. Menon, V. Ferrera, M. Kinsey, N. DeVault, C. Kim, J. Shalaev, V. Boltasseva, A. Valentine, J. Pfeiffer, C. Grbic, A. Narimanov, E. Zhu, L. X. Fan, S. H. Alu, A. Poutrina, E. Litchinitser, N. M. Noginov, M. A. MacDonald, K. F. Plum, E. Liu, X. Y. Nealey, P. F. Kagan, C. R. Murray, C. B. Pawlak, D. A. Smolyaninov, I. I. Smolyaninova, V. N. Chanda, D.. Roadmap on optical metamaterials. Journal of Optics. Vol. 18, Pg. 093005.
Post-directed-self-assembly membrane fabrication for in situ analysis of block copolymer structures
J Ren, L E Ocola, R Divan, D A Czaplewski, T Segal-Peretz, S Xiong, R J Kline, C G Arges and P F Nealey. Post-directed-self-assembly membrane fabrication for in situ analysis of block copolymer structures. Nanotechnology. 2016. Vol. 27, Pg. 435303.