title: Multiplex lithography for multilevel multiscale architectures and its application to polymer electrolyte membrane fuel cell.
abstract: The production of multiscale architectures is of significant interest in materials science, and the integration of those structures could provide a breakthrough for various applications. Here we report a simple yet versatile strategy that allows for the LEGO-like integrations of microscale membranes by quantitatively controlling the oxygen inhibition effects of ultraviolet-curable materials, leading to multilevel multiscale architectures. The spatial control of oxygen concentration induces different curing contrasts in a resin allowing the selective imprinting and bonding at different sides of a membrane, which enables LEGO-like integration together with the multiscale pattern formation. Utilizing the method, the multilevel multiscale Nafion membranes are prepared and applied to polymer electrolyte membrane fuel cell. Our multiscale membrane fuel cell demonstrates significant enhancement of performance while ensuring mechanical robustness. The performance enhancement is caused by the combined effect of the decrease of membrane resistance and the increase of the electrochemical active surface area.
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Seoul National University, Seoul 151-744, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Hyesung
authors.initials: H
authors.lastname: Cho
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Seoul National University, Seoul 151-744, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Sang
authors.initials: S
authors.lastname: Moon Kim
authors.affiliation: Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742, Korea.|School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Yun
authors.initials: Y
authors.lastname: Sik Kang
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Seoul National University, Seoul 151-744, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.|Energy Harvesting Devices Research Section, Electronics and Telecommunications Research Institute, Daejeon 305-700, Korea.
authors.forename: Junsoo
authors.identifier: http://orcid.org/0000-0001-7340-2770
authors.initials: J
authors.lastname: Kim
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Seoul National University, Seoul 151-744, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Segeun
authors.initials: S
authors.lastname: Jang
authors.affiliation: Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742, Korea.|School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Minhyoung
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.|Center for Materials Architecturing, Korea Institute of Science and Technology, Seoul 136-791, Korea.
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Park
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Seoul National University, Seoul 151-744, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Jung
authors.initials: J
authors.lastname: Won Bang
authors.affiliation: College of BioNano Technology, Gachon University, Gyeonggi 461-701, Korea.
authors.forename: Soonmin
authors.initials: S
authors.lastname: Seo
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Kahp-Yang
authors.initials: KY
authors.lastname: Suh
authors.affiliation: Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742, Korea.|School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: Yung-Eun
authors.identifier: http://orcid.org/0000-0002-1563-8328
authors.initials: YE
authors.lastname: Sung
authors.affiliation: Global Frontier Center for Multiscale Energy Systems, Seoul National University, Seoul 151-744, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea.|Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Mansoo
authors.initials: M
authors.lastname: Choi