title: In situ curing of sliding SU-8 droplet over a microcontact printed pattern for tunable fabrication of a polydimethylsiloxane nanoslit.
abstract: A tunable process for polydimethylsiloxane (PDMS) nanoslit fabrication is developed for nanofluidic applications. A microcontact printing (μCP) of a laterally spreading self-assembled hexadecanethiol (HDT) layer, combined with in situ curing of a sliding SU-8 droplet, enables precise and independent tuning of a nanoslit-mold width and height using a single μCP master mold. The SU-8 nanoslit-mold is replicated using a hard-soft composite PDMS to prevent channel collapse at low (<0.2) aspect ratio (height over width). The fluidic characteristics as well as dimensions of nanoslits fabricated with various conditions are analyzed using a fluorescein sample and AFM images. Finally, concentration polarization-based sample preconcentration is successfully demonstrated at the nanoslit boundary where an electric double-layer is overlapped.
authors.affiliation: Department of Biomedical Engineering, Korea University, Seoul, Korea.
authors.forename: Chang-Beom
authors.initials: CB
authors.lastname: Kim
authors.forename: Honggu
authors.initials: H
authors.lastname: Chun
authors.forename: JaeHun
authors.initials: J
authors.lastname: Chung
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Ki-Bong
authors.initials: KB
authors.lastname: Song
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Lee
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D019793:Fluorescein / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D004129:Dimethylpolysiloxanes; D013438:Sulfhydryl Compounds; C086974:hexadecanethiol; C013830:baysilon; D019793:Fluorescein