Fabrication of single nanofluidic channels in poly(methylmethacrylate) films via focused-ion beam milling for use as molecular gates
- Department of Chemistry, Frederick Seitz Materials Research Laboratory, Department of Mechanical and Industrial Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)
Focused-ion beam (FIB) milling provides rapid fabrication of individual cylindrical submicrometer channels with reproducible dimensions ({+-}5% diameters) through 8-{mu}m thick poly(methylmethacrylate) (PMMA) films. PMMA films are spincast on sacrificial Si carriers and sputter-coated with Au before the 30-kV gallium FIB milling process. By adding a trace amount of poly(ethyleneoxide) and poly(dimethylsiloxane) to the PMMA solution before casting, the films can be released for subsequent mounting in microfluidic devices to create hybrid microfluidic-nanofluidic multilevel architectures. In situ FIB sectioning demonstrates the smooth cylindrical surface within the pore. Placing a milled film in contact with an aqueous fluorescein solution fills the channel by capillary action, as verified by confocal fluorescence microscopy. Confocal fluorescence of dyed films reveals that the pores span the thickness of the PMMA film. Small arrays of channels with a defined number and density and arbitrary in-plane spatial arrangement are fabricated with this process, allowing a unique testbed for high aspect ratio nanofluidic devices.
- OSTI ID:
- 20632732
- Journal Information:
- Applied Physics Letters, Vol. 85, Issue 7; Other Information: DOI: 10.1063/1.1780605; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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