Apparent Slip at Hydrophilic Surface: Fluorescence Resonance Energy Transfer Study

POSTER

Abstract

We have used a fluorescence resonance energy transfer (FRET) technique to measure the apparent slip velocity a separations $<$ 10 nm from a hydrophilic surface. A focused laser beam was used to excite Tb3+ dye in solution and the excited energy was transferred to Rhodamine 6G that was previously immobilized on the solid surface. In addition, with diffraction-limited spatial resolution, we have measured the fluorescence intensity profile of Rhodamine 6G to monitor the flow profile near the interface. The relevance is to present a greatly improved estimate of what determines the boundary condition of fluid flow in situations where details of the near-surface velocity profile matters, as in microfluidic devices.

Authors

  • Chang-Ki Min

    • Materials Science and Engineering, University of Illinois
    • University of Illinois at Urbana-Champaign

  • Stephen Anthony

    • Department of Chemistry, University of Illinois
    • Chemistry, UIUC
    • Dept of Chemistry, University of Illinois at Urbana-Champaign
    • University of Illinois
    • Dept of Chemistry, Univ of Illinois at Urbana-Champaign

  • Sung Chul Bae

    • Department of Materials Science and Engineering, University of Illinois
    • Materials Science and Engineering, University of Illinois

  • Steve Granick

    • Department of Materials Science and Engineering, University of Illinois
    • University of Illinois, Urbana-Champaign
    • material science and engineering, UIUC
    • Materials Science and Engineering, University of Illinois
    • Dept of Materials Science \& Engineering, University of Illinois at Urbana-Champaign
    • Dept. Materials Science and Engineering, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign
    • University of Illinois
    • Dept of Materials Science \& Engineering, Univ of Illinois at Urbana-Champaign
    • Material Science and Engineering, UIUC