Advanced Materials

Microfluidics: Controlling Liquid Drops with Texture Ratchets (Adv. Mater. 12/2012)

Authors

  • Todd A. Duncombe,

    1. Department of Electrical Engineering, University of Washington, Box 352500, Seattle, WA 98195-2500, USA
    Search for more papers by this author
    • T.A.D, E.Y.E., and A.S. contributed equally to this work; they are listed in alphabetical order.

    • UC Berkeley, UCB-UCSF Graduate Program in Bioengineering, Berkeley, CA, USA

  • E. Yegân Erdem,

    1. Department of Mechanical Engineering, University of Washington, Box 352500, Seattle, WA 98195-2500, USA
    Search for more papers by this author
    • T.A.D, E.Y.E., and A.S. contributed equally to this work; they are listed in alphabetical order.

    • UC Berkeley, Department of Mechanical Engineering, Berkeley, CA, USA

  • Ashutosh Shastry,

    1. Department of Electrical Engineering, University of Washington, Box 352500, Seattle, WA 98195-2500, USA
    Search for more papers by this author
    • T.A.D, E.Y.E., and A.S. contributed equally to this work; they are listed in alphabetical order.

    • Corium International, Menlo Park, CA, USA

  • Rajashree Baskaran,

    1. Components Research, Intel Corporation, Hillsboro, OR, USA
    Search for more papers by this author
  • Karl F. Böhringer

    Corresponding author
    1. University of Washington, Departments of Electrical Engineering and Bioengineering, Box 352500, Seattle, WA 98195-2500, USA
    • University of Washington, Departments of Electrical Engineering and Bioengineering, Box 352500, Seattle, WA 98195-2500, USA.
    Search for more papers by this author

Abstract

Controlled vibration selectively propels multiple microliter-sized drops along texture ratchets: microstructured tracks that rectify oscillations of the three-phase contact line into asymmetric pinning forces that propel each drop in the direction of higher pinning, as investigated by K. F. Böhringer and co-workers on page 1545. This superimposed time-lapse image depicts two pairs of 5 μL dyed water drops traveling and finally merging simultaneously on regular and upside-down texture ratchets molded in polydimethylsiloxane elastomer.

original image

Ancillary