This paper presents a lab-on-a-chip development method that applies the Young-Laplace equation to design the geometries of a patterned water droplet, and then using the droplet as a mold to fabricate three-dimensional polydimethylsiloxane (PDMS) channels. We demonstrate the method by designing and fabricating an on-chip funnel. We then subsequently trap beads of graded diameter in the tapered section of the funnel to make on-chip filters of controllable pore size. After packing the funnel with beads, the cutoff pore size of the fabricated filter agrees closely with our estimate. This approach provides a straight-forward, low-cost, yet powerful way to design and fabricate microfluidic devices with 3D features.

Original languageEnglish (US)
Pages (from-to)891-897
Number of pages7
JournalMicrofluidics and Nanofluidics
Issue number6
StatePublished - Dec 2012


ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry

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