A hybrid microfluidic chip with electrowetting functionality using ultraviolet (UV)-curable polymer

Research output: Contribution to journalArticleAcademicpeer-review

20 Citations (Scopus)

Abstract

Electrowetting (EW) is widely used in digital microfluidics for the manipulation of drops sandwiched between two parallel plates. In contrast, demonstrations of closed microfluidic channels enhanced with EW functionality are scarce. Here, we report a simple, low-cost method to construct such microchannels enclosed between two glass plates, each of which comprises electrodes and insulating layers. Our method uses soft imprint lithography with thiolene precursors to design the channel geometry. UV exposure is used to seal the chips permanently and a silanization treatment renders all inner channel surfaces hydrophobic. Compared to earlier polydimethylsiloxane-based designs, this method allows us to make microchannels with smaller dimensions (down to 10 microns), lower aspect ratios (down to height/length = 1/10), and symmetric electrodes both on the top and the bottom of the channel. We demonstrate the new capabilities with two examples: (i) EW-enhanced drop generation in a flow focusing geometry allows precise and continuous control on drop diameter in the range ≈ 1–15 microns while maintaining monodispersity; (ii) EW allows tuning of the excess water pressure needed to displace oil in a microchannel, leading to spontaneous imbibition at EW number η > 0.89.
Original languageUndefined
Pages (from-to)1550-1556
Number of pages7
JournalLab on a chip
Volume10
Issue number12
DOIs
Publication statusPublished - 2010

Keywords

  • METIS-266889
  • IR-73441

Cite this

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title = "A hybrid microfluidic chip with electrowetting functionality using ultraviolet (UV)-curable polymer",
abstract = "Electrowetting (EW) is widely used in digital microfluidics for the manipulation of drops sandwiched between two parallel plates. In contrast, demonstrations of closed microfluidic channels enhanced with EW functionality are scarce. Here, we report a simple, low-cost method to construct such microchannels enclosed between two glass plates, each of which comprises electrodes and insulating layers. Our method uses soft imprint lithography with thiolene precursors to design the channel geometry. UV exposure is used to seal the chips permanently and a silanization treatment renders all inner channel surfaces hydrophobic. Compared to earlier polydimethylsiloxane-based designs, this method allows us to make microchannels with smaller dimensions (down to 10 microns), lower aspect ratios (down to height/length = 1/10), and symmetric electrodes both on the top and the bottom of the channel. We demonstrate the new capabilities with two examples: (i) EW-enhanced drop generation in a flow focusing geometry allows precise and continuous control on drop diameter in the range ≈ 1–15 microns while maintaining monodispersity; (ii) EW allows tuning of the excess water pressure needed to displace oil in a microchannel, leading to spontaneous imbibition at EW number η > 0.89.",
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author = "H. Gu and Duits, {Michael H.G.} and Mugele, {Friedrich Gunther}",
year = "2010",
doi = "10.1039/C001524E",
language = "Undefined",
volume = "10",
pages = "1550--1556",
journal = "Lab on a chip",
issn = "1473-0197",
publisher = "Royal Society of Chemistry",
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A hybrid microfluidic chip with electrowetting functionality using ultraviolet (UV)-curable polymer. / Gu, H.; Duits, Michael H.G.; Mugele, Friedrich Gunther.

In: Lab on a chip, Vol. 10, No. 12, 2010, p. 1550-1556.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - A hybrid microfluidic chip with electrowetting functionality using ultraviolet (UV)-curable polymer

AU - Gu, H.

AU - Duits, Michael H.G.

AU - Mugele, Friedrich Gunther

PY - 2010

Y1 - 2010

N2 - Electrowetting (EW) is widely used in digital microfluidics for the manipulation of drops sandwiched between two parallel plates. In contrast, demonstrations of closed microfluidic channels enhanced with EW functionality are scarce. Here, we report a simple, low-cost method to construct such microchannels enclosed between two glass plates, each of which comprises electrodes and insulating layers. Our method uses soft imprint lithography with thiolene precursors to design the channel geometry. UV exposure is used to seal the chips permanently and a silanization treatment renders all inner channel surfaces hydrophobic. Compared to earlier polydimethylsiloxane-based designs, this method allows us to make microchannels with smaller dimensions (down to 10 microns), lower aspect ratios (down to height/length = 1/10), and symmetric electrodes both on the top and the bottom of the channel. We demonstrate the new capabilities with two examples: (i) EW-enhanced drop generation in a flow focusing geometry allows precise and continuous control on drop diameter in the range ≈ 1–15 microns while maintaining monodispersity; (ii) EW allows tuning of the excess water pressure needed to displace oil in a microchannel, leading to spontaneous imbibition at EW number η > 0.89.

AB - Electrowetting (EW) is widely used in digital microfluidics for the manipulation of drops sandwiched between two parallel plates. In contrast, demonstrations of closed microfluidic channels enhanced with EW functionality are scarce. Here, we report a simple, low-cost method to construct such microchannels enclosed between two glass plates, each of which comprises electrodes and insulating layers. Our method uses soft imprint lithography with thiolene precursors to design the channel geometry. UV exposure is used to seal the chips permanently and a silanization treatment renders all inner channel surfaces hydrophobic. Compared to earlier polydimethylsiloxane-based designs, this method allows us to make microchannels with smaller dimensions (down to 10 microns), lower aspect ratios (down to height/length = 1/10), and symmetric electrodes both on the top and the bottom of the channel. We demonstrate the new capabilities with two examples: (i) EW-enhanced drop generation in a flow focusing geometry allows precise and continuous control on drop diameter in the range ≈ 1–15 microns while maintaining monodispersity; (ii) EW allows tuning of the excess water pressure needed to displace oil in a microchannel, leading to spontaneous imbibition at EW number η > 0.89.

KW - METIS-266889

KW - IR-73441

U2 - 10.1039/C001524E

DO - 10.1039/C001524E

M3 - Article

VL - 10

SP - 1550

EP - 1556

JO - Lab on a chip

JF - Lab on a chip

SN - 1473-0197

IS - 12

ER -