Surface micromachining of polydimethylsiloxane for microfluidics applications

Staci Hill, Weiyi Qian, Weiqiang Chen, Jianping Fu

Research output: Contribution to journalArticle

Abstract

Polydimethylsiloxane (PDMS) elastomer has emerged as one of the most frequently applied materials in microfluidics. However, precise and large-scale surface micromachining of PDMS remains challenging, limiting applications of PDMS for microfluidic structures with high-resolution features. Herein, surface patterning of PDMS was achieved using a simple yet effective method combining direct photolithography followed by reactive-ion etching (RIE). This method incorporated a unique step of using oxygen plasma to activate PDMS surfaces to a hydrophilic state, thereby enabling improved adhesion of photoresist on top of PDMS surfaces for subsequent photolithography. RIE was applied to transfer patterns from photoresist to underlying PDMS thin films. Systematic experiments were conducted in the present work to characterize PDMS etch rate and etch selectivity of PDMS to photoresist as a function of various RIE parameters, including pressure, RF power, and gas flow rate and composition. We further compared two common RIE systems with and without bias power and employed inductively coupled plasma and capacitively coupled plasma sources, respectively, in terms of their PDMS etching performances. The RIE-based PDMS surface micromachining technique is compatible with conventional Si-based surface and bulk micromachining techniques, thus opening promising opportunities for generating hybrid microfluidic devices with novel functionalities.

Original languageEnglish (US)
Article number054114
JournalBiomicrofluidics
Volume10
Issue number5
DOIs
StatePublished - Sep 1 2016

Fingerprint

Microtechnology
Surface micromachining
Microfluidics
Polydimethylsiloxane
micromachining
etching
Reactive ion etching
photoresists
photolithography
ions
Ions
Photoresists
Photolithography
Lab-On-A-Chip Devices
microfluidic devices
oxygen plasma
elastomers
gas flow
baysilon
adhesion

ASJC Scopus subject areas

  • Materials Science(all)
  • Molecular Biology
  • Genetics
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

Cite this

Surface micromachining of polydimethylsiloxane for microfluidics applications. / Hill, Staci; Qian, Weiyi; Chen, Weiqiang; Fu, Jianping.

In: Biomicrofluidics, Vol. 10, No. 5, 054114, 01.09.2016.

Research output: Contribution to journalArticle

Hill, Staci ; Qian, Weiyi ; Chen, Weiqiang ; Fu, Jianping. / Surface micromachining of polydimethylsiloxane for microfluidics applications. In: Biomicrofluidics. 2016 ; Vol. 10, No. 5.
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