Simplified ground-type single-plate electrowetting device for droplet transport

Jong Hyeon Chang, Dong-Sik Kim, James Jungho Pak

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The current paper describes a simpler ground-type, single-plate electrowetting configuration for droplet transport in digital microfluidics without performance degradation. The simplified fabrication process is achieved with two photolithography steps. The first step simultaneously patterns both a control electrode array and a reference electrode on a substrate. The second step patterns a dielectric layer at the top to expose the reference electrode for grounding the liquid droplet. In the experiment, a 5 μm thick photo-imageable polyimide, with a 3.3 dielectric constant, is used as the dielectric layer. A 10 nm Teflon-AF is coated to obtain a hydrophobic surface with a high water advancing angle of 116° and a small contact angle hysteresis of 5°. The droplet movement of 1 mM methylene blue on this simplified device is successfully demonstrated at control voltages above the required 45 V to overcome the contact angle hysteresis.

Original languageEnglish
Pages (from-to)402-407
Number of pages6
JournalJournal of Electrical Engineering and Technology
Volume6
Issue number3
DOIs
Publication statusPublished - 2011 May 1

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Keywords

  • Digital microfluidics
  • Droplet transport
  • Electrowetting
  • Single-plate configuration

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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