Electrowetting on plasma-deposited fluorocarbon hydrophobic films for biofluid transport in microfluidics

Journal Article · Tue May 15 04:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2735682· OSTI ID:20982880

Bayiati, P; Tserepi, A; Petrou, P S; Kakabakos, S E; Misiakos, K; Gogolides, E ^[1]

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1. Institute of Microelectronics-NCSR 'Demokritos', POB 60228, 153 10 Aghia Paraskevi, Attiki (Greece)

The present work focuses on the plasma deposition of fluorocarbon (FC) films on surfaces and the electrostatic control of their wettability (electrowetting). Such films can be employed for actuation of fluid transport in microfluidic devices, when deposited over patterned electrodes. Here, the deposition was performed using C{sub 4}F{sub 8} and the plasma parameters that permit the creation of films with optimized properties desirable for electrowetting were established. The wettability of the plasma-deposited surfaces was characterized by means of contact angle measurements (in the static and dynamic mode). The thickness of the deposited films was probed in situ by means of spectroscopic ellipsometry, while the surface roughness was provided by atomic force microscopy. These plasma-deposited FC films in combination with silicon nitride, a material of high dielectric constant, were used to create a dielectric structure that requires reduced voltages for successful electrowetting. Electrowetting experiments using protein solutions were conducted on such optimized dielectric structures and were compared with similar structures bearing commercial spin-coated Teflon registered amorphous fluoropolymer (AF) film as the hydrophobic top layer. Our results show that plasma-deposited FC films have desirable electrowetting behavior and minimal protein adsorption, a requirement for successful transport of biological solutions in 'digital' microfluidics.

• OSTI ID: 20982880
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 101; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADSORPTION
ATOMIC FORCE MICROSCOPY
CARBON FLUORIDES
DEPOSITION
DIELECTRIC MATERIALS
ELECTRIC POTENTIAL
ELECTRODES
ELLIPSOMETRY
LAYERS
PERMITTIVITY
PLASMA
PROTEINS
ROUGHNESS
SILICON NITRIDES
SOLUTIONS
TEFLON
THICKNESS
THIN FILMS
WETTABILITY