Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 1005-1011 |
| Number of pages | 7 |
| Journal | Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films |
| Volume | 24 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2006 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- polymer films
- sputter etching
- adhesion
- plasma
- plasma deposition
- plasma deposited coatings
- etching
- fluorocarbons
- polymer coatings
- silicon
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Tunable hydrophilicity on a hydrophobic fluorocarbon polymer coating on silicon. / Kolari, Kai; Hokkanen, Ari.
In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 24, No. 4, 2006, p. 1005-1011.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Tunable hydrophilicity on a hydrophobic fluorocarbon polymer coating on silicon
AU - Kolari, Kai
AU - Hokkanen, Ari
PY - 2006
Y1 - 2006
N2 - An efficient, economic, reliable, and repeatable patterning procedure of hydrophobic surfaces was developed. A fluorocarbon polymer derived from the C4F8 gas in an inductively coupled plasma etcher was used as the hydrophobic coating. For a subsequent patterning of hydrophilic apertures on the polymer, a short O2 plasma exposure through a silicon shadow mask was utilized. The overall hydrophilicity of the patterned surface can be tuned by the duration of the O2 plasma exposure, and also by the density and the size of the hydrophilic apertures. The laborious photolithography and tricky lift-off procedures are avoided. Optimization of the whole patterning process is explained thoroughly and supported with experimental data. The hydrophilic adhesion of the patterned polymer was evaluated with aqueous droplets, which were studied on matrices of the hydrophilic apertures of different sizes. The deposition parameters of the fluorocarbon polymer, the size of the droplet required to enable rolling on the patterned surface, and the duration of the O2 plasma exposure were considered as the main parameters. To determine the achievable resolution of the patterning procedure, the subsurface etching beneath the shadow mask was evaluated. The results show that a resolution of less than 10μm can be achieved. The simple hydrophilic patterning procedure described here can be used for the production of on-plane microfluidics, where a controlled adhesion or decohesion of 8–50μl droplets on the surface with a variable hydrophilicity from one location to another can be achieved.
AB - An efficient, economic, reliable, and repeatable patterning procedure of hydrophobic surfaces was developed. A fluorocarbon polymer derived from the C4F8 gas in an inductively coupled plasma etcher was used as the hydrophobic coating. For a subsequent patterning of hydrophilic apertures on the polymer, a short O2 plasma exposure through a silicon shadow mask was utilized. The overall hydrophilicity of the patterned surface can be tuned by the duration of the O2 plasma exposure, and also by the density and the size of the hydrophilic apertures. The laborious photolithography and tricky lift-off procedures are avoided. Optimization of the whole patterning process is explained thoroughly and supported with experimental data. The hydrophilic adhesion of the patterned polymer was evaluated with aqueous droplets, which were studied on matrices of the hydrophilic apertures of different sizes. The deposition parameters of the fluorocarbon polymer, the size of the droplet required to enable rolling on the patterned surface, and the duration of the O2 plasma exposure were considered as the main parameters. To determine the achievable resolution of the patterning procedure, the subsurface etching beneath the shadow mask was evaluated. The results show that a resolution of less than 10μm can be achieved. The simple hydrophilic patterning procedure described here can be used for the production of on-plane microfluidics, where a controlled adhesion or decohesion of 8–50μl droplets on the surface with a variable hydrophilicity from one location to another can be achieved.
KW - polymer films
KW - sputter etching
KW - adhesion
KW - plasma
KW - plasma deposition
KW - plasma deposited coatings
KW - etching
KW - fluorocarbons
KW - polymer coatings
KW - silicon
U2 - 10.1116/1.2207149
DO - 10.1116/1.2207149
M3 - Article
VL - 24
SP - 1005
EP - 1011
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
SN - 0734-2101
IS - 4
ER -