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Determination of dynamic contact angles within microfluidic devices
- Source :
- Microfluidics and Nanofluidics. 22
- Publication Year :
- 2018
- Publisher :
- Springer Science and Business Media LLC, 2018.
-
Abstract
- Here, we report a single-point detection method for the determination of dynamic surface conditions inside microfluidic channels. The proposed method is based on monitoring fluorescence amplitude as a function of the convolution of a laser beam with segmented flow consisting of two immiscible liquids, one containing fluorescent dye. The fluorescence amplitude is determined by the flow rate and the droplet shape, which is affected by the channel surface properties. We modeled the interaction of a droplet and a laser beam via computer-aided design software, using the laser beam location in relation to the droplet shape as a parameter. The method was applied to fused silica capillaries with both unmodified and modified surfaces, with segmented flow exhibiting water contact angles of ≈ 30° and ≈ 100°, respectively. The method allows discrimination between hydrophillic and hydrophobic surfaces, as well as the quality of the treatment. The results were verified using fluorescence imaging of the droplets via a stroboscopic technique. We also applied this method to the analysis of microfabricated channels with non-circular cross sections. We demonstrated that the technique enables the determination of the hydrophobicity of channel surfaces, a crucial property required for the generation of segmented flow or emulsions for applications such as digital PCR.
- Subjects :
- Fluorescence-lifetime imaging microscopy
Materials science
business.industry
010401 analytical chemistry
Flow (psychology)
Microfluidics
02 engineering and technology
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
Fluorescence
0104 chemical sciences
Electronic, Optical and Magnetic Materials
Convolution
Volumetric flow rate
Physics::Fluid Dynamics
Contact angle
Amplitude
Optics
Materials Chemistry
0210 nano-technology
business
Subjects
Details
- ISSN :
- 16134990 and 16134982
- Volume :
- 22
- Database :
- OpenAIRE
- Journal :
- Microfluidics and Nanofluidics
- Accession number :
- edsair.doi...........7b3e7c90334223833a71475aef557fb5