title: Surface-directed capillary system; theory, experiments and applications.
abstract: We present a capillary flow system for liquid transport in microsystems. Our simple microfluidic system consists of two planar parallel surfaces, separated by spacers. One of the surfaces is entirely hydrophobic, the other mainly hydrophobic, but with hydrophilic pathways defined on it by photolithographic means. By controlling the wetting properties of the surfaces in this manner, the liquid can be confined to certain areas defined by the hydrophilic pathways. This technique eliminates the need for alignment of the two surfaces. Patterned plasma-polymerized hexafluoropropene constitutes the hydrophobic areas, whereas the untreated glass surface constitutes the hydrophilic pathways. We developed a theoretical model of the capillary flow and obtained analytical solutions which are in good agreement with the experimental results. The capillarity-driven microflow system was also used to pattern and immobilize biological material on planar substrates: well-defined 200 microm wide strips of human cells (HeLa) and fluorescence labelled proteins (fluorescein isothiocyanate-labelled bovine serum albumin, i.e., FITC-BSA) were fabricated using the capillary flow system presented here.
authors: Scandinavian Micro Biodevices, Gammelgårdsvej 87C, DK-3520 Farum, Denmark. sab@smb.dk
authors: Salim
authors: S
authors: Bouaidat
authors: Ole
authors: O
authors: Hansen
authors: Henrik
authors: H
authors: Bruus
authors: Christian
authors: C
authors: Berendsen
authors: Niels Kristian
authors: NK
authors: Bau-Madsen
authors: Peter
authors: P
authors: Thomsen
authors: Anders
authors: A
authors: Wolff
authors: Jacques
authors: J
authors: Jonsmann
mesh_terms: D000327:Adsorption; D002197:Capillary Action; D018929:Cell Culture Techniques; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D008962:Models, Theoretical; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: C039217:fluorescein isothiocyanate bovine serum albumin; D012710:Serum Albumin, Bovine; D016650:Fluorescein-5-isothiocyanate