title: Spatial Site-Patterning of Wettability in a Microcapillary Tube.
abstract: Substrate functionalization is of great importance in successfully manipulating flows and liquid interfaces in microdevices. Herein, we propose an alternative approach for spatial patterning of wettability in a microcapillary tube. The method combines a photolithography process with self-assembled monolayer formation. The modified microcapillaries show very sharp boundaries between the alternating hydrophilic/hydrophobic segments with an achieved smallest domain dimension down to 60 μm inside a 580 μm inner diameter capillary. Our two-step method allows us to pattern multiple types of functional groups in an enclosed channel. Such structures are promising regarding the manipulation of segmented flows inside capillaries.
authors.affiliation: Soft Matter, Fluidics and Interfaces, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente , Enschede, The Netherlands.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Soft Matter, Fluidics and Interfaces, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente , Enschede, The Netherlands.
authors.forename: Jan W
authors.initials: JW
authors.lastname: van Nieuwkasteele
authors.affiliation: Mechanical Engineering, University of Science and Technology Beijing , Beijing, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Qiang
authors.affiliation: Department of Mechanical Engineering, University of Alberta , Edmonton, Alberta, Canada.
authors.forename: Peichun Amy
authors.initials: PA
authors.lastname: Tsai
authors.affiliation: Soft Matter, Fluidics and Interfaces, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente , Enschede, The Netherlands.
authors.forename: Rob G H
authors.initials: RG
authors.lastname: Lammertink
keywords: micro channel; patterning; surface modification; wetting