title: A fast and simple method to fabricate circular microchannels in polydimethylsiloxane (PDMS).
abstract: A simple method to fabricate circular microchannels in polydimethylsiloxane (PDMS) is presented. A coating of liquid PDMS is applied on the walls of rectangular microchannels, fabricated using standard soft-lithography, by introducing a pressurized air stream inside the PDMS filled microchannels. Surface tension of the liquid PDMS forces the coating to take a circular cross-section which is preserved by baking the device to cure the coated layer. Diameters ranging from a few micrometres to a few hundreds of micrometres were achieved. The method was verified to work on microchannel networks as well as in straight channels. Different coating conditions were systematically tested. Design curves are reported for one to choose appropriate coating conditions for obtaining a desired diameter. A comparison between the performance of square and circular microchannels in trapping SiHa cells (cervical cancer cell line) is shown.
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdelgawad
authors.forename: Chun
authors.initials: C
authors.lastname: Wu
authors.forename: Wei-Yin
authors.initials: WY
authors.lastname: Chien
authors.forename: William R
authors.initials: WR
authors.lastname: Geddie
authors.forename: Michael A S
authors.initials: MA
authors.lastname: Jewett
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
mesh_terms: D045744:Cell Line, Tumor; D058868:Compressed Air; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D009757:Nylons / Q000737:chemistry*
chemical_list: D004129:Dimethylpolysiloxanes; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer