title: Passive microfluidic control of two merging streams by capillarity and relative flow resistance.
abstract: In the progress of microfluidic devices, a simple and precise control of multiple streams has been essential for complex microfluidic networks. Consequently, microfluidic devices, which have a simple structure, typically use external energy sources to control the multiple streams. Here, we propose a pure passive scheme that uses capillarity without using external force or external regulation to control the merging of two streams and even to regulate their volumetric flow rate (VFR). We accomplish this process by controlling the geometry of two inlets and a junction, and by regulating the hydrophilicity of a substrate. Additionally, we use the relative flow resistance to control the VFR ratio of the merged two streams. Our results will significantly simplify the control of multiple streams without sacrificing precision.
authors.affiliation: Biosensor Group, Electronics and Telecommunications Research Institute, Daejeon 305-350, Korea. yahokim@etri.re.kr
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Yong Taik
authors.initials: YT
authors.lastname: Lim
authors.forename: Haesik
authors.initials: H
authors.lastname: Yang
authors.forename: Yong Beom
authors.initials: YB
authors.lastname: Shin
authors.forename: Kyuwon
authors.initials: K
authors.lastname: Kim
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Lee
authors.forename: Se Ho
authors.initials: SH
authors.lastname: Park
authors.forename: Youn Tae
authors.initials: YT
authors.lastname: Kim
mesh_terms: D002197:Capillary Action; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water