title: Generation of digitized microfluidic filling flow by vent control.
abstract: Quantitative microfluidic point-of-care testing has been translated into clinical applications to support a prompt decision on patient treatment. A nanointerstice-driven filling technique has been developed to realize the fast and robust filling of microfluidic channels with liquid samples, but it has failed to provide a consistent filling time owing to the wide variation in liquid viscosity, resulting in an increase in quantification errors. There is a strong demand for simple and quick flow control to ensure accurate quantification, without a serious increase in system complexity. A new control mechanism employing two-beam refraction and one solenoid valve was developed and found to successfully generate digitized filling flow, completely free from errors due to changes in viscosity. The validity of digitized filling flow was evaluated by the immunoassay, using liquids with a wide range of viscosity. This digitized microfluidic filling flow is a novel approach that could be applied in conventional microfluidic point-of-care testing.
authors.affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
authors.forename: Junghyo
authors.initials: J
authors.lastname: Yoon
authors.affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
authors.forename: Eundoo
authors.initials: E
authors.lastname: Lee
authors.affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Kim
authors.affiliation: The California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Sewoon
authors.initials: S
authors.lastname: Han
authors.affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea. Electronic address: sidchung@korea.ac.kr.
authors.forename: Seok
authors.initials: S
authors.lastname: Chung
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation; D004867:Equipment Design; D007118:Immunoassay / Q000295:instrumentation; D007074:Immunoglobulin G / Q000737:chemistry; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D000067716:Point-of-Care Testing; D014783:Viscosity
chemical_list: D055910:Antibodies, Immobilized; D007074:Immunoglobulin G
keywords: Digitized fluidic filling; Immunoassay; Microfluidic channel filling; Nanointerstice