title: Microfluidic device for sheathless particle focusing and separation using a viscoelastic fluid.
abstract: Continuous sheathless particle separation with high efficiency is essential for various applications such as biochemical analyses and clinical diagnosis. Here, a novel microfluidic device for highly efficient, sheathless particle separation using an elasticity-dominant non-Newtonian fluid is proposed. Our device consists of two stages: sheathless three-dimensional focusing (1 st stage) and separation (2nd stage). It is designed based on the principle of a viscoelasticity-induced particle lateral migration, which promises precise separation of particles in a microfluidic device. Particles of 5- and 10-μm diameters were all focused at the centerline of a circular channel at the 1st stage and successfully separated at the 2nd stage with an efficiency of ∼99.9% using size-based lateral migration of particles induced by the viscoelasticity of the medium. We also demonstrated the capability of our device for separation of blood cells into multiple fractions. The tunability of separable particle size could be achieved by changing the viscoelastic property of the medium and flow rate.
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore.
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Nam
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore.
authors.forename: Bumseok
authors.initials: B
authors.lastname: Namgung
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore; Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Chwee Teck
authors.initials: CT
authors.lastname: Lim
authors.affiliation: Department of Polymer Science and Engineering, Kyungpook National University, Daegu, South Korea.
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Bae
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore.
authors.forename: Hwa Liang
authors.initials: HL
authors.lastname: Leo
authors.affiliation: Department of Polymer Science and Engineering, Kyungpook National University, Daegu, South Korea.
authors.forename: Kwang Soo
authors.initials: KS
authors.lastname: Cho
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore; Department of Surgery, National University of Singapore, 1E Kent Ridge Road, Singapore 119228, Singapore. Electronic address: bieks@nus.edu.sg.
authors.forename: Sangho
authors.initials: S
authors.lastname: Kim
mesh_terms: D001773:Blood Cells / Q000166:cytology; D002469:Cell Separation / Q000295:instrumentation* / Q000379:methods*; D002623:Chemistry Techniques, Analytical; D004548:Elasticity; D006801:Humans; D046210:Microfluidic Analytical Techniques; D010316:Particle Size; D014783:Viscosity
keywords: Blood component separation; Microfluidics; Non-Newtonian fluid; Viscoelastic separation