1. Electro-Viscoelastic Migration under Simultaneously Applied Microfluidic Pressure-Driven Flow and Electric Field
- Author
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Caglar Elbuken, Melis Özkan, Ziya Isiksacan, Murat Serhatlioglu, Dönüs Tuncel, Serhatlıoğlu, Murat, Işıksaçan, Ziya, Özkan, Melis, Tuncel, Dönüş, and Elbüken, Çağlar
- Subjects
Chemistry ,010401 analytical chemistry ,Microfluidics ,Dynamics (mechanics) ,Pressure-driven flow ,Mechanics ,010402 general chemistry ,01 natural sciences ,Viscoelasticity ,0104 chemical sciences ,Analytical Chemistry ,Condensed Matter::Soft Condensed Matter ,Physics::Fluid Dynamics ,Flow (mathematics) ,Electric field ,Microfluidic channel - Abstract
Under the simultaneous use of pressure-driven flow and DC electric field, migration of particles inside microfluidic channels exhibits intricate focusing dynamics. Available experimental and analytical studies fall short in giving a thorough explanation to particle equilibrium states. Also, the understanding is so far limited to the results based on Newtonian and neutral viscoelastic carrier fluids. Hence, a holistic approach is taken in this study to elaborate the interplay of governing electrophoretic and slip-induced/elastic/shear gradient lift forces. First, we carried out experimental studies on particle migration in Newtonian, neutral viscoelastic, and polyelectrolyte viscoelastic media to provide a comprehensive understanding of particle migration. The experiments with the viscoelastic media led to contradictory results with the existing explanations. Then, we introduced the Electro-Viscoelastic Migration (EVM) theory to give a unifying explanation to particle migration in Newtonian and viscoelastic solutions. Confocal imaging with fluorescent-labeled polymer solutions was used to explore the underlying migration behavior. A surprising outcome of our results is the formation of cross-sectionally nonuniform viscoelasticity that may have unique applications in microfluidic particle focusing.
- Published
- 2020