Berlin 2015 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 54: Wetting, Micro and Nanofluidics (joint session CPP, DY)

CPP 54.11: Vortrag

Mittwoch, 18. März 2015, 17:45–18:00, C 243

Inertial microfluidics: control of lift forces and dynamics of microfluidic crystals — •Christopher Prohm and Holger Stark — Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin

At intermediate Reynolds numbers, particles in microfluidic channels assemble at fixed distances from the channel axis and bounding walls [1]. This Segré-Silberberg effect can be described in terms of an inertial lift force acting on the particles. At increasing densities the particles form microfluidic crystals due to an interplay of hydrodynamic interactions and inertial lift forces [2]. Microfluidic devices utilizing inertial migration have recently been demonstrated for biomedical tasks such as particle sorting or separation [1].

Here, we investigate the motion of colloidal particles in microfluidic channels using the lattice Boltzmann method [3]. First, we show how the geometry of the channel influences inertial focusing of a single particle. We also demonstrate that manipulating the axial or angular velocity of the particle modifies its lift-force profile, which permits control of the lateral particle position. Second, we investigate suspensions of particles. We describe how they self-assemble into microfluidic particle crystals and discuss the dynamic properties of these crystals.

[1] H. Amini, W. Lee, and D. Di Carlo, Lab Chip 14, 2739 (2014).

[2] W. Lee, H. Amini, H. A. Stone, and D. Di Carlo, Proc. Natl. Acad. Sci. U.S.A. 107, 22413 (2010).

[3] C. Prohm and H. Stark, Lab Chip 14, 2115 (2014).