Geometry-Dependent Efficiency of Dean-Flow Affected Lateral Particle Focusing and Separation in Periodically Inhomogeneous Microfluidic Channels

Abstract

In this study, inertial focusing phenomenon was investigated, which can be used as a passive method for sample preparation and target manipulation in case of particulate suspensions. Asymmetric channel geometry was designed to apply additional inertial forces besides lift forces to promote laterally ordered particles to achieve sheathless focusing or size-dependent sorting. The evolving hydrodynamic forces were tailored with altered channel parameters (width and height), and different flow rates, to get a better understanding of smaller beads’ lateral migration. Fluorescent beads (with the diameter of 4.8 µm and 15.8 µm) were used to distinguish the focusing position in continuous flow, and experimental results were compared to in silico models for particle movement prediction, made in COMSOL Multiphysics. The focusing behaviour of the applied microfluidic system was mainly characterised for particle size in the range close to blood cells and bacteria.

Dean-Flow Affected Lateral Focusing and Separation of Particles and Cells in Periodically Inhomogeneous Microfluidic Channels

“…The phenomenon evolving in the curved channel was explained in more detail in our previous publication [ 20 ]. To study the concept, rigid spherical polystyrene beads were used, which do not take on a special form of movement in continuous flow.…”

“…In this report, the measurements were executed in a PDMS-glass hybrid platform. In our previous work [ 20 ], experiments were prepared to understand how the microfluidic channel’s parametric change (height and critical width) can affect the focusing efficiency of smaller beads; what are the minimal flow rates for particle focusing of the specific parameters; and how extending the length of the curved channel would affect the focusing process. The purpose of the current report is to give a detailed explanation in the interpretation of the particle-size-dependent focusing phenomenon.…”

Generation of colloidal crystals under pressure driven flow within converging diverging nozzle geometry

“…Similarly, the assembly of colloidal particles on porous material has been achieved through continuous flow printing within microfluidic devices [9]. Furthermore, utilizing expanding and contracting microfluidic geometry, Banyal et al achieved particle focusing within the channels [3].…”