Microparticle Inertial Focusing in an Asymmetric Curved Microchannel

Abstract

Inertial Microfluidics offer a high throughput, label-free, easy to design, and cost-effective solutions, and are a promising technique based on hydrodynamic forces (passive techniques) instead of external ones, which can be employed in the lab-on-a-chip and micro-total-analysis-systems for the focusing, manipulation, and separation of microparticles in chemical and biomedical applications. The current study focuses on the focusing behavior of the microparticles in an asymmetric curvilinear microchannel with curvature angle of 280 • . For this purpose, the focusing behavior of the microparticles with three different diameters, representing cells with different sizes in the microchannel, was experimentally studied at flow rates from 400 to 2700 µL/min. In this regard, the width and position of the focusing band are carefully recorded for all of the particles in all of the flow rates. Moreover, the distance between the binary combinations of the microparticles is reported for each flow rate, along with the Reynolds number corresponding to the largest distances. Furthermore, the results of this study are compared with those of the microchannel with the same curvature angle but having a symmetric geometry. The microchannel proposed in this study can be used or further modified for cell separation applications.

A passive microfluidic device for continuous microparticle enrichment

“…Özbey et al. also found that large particles were focused better than small ones in the inertial focusing microchannel . Hence the present microchannel could focus microparticles with a wide range of diameter.…”

“…It shows that 9.94 μm particles were focused one by one in a single line in the present device. The bandwidth of the 9.94 μm particle beam was less than 1.5 times the diameter of a single particle, which was much narrower than that of 10 μm particles in the asymmetric curved microchannel . Therefore, the present microchannels can be applied to enrich microparticles with various sizes simultaneously.…”

“…The passive methods for particle enrichment are mainly based on the hydrodynamic forces induced by various geometrical properties of the microchannels , including pinch flow , viscoelastic focusing , hydrodynamic filtration , deterministic lateral displacement arrays , and inertial focusing . Specifically, because of the simple structure and good performance, inertial focusing has attracted great attention since first observed by Segre and Silberberg .…”

“…Specifically, because of the simple structure and good performance, inertial focusing has attracted great attention since first observed by Segre and Silberberg . Microchannels used for the inertial focusing include the straight channel , the straight channel with three dimensional (3D) microstructures on top or bottom walls , the straight channel with expansion‐contraction cavity arrays , the spiral channel and the curved serpentine channel . For instance, subjected to the inertial lift force, microparticles were focused in four‐point attractor positions in square microchannel while they were focused in two or three laterally positioned streams in a rectangular microchannel with appropriate aspect ratio and Reynolds number ( Re ) .…”

Inertial focusing of microparticles, bacteria, and blood in serpentine glass channels

“…The glass devices in this communication were isotropically etched, resulting in "D-shaped" cross-section microchannels (Fig. S1.2), unlike the majority of inertial focusing devices with rectangular/squared shapes fabricated from PDMS [23,51,[53][54][55][56]76] or thermoset polyester [49]. Two designs were employed, etched at two different depths from the same photomask, and referred to as "shallow design" (25 μm depth) and "deep design" (40 μm depth).…”