Analysis of Hydrodynamic Mechanism on Particles Focusing in Micro-Channel Flows

Wang, Qikun; Yuan, Dan; Li, Weihua

doi:10.3390/mi8070197

Cited by 21 publications

(20 citation statements)

References 13 publications

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“…In Figure 7 , the positive and negative values of

indicate the direction of the force toward the channel center and the corner bisector. For the flow rate of 10 μL/min (Case D13Q10), the net forces in both directions are mainly negative with one zero point at the channel center, which constitutes the opposite behavior compared with that in Newtonian fluids [ 12 , 26 , 30 ]. This indicates that particles suspended in the rhombic channel are likely to migrate toward the channel center.…”

Section: Resultsmentioning

confidence: 99%

Particle Focusing under Newtonian and Viscoelastic Flow in a Straight Rhombic Microchannel

Kwon

Kim

et al. 2020

Micromachines

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Particle behavior in viscoelastic fluids has attracted considerable attention in recent years. In viscoelastic fluids, as opposed to Newtonian fluids, particle focusing can be simply realized in a microchannel without any external forces or complex structures. In this study, a polydimethylsiloxane (PDMS) microchannel with a rhombic cross-sectional shape was fabricated to experimentally investigate the behavior of inertial and elasto-inertial particles. Particle migration and behavior in Newtonian and non-Newtonian fluids were compared with respect to the flow rate and particle size to investigate their effect on the particle focusing position and focusing width. The PDMS rhombic microchannel was fabricated using basic microelectromechanical systems (MEMS) processes. The experimental results showed that single-line particle focusing was formed along the centerline of the microchannel in the non-Newtonian fluid, unlike the double-line particle focusing in the Newtonian fluid over a wide range of flow rates. Numerical simulation using the same flow conditions as in the experiments revealed that the particles suspended in the channel tend to drift toward the center of the channel owing to the negative net force throughout the cross-sectional area. This supports the experimental observation that the viscoelastic fluid in the rhombic microchannel significantly influences particle migration toward the channel center without any external force owing to coupling between the inertia and elasticity.

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“…In Figure 7 , the positive and negative values of

Section: Resultsmentioning

confidence: 99%

Particle Focusing under Newtonian and Viscoelastic Flow in a Straight Rhombic Microchannel

Kwon

Kim

et al. 2020

Micromachines

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“…In parallel to the development of the theory of inertial migration of particles, numerical methods have emerged as a powerful tool to predict inertial forces and particle focusing positions. Aiming at reducing the computational complexity of the simulated dynamics of particles in confined flows, many authors have proposed the use of an iterative procedure according to which the variables of the problem are referred to a moving frame of reference fixed to the moving sphere [21][22][23][24][25]. Since the sphere is stationary with respect to this frame of reference, the velocity of the backwards-moving walls and the angular velocity of the particle are then iteratively updated until the particle moves force and torque free.…”

Section: Introductionmentioning

confidence: 99%

“…Using a provided definition for the transverse flow (Dean flow), we present a phenomenological relationship about the behavior of the rotating particle and its interaction with the Dean and gradients of the flow. We believe that the description about the evolution of the angular velocity of the particle can be incorporated in a variety of systems, e.g., spirals [10,42,43], symmetric serpentines [44], and expansion/contraction chambers [45], to name a few, in order to define pre-set angular velocity components in less computation-intensive simulations like the ones we find in the literature for the more-simple straight channel case [21][22][23][24][25]. This would allow a substantial time improvement for simulations involving complex microfluidic systems in which some form of transverse flow is present.…”

Section: Introductionmentioning

confidence: 99%

Two-Way Coupling Fluid-Structure Interaction (FSI) Approach to Inertial Focusing Dynamics under Dean Flow Patterns in Asymmetric Serpentines

Pedrol

Díaz

Aguiló

2018

Fluids

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The dynamics of a spherical particle in an asymmetric serpentine is studied by finite element method (FEM) simulations in a physically unconstrained system. The two-way coupled time dependent solutions illustrate the path of the particle along a curve where a secondary flow (Dean flow) has developed. The simulated conditions were adjusted to match those of an experiment for which particles were focused under inertial focusing conditions in a microfluidic device. The obtained rotational modes inferred the influence of the local flow around the particle. We propose a new approach to find the decoupled secondary flow contribution employing a quasi-Stokes flow.

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“…The main difficulty in the study of non-spherical particles is that their migration is strongly coupled with their orientation and rotational regime [ 17 ]. For example, the lift component induced by the particle’s rotation has an obvious influence on the transverse focusing position of the particles, which cannot be neglected [ 65 ].…”

Section: Rotational and Migratory Behaviors Of A Particle Flowing mentioning

confidence: 99%

Transport of Non-Spherical Particles in Square Microchannel Flows: A Review

2021

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Understanding the behavior of a single particle flowing in a microchannel is a necessary step in designing and optimizing efficient microfluidic devices for the separation, concentration, counting, detecting, sorting, or mixing of particles in suspension. Although the inertial migration of spherical particles has been deeply investigated in the last two decades, most of the targeted applications involve shaped particles whose behavior in microflows is still far from being completely understood. While traveling in a channel, a particle both rotates and translates: it translates in the streamwise direction driven by the fluid flow but also in the cross-section perpendicular to the streamwise direction due to inertial effects. In addition, particles’ rotation and translation motions are coupled. Most of the existing works investigating the transport of particles in microchannels decouple their rotational and lateral migration behaviors: particle rotation is mainly studied in simple shear flows, whereas lateral migration is neglected, and studies on lateral migration mostly focus on spherical particles whose rotational behavior is simple. The aim of this review is to provide a summary of the different works existing in the literature on the inertial migration and the rotational behavior of non-spherical particles with a focus and discussion on the remaining scientific challenges in this field.

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Analysis of Hydrodynamic Mechanism on Particles Focusing in Micro-Channel Flows

Cited by 21 publications

References 13 publications

Particle Focusing under Newtonian and Viscoelastic Flow in a Straight Rhombic Microchannel

Particle Focusing under Newtonian and Viscoelastic Flow in a Straight Rhombic Microchannel

Two-Way Coupling Fluid-Structure Interaction (FSI) Approach to Inertial Focusing Dynamics under Dean Flow Patterns in Asymmetric Serpentines

Transport of Non-Spherical Particles in Square Microchannel Flows: A Review

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