Mechanism for clogging of microchannels

Wyss, Hans M.; Blair, David F.; Morris, Jeffrey F.; Stone, Howard A.; Weitz, David A.

doi:10.1103/physreve.74.061402

Cited by 236 publications

(256 citation statements)

References 9 publications

Supporting

Mentioning

240

Contrasting

Order By: Relevance

“…The characteristic distance is closely related to the colloidal and hydrodynamic forces that control particle stability. This capture mechanism is known as interception and has been investigated recently by Wyss et al [64] at the level of a single pore using microfluidic channels.…”

Section: Particle Capture Mechanismsmentioning

confidence: 99%

Clogging of microchannels by nano-particles due to hetero-coagulation in elongational flow

Georgieva

Dijkstra

Fricke

et al. 2010

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

We have investigated the phenomenon of flow-induced aggregation in highly concentrated colloidal dispersions exposed to strongly converging flow fields. This phenomenon is relevant not only for classical technical operations like coating, pumping or filtration, but also for the application of concentrated suspensions in upcoming processing technologies based on microfluidic devices. A ring-slit device (gap height 10 micrometers to 25 micrometers), which allows for a variation of flow kinematics in a wide range, has been developed in order to investigate this phenomenon. Various polymer dispersions with different particle surface properties have been used as model systems. Our experiments exclude, that channel clogging is due to retention of pre-existing aggregates, fouling or hydrodynamic bridging. Instead, we demonstrate that clogging of the microchannel is induced by hetero-coagulation between primary colloidal particles and micron-sized impurities present at concentrations on the order of 100 ppm to 1000 ppm. Clogging can occur even if the diameter of these impurities is less than a tenth of the gap height. Aggregation takes place in the converging flow field at the channel entrance, but not in the shear field within the slit. It can be suppressed by appropriate stabilization of the primary particles

show abstract

Section: Particle Capture Mechanismsmentioning

confidence: 99%

Clogging of microchannels by nano-particles due to hetero-coagulation in elongational flow

Georgieva

Dijkstra

Fricke

et al. 2010

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

show abstract

“…They showed that a stable balance between the hydrodynamic forces and contact forces (mainly solid friction) between particles and the wall provokes the formation of arches. Wyss et al [5] studied PDMS microchannels clogging by an aqueous suspension of monodisperse polystyrene beads. The formation of plugs at the microchannel entrance occurred when a critical number of particles had flowed through the pore whatever the flowrate and the particle volume fraction.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of channel blockage by flowing microparticles

2014

View full text Add to dashboard Cite

a b s t r a c tThe dynamic formation of 3D structures of microparticle aggregates blocking the flow through straight microchannels is investigated by direct numerical simulation of the coupled motion of particles and fluid. We use the Force Coupling Method to handle simultaneously multibody hydrodynamic interactions of confined flowing suspension together with particle-particle and particle-wall surface interactions leading to adhesion and aggregation of particles. The basic idea of the Force Coupling Method relies on a multipole expansion of forcing terms (added to the Navier-Stokes equations) accounting for the velocity perturbation induced by the presence of particles in the fluid flow. When a particle reaches the wall or an attached particle, we consider that the adhesion is irreversible and this particle remains fixed. We investigate the kinetics of the microchannel blockage for several solid volumetric concentrations and different surface interaction forces. Many physical quantities such as the temporal evolution of the bulk permeability, capture efficiency, modification of the fluid flow and forces acting on attached particles are analyzed. We show that physical-chemical interactions, modeled by DLVO forces, are essential features which control the blockage dynamics and aggregate structure. IntroductionThe physics of transport, deposition, detachment and reentrainment of colloidal particles suspended in a fluid are of major interest in many areas of fluids engineering: fouling of heat exchangers, contamination of nuclear reactors, plugging of filtration membranes and occlusion of human veins, deposits in microelectronics and in the paper industry. In many solid/liquid separation processes such as micro-filtration or ultrafiltration of water, the limitation of the process performance is related to the fouling of filtration devices. To prevent or control the occurrence of fouling, it is necessary to achieve a better understanding of the respective roles of physical-chemical phenomena and hydrodynamic interactions in a confined suspension of particles. Non-hydrodynamic surface interactions and the adhesion of particles onto solid surfaces are the essential features to be modeled. However, mainly because of a complex interplay between the hydrodynamics of the flow, the physical-chemical properties of the filtered suspensions (often in a colloidal state) and the nature of the solid material, predicting fouling dynamics is still challenging.Different experimental techniques and numerical approaches have been developed to achieve new insights on the local structure of particle aggregates and the kinetics of blockage. Sharp and Adrian [4], by means of experiments in microtubes, observed blockage due to arch formation. The experiments were performed using liquids seeded with polystyrene beads at low volumetric concentration. They showed that a stable balance between the hydrodynamic forces and contact forces (mainly solid friction) between particles and the wall provokes the formation of arches. Wyss et al.[5] stu...

show abstract

“…As a result, unwanted microspheres aggregate in that region. 17 ). Such separations also eliminate the possibility of two microspheres arriving at a trap simultaneously and intending to fill in the same trap.…”

Section: Optimizing Microfluidic Microsphere-trap Arraysmentioning

confidence: 99%

“…We have optimized this geometry to increase the microspheres' packing density and simultaneously satisfied other design criteria, such as eliminating channel clogging, 17 avoiding multiple microspheres trapping at one trap location, satisfying the trap array device's microfabrication tolerance and feasibility, 20 and achieving the optimal distance d 0 between microspheres obtained in the statistical design to minimize image analysis error. 6 Image analysis error is experienced during analysis of the fluorescence images of targets captured by the microsphere array device.…”

Section: Trap Geometry and Optimizationmentioning

confidence: 99%

Optimization of microfluidic microsphere-trap arrays

Sarder

et al. 2013

Biomicrofluidics

View full text Add to dashboard Cite

Microarray devices are powerful for detecting and analyzing biological targets. However, the potential of these devices may not be fully realized due to the lack of optimization of their design and implementation. In this work, we consider a microsphere-trap array device by employing microfluidic techniques and a hydrodynamic trapping mechanism. We design a novel geometric structure of the trap array in the device, and develop a comprehensive and robust framework to optimize the values of the geometric parameters to maximize the microsphere arrays' packing density. We also simultaneously optimize multiple criteria, such as efficiently immobilizing a single microsphere in each trap, effectively eliminating fluidic errors such as channel clogging and multiple microspheres in a single trap, minimizing errors in subsequent imaging experiments, and easily recovering targets. We use finite element simulations to validate the trapping mechanism of the device, and to study the effects of the optimization geometric parameters. We further perform microsphere-trapping experiments using the optimized device and a device with randomly selected geometric parameters, which we denote as the un-optimized device. These experiments demonstrate easy control of the transportation and manipulation of the microspheres in the optimized device. They also show that the optimized device greatly outperforms the un-optimized device by increasing the packing density by a factor of two, improving the microsphere trapping efficiency from 58% to 99%, and reducing fluidic errors from 48% to a negligible level (less than 1%). The optimization framework lays the foundation for the future goal of developing a modular, reliable, efficient, and inexpensive lab-on-a-chip system.

show abstract

Mechanism for clogging of microchannels

Cited by 236 publications

References 9 publications

Clogging of microchannels by nano-particles due to hetero-coagulation in elongational flow

Clogging of microchannels by nano-particles due to hetero-coagulation in elongational flow

Numerical investigation of channel blockage by flowing microparticles

Optimization of microfluidic microsphere-trap arrays

Contact Info

Product

Resources

About