Wall-induced lateral migration in particle electrophoresis through a rectangular microchannel

Liang, Litao; Ai, Ye; Zhu, Junjie; Qian, Shizhi; Xuan, Xiangchun

doi:10.1016/j.jcis.2010.03.039

Cited by 73 publications

(74 citation statements)

References 58 publications

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“…In contrast, 3 mm particles entered into the serpentine section in an already focused stream along the channel centerline. This happened mainly due to the wall-induced lateral migration as demonstrated recently by Liang et al [37]. Moreover, since they experienced a much larger dielectrophoretic force than 1 mm particles, 3 mm particles were deflected past the channel centerline to the outer sidewall.…”

Section: Resultsmentioning

confidence: 83%

Negative dielectrophoresis‐based particle separation by size in a serpentine microchannel

2011

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Dielectrophoresis has been widely used to focus, trap, concentrate, and sort particles in microfluidic devices. This work demonstrates a continuous separation of particles by size in a serpentine microchannel using negative dielectrophoresis. Depending on the magnitude of the turn-induced dielectrophoretic force, particles travelling electrokinetically through a serpentine channel either migrate toward the centerline or bounce between the two sidewalls. These distinctive focusing and bouncing phenomena are utilized to implement a dielectrophoretic separation of 1 and 3 μm polystyrene particles under a DC-biased AC electric field of 880 V/cm on average. The particle separation process in the entire microchannel is simulated by a numerical model.

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Section: Resultsmentioning

confidence: 83%

Negative dielectrophoresis‐based particle separation by size in a serpentine microchannel

2011

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“…It has become one of the most promising techniques for the delivery and manipulation of colloidal particles in lab-on-a-chip devices in the absence of complicated moving components [1]. So far, extensive theoretical analysis [2][3][4][5][6][7][8][9][10][11][12] and experimental studies [8,10,[13][14][15][16][17] have been performed on the electrokinetic particle translocation in microchannels.…”

Section: Introductionmentioning

confidence: 99%

Direct numerical simulation of electrokinetic translocation of a cylindrical particle through a nanopore using a Poisson–Boltzmann approach

Qian

2011

Electrophoresis

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Nanopore-based sensing of single molecules is based on a detectable change in the ionic current arising from the electrokinetic translocation of individual nanoparticles through a nanopore. In this study, we propose a continuum-based model to investigate the dynamic electrokinetic translocation of a cylindrical nanoparticle through a nanopore and the corresponding ionic current response. It is the first time to simultaneously solve the Poisson-Boltzmann equation for the ionic concentrations and the electric field contributed by the surface charges of the nanopore and the nanoparticle, the Laplace equation for the externally applied electric field, and the modified Stokes equations for the flow field using an arbitrary Lagrangian-Eulerian method. Current blockade due to the particle translocation is predicted when the electric double layers (EDLs) of the particle and the nanopore are not overlapped, which is in qualitative agreement with existing experimental observations. Effects due to the electric field intensity imposed, the EDL thickness, the nanopore's surface charge, the particle's initial orientation and lateral offset from the nanopore's centerline on the particle translocation including both translation and rotation, and the ionic current response are comprehensively investigated. Under a relatively low electric field imposed, the particle experiences a significant rotation and a lateral movement. However, the particle is aligned with its longest axis parallel to the local electric field very quickly due to the dielectrophoretic effect when the external electric field is relatively high.

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“…We approximate diffusion as negligible (Pe, the P eclet number, ) 1), particle inertial effects as small compared to the fluid and DEP forces (St, the Stokes number, ( 1), and neglect the wall-induced particle migration effects observed in long microchannels. [34][35][36] (As the length of the constriction between adjacent obstacles is on the order of the obstacle diameter, 2a ¼ 100 lm.) In the absence of DEP forces, each cell acts as a Lagrangian tracer, passively following the fluid streamlines unless the cell contacts an obstacle, at which time a no-penetration condition is enforced using an ad hoc quadratic penalty function designed to mimic the compression of a deformable sphere.…”

Section: Cell Transport Simulationsmentioning

confidence: 99%

Enhancing sensitivity and specificity in rare cell capture microdevices with dielectrophoresis

2015

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The capture and subsequent analysis of rare cells, such as circulating tumor cells from a peripheral blood sample, has the potential to advance our understanding and treatment of a wide range of diseases. There is a particular need for high purity (i.e., high specificity) techniques to isolate these cells, reducing the time and cost required for single-cell genetic analyses by decreasing the number of contaminating cells analyzed. Previous work has shown that antibody-based immunocapture can be combined with dielectrophoresis (DEP) to differentially isolate cancer cells from leukocytes in a characterization device. Here, we build on that work by developing numerical simulations that identify microfluidic obstacle array geometries where DEP-immunocapture can be used to maximize the capture of target rare cells, while minimizing the capture of contaminating cells. We consider geometries with electrodes offset from the array and parallel to the fluid flow, maximizing the magnitude of the resulting electric field at the obstacles' leading and trailing edges, and minimizing it at the obstacles' shoulders. This configuration attracts cells with a positive DEP (pDEP) response to the leading edge, where the shear stress is low and residence time is long, resulting in a high capture probability; although these cells are also repelled from the shoulder region, the high local fluid velocity at the shoulder minimizes the impact on the overall transport and capture. Likewise, cells undergoing negative DEP (nDEP) are repelled from regions of high capture probability and attracted to regions where capture is unlikely. These simulations predict that DEP can be used to reduce the probability of capturing contaminating peripheral blood mononuclear cells (using nDEP) from 0.16 to 0.01 while simultaneously increasing the capture of several pancreatic cancer cell lines from 0.03-0.10 to 0.14-0.55, laying the groundwork for the experimental study of hybrid DEP-immunocapture obstacle array microdevices. V C 2015 AIP Publishing LLC.

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Wall-induced lateral migration in particle electrophoresis through a rectangular microchannel

Cited by 73 publications

References 58 publications

Negative dielectrophoresis‐based particle separation by size in a serpentine microchannel

Negative dielectrophoresis‐based particle separation by size in a serpentine microchannel

Direct numerical simulation of electrokinetic translocation of a cylindrical particle through a nanopore using a Poisson–Boltzmann approach

Enhancing sensitivity and specificity in rare cell capture microdevices with dielectrophoresis

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