Theoretical analysis of ferromagnetic microparticles in streaming liquid under the influence of external magnetic forces

Brandl, Martin; Mayer, Michael; Hartmann, Jens; Posnicek, Thomas; Fabián, Christian; Falkenhagen, D

doi:10.1016/j.jmmm.2010.02.056

Cited by 11 publications

(4 citation statements)

References 23 publications

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“…Because the Maxwell coils would produce a field free point in the central area, the center of the concentric sphere was set at (0, 0, 150) mm. The concentration of MNPs was 4 × 10 20 particles/m 3 [34]. The permeability µ of the MNPs with uniaxial anisotropy was a diagonal matrix.…”

Section: Numerical Simulationmentioning

confidence: 99%

Simulation Research on Magnetoacoustic Concentration Tomography With Magnetic Induction Based on Uniaxial Anisotropy of Magnetic Nanoparticles

Yan¹,

Hu²,

Shi³

et al. 2021

PIER C

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Magnetoacoustic concentration tomography with magnetic induction (MACT-MI) is a noninvasive imaging method that reconstructs the concentration image of magnetic nanoparticles (MNPs) based on the acoustic pressure signal generated by the magnetic properties of MNPs. The performance of MNPs is of great significance in MACT-MI. To study influences of the uniaxial anisotropy of MNPs on MACT-MI, firstly, based on the static magnetization curve, the force characteristic that the MNPs with uniaxial anisotropy experienced was analyzed. The magnetic force equation with the space component separated from the time term was deduced. The acoustic pressure equation containing the concentration of the MNPs with uniaxial anisotropy was derived. Then, a two-dimensional axisymmetric simulation model was constructed to compare magnetic force, acoustic source, and acoustic pressure before and after considering the uniaxial anisotropy of MNPs. The effect of scanning angle and detection radius of ultrasonic transducer on the acoustic pressure was studied. Finally, the concentration image of the MNPs with uniaxial anisotropy was reconstructed by the time reversal method and the method of moments (MoM). Theoretical considerations and simulation results have shown that the magnetic force has a triple increase after taking into account the uniaxial anisotropy of MNPs. The take-off time of acoustic pressure waves is only related to the position of the uniaxial anisotropy MNPs region. From the reconstructed image, concentration distribution and spatial location and size information of the uniaxial anisotropy MNPs region can be distinguished. The research results may lay the foundation for MACT-MI in subsequent experiments and even clinical applications.

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Section: Numerical Simulationmentioning

confidence: 99%

Simulation Research on Magnetoacoustic Concentration Tomography With Magnetic Induction Based on Uniaxial Anisotropy of Magnetic Nanoparticles

Yan¹,

Hu²,

Shi³

et al. 2021

PIER C

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“…Shinha et al [30] compared numerical prediction with measured data for magnetic particle trajectories and showed a very good agreement where they introduced a dimensionless ratio of the magnetic and the drag forces determining the capture efficiency of particles. Chen et al [31] and Brandl et al [32] have developed detoxification systems as a therapeutic tool for selective and rapid removal of biohazards using a magnetic separator. Convection-diffusion equations governing the concentration of magnetic beads have been integrated with numerical models for cell separation system (Mikkelsen and Bruus [33] and Li et al [34].…”

Section: The Mechanics Of a Magnetic Cell Separatormentioning

confidence: 99%

Removal of malaria-infected red blood cells using magnetic cell separators: A computational study

Kim

Massoudi

Antaki

et al. 2012

Applied Mathematics and Computation

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High gradient magnetic field separators have been widely used in a variety of biological applications. Recently, the use of magnetic separators to remove malaria-infected red blood cells (pRBCs) from blood circulation in patients with severe malaria has been proposed in a dialysis-like treatment. The capture efficiency of this process depends on many interrelated design variables and constraints such as magnetic pole array pitch, chamber height, and flow rate. In this paper, we model the malaria-infected RBCs (pRBCs) as paramagnetic particles suspended in a Newtonian fluid. Trajectories of the infected cells are numerically calculated inside a micro-channel exposed to a periodic magnetic field gradient. First-order stiff ordinary differential equations (ODEs) governing the trajectory of particles under periodic magnetic fields due to an array of wires are solved numerically using the 1st –5th order adaptive step Runge-Kutta solver. The numerical experiments show that in order to achieve a capture efficiency of 99% for the pRBCs it is required to have a longer length than 80 mm; this implies that in principle, using optimization techniques the length could be adjusted, i.e., shortened to achieve 99% capture efficiency of the pRBCs.

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“…[20][21][22][23][24] Typically, trapping MBs within a small section of a microfluidic channel to form a dense clump is an effective way to realize analyte capture. 25,26 A MB clump can be realized by applying a magnetic field generated by external permanent magnets, [27][28][29][30][31] electromagnets, [32][33][34][35] or on-chip magnetizable microstructures. [36][37][38] MB clumps based on static magnetic field suffer from a relatively low capture efficiency because the clumps cannot fill the cross section 26 or require a large amount of MBs.…”

Section: Introductionmentioning

confidence: 99%

On-chip immuno-agglutination assay based on a dynamic magnetic bead clump and a sheath-less flow cytometry

Zhang

et al. 2019

Biomicrofluidics

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Immunoagglutination assay is a promising approach for the detection of waterborne analytes like virus, cells, proteins with its advantages such as a smaller amount of reagents and easier operation. This paper presents a microfluidic agglutination assay on which all the assay processes including analyte capture, agglutination, and detection are performed. The chip integrates an on-chip pump for sample loading, a dynamic magnetic bead (MB) clump for analyte capture and agglutination, and a sheath-less flow cytometry for particle detection, sizing, and counting. The chip is tested with streptavidin-coated MBs and biotinylated bovine serum albumin as a model assay, which realizes a limit of detection (LOD) of 1 pM. Then, an antigen/antibody assay using rabbit IgG and goat anti-rabbit IgG coated MBs is tested and a LOD of 5.5 pM is achieved. At last, human ferritin in 10% fetal bovine serum is tested with Ab-functionalized MBs and the detection achieves a LOD of 8.5 pM. The whole procedure takes only 10 min in total.

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Theoretical analysis of ferromagnetic microparticles in streaming liquid under the influence of external magnetic forces

Cited by 11 publications

References 23 publications

Simulation Research on Magnetoacoustic Concentration Tomography With Magnetic Induction Based on Uniaxial Anisotropy of Magnetic Nanoparticles

Simulation Research on Magnetoacoustic Concentration Tomography With Magnetic Induction Based on Uniaxial Anisotropy of Magnetic Nanoparticles

Removal of malaria-infected red blood cells using magnetic cell separators: A computational study

On-chip immuno-agglutination assay based on a dynamic magnetic bead clump and a sheath-less flow cytometry

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