Two-dimensional flow magnetophoresis of microparticles

Abstract

A new two-dimensional micro-flow magnetophoresis device was constructed in a superconducting magnet (10 T) using triangular shaped pole pieces, which could apply a magnetic strength, B(dB/dx), in the range of ca. 0-14,000 T(2) m(-1) across a capillary cell. Polystyrene particles with diameters of 1, 3, and 6 μm were used as test samples in a paramagnetic medium of 1 M MnCl(2) to evaluate the performance of this method. Microparticles migrated across the capillary along the edge of the pole pieces, and then flowed through the gap in the pole piece at a position defined as the migration distance, depending on the magnetic susceptibility and the size of particles as well as the flow rate. The most effective flow rate to exhibit the largest resolution among the particles was theoretically predicted and experimentally confirmed. By this method, the magnetic susceptibilities of individual deoxygenated and non-deoxygenated red blood cells were measured from the relative migration distance.

Label‐Free Microfluidic Manipulation of Particles and Cells in Magnetic Liquids

“…Reproduced from ref. [59] (c) Deflection of diamagnetic particles by a permanent magnet in a microfluidic system. Reproduced from ref.…”

“…Tarn et al [ 51 ] applied diamagnetophoresis for a continuous separation of diamagnetic particles in MnCl 2 solution (0.48 and 0.79 M ), as shown in Figure 3 a. They examined the separation of 5 μm and 10 μm diameter particles in different concentrations of this salt solution and concluded that better separation performance could be achieved with a higher concentration of MnCl 2 solution in a superconducting magnet with an external magnetic fl ux of 10 T. Kawano et al [ 59 ] developed a two-dimensional capillary cell to separate particles in MnCl 2 solution (1 M ) using triangular shaped pole pieces, as shown in Figure 3 b. Fractionation of particles with different diameters (1, 3, and 6 μm) was achieved in a superconducting magnet. They also fractionated deoxygenated and nondeoxygenated red blood cells using a wider capillary cell.…”

“…[ 51 ] b) Separation of particles in MnCl 2 solution using triangular shaped pole pieces in a capillary. [ 59 ] c) Defl ection of diamagnetic particles by a permanent magnet in a microfl uidic system. [ 26 ] d) Microfl uidic separation of diamagnetic particles/cells with a microfabricated nickel microstructures.…”

Option of the Optical-mechanical Positioning of the Sensor and Sample in the Magnetometer. Determination of Magnetic Susceptibility of Powders and particles

“…Faraday's ponderomotive method is preferable in a case of statement of the problem about determining a sample' s magnetic susceptibility χ with a small volume V. Herewith it could be both solid and disperse sample (for example, powder sample of ferro-or ferromagnetic particles, which are disperse phase of many technological mediums, including those which are affected by magnetophoresis and magnetic control [1][2][3][4][5][6]). A magnetic (ponderomotive) force F, acting on study "microsample", becomes basic measurement value when magnetic loop of Faraday balance of field with intensity H (induction B = μ 0 H) and nonuniformity gradH (gradB) is creating between pole pieces.…”

The working zone in the interpolar area of the Faraday balance: an approach to testing the magnetic force factor stability criterion

“…We are talking about the advancing applied scientific research in magnetophoresis and magnetic control of highly dispersed ferro-or ferrimagnetic particles (ferrofractions of many technological, natural and industry-specific media) [1][2][3][4][5][6], where one of the key issues is to obtain the data on the particles magnetic susceptibility. So, by the yielded (almost direct) results of the susceptibility of the sample represented by a conglomerate of the particles experimentally separated from some medium and necessary to realise the Faraday method, we can quite definitely estimate the susceptibility of single particles by dividing these data by the values of their packaging bulk density (under condition of their sufficient mutual separation).…”