Hydrodynamic instability in a magnetically driven suspension of paramagnetic red blood cells.

We investigate the magnetically driven motion in suspensions of paramagnetic particles. Our object is diluted deoxygenated whole blood with paramagnetic red blood cells (RBCs). We use direct observations in a closed vertical Hele-Shaw channel, and a well-defined magnetic force field applied horizontally in the channel plane.

Analytical model of batch magnetophoretic separation.

Magnetophoresis (the motion of magnetic particles driven by the nonuniform magnetic field), that for a long time has been used for extracting magnetically susceptible objects in diverse industries, now attracts interest to develop more sophisticated microfluidic and batch techniques for separation and manipulation of biological particles, and magnetically assisted absorption and catalysis in organic chemistry, biochemistry, and petrochemistry. A deficiency of magnetic separation science is the lack of simple analytical models imitating real processes of magnetic separation. We have studied the motion of superparamagnetic (generally, soft magnetic) particles in liquid in the three-dimensional field of the diametrically polarized permanent cylindrical magnet; this geometry is basically representative of the batch separation mode.

Magnetophoretic trajectory tracking magnetometry: a new technique for assessing magnetic properties of submagnetic microparticles and cells.

We develop a new approach for assessing magnetic properties of submagnetic microparticles and cells, magnetophoretic trajectory tracking magnetometry (MTTM), that employs recording of long 2D trajectories of particle motion in a slot fluid channel caused by the action of crossed gravitational and magnetic forces. The studies are focused on the development of theoretical backgrounds of the method and evaluation of its uncertainty caused by the mutual hydrodynamic entrainment of moving particles. Computerized equipment implementing MTTM technique is described and its performance is illustrated.