Magnetic Pressure as a Scalar Representation of Field Effects in Magnetic Suspensions.
Magnetic microsphere suspensions undergo complex motion when exposed to finite sources of the magnetic field, such as small permanent magnets. The computational complexity is compounded by a difficulty in choosing a suitable choice of visualization tools because this often requires using the magnetic force vector field in three dimensions. Here we present a potentially simpler approach by using the magnetic pressure. It is a scalar quantity,pm=B2/2μ0, and its usefulness has been already demonstrated in applications to magnetohydrodynamics and ferrohydrodynamics (whereBis the applied field andμ0= 4π×10-7T.m/A). The equilibrium distribution of the magnetic bead plug in aqueous suspension is calculated as an isosurface of the magnitude of the magnetic pressurepm=const, in the field of two permanent magnet blocks calculated from closed formulas. The geometry was adapted from a publication on the magnetic bead suspensions in microsystems and the predicted bead plug distribution is shown to agree remarkably well with the experiment.
Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio 44195, U.S.A.
Maciej
M
Zborowski
Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio 44195, U.S.A.
Lee R
LR
Moore
Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio 44195, U.S.A.
P Stephen
PS
Williams
Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, U.S.A.
Jeffrey J
JJ
Chalmers
magnetic body force; magnetic separation; superparamagnetic bead