Motions of magnetic nanosphere under the magnetic field in the rectangular microchannel

The nano-sized magnetite and the magnetic nanospheres (MNS) were synthesized for biomedical applications by co-precipitation method and emulsion solvent evaporation method, respectively. The prepared magnetite and the MNS (∼250 nm) exhibited superparamagnetic behaviors with the saturation of magnetization of 52.6 and 38.7 emu/g, respectively. The size, distribution and morphology were investigated by light scattering and electron microscopy. The motions of the MNS under the magnetic field in rectangular microchannel were investigated by using the particle tracking velocimetry (PTV) method. The particle motions due to both the fluid flow and the magnetic field were calculated and the experimentally observed data were in good agreement with theoretical model.