Rotational dynamics of anisotropic particle in magnetic nanofluid

Abstract

We demonstrate dynamics of non magnetic particle in magnetic nanofluid media subjected to rotational magnetic field. We developed such technique which can able to rotate non magnetic microstructure at any angle between 0° to 360° using magnetic field. A single Bentonite particle of the order of ∼ 600nm was trapped by magnetic nano particles (∼ 9.3 nm) which posses’ magnetic moment, direction of such magnetic moment changes according to rotational magnetic field. Small asymmetries in nano particle orientation within media cause micro particle as whole exhibit prefers direction of magnetization or easy axis. These small anisotropies provide directional preference thus particle can be orientation controlled. In the influence of rotational magnetic field micro particle displays rotational as well as tumbling motion under certain conditions. This method of manipulation of anisotropic non magnetic particle has potential application to manipulating biological assemblies.