Motion of bio-functionalized magnetic nanoparticle clusters under a rotating magnetic field

Ji-Ching Lai - Chia-Chun Tang - Chin-Yih Hong

Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taiwan

Abstract
Bio-functionalized magnetic nanoparticles in an aqueous solution agglomerate and form clusters with various sizes and shapes due to the interaction between biomolecules. In this study, the motion of magnetic nanoparticle clusters in an aqueous solution under rotating magnetic fields was investigated. Due to the interaction between the rotating magnetic field and the net magnetic dipole moment, the clusters were subjected to a forced vibration. Two motion modes of clusters were observed as the magnetic field rotated. These two modes were rotation and oscillation, depending on each cluster’s size. The characteristics of these motions were also examined. With oscillatory motion, the oscillation frequency of the clusters was twice that of the field frequency. On the other hand, for the rotational motion, the rotation frequency of the clusters was the same as the field frequency. The angular velocities and accelerations of the clusters were also analyzed for both motion modes. Figs 6, Refs 9.