Numerical Modelling of Magnetic Nanoparticle Behavior in an Alternating Magnetic Field Based on Multiphysics Coupling

Abstract

In magnetic nanoparticle hyperthermia, the magnetic nanoparticles (MNPs) start oscilla- tions when they are exposed to an alternating magnetic field, which may generate ultra- sound waves. These resulting oscillations of nanoparticles can lead to the movement of drug carrier liposomes. In this study, a multiphysics coupling model of magnetic nanoparticle behavior in an alternating magnetic field was developed, implementing solid mechanics compliance parameters and piezomagnetic coupling matrices. A detailed sensitivity study was conducted to to examine the effects of size and elastic modulus of MNPs, distribution and distance between two MNPs, elasticity and viscosity of the glycerol medium and mesh element sizes on the output displacement signals of MNPs. The results indicated that mag- netic nanoparticles undergo some displacements when they are exposed to an alternating magnetic field. These oscillations may generate ultrasound waves, though the amount of displacement for each nanoparticle is negligibly small. It is expected that aggregated nanoparticles result in much higher oscillations.