Brownian dynamics simulations of interacting magnetic tri-axial ellipsoids

Magnetic nanorobots have immense potential for medical treatment at the cellular level. Colloidal nanorobots with independent locomotion and multi-actuating capabilities controlled by electromagnetic fields are still challenging. Our approach to fabricate nanorobots uses the dipolar interaction between anisotropic particles with different shapes and materials to generate tunable configurations between particles. Quantifying the high-dimensional dependence of dipolar interactions of tri-axial particles in position and orientation is crucial to model magnetic nanorobots. We report the analytical expressions for the interaction dipolar forces and torques between permanently magnetized tri-axial ellipsoids with different shapes and materials. We combine the novel ellipsoid-dipole model with unit quaternions to parameterize the orientational space. The analytical expressions capture the established behavior of uniform magnetic spheres. Additionally, we report Brownian dynamics simulations of interacting permanently magnetized ellipsoids under the influence of time-varying magnetic fields. We will show simulation results for binary systems composed of tri-axial ellipsoids with different shapes and sizes. We characterize the relative dynamic patterns between particles in the relative particle space. Simulation results show a synchronous particle rotation for small dipolar interactions; however, results show coupling rotation dynamics for strong dipolar interactions.