Electromagnetic Actuation System for Focused Capturing of Magnetic Particles with a Half of Static Saddle Potential Energy Configuration.

Targeted drug delivery using magnetic particles (MPs) and external magnets for focusing them at the diseased regions, called magnetic drug targeting (MDT), is a next-generation therapeutic method that is being continually improved. However, most existing magnetic systems cannot focus MPs in the targeted region due to there not being enough magnetic capturing force and absence of schemes to generate localized high magnetic field at the wall of the target region. This paper suggests a novel scheme to utilize half of a static saddle potential energy configuration generated using four electromagnets that not only enhances the pushing magnetic forces but also simultaneously generates pushing and attracting forces in the desired direction to help focus spherical MPs on the wall of the target region. Furthermore, by changing amplitudes or directions of the currents, the focal point in the target region can be changed. Through extensive simulations and in vitro experiments, we demonstrate that half of a static saddle magnetic potential energy configuration can be successfully utilized to attract and focus MPs at the wall of a target region.