Design of Magnetic Force Field for Trajectory Control of Levitated Diamagnetic Graphite

Abstract

A diamagnetic material can be levitated in a strong magnetic field using a repulsive force due to its negative magnetic susceptibility. The magnitude of the repulsive force is proportional to the magnetic force field and the magnetic susceptibility of the material. Using this simple concept, a novel method is developed for trajectory control of the levitated diamagnetic material without a power source. In this study, pyrolytic graphite (PG) is adopted as the levitated material due to its strong diamagnetic response. Various motions of a PG disk, such as linear, curved, and pendulum motions, are realized with unique permanent magnet arrays. These movements are successfully achieved through manipulating the magnetic force field variation, which is verified with simulation results. Furthermore, a photo-gated motion is accomplished through utilizing photo-thermal energy that is transferred with a laser beam. This study demonstrates the possibility of developing frictionless transport systems.