Optically Three-Dimensional Control of Magnetic Levitation Using Temperature-Sensitive Ferrite

Optically driven actuators have a feature of a noncontact for applying moving energy remotely. In this paper, we propose a new method for optically driving a magnetic levitation system, which consists of a neodymium magnet as a movement object, a ferrite magnet, two blocks of graphite and a temperature-sensitive ferrite. The neodymium magnet is levitated by the diamagnetism of the graphite and the magnetic force between the neodymium and the ferrite. When a laser beam is irradiated on one of the temperature-sensitive ferrites, its magnetic susceptibility easily decreases owing to the photothermal effect. A levitated condition is derived from a numerical approach. As a result, the movement is successfully controlled in a three-dimensional area.