Oscillation of a magnetically levitated diamagnetic droplet under a vertical magnetic disturbance

The oscillation of a magnetically levitated liquid droplet in a magnetic fl uid is studied theoretically and experimentally. In the theoretical analysi s, a small amplitude nonviscous linear theory is adopted. Two models are em ployed according to the difference in both the magnetic and capillary press ures acting on the interface. Resonance angular frequencies of the levitate d liquid droplet are obtained. The responses of the droplet to magnetic fie ld disturbances are discussed. A pair of cylindrical permanent magnetic lik e poles was set face to face to form a static magnetic field that was used to levitate a diamagnetic liquid or water droplet in a diluted oil-base mag netic fluid, and a pair of electromagnets was used to produce the magnetic disturbances in experiments.