A miniaturized levitation system with motion control using a piezoelectric actuator

A microlevitation system utilizing a permanent magnet attached to a linear actuator is proposed for the purpose of micromanipulation. The air gap length between a small iron ball and a permanent magnet is adjusted to balance the magnetic force and gravity force. A piezoelectric actuator is used to control the air gap length because of its simple construction and low potential for thermal problems. A small iron ball 2.0 mm in diameter was successfully levitated about 40 /spl mu/m from the starting position. The time constant was within the range of 20 ms. This success should contribute to future efforts that utilize electrostatic or intermolecular forces for the noncontact suspension.