Precise positioning of a micro conveyor based on superconducting magnetic levitation

Abstract

The design and the driving characteristics of a micro conveyor based on superconducting magnetic levitation are reported. This actuator consists of three parts; a superconductor (Y-Ba-Cu-O), a stator layer made by patterned copper electrodes (line pitch: 180 /spl mu/m, width: 70 /spl mu/m) on the polyimide film and a slider with four permanent magnets (the size of one magnet is 1 mm cube). This conveyance actuator is free from particle generation, because there is no friction by the magnetic levitation. The position of the slider is controlled by the current in the patterned electrodes. We have obtained quick conveyance (280 /spl mu/m/s over 2.8 mm) and precise positioning with an accuracy of 40 /spl mu/m by combining the step actuation in the entire area and the micro-step actuation in the local area near the target position.