The subject of this paper is focused on the design and control of precision linear actuator system with sub-micron order positioning resolution. Externally pressurized static air-bearing was adopted in order to minimize the mechanical loss being infiltrated in supporting system of moving part, also to make motion smooth. Design of air-bearing is based on the obtaining required load capacity, vertical direction static stiffness by pressure-distribution FDM simulation. Four-sided bearing pad configuration ensures supporting least 15kg load, improving stiffness required to sustain the pitch, roll, yaw motion error bellow sub-micron over full travel length. Direct linear motion without any power transmiting mechanism is important to maintain sub-micron resolution promised by the air-bearing. Coil windings on the moving part, both L-type side yokes make the actuator's configuration simple and easy to assemble. Linear DC motor's stability was ensured through feedback loop composed of analog controller and capactive sensor with measuring length 250 micron. Experimental results verifies that it is possible to construct direct linear actuator whose positioning resolution is 25 nm, and to make linear actuator's mechanism simple.
