Abstract : Ultra-precision stages are required in many high-tech fields as technical support. This paper introduces the principles, performance, and applications of electromagnetic stages, linear motor stages, piezoelectric stages, friction-driven stages, MEMS stages, and other types of stages. Their respective characteristics are also analyzed. Appropriate ultra-precision positioning schemes can be selected according to different application requirements. Keywords : Ultra-precision positioning [b]1 Introduction[/b] In fields such as semiconductor lithography, micromechanics, precision measurement, ultra-precision machining, micro-assembly, biological cell manipulation, and nanotechnology, extremely precise positioning and very fine motion are required. Therefore, high-performance ultra-precision positioning stages have become the technical support for these fields. For example, with the increasing integration of integrated circuits, linewidths have developed towards sub-micrometer levels, thus imposing stringent limitations on positioning accuracy during manufacturing. When machining non-spherical surfaces, strict requirements are placed on the motion accuracy of the tool relative to the workpiece in order to obtain accurate shapes and high-quality surfaces. Existing MEMS processing technology is suitable for manufacturing two-dimensional or quasi-three-dimensional micromechanical structures. To obtain complex micro-3D structures, a feasible approach currently is to employ micro-assembly technology, which involves assembling microstructures manufactured using MEMS in a specific manner. Micro-assembly requires a compact, ultra-precision stage with a large in-plane travel. Furthermore, to expand the measurement range of the scanning tunneling microscope (M), a high-precision stage is needed to achieve large-scale ultra-precision positioning together with the probe. Conventional drive and transmission methods are no longer suitable for achieving sub-micron or even nanometer-level positioning. For example, servo motor drives and precision lead screw drives are often used for precise positioning; however, due to thread idle and transmission friction, the positioning accuracy of this method is generally limited to the micrometer level. Therefore, seeking special drive and transmission methods to enable the stage to achieve nanometer-level displacement resolution has become essential. [b][align=center]For more details, please click: Ultra-precision Positioning Stage[/align][/b]