Abstract: Precision and ultra-precision 3D miniature components are increasingly in demand in the sector of aerospace, defense, micro-electronics, modem medicine and biological engineering industries in recent years. Micro-cutting technology draws more and more attention all around the world not only because of its ability to manufacture geometrically complex 3D miniature components in a wide range of engineering materials but also small equipments and low energy consumption. As key components of micro-machine tools, micro-spindles directly determine the performance of micro-machine tools and the development and application of micro-cutting technology. Therefore, it is necessary to review the performance requirements and research state of micro-spindles systematically and intensively. The performance requirements of micro-spindles for micro-cutting on cutting force, torque, rotating speed and rotary accuracy are systematically analyzed. The research state of micro spindles in respects of their structures, high-speed power sources, high-speed and precision bearings, tool holders, control and compensation is comprehensively elaborated. Some main problems existing in micro-spindles, such as rotating speed less than the requirement, large error motion of the tool and low chip load capacity at high rotating speed are pointed out in detail by comparing the present achievements with the performance requirements, and the feasible countermeasures presented. And the future development tendency of micro spindles is predicted and prospected.

Key words: Micro-cutting, Micro-machine tools, Micro-spindles, Ultra-high speed, Grinding energy consumption, Material removal rate, Non-circular grinding, Parameter identification, Torque model