Surveys on ultra-precision positioning held seven times since 1986 are summarized in this paper. According to questionnaires in these surveys, including the latest in 2010, averaged recognition of "precision" is 1 μm and of "ultra-precision" 10 nm. Although positioning accuracy currently appears to have reached the development limit, accuracy under 1 nm is expected to be attained. Demand for higher speed, greater acceleration, and longer stroke increasing yearly has made the linear motor drive more popular. Improved displacement sensor performance now regularly uses the linear scale unit for practical reasons. Environmental concerns have led to hydraulic actuators being increasingly replaced by electromagnetic actuators, thus saving lubricating oil.
- Ultra-precision positioning