Structural design and multiphysics coupling analysis of aerostatic bearings for ultra-precision and high-stability applications: A review

Aerostatic bearings are key enabling components in ultra-precision and high-stability engineering applications owing to their negligible friction, high motion accuracy, and excellent stability. As advanced manufacturing and precision motion systems move toward nanometer- and subnanometer-level accuracy, traditional passive bearing systems face serious physical limitations. For example, very small film gaps that are used to increase stiffness often cause air hammer instability. Also, passive structures do not have the ability to adjust to multiphysics coupling errors during operation. And common continuum models cannot accurately predict nanoscale flow behavior, such as rarefied gas effects. To solve this problem, this review analyzes advanced analytical methods. In particular, it focuses on high-fidelity Fluid-Structure Interaction (FSI) models and Direct Simulation Monte Carlo (DSMC) methods for micro-scale gas flows. At the same time, recent structural designs are also examined. These include biomimetic micro-texture designs based on topological optimization and intelligent compensation using piezoelectric actuators. Evidence shows that combining optimized micro-grooves and active restrictors can increase load-carrying capacity and reduce vortex-induced micro-vibrations.