Micro-rotor dynamics for micro-electro-mechanical systems (MEMS)

An overview of the development of micro-rotor dynamics for micro-electro-mechanical systems (MEMS) in China is presented. We consider the most important coupling between mechanical and electrical phenomena, and then focus on the dynamic modeling and simulation for micro-motors and power MEMS devices. A description of wear and friction for the rotor and dry friction bearing, where the scaling effect is considered, is given, and its dynamical characteristics are studied. The contact dynamics of the rotor and bearing bushing in an electrostatic micro-motor are represented analytically and numerically. Nonlinear dynamic characteristics of a rub-impact micro-rotor system are described and discussed. Lastly, we briefly review the scaling effect and slip effect on the gas micro-bearings and consider further the response and stability of the rotor-bearing system in micro rotating machinery. It is indicated that a comprehensive investigation on the nonlinear micro-rotor dynamics at micro-scale is of great import to help design a reasonable system and establish a reliable diagnosis system for micro rotating machinery in MEMS.