Abstract: A linear sliding wear model of the contact between hemispherical bushing and ground plane is presented to describe the wear process for the issues of typical friction and wear of the rotor bushings in high-speed rotating micro-motors.A hemispherical-bushing-on-ground-plane configuration finite element model(FEM) was set up to investigate the wear characteristics of the micro-rotor bushings and the contact characteristics of the bushing-on-ground-plane elements.Effects of geometry parameters and applied operating conditions on the wear were investigated.Results indicate that radial distance of the bushing from the rotor center and the radius of the hemispherical bushing significantly affect wear rate,and minimzing both two values will result in lowest wear for micro-rotor systems in MEMS.However,it is noted that the bearing radius sets a lower limit on the hemispherical bushing radius since the bushings are located beyond the rotor inner radius.It is desirable to reduce their effects on friction and wear on micro-rotors by regulating the radius of the bushing and the radial distance of the bushing from the rotor center within permissive range of micro-fabrication.Severe wear exists with increasing applied load and rotating speed of the rotor.Stress distributions in the contact region are different from Hertz solutions due to the convergence stresses apearing on the uncontinuous curvature line and the contact pressures display symmetrical parabola in the contact region.This model can be used to predict wear of rotor bushing,to solve contact problem,and to analyze wear characteristics of the micro-rotor system.