Contact dynamics between the rotor and bearing hub in an electrostatic micromotor

Abstract

The most widely known nonlinear phenomena in microelectromechanical systems are probably the contact instabilities. Here, a mathematical model of the contact between the rotor and bearing hub of an electrostatic micromotor, which actuates MEMS, is constructed for the purpose of investigating the contact dynamics. The contact problem of the contact stress and strain equations is presented under the scaling effects of micro-scale. The parameters, geometries of the micromotor, electrostatic force, and applied gap voltages, which are related to the contact, are discussed in detail. The discriminations between unchanged gap and maximum changed gap are studied under different applied voltages. The model is studied by using a combination of numerical and finite element analytical techniques. Some results of the contact width, the contact stress, the contact strain, are compared with finite element model (FEM) solutions of an equivalent problem. The 1^st principal stress and strain and whole contact stress are shown for expressing the distributions.