DESIGNING AND ANALYSING DIFFERENT SHAPES OF MEMS BASED ELECTROSTATICALLY CONTROLLED MICROMIRRORS

N adaptive optics and point - to - point communication, various micro mirror devices have been used to reshape the wavefront of a propagating beam to compensate for aberrations in the beam path. Such MEMS mirrors offer inherent advantages in speed, compactness, and economy in comparison to their macroscale counterparts. [6].Mirrors are fundamental components of most op tical systems. The miniaturization of optical components leads to higher packaging density and increased speed of devices that manipulate light. This is part of the vast field of Microsystems technology, designated by Micro - Opto - Electro - Mechanical Systems (MOEMS), in which electronic, mechanical, and optical devices are integrated on the micron scale [4]. This paper describes about various micromirror shapes to allow for determination of optimal, distortion minimizing Micromirrors .Different shapes of micro mirrors namely square , circular[3] and hexagon shaped [5]are designed and these micro mirror models are simulated by using COMSOL Multi physics Software . Electrostatic actuation is used to defect the micromirror. The most important parameter involved in the working of micromirror during lift off is the surface deformation and here mirror is designed to reduce mirror deformation i.e., to maintain flat surface at top during lift off so that distortion can be minimized .So the results of all the three differ ently shaped micromirrors are analyzed in terms of less induced stress along edges of micromirror due to lift off ,least surface deformation during lift off and maximum displacement of the micromiror [1,2]