Authors: J. You, M. Packirisamy and I. Stiharu
Affilation: Concordia University, Canada
Pages: 590 - 593
Keywords: torsional micromirror, electrostatic actuation, surface micromachining, static performance, dynamic response, modelling, simulation, finite element analysis
In general, this paper presents the deduced analytical model and numerical simulation of electrostatically actuated torsional micromirrors with two symmetrical side springs of multiple rotational serpentine elements. Modelling of these kinds of micromirrors is carried out for the purpose of designing very soft planar springs for torsional micromirrors using sophisticated surface micromachining technology. Deduction of torsional and bending stiffnesses for a general rotational serpentine spring with multiple serpentine elements is given in detail by using the generalized method and results are compared with those by unit-load method. The error between analytical and simulated results and its effect on electrostatic pull-in phenomenon of torsion micromirrors are also discussed and analyzed. The static performance of the micromirror based on two meshing elements, BEAM4 and SOLID45 in FEA software, is compared with prediction results. These above mentioned simulation results for the same micromirror have shown significant variation. More simulations have been done on some typical structures that have varied positions of the fixed ends of the springs. Then further discussion focuses on analysis of dynamic performance of the micromirror. Verification of the dynamic model is realized through a series of simulations.