title: Accurate Simulation of Parametrically Excited Micromirrors via Direct Computation of the Electrostatic Stiffness.
abstract: Electrostatically actuated torsional micromirrors are key elements in Micro-Opto-Electro- Mechanical-Systems. When forced by means of in-plane comb-fingers, the dynamics of the main torsional response is known to be strongly non-linear and governed by parametric resonance. Here, in order to also trace unstable branches of the mirror response, we implement a simplified continuation method with arc-length control and propose an innovative technique based on Finite Elements and the concepts of material derivative in order to compute the electrostatic stiffness; i.e., the derivative of the torque with respect to the torsional angle, as required by the continuation approach.
authors.affiliation: Department of Civil and Environmental Engng., Politecnico di Milano, 20133 Milano, Italy. attilio.frangi@polimi.it.
authors.forename: Attilio
authors.initials: A
authors.lastname: Frangi
authors.affiliation: Department of Civil and Environmental Engng., Politecnico di Milano, 20133 Milano, Italy. andrea.guerrieri@polimi.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Guerrieri
authors.affiliation: MSH Division, ST Microelectronics, 20010 Cornaredo (MI), Italy. nicolo.boni@st.com.
authors.forename: Nicoló
authors.initials: N
authors.lastname: Boni
keywords: MOEMS; Mathieu equation; arc length algorithm; comb-fingers; continuation approach; electrostatic force and torque; electrostatic stiffness; material derivative; micromirrors; parametric resonance