title: Complex oscillations and chaos in electrostatic microelectromechanical systems under superharmonic excitations.
abstract: In this Letter, the formation of complex oscillations of the type 2n M oscillations per period at the Mth superharmonic excitation is reported for electrostatic microelectromechanical systems. A dc bias (beyond "dc symmetry breaking") and an ac signal (at the Mth superharmonic frequency) with an amplitude around "ac symmetry breaking" gives rise to M oscillations per period or period M response. On increasing the ac voltage, a cascade of period doubling bifurcations take place giving rise to 2n M oscillations per period. An interesting chaotic transition (1-band and 2-band chaos) is observed during the first period doubling bifurcation. The nonlinear nature of the electrostatic force is shown to be responsible for the reported observations.
authors.affiliation: Department of Mechanical and Industrial Engineering Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Sudipto K
authors.initials: SK
authors.lastname: De
authors.forename: N R
authors.initials: NR
authors.lastname: Aluru