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Synchronized micromechanical oscillators have potential for applications in signal processing, neural computing, sensing, and other fields. This paper explores the conditions under which coupled nonlinear limit cycle microoscillators can synchronize. As an example of the modeling approach and to be able to obtain results for a system that has been experimentally realized, thermally excited dome oscillators, which are fabricated by buckling of a thin circular film of polysilicon, are modeled. Starting with the von Kármán plate equations and an assumed mode shape, a Galerkin projection is performed to obtain an ordinary differential equation for the postbuckled dynamics of the mode. Because the structure is thermally excited, a thermal model is built by solving the heat equation on a disk with appropriate boundary conditions. Bifurcation analysis of the single oscillator model is performed to look for basic underlying phenomena. Conditions under which two slightly detuned coupled limit cycle dome oscillators will synchronize are explored. [ABSTRACT FROM AUTHOR]

Abstract: The small size and low damping of MEMS oscillators give rise to phenomena that are not observed routinely at the macroscopic scale. In this work we document and explain an experimentally observed transition in the response of a doubly clamped micromechanical oscillator with pretension. The transition from softening to hardening is repeatedly observed upon increasing the power of an incident sensing laser beam, a procedure routinely used to improve signal strength during optical detection of resonant motion of microstructures. At intermediate laser power, a novel resonant response that displays characteristics of both softening and hardening in the same sweep, is observed experimentally. Increased laser heating of a structure in tension may be expected to increase softening behavior. Using tools from non-linear dynamics and continuum mechanics, we show that the observed counter-intuitive behavior can be explained by a competition between the opposing responses of linear and non-linear stiffnesses to a change in temperature. [Copyright &y& Elsevier]