  Dynamic interactions between two oscillating micromechanical cantilevers are
studied. In the experiment, the tip of a high-frequency cantilever is
positioned near the surface of a second low-frequency cantilever. Due to the
highly nonlinear interaction forces between the two surfaces, thermal
oscillations of the low-frequency cantilever modulate the driven oscillations
of the high-frequency cantilever. The dissipations and the frequencies of the
two cantilevers are shown to be coupled, and a simple model for the
interactions is presented. The interactions studied here may be useful for the
design of future micro and nanoelectromechanical systems for mechanical signal
processing; they may also help realize coupled mechanical modes for experiments
in non-linear dynamics.
