Visualizing intrinsic localized modes with a nonlinear micromechanical array
Graduate School of Natural Science and Technology, Kanazawa University Kanazawa, Ishikawa 920-1192, Japan
Laboratory of Atomic and Solid State Physics, Cornell University Ithaca, NY 14853-2501, USA
Received November 26, 2007
Micromechanical cantilever arrays provide the opportunity to visualize the nonlinear excitations of a discrete nonlinear system in real time. Both stationary and moving localized nonlinear excitations can be
produced either by driving the system at a frequency outside the plane wave spectrum or by driving the system at a frequency within the small amplitude dispersion curve range. To see these modes the tips of the cantilevers are imaged on a 1D CCD camera. The brightness of the image depends on the oscillation amplitude of the cantilever so that a distribution of amplitudes in the array can be recorded as a function of position and time. Both the stationary and traveling excitations have been successfully simulated using a nonlinear lumped element lattice model. The former ILM can appear in any size lattice while the latter requires a low density of modes for the formation of smoothly running excitation.
PACS: 05.45.–a Nonlinear dynamics and chaos; PACS: 63.20.Pw Localized modes; PACS: 63.20.Ry Anharmonic lattice modes; PACS: 85.85.+j Micro- and nano-lectromechanical systems (MEMS/NEMS) and devices.