Characterization of Disturbances in Systems of Coupled Micro-Resonator Arrays

This paper describes a method for processing signals from an array of coupled resonators to detect perturbations due to external stimuli. This method is based on simultaneous monitoring of the relative changes in all eigenvalues of the characteristic equation and processing this information to quantify the amount of perturbations and to determine the resonators whose properties have changed. Since the method is based on the relative movements of eigenvalues, the variations in the absolute values of the eigenfrequencies do not strongly affect its accuracy. It will be shown that this technique is capable of detecting perturbations even if direct signals from some of the coupled resonators are not available. The role of coupling strength on the sensitivity of the system is also discussed. It is shown that it is possible to increase the sensitivity of the sensor system to perturbations by a large factor through proper selection of the coupling coefficient between the resonators. The proposed model is experimentally verified using an array of coupled micro-cantilever resonators fabricated in a standard micro-fabrication process.