Mode-Localized Displacement Sensing

We report the construction of a new class of micromachined displacement sensors that employ the phenomenon of vibration-mode localization for monitoring minute inertial displacements. It is demonstrated both theoretically and experimentally that the eigenstate-shifted output signal of such mode-localized displacement sensors may be as high as 1000 times greater than corresponding resonant-frequency variations that serve as the output in the more traditional vibratory resonant micromechanical displacement/motion sensors. The high parametric sensitivities attainable in such mode-localized displacement sensors, together with their inherent advantages of improved environmental robustness and electrical tunability, suggest an alternative approach in achieving improved sensitivity and stability in high-resolution displacement transduction.