Performance-enhanced micro-machined resonant systems with two-degrees-of-freedom resonators

Two-degrees-of-freedom (2-DOF) resonant systems are employed to improve the resonating properties of micro-machined vibratory devices. Two mass-spring -damping units of identical natural frequency, are mechanically linked toge ther to form a 2-DOF resonator. A great disparity was designed for the rati o of the two masses. Theoretical analysis and simulation both demonstrate t hat, under the condition of a low damping effect, the resonant amplitude of the small mass can be amplified and, becomes much higher than that of the big mass, This amplification effect can be used in applications of high mec hanical sensitivity. On the other hand, the very broad resonant bandwidth o f the small mass can be pursued by overlapping two split resonant modes tog ether under certain damping conditions. Measurement results of a silicon mi cro-machined 2-DOF resonator in an atmospheric environment have verified th e resonant amplification effect. As an application of the 2-DOF resonator, a silicon micro-machined vibratory gyroscope has been designed based on thi s amplification concept and has been fabricated using a bonded silicon-on-i nsulator wafer and a deep reactive-ion-etching process.