Analysis of a micromachined vibrating beam accelerometer for early earthquake warning system

This paper presents the dimensional analysis of a micromachined vibrating beam accelerometer (VBA) for early earthquake warning system. Two beam resonators with natural frequencies of 124 kHz are determined. The primary benefit of this type of device over a capacitive accelerometer is its thickness independent sensitivity. This device serves for low-g acceleration detection with minimal noise and high sensitivity. The beams are suspended between two anchors, which support all mechanical and structural operations. The anchor dimensions have a significant impact on VBA’s natural frequency. The movement of proof mass creates an axial load on the beam when there is an external acceleration. The external acceleration application results in a shift in the frequency of vibration of beam. To see the parametric analysis, several single-beam dimensions are modeled. Proposed electromechanical and analytical mechanics of vibrating beam are used to validate the finite element method (FEM) simulation results.