Analytical and finite element analysis of a new tri-axial piezoelectric accelerometer

A new type of tri-axial piezoelectric accelerometer is proposed in this study. It consists of a seismic mass and four cantilever beams that is distributed in a shape of X. Analytical model and FEM analysis were conducted to study its charge sensitivity and the fundamental/first order resonance frequency in the Z-axis, X-axis and Y-axis direction. The errors between the calculated results from analytical model and that from the FEM analysis in ANSYS is about 8% for the charge sensitivity and 12% for the first-order resonance frequency. For a single chip with the same chip area, charge sensitivity of the proposed new X-shaped piezoelectric accelerometer is higher than that of the conventional cross-shaped piezoelectric accelerometer by 21%, which suggests that overall size of the accelerometer could be greatly reduced under the premise of meeting the design objectives.