Analytical Model of a PZT Thick-Film Triaxial Accelerometer for Optimum Design

We present a mechanical model of a triaxial micro accelerometer design using PZT thick-film as the sensing material. The model is based on the full anisotropic material tensors and Eulers´ beam equation using simplifying assumptions where the smaller stress contributions are ignored. The model results in design equations that are useful for optimization of the sensitivity and bandwidth and for matching the sensitivity in the three orthogonal directions. A finite-element method (FEM) model is used to verify the analytical model. Equal sensitivity in all three geometrical directions is preferred, which induces a number of limitations in design parameter space, this is used in a design strategy for setting the six independent dimensions of the accelerometer. Design methods for optimum sensitivity of each axis and for equal sensitivity between different axes have been proposed.