Design and fabrication of a highly symmetrical capacitive triaxial accelerometer

A monolithic capacitive triaxial accelerometer using a highly symmetric qua d-beam structure with a single seismic mass is developed. The structure of the accelerometer is analysed in detail theoretically and numerically. Stat ic and modal simulations with a finite element method simulator are done to analyse the mechanical response at accelerations of different directions. The simulated results show that the accelerometer can sense triaxial accele ration separately and synchronously. It has sensitivities of about 7.66, 6. 08 and 6.08 fF g(-1) in the z-axis, x-axis and y-axis, respectively, and ha s nearly zero cross-axis sensitivity theoretically. Moreover, some design o ptimizations are made to improve its performance. Finally, the fabrication and the basic performance of the device are presented.