Simulation of a Dual Axis MEMS Seismometer For Building Monitoring System
A dual axis MEMS seismometer targeted for building monitoring system has been simulated for a full scale of ±5g acceleration. The design uses the capacitive effect for vibration sensing. This comb drive capacitive MEMS seismometer consists of 8 springs with two proof masses. The device is very low cross axis sensitive (almost negligible cross axis error). The cross axis sensitivity of x-axis is 0.001% towards y-axis, while the y-axis cross axis sensitivity towards x-axis is 0.000005% when maximum input acceleration of 5g is applied. COMSOL Multiphysics® software has been used to compute the eigenfrequencies and static responses of the device. From simulation results, the displacement sensitivities of x-axis=0.114µm/g and y-axis=0.204µm/g while capacitive sensitivities of X-axis=0.551pF/g and Y-axis= 0.346pF/g were calculated.