Investigation of the Effects of Random Vibration on the Characteristics of Micromechanical Accelerometers

For modern information, measuring, and optoelectronic systems based on micro- and nanomechanical sensors of angular velocity and linear acceleration, it is important to ensure their stable functioning in the presence of external factors. The paper presents the results of a study of the effect of a random vibration on the characteristics of micromechanical accelerometers (MMAs) obtained using the LDS V455 vibration bench. The dependence of the spectral density of vibration acceleration on the frequency of one of the samples, intended for acceleration measurements in the range up to ±1.2 g, has a noticeable shift from its predetermined profile. To establish the reasons for this discrepancy, the design of the MMAs’ sensitive element (SE) under the effect of a random vibration is studied. Calculations and simulations are performed in the ANSYS program. The deformations of the MMAs’ SE along the sensitivity axis Z and the capacitance changes due to the acceleration and random vibration along the X, Y, and Z axes, taking into account the crystallographic orientation of the SE’s material (silicon) are determined. The effect of the crystallographic orientation of silicon used to manufacture the MMAs’ SE on the deformation (deflection) of the rotor is considered. The presented results of the theoretical and experimental studies, as well as computer modeling, coincide, which allows us to improve the design of the MMAs’ SE.