Electrostatic compensation method in frequency robustness design of micro accelerometer

An electrostatic compensation method is proposed to realize the frequency robustness of a capacitive accelerometer by taking advantage of the electromechanical coupling characteristics, rather than mechanical structure alone. The limitations of microfabrication on structural configuration are overcome by an efficient adjustment of circuit parameters, which have equivalent contributions on the natural frequency as mechanical structures. The results of theoretical analysis and experiments indicate that this design method is practical for different microprocessing conditions, and the robustness of a mechanical structure to error can be achieved by a reasonable electrostatic compensation in electromechanical coupling microdevices. The test results have shown that the frequency deviations in more than 80% of fabricated sensors are less than 1%. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JMM.11.4.043001]