Abstract: A new simulation method is introduced to solve the problem of high calculating
errors of the ideal model caused by the edge effect for MEMS (Micro-electromechanical System)
comb capacitor. In this method, the energy method in FEM (Finite Element Method) is used and
the MEMS comb actuator (90 pairs of comb teeth) which is fabricated on a MEMS gyroscope is
used for simulation. The simulated results of capacitance with this method and the conventional
method CMATRIX are 1.5283pF and 1.5793pF. The relative errors between them and the LCR
high precision capacitance measuring device measured result 1.5172pF are 0.73% and 4.09%
respectively. It is concluded from the experiment this method can obtain high calculating precision
for MEMS comb capacitor.

Key words: MEMS, comb actuator, edge effect, finite element method, energy method