Theoretical study on the capacitance of comb actuator considering fabrication technology and edge effect

With plate capacitor theory and calculus method, the capacitance of micro electro-mechanical system (MEMS) electrostatic comb actuator is studied. Considering the affections of fabrication technology and edge effect, a calculating model is built, by which the calculations for the fabricated comb actuator are carried out under the ideal condition and the condition of considering border effect and fabricating technology. The calculated results are 1.2673 pF and 1.4403 pF respectively, of which the relative errors with the high precision LCR device measured value 1.5172 pF are 16.47% and 5.07%. This indicates that the model can be used to get higher precision, if the border effect and fabrication process are taken into account.