Patent ID: 7949508

Claim:
A method for reducing rectification error in a microelectromechanical system (MEMS) electrostatic comb-drive, closed-loop, in-plane, capacitive device, the method comprising: selecting an initial comb tooth geometry, including selecting initial tooth width and length dimensions, and an initial lateral gap dimension; constructing a finite element model of one or more tooth pitch of the initially selected comb tooth geometry; selecting an initial overlap dimension; using the finite element model of the initial comb tooth geometry, performing a finite element analysis calculation of capacitance for both the selected initial overlap dimension and for each of a plurality of different overlap dimensions both greater than and less than the initial overlap dimension; constructing a mathematical model of a capacitance versus overlap dimension relationship as a function of the finite element analysis calculation of capacitance for both the selected initial overlap dimension and for each of the plurality of different overlap dimensions; selecting an overlap dimension producing a zero third derivative of the capacitance versus overlap dimension relationship; setting the overlap in the device to said selected dimension; setting the overlap in the device to said selected dimension.