  Micro-Electro-Mechanical Systems (MEMS) comb drives are used for both as
sensors and actuators. As a result, they have been considered to be very
important in MEMS technology and has been under intense study for last few
years. The actuation and the sensitivity are both dependent in a major way on
the electrostatic configuration of the comb structure. As a result, accurate
estimation of the electrostatic configuration of comb drives is crucial in both
design and interpretation phases. The nearly exact Boundary Element Method
(neBEM) solver has been developed recently and used successfully to solve
difficult problems related to electrostatics. This solver uses exact analytic
expression for computing the influence of singularity distributions instead of
adopting the conventional and convenient approximation of nodal concentration
of charges. Due to the exact foundation expressions, the solver has been found
to be exceptionally accurate in the complete physical domain, including the
near field. In this work, we explore the possibility of using the neBEM solver
to solve 3D electrostatic problems related to comb drives. In particular, we
investigate the relationship between the accuracy achieved and the
computational expenses incurred for a realistic comb drive geometry. In the
process, we estimate the charge density distribution, potential distribution
and the capacitance of the comb structure. The study has led us to the
conclusion that the neBEM solver can yield very accurate estimates of all the
properties of interest at a reasonable computational expenditure.
