Galerkin method for discs capacitors

The physics of nano and micro electro-mechanical systems would benefit from an accurate knowledge of electrostatics forces between electrodes. Quite complicated behaviors can arise and a precise computation of capacity matrices, from which forces can be derived, is required. We develop, for circular thick electrodes, a method based on the Galerkin approximation. Almost all the matrix elements needed are evaluated analytically and consequently high precision results can be obtained. In parallel we provide an implementation of the Boundary Elements Method (BEM) which gives a check of the computations and can be used independently. We test our method on the well studied problem of two flat discs capacitor, obtaining results in excellent agreement with expected asymptotic estimates.