Electromagnetic Casimir Energies of Semi-Infinite Planes

Using recently developed techniques based on scattering theory, we find the
electromagnetic Casimir energy for geometries involving semi-infinite planes, a
case that is of particular interest in the design of microelectromechanical
devices. We obtain both approximate analytic formulae and exact results
requiring only modest numerical computation. Using these results, we analyze
the effects of edges and orientation on the Casimir energy. We also demonstrate
the accuracy, simplicity, and utility of our approximation scheme, which is
based on a multiple reflection expansion.