Leading- and next-to-leading-order lateral Casimir force on corrugated   surfaces
  We derive explicit analytic expressions for the lateral force for two different configurations with corrugations, parallel plates and concentric cylinders. By making use of the multiple scattering formalism, we calculate the force for a scalar field under the influence of a delta-function potential that has sinusoidal dependence in one direction simulating the corrugations. By making a perturbative expansion in the amplitude of the corrugation we find the leading order for the corrugated concentric cylinders and the next-to-leading order for the corrugated parallel plates. 
Ines Cavero-Pelaez, Kimball A. Milton, Prachi Parashar and K.V.   Shajesh