  The Casimir effect is a force arising in the macroscopic world as a result of
radiation pressure of vacuum fluctuations. It thus plays a key role in the
emerging domain of nano-electro-mechanical systems (NEMS). This role is
reviewed in the present paper, with discussions of the influence of the
material properties of the mirrors, as well as the geometry dependence of the
Casimir effect between corrugated mirrors. In particular, the lateral component
of the Casimir force and restoring torque between metal plates with misaligned
corrugations are evaluated.
