The Casimir force and micro-electromechanical systems at submicron-scale separations

Quantum mechanics teaches us that vacuum is not empty. Rather, it contains all kinds of virtual particles. The energy of such particles is called zero point energy. If two surfaces come in close proximity of each other, they will create a difference between the zero point energies in between them and on the outside. Consequently the surfaces will be pushed toward each other. This phenomenon is known as the Casimir effect. It has turned out to be a generalization of the more familiar van der Waals force.Present technology has only recently enabled us to measure the Casimir force directly. Part of this thesis is about a complication that arises in such measurements: a real surface does not have a nice, smooth shape, but it is often rough. Surface roughness influences the Casimir force mainly at relatively short distances of one ten millionth meter or less. This influence is predominantly determined by statistically rare high asperities in the surfaces. This thesis introduces a model that reproduces measurements of the Casimir force between rough surfaces.The Casimir force is unavoidable: the existence of virtual particles cannot be shut down in any way. The smaller the distance between the surfaces, the larger the Casimir force. Hence at short distances it is of interest for technology of micro electromechanical systems (MEMS), such as micro switches or accelerometers. The Casmir force has a considerable influence on the motion of MEMS components at short distances. Surface roughness turns out to make this motion more predictable