Casimir3

Casimir Interactions

Richard Feynman foresaw the importance of quantum vacuum forces in nano and micro electromechanical systems in his famous talk There's Plenty of Room at the Bottom :
As we go down in size, there are a number of interesting problems that arise. All things do not simply scale down in proportion. There is the problem that materials stick together by the molecular (Van der Waals [Casimir]) attractions. It would be like this: After you have made a part and you unscrew the nut from a bolt, it isn't going to fall down because the gravity isn't appreciable; it would even be hard to get it off the bolt. It would be like those old movies of a man with his hands full of molasses, trying to get rid of a glass of water. There will be several problems of this nature that we will have to be ready to design for. In fact, due to the small distances between its elements, the Casimir force becomes very important for these systems. It may for example produces sticking between them, but it may also be used to control the MEMS. The only experiment which studied the plane-plane geometry considered by Casimir has been performed at the University of Padova (Italy). In this experiment the specific experimental difficulties associated with the plane-plane geometry had to be faced and were successfully mastered. For more reviews of recent experiments see this paper.
This new generation of high precision experiments are to a very large extent at the origin of a revival of the theoretical studies on the Casimir effect. To compare precisely the experimental results with the theoretical predictions, it is necessary to take into account the differences between the ideal case considered by Casimir and the real situations of the experiments. Lifshitz was first to develop a theory of the Casimir effect between dielectric mirrors. Since then, a great number of theoretical papers have been dedicated to the Casimir effect in various configurations.

Francesco Intravaia Jun 30, 2010