The theme of this book is Nanotechnology, it's a technology applied in the grey area between classical mechanics and quantum mechanics. Classical mechanics is the mechanics governing the motion of all the objects we can see with our naked eye. By contrast, quantum mechanics which is the mechanics controlling the motion of things like the electron, the proton, the neutron and the like is completely probabilistic. There is a grey area between these two scales which is neither classical nor quantum. Theoretical physicists call it the mesoscopic system. This is what is called by non-physicists the nanoworld. A nanosystem is therefore something which is sufficiently small that we could not see with our naked eye and not even with an ordinary microscope.