Foreword

Abstract

Quite often in the last centuries some outstanding technological achievement produced a tumultuous increase of the available information concerning basic physical and biological events.  Having in mind the scientific more than the economic relevance,  one could mention the invention of telescopes, microscopes, voltaic cells, transistors, particle accelerators and, more recently, fast and automatic nucleotide sequencers.  In this frame, the ability to miniaturize  down to the nano scale the experimental set-up should be considered among the characteristic signatures of our times.