Everyday we here of new technology being implemented and today more and ever we have needs to help us as humans better ourselves and develop a greater sense of reason and logic. Robots are intended to do just that and protect us from things that can potentially harm us.
If we were to take a look at a nano we'd see that it can't be compared geometrically to our outside vision without first setting up constant's that don't move.
A nano is bigger than the width of an atom and this is a easier scale to observe and manipulate nano's. We could use nano technology to create music, health devices or services, and even more it's all up to our imagination on how and why we want nano technology.