Nanotechnology promises to do all that in the future, but like almost any technology that can bring great benefits, it can also bring great dangers. Nanotechnology is machines built on a scale of nanometers. All living things come from strings of atoms, protein molecules, that make copies of themselves. Assembling atoms is how trees, humans, and other forms of life are born, grow, and live.
Nature builds from the atoms up.
Since human hands are too big to handle atoms, we build down from giant chunks of atoms. From an atom's perspective, a pencil is a giant chunk of atoms, and putting it in a pencil sharpener is a very clumsy way to remove lots of those atoms. The wood in the pencil was built up from atoms by a tree. Humans cut the tree down and then built down to the pencil by breaking away many of the atoms. Since humans first started making things, we have developed finer and finer control.