If you have read "What is Light?" hopefully you will have understood that light displays both particle-like and wave-like properties.

The same kind of principle applies also to the quantum world. Elementary particles are the smallest physical units we know of matter, they are both particles and waves.

The properties of elementary particles, as revealed through quantum mechanics, include the tunneling effect introduced here, and various other properties not found in the ordinary-sized world. Because the materials with which nanotechnology is concerned are closer in scale to the quantum world than to the ordinary world, they frequently display quantum-like properties. Using these properties raises the potential of nanotechnology to make things possible at the quantum level that are impossible at the level of the visible world.