Democritus, a Greek philosopher (c. 370 B.C.), widely attributed with developing an atomic theory of matter. According to his theory, all things are composed of minute and indivisible units of matter ('atoma'). Nanotechnology is concerned with phenomena originating from nanometer (10-9 m) scale structures of matter, corresponding to the atomic or molecular scale.
Richard Feynman, a Nobel laureate in physics (1918-1988), renowned for his classic talk entitled, "There's Plenty of Room at the Bottom, An Invitation to Enter a New Field of Physics" (presented on December 29th 1959 at the annual meeting of the American Physical Society at the California Institute of Technology (Caltech): "The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big."