ABSTRACT
The meter, a dimension unit closest to everyday human experience, is often considered as the basic
dimension of reference for human beings. Let us look up in the dimension scale, up to the outer edges of
our ‘‘local universe,’’ the Milky Way, a galaxy of 100-400 billion stars. This universe revealed to us has a
dimension of 50,000 light-years from the outer edges to its center. A light-year is the distance that light
travels in 1 y at the speed of approximately 300 million (300,000,000) m=s, which corresponds to
approximately 10,000,000,000,000,000 (16 zeros) or 1016 m. Therefore, the distance from the center to
the outer edge of the Milky Way is 500,000,000,000,000,000,000 or 5 1020 m. Let us now look down in the other direction of the dimensional scale, down to a nanometer, which is a billion (1,000,000,000)
times smaller than a meter (i.e., 109 m). The word nano is derived from the Greek word meaning ‘‘dwarf.’’ In dimensional scaling nano refers to 109-i.e., one billionth of a unit. A human hair has a diameter of approximately 10 mm, which is 10,000 nm. Diameters of atoms are in the order of tenths
(101) of nanometers, whereas the diameter of a DNA strand is about a few nanometers. Thus, nanotechnology is a general term that refers to the techniques and methods for studying, designing,
and fabricating devices at the level of atoms and molecules. The initial concept of investigating materials
and biological systems at the nanoscale dates to more than 40 years ago, when Richard Feynman
presented a lecture in 1959 at the annual meeting of the American Physical Society at the California
Institute of Technology. This lecture, entitled ‘‘There’s Plenty of Room at the Bottom,’’ is generally
considered to be the first look into the world of materials, species, and structures at the nanoscale levels.
Thinking small, however, is not a new idea. Thousands of years ago, the Greek philosophers Leucippus
and Democritus have suggested that all matter was made from tiny particles like atoms. Only now, the
advent of nanotechnology will lead to the development of a new generation of instruments capable of
revealing the structure of these tiny particles conceived since the Hellenic Age.
