The Nanotechnology Revolution

In the world of science, the latest buzz-word is "nanotechnology". Nanotechnology and related "nano" subjects, such as nanoscience, nanostructures, nanobusiness, nanocomposites, and the like, have been the topic of everything from tradeshows and technical papers to Michael Crichton's latest science-fiction bestseller. All this publicity leads many to ask: What is nanotechnology?

Nanotechnology is, in general, any technology involving the characterization and manipulation of matter at the atomic and molecu-lar level. This level has been described to include molecules and structures (nanostructures) having at least one dimension between roughly 1 and 100 nanometers, where a nanometer is one billionth of a meter. To get a sense of the nano scale:

• a human hair measures 50,000 nanometers in width;

• the smallest thing seeable with the unaided human eye is 10,000 nanometers across;

• 10 hydrogen atoms in a line make up one nanometer; and

• the size difference between a nanometer and a person is roughly the same as the size difference between a person and the orbit of the moon.

Nanostructures aren't just small, they're the smallest structures possible to make. Of course, this definition of nanotechnology does little to explain the surrounding hype. To understand the importance of nanotechnology, one must look to the implications of characterizing and manipulating matter at the nano scale.

For hundreds of years, scientists have documented the chemical, electrical, and physical properties of matter. These physical proper-ties include, for example, color, melting point, conductivity, and hardness. At bulk scales (i.e., scales bigger than the nano scale), these properties are independent of size, and have been used in designing the tallest sky-scraper to the smallest microchip. At the nano scale, however, the most fundamental properties of materials and structures depend on their size in a way they don't at any other scale. For example, a gold nanoparticle may be orange, purple, red, or green in color depending on its size. In another example, a nano scale wire or circuit component does not necessarily obey Ohm's law (the relationship between electrical current, voltage, and resistance upon which electronic design is based). Characterizing the physical properties and relationships of matter at the nano scale represents a new frontier of discovery for biologists, chemists, materials scientists, and engineers of all disciplines.

Today, scientists are not only beginning to understand the properties of matter on the nano scale, but are developing ways to manipulate this matter to create designer materials with properties of their choosing. It is the ability to manipulate individual molecules and atoms to create and improve materials and devices that has led some experts to identify nanotechnology as the potential Industrial Revolution of the 21st Century.

One promising nanomaterial, known as carbon nanotubes, has been found to have amazing mechanical and electrical proper-ties. Carbon nanotubes are comprised of individual carbon atoms that are linked together hexagonally and rolled into tubes. While estimates vary, the tensile strength of a carbon nanotube is said to be in excess of 60 times stronger than high-grade steel. By some estimates, a nanotube fiber narrower than a human hair might be able to suspend thousands of pounds, though no one has yet been able to make a tube big enough to find out for sure. Although carbon nanotube manufacture is still in its infancy, visionaries foresee the use of carbon nanotubes in the construction of everything from automobile bridges to a cable for a "space elevator" that would transport cargo between the earth and a satellite. In the nearer future, it is likely that carbon nanotubes will be used in composite materials for tennis rackets, golf clubs, and skis.

In addition to their amazing mechanical properties, carbon nanotubes have also been found to have amazing electrical properties. When rolled in one configuration, carbon nanotubes have been found to act almost like a superconductor, transmitting electricity with virtually no resistance. When rolled in another configuration, carbon nanotubes have been found to act like a semiconductor. These two properties are ideal for the manufacture of microchips, and companies have already used nanotubes to create usable transistors and logic gates.

Nanotechnology promises to yield materials and systems with superior electrical, chemical, mechanical, or optical properties with the potential for widespread uses in many industries, including electronics and information technology, healthcare, defense and aerospace. Nanotechnology may also one day enable the detection of disease on the cellular level and the targeting of treatment only to tissues where it is needed in a patient's body.

The National Science Foundation predicts that nano-related goods and services could be a $1 trillion market by 2015. Technology companies and major universities through-out the world have identified nanotechnology as a priority, and on December 3, 2003, President Bush signed into law the 21st Century Nanotechnology Research and Development Act, which appropriates nearly $4 billion for nanotechnology research and development over the next four years.

Nanotechnology is more than just technology on a small scale. It is a new frontier of scientific study, and is poised to be the next big technological advancement.