Nanotechnology

The prefix nano (Greek for “dwarf”)means billionth -a billionth of a meter is a nanometer- but is also applied to small devices whose size might conveniently be measured in nanometers. Creation of such devices, usually those less than 100 nanometers in any dimension, is called nanotechnology.

The idea of nanotechnology was introduced in 1959 by Richard Feynman [American: 1918-1988]. He envisioned making devices by joining as few as 7 atoms-about 2 nanometers. Feynman was inspired by the miniaturization introduced in the U.S. space program in 1958, and by microprocessors (computer chips), also invented in 1958. Soon, tiny motors and other devices-still hundreds or thousands of nanometers in size-were built. Some became commercially useful, embedded in such devices as automobile airbags or switching networks for telephones.

The word nanotechnology was coined in 1974, but the first real advances near atomic levels came in the 1980s. The scanning tunneling microscope (STM), invented in 1981, provided the break-through. The STM can image individual atoms. A modification called the atomic force microscope (AFM) can also move them-demostrated in 1989 when researchers spelled “IBM” with 35 xenon atoms. In 1985, physicists also began to use paired lasers as pincers to handle individual atoms. Using technology developed for etching transistors into silicon chips, scientists at the University of California at Berkeley created the first electric micromotor in 1988, not from single atoms, but at a nanometer scale.

In the 1990s, chemists began to fabricate complex molecules that self-assemble from simpler molecules. Also in 1990, several groups of chemists announced successful creation of molecules that replicate themselves. In 1994, Leonard Adleman [American: 1945- ] created a computer equipped with a memory and stored program consisting of single molecules, albeit giant molecules, of DNA. Another giant molecule, the carbon molecule called a nanotube-especially an elongated buckyball-showed that it had many properties that could be exploited in nanotechnology.

Nanotechnology grew rapidly at the start of the 21st century. A modified AFM became an inkjet printer that sprays individual molecules into nanoscale designs. Workers used silicon-chip technology to fabricate “nanowires” a few hundred atoms in diameter that they then combined to make transistors only 20 nanometers across. Biochemists crafted a form of DNA with a metal conductor running along the middle of the molecule, creating a nanoscale combination that could be called “intelligent electronics.” In 2000, the University of Michigan started a center to apply nanotechnology to medicine, aimed at cell manipulation with tools smaller than the cells themselves.

Source: The Blackbirch Encyclopedia of Science & Invention