Nanotechnology

The science of constructing devices at the molecular level. Taking its name from a nanometer (one-billionth of a meter), nanotechnology is poised to change numerous aspects of industrial technology; it also promises potentially wide-ranging social ramifications.

Everything in the physical world is composed of atoms, and the properties of any material depend on how its atoms are arranged. Arranging carbon atoms one way produces coal; arranging them in a different way produces diamonds. With modern technology, scientists can rearrange the atoms in sand, add in other elements, and produce computer chips. However, current manufacturing methods at this low level are very crude.

Today's computer chips are produced by etching electrical circuits onto a silicon wafer in a process known as lithography. Using this technique, chip designers can manipulate bits of silicon approximately as small as a micron (1,000 nanometers). With nanotechnology, however, designers could manipulate pieces of silicon thousands of times smaller, thus dramatically reducing the size of computer chips. Nano-technology has been heralded as the next major leap in the evolution of computing.

Research in nanotechnology began in the late 1950s, when the famed physicist Richard Feynman (who worked on the Manhattan Project that developed the atomic bomb) gave a talk titled “There's Plenty of Room at the Bottom.” Feynman envisioned the ability to manipulate atoms and molecules directly by developing machine tools at one-tenth scale. These tools would then be used to help develop one-hundredth scale machine tools, and so on until a truly microscopic scale was reached. As the tools get smaller, however, the relative strength of various forces, such as gravity and surface tension, would change. This would require redesigning some tools to account for these changes.

In the late 1980s, development of the scanning tunneling microscope (STM) by Gerd Binnig and Heinrich Rohrer made true nanotechnology research and development possible. The STM allows the imaging of solid surfaces with unprecedented resolution, down to the nanometer level. This process gives researchers the opportunity to move molecules and fabricate new, never-before-seen particles and devices. Since that time, the U.S. government has become increasingly involved in nanotechnology research. Government-sponsored spending on nanotechnology has risen from $116 million in 1997 to nearly $1 billion in 2004. Meanwhile, private industry is investing billions more in nanotechnology research and development. The National Science Foundation has predicted that the nanotechnology goods and services market could reach $1 trillion by 2015.

The U.S. military is especially interested in nano-technology. Among the current military research related to nanotechnology are efforts to reduce the weight and increase the strength of armor, produce advanced protective materials for soldiers, develop sensors for biological and chemical agents and land mines, and make ever-smarter weapons. The development of smaller thermonuclear devices with decreased radioactive fallout also appears possible. Many other countries are also at work on military applications of nanotechnology.

Besides studying its possible beneficial uses, the U.S. government is also concerned about possible negative effects of nanotechnology, which could compromise national security. One of these concerns is the possibility of creating grey goo—out-of-control, self-replicating nanomachines. One of the principles of nanotechnology is that the devices created with it would be capable of making copies of them without human direction. Opponents of nanotechnology worry that science will be unable to control the nanodevices it creates. A similar fear is green goo—the creation of artificial molecules that could displace or destroy vital natural elements, leading to ecological catastrophe.

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