sealPurdue News

September 7, 2001

Nanotechnology: What is it?

WEST LAFAYETTE, Ind. – Nanotechnology is an emerging science in which new materials and tiny structures are built atom-by-atom, or molecule-by-molecule, instead of the more conventional approach of sculpting parts from pre-existing materials.

Nano is a prefix meaning one-billionth, so a nanometer is one-billionth of a meter.

"We think of nanotechnology as things that are on the order of 100-150 nanometers or smaller," said George Adams, a Purdue engineer who headed the planning committee for the new nanotechnology center.

To put that scale of measurement into perspective, a human red blood cell is about 7,500 nanometers across, and one nanometer is roughly 10 atoms wide. The letter "I" printed here is about one million nanometers wide.

"Just as antibiotics, the silicon transistor and plastics affected nearly every aspect of society in the 20th century, nanotechnology is likely to have profound influences in the 21st century," Adams said.

The possibilities include:

• The creation of entirely new materials with superior strength, electrical conductivity, resistance to heat and other properties.

• Microscopic machines for a variety of uses, including probes that could be injected into the body for medical diagnostics and repair.

• A new class of ultra-small, super-powerful computers and other electronic devices, including spacecraft.

• A technology in which biology and electronics are merged, creating "gene chips" that instantly detect food-borne contamination, dangerous substances in the blood or chemical warfare agents in the air.

• Artificial organs.

• The development of "molecular electronics" and devices that "self assemble," similar to the growth of complex organic structures in living organisms. Theoretically, once set in motion, such self-assembling devices would build themselves, making electronics processing far less expensive than conventional semiconductor processing.

Nanotechnology requires specialized laboratory facilities for research and development, said James Cooper, a professor of electrical and computer engineering at Purdue University.

These facilities include state-of-the-art "clean rooms," or labs in which the air is constantly filtered to remove minute dust particles. Such labs must be equipped with high-tech instruments like atomic-force microscopes, which use a tiny probe that can actually touch and feel individual atoms; molecular beam epitaxy equipment to build new semiconductor crystals, atom-by-atom, for advanced computers and electronics; and chemical vapor deposition machines, which allow extremely precise, layer-by-layer construction of entirely new materials that never existed in nature.

Meanwhile, factors such as temperature, humidity and vibration must be scrupulously controlled. Because the research is conducted on such a small scale, even the slightest increase in temperature, or the smallest vibration, might ruin an experiment.

"When you are manipulating atoms and making things only a few atoms across, you need an extremely clean environment," Cooper said. "The air has to be filtered so that there are very few particulates in the air. It's much more clean than a surgery room in a hospital."

Writer: Emil Venere, (765) 494-4709,

Sources: George Adams, (765) 494-2698,

James Cooper, (765) 494-3514,

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