Promoted as a cure for cancer, a basis for more effective sunscreen, and a source of clean water, nanotechnology promises revolutions in science, medicine, and manufacturing. Where did this technology come from and where is it going?
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When humanity uses nature’s materials – wood for construction, cotton for clothes, corn and cattle for food – we refine and manipulate them using chemistry and biology, turning iron ore into steel or selectively breeding animals and crops.
Nanotechnology takes this manipulation a step further: it alters not just the form of materials, but their very essence, the atoms and molecules they are composed of. It offers the potential for unprecedented control over the physical world, enabling the creation of a new generation of materials. But by the same token it might also create new risks and uncontrollable side-effects.
Plenty of room at the bottom
It was U.S. physicist Richard Feynman who first proposed “the possibility of manoeuvring things atom by atom" in his “Plenty of Room at the Bottom” speech in 1959. Feynmann not only introduced the idea of manipulations at the atomic level, but also suggested practical applications like miniature robots that could be swallowed to perform operations from inside the human body.
Technology at the time was no match for Feynmann’s imaginative spirit. It took about 15 years and a number of revolutionary new inventions until the term nanotechnology emerged. It was coined by the Japanese scientist Norio Taniguchi, who used it to describe technologies that manipulate matter at the nanometer (nm) scale - one nanometer equals one billionth of a meter, comparable to the size difference between a marble and the earth. Atoms, molecules, and viruses range from under 1nm to around 100nm in size.
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The most obvious advantage of nanotechnology is greater precision. Atomic-level precision should deliver efficiency savings in manufacturing processes of, for example, semi-conductors. It could help reduce pollution and waste, achieve greater agricultural productivity, and more accurate delivery of nutrients and medicines within the body.
Nanotechnology, however, means more than just reducing scale, it also implies a whole new set of physical laws. At the nano level, gravity is of less importance, so-called inter-molecular forces appear and properties of natural materials can change radically. Carbon becomes immensely stronger. Copper turns from being opaque to being transparent, while silicon turns from an insulator into a conductor.
The revolution will be miniaturized
Some nanotechnology, although not on the smallest scale, products have already been commercialized. So-called “nanomaterials” can be found in cosmetics and sunscreens, coatings, water and stain resistant fabrics, some foods, energy sources, and medical products.
Scientists are also trying to imitate nature. The nanostructure of spiders’ silk is so complex that it becomes one of the strongest and most flexible materials that exists. More advanced research is directed towards producing “nanodevices,” such as tiny computer chips, water filtration devices, or monitors planted in a patient’s bloodstream.
Theoretically, nanotechnology could even evolve towards “nanosystems,” using nanodevices to build products designed from the atomic level upwards. Close to Feynman’s vision, this “bottom-up” approach would put certain atoms and molecules together, allowing them to self-assemble into larger structures.
This process is known as molecular or “bottom-up” manufacturing, in contrast to traditional “top-down” manufacturing processes that cut up large blocks of material to make much smaller products, generating tremendous waste material in the process.
The advantage of molecular manufacturing would be a nearly infinite flexibility to create any substance, object, device, machine, or material through atom-by-atom construction. Waste would be nearly inexistent, efficiency extremely high. If such promises hold true, nanotechnology could represent the next industrial revolution.
Read more:
Nanotechnolgy: Hidden Hazards?
editor: James Tulloch
publishing date: June 3, 2008
