February 21, 2006 > TechKnow Talk: What is nanotechnology and what is it good for?
TechKnow Talk: What is nanotechnology and what is it good for?
by Todd Griffin
One of the reasons nanotechnology is such a confusing subject is that people use the term to mean different things. Ask a materials scientist, a molecular biologist, and a NASA astrophysicist about nanotechnology and each is likely to provide a very different response. Another reason this subject is so difficult for most of us to comprehend is that it deals with the very, very small. Just as the vastness of the universe is unimaginable, so too is the realm of the exceedingly tiny.
But the basic concepts are easily understood. Let's start with a simple definition: nanotechnology refers to any man-made process or product that can be measured on the nanometer scale. A nanometer is one-billionth of a meter. A human hair is about 50,000 nanometers in diameter. Objects in the realm of a fraction of a nanometer to a few hundred nanometers include many atoms and molecules, as well as the components of DNA, the building-block of life. Nanotechnology is, in broad terms, nothing more than the ability to manipulate these tiny objects.
How would one go about positioning individual atoms? This is the subject of much of the nanotechnology research today. Approaches under study include using forces inherent in atoms to bring them together in the desired manner, as well as designing miniscule robotic assembly devices (nanorobots or nanobots) to perform this function. As amazing as that sounds, some limited successes have already been achieved.
To construct a large-scale part, something you could hold in your hand, using nanotechnology would require trillions of nanobots. This is not as outrageous as it may seem. If researchers can surmount the technical obstacles to creating the nanobots, they can program some to build copies of themselves. These self-replicating devices would reproduce quickly, similar to the way a virus, bacterium, or other living cell multiplies. Though an individual flu virus cell entering your body seems inconsequentially small, it can create enough copies of itself in a few days to make your whole body feel miserable!
We have always made the things we need by essentially pushing material around, through processes such as casting, grinding, machining, etc. These traditional manufacturing methods produce parts and materials full of microscopic flaws. They must be made larger and heavier to compensate for the weaknesses created by these flaws. Imagine instead the ability to build something "bottom up," i.e., by creating it "from scratch," atom by atom. The result would be perfect, completely flawless material.
The implications are enormous. Such perfect material would allow much smaller, lighter, and more efficient parts, which would certainly fuel a revolution in aircraft and spacecraft design, as well as more down-to-earth fields such as automotive technology. One of the most promising areas of development is in carbon fibers. Imagine a material made of pure, flawless carbon with five times the strength of steel at a fraction of the weight. In addition, this material would be very inexpensive, as inexhaustible supplies of carbon are available all around us, and needn't be dug out of the ground.
Even more exciting prospects loom. The amazing advances of recent decades in computer miniaturization are nearing the practical limit of what can be accomplished by refining existing technologies. The ability to very accurately position individual atoms could result in a revolutionary leap in computer technology. In theory, billions of bytes of data could be stored or billions of logic circuits created on a device too small to see with the naked eye. The field of molecular computing or "nanoelectronics" is studying ways to make this a reality.
But perhaps the most intriguing potential applications of nanotechnology lie in the field of medical technology. Patients may someday be given an injection containing nanobots programmed to locate cancer or virus cells and rearrange their molecular structure to render them harmless. Surgeries could be performed at the molecular and cellular level, eliminating the need for the relatively crude and invasive surgery techniques of today.
Looking further into the future, nanotechnology has the potential to manufacture nearly everything we need. Why cut down trees when we can make our own wood-quickly, inexpensively, and of more uniform quality than nature provides? Oil could be manufactured in unlimited quantities. But why stop there? Food and water could be manufactured as well, ending drought and famine forever.
It's easy to understand why governments and private industry are pouring billions of dollars into nanotechnology research. The theoretical benefits have the potential to radically change life on earth. While many predictions seem far-fetched, some experts believe nanomaterials will be in widespread use in as few as five years, and that some of the advances in computing and medical technologies discussed above are no more than 10 to 15 years away.
However, as many people have sounded warnings regarding genetic engineering, many are also concerned about the dangers of nanotechnology. In one disturbing scenario, scientists release nanobots into the environment- programmed to clean up an oil spill or rebuild the ozone layer, for example- but they continue to reproduce and rearrange their environment unchecked, until they literally consume the entire planet, converting it to the material they were designed to create. Is this merely a science fiction fantasy? Perhaps. But a technology that offers such powerful benefits is likely to bring some risk as well.
There is a wealth of data available on this topic. Here are some good starting points.