How Nanotechnology Works

­Experts sometimes disagree about what constitutes the nanoscale, but in general, you can think of nanotechnology dealing with anything measuring between 1 and 100 nm. Larger than that is the microscale, and smaller than that is the atomic scale.

Nanotechnology is rapidly becoming an interdisciplinary field. Biologists, chemists, physicists and engineers are all involved in the study of substances at the nanoscale. Dr. Störmer hopes that the different disciplines develop a common language and communicate with one another [source: Störmer]. Only then, he says, can we effectively teach nanoscience since you can't understand the world of nanotechnology without a solid background in multiple sciences.

One of the exciting and challenging aspects of the nanoscale is the role that quantum mechanics plays in it. The rules of quantum mechanics are very different from classical physics, ­which means that the behavior of substances at the nanoscale can sometimes contradict common sense by behaving erratically. You can't walk up to a wall and immediately teleport to the other side of it, but at the nanoscale an electron can -- it's called electron tunneling. Substances that are insulators, meaning they can't carry an electric charge, in bulk form might become semiconductors when reduced to the nanoscale. Melting points can change due to an increase in surface area. Much of nanoscience requires that you forget what you know and start learning all over again.

So what does this all mean? Right now, it means that scientists are experimenting with substances at the nanoscale to learn about their properties and how we might be able to take advantage of them in various applications. Engineers are trying to use nano-size wires to create smaller, more powerful microprocessors. Doctors are searching for ways to use nanoparticles in medical applications. Still, we've got a long way to go before nanotechnology dominates the technology and medical markets.

In the next section, we'll look at two important nanotechnology structures: nanowires and carbon nanotubes.

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Currently, scientists find two nano-size structures of particular interest: nanowires and carbon nanotubes. Nanowires are wires with a very small diameter, sometimes as small as 1 nanometer. Scientists hope to use them to build tiny transistors for computer chips and other electronic devices. In the last couple of years, carbon nanotubes have overshadowed nanowires. We're still learning about these structures, but what we've learned so far is very exciting.

A carbon nanotube is a nano-size cylinder of carbon atoms. Imagine a sheet of carbon atoms, which would look like a sheet of hexagons. If you roll that sheet into a tube, you'd have a carbon nanotube. Carbon nanotube properties depend on how you roll the sheet. In other words, even though all carbon nanotubes are made of carbon, they can be very different from one another based on how you align the individual atoms.

With the right arrangement of atoms, you can create a carbon nanotube that's hundreds of times stronger than steel, but six times lighter [source: The Ecologist]. Engineers plan to make building material out of carbon nanotubes, particularly for things like cars and airplanes. Lighter vehicles would mean better fuel efficiency, and the added strength translates to increased passenger safety.

Carbon nanotubes can also be effective semiconductors with the right arrangement of atoms. Scientists are still working on finding ways to make carbon nanotubes a realistic option for transistors in microprocessors and other electronics.

In the next section, we'll look at products that are taking advantage of nanotechnology.

You might be surprised to find out how many products on the market are already benefiting from nanotechnology.

[source: The Ecologist]

New products incorporating nanotechnology are coming out every day. Wrinkle-resistant fabrics, deep-penetrating cosmetics, liquid crystal displays (LCD) and other conveniences using nanotechnology are on the market. Before long, we'll see dozens of other products that take advantage of nanotechnology ranging from Intel microprocessors to bio-nanobatteries, capacitors only a few nanometers thick. While this is exciting, it's only the tip of the iceberg as far as how nanotechnology may impact us in the future.

In the next section, we'll look at some of the incredible things that nanotechnology may hold for us.­

In the world of "Star Trek," machines called replicators can produce practically any physical object, from weapons to a steaming cup of Earl Grey tea. Long considered to be exclusively the product of science fiction, today some people believe replicators are a very real possibility. They call it molecular manufacturing, and if it ever does become a reality, it could drastically change the world.

Atoms and molecules stick together because they have complementary shapes that lock together, or charges that attract. Just like with magnets, a positively charged atom will stick to a negatively charged atom. As millions of these atoms are pieced together by nanomachines, a specific product will begin to take shape. The goal of molecular manufacturing is to manipulate atoms individually and place them in a pattern to produce a desired structure.

The first step would be to develop nanoscopic machines, called assemblers, that scientists can program to manipulate atoms and molecules at will. Rice University Professor Richard Smalley points out that it would take a single nanoscopic machine millions of years to assemble a meaningful amount of material. In order for molecular manufacturing to be practical, you would need trillions of assemblers working together simultaneously. Eric Drexler believes that assemblers could first replicate themselves, building other assemblers. Each generation would build another, resulting in exponential growth until there are enough assemblers to produce objects [source: Ray Kurzweil].

Trillions of assemblers and replicators could fill an area smaller than a cubic millimeter, and could still be too small for us to see with the naked eye. Assemblers and replicators could work together to automatically construct products, and could eventually replace all traditional labor methods. This could vastly decrease manufacturing costs, thereby making consumer goods plentiful, cheaper and stronger. Eventually, we could be able to replicate anything, including diamonds, water and food. Famine could be eradicated by machines that fabricate foods to feed the hungry.

Nanotechnology may have its biggest impact on the medical industry. Patients will drink fluids containing nanorobots programmed to attack and reconstruct the molecular structure of cancer cells and viruses. There's even speculation that nanorobots could slow or reverse the aging process, and life expectancy could increase significantly. Nanorobots could also be programmed to perform delicate surgeries -- such nanosurgeons could work at a level a thousand times more precise than the sharpest scalpel [source: International Journal of Surgery]. By working on such a small scale, a nanorobot could operate without leaving the scars that conventional surgery does. Additionally, nanorobots could change your physical appearance. They could be programmed to perform cosmetic surgery, rearranging your atoms to change your ears, nose, eye color or any other physical feature you wish to alter.

Nanotechnology has the potential to have a positive effect on the environment. For instance, scientists could program airborne nanorobots to rebuild the thinning ozone layer. Nanorobots could remove contaminants from water sources and clean up oil spills. Manufacturing materials using the bottom-up method of nanotechnology also creates less pollution than conventional manufacturing processes. Our dependence on non-renewable resources would diminish with nanotechnology. Cutting down trees, mining coal or drilling for oil may no longer be necessary -- nanomachines could produce those resources.

Many nanotechnology experts feel that these applications are well outside the realm of possibility, at least for the foreseeable future. They caution that the more exotic applications are only theoretical. Some worry that nanotechnology will end up like virtual reality -- in other words, the hype surrounding nanotechnology will continue to build until the limitations of the field become public knowledge, and then interest (and funding) will quickly dissipate.

In the next section, we'll look at some of the challenges and risks of nanotechnology.

The most immediate challenge in nanotechnology is that we need to learn more about materials and their properties at the nanoscale. Universities and corporations across the world are rigorously studying how atoms fit together to form larger structures. We're still learning about how quantum mechanics impact substances at the nanoscale.

Because elements at the nanoscale behave differently than they do in their bulk form, there's a concern that some nanoparticles could be toxic. Some doctors worry that the nanoparticles are so small, that they could easily cross the blood-brain barrier, a membrane that protects the brain from harmful chemicals in the bloodstream. If we plan on using nanoparticles to coat everything from our clothing to our highways, we need to be sure that they won't poison us.

Closely related to the knowledge barrier is the technical barrier. In order for the incredible predictions regarding nanotechnology to come true, we have to find ways to mass produce nano-size products like transistors and nanowires. While we can use nanoparticles to build things like tennis rackets and make wrinkle-free fabrics, we can't make really complex microprocessor chips with nanowires yet.

There are some hefty social concerns about nanotechnology too. Nanotechnology may also allow us to create more powerful weapons, both lethal and non-lethal. Some organizations are concerned that we'll only get around to examining the ethical implications of nanotechnology in weaponry after these devices are built. They urge scientists and politicians to examine carefully all the possibilities of nanotechnology before designing increasingly powerful weapons.

If nanotechnology in medicine makes it possible for us to enhance ourselves physically, is that ethical? In theory, medical nanotechnology could make us smarter, stronger and give us other abilities ranging from rapid healing to night vision. Should we pursue such goals? Could we continue to call ourselves human, or would we become transhuman -- the next step on man's evolutionary path? Since almost every technology starts off as very expensive, would this mean we'd create two races of people -- a wealthy race of modified humans and a poorer population of unaltered people? We don't have answers to these questions, but several organizations are urging nanoscientists to consider these implications now, before it becomes too late.

Not all questions involve altering the human body -- some deal with the world of finance and economics. If molecular manufacturing becomes a reality, how will that impact the world's economy? Assuming we can build anything we need with the click of a button, what happens to all the manufacturing jobs? If you can create anything using a replicator, what happens to currency? Would we move to a completely electronic economy? Would we even need money?

Whether we'll actually need to answer all of these questions is a matter of debate. Many experts think that concerns like grey goo and transhumans are at best premature, and probably unnecessary. Even so, nanotechnology will definitely continue to impact us as we learn more about the enormous potential of the nanoscale.

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