How Things Work: Nanotechnology

A college student might spend the night nursing a sore back because of carrying around volumes of books and a laptop all day. Given this, it is reasonable enough to wish for a scrap of paper which would have everything written on it. However, compared to particles that are one-billionth of a meter in each dimension, a scrap of paper is gigantic.

Thanks to the field of nanotechnology, the word “small” has a taken on a completely new definition. Nanotechnology deals with particles within the range of nanometers. (A nanometer is 10 to the power of negative nine meters.)

Although we can easily imagine such an idea today, it would have found its place in science fiction books some decades ago.

The concept of nanotechnology was proposed almost 50 years ago, when the bizarre idea of consolidating volumes of information onto a tiny surface was discussed by Nobel Prize-winner Richard Feynman. Feynman introduced nanotechnology in a talk called “There’s Plenty of Room at the Bottom,” delivered at the annual meeting of the American Physical Society at the California Institute of Technology (Caltech).

In the talk, given in 1959, Feynman asked, “Why cannot we write the entire 24 volumes of the Encyclopedia Britannica on the head of a pin?”

Feynman then explained his ideas for why putting an entire encyclopedia on a pin is possible and how it can be done. Although the talk probably raised a lot of eyebrows at that time, it got people thinking about nanotechnology and brought the field to where it stands today.

Nanotechnologists use devices like the scanning tunneling microscope, which takes images of the arrangement of atoms in a particular substance. After knowing the arrangement of atoms in a substance, two different approaches can be used to create nano-devices.

The first is the bottom-up approach, in which small particles are arranged in an orderly manner to form larger, complex objects. The second approach is the top-down approach, where large objects are scaled down to a smaller size.

Depending on what device or technology is to be developed, either approach can be employed. The applications of nanotechnology span a variety of different fields, ranging from quantum physics to medicine. Perhaps one of the most popular applications has been in the field of drug delivery.

Chemotherapy has been used to treat cancer since early 1940s. Traditional chemotherapy, which does not involve nanotechnology, has a number of side effects that make the treatment painful for the patient. The main reason for this is that chemotherapy affects all types of cells and does not specifically target the cancerous cells.

New technology now enables scientists to attach RNA molecules to nanoparticles filled with chemotherapy drugs. The RNA molecules are synthesized such that they specifically target cancerous cells. Therefore, the drugs are delivered only to cancerous cells, leaving the other cells of the body unharmed.

Another application is the creation of extremely strong materials. Carbon nanotubes consist of allotropes, or different forms of carbon. These have astonishing properties; one of which is strength, making them useful in devices like bulletproof jackets.

Nanotechnology is also being applied to produce different kinds of fabrics. Clothes can now be coated with zinc oxide nanoparticles, which act as protection from the ultraviolet rays of the sun. Some clothes also have little hair-like nanoparticles on them, which can repel water and dirt particles to make the clothes stain free. Stain-resistant clothing and pain-free chemotherapy are definitely useful innovations, but the best is yet to come.

Researchers now believe that using nanotechnology, virtually any object can be manufactured out of thin air.

These materials will actually be built out of atoms, since atoms and molecules can stick together because of magnetic and electrical properties.

If the particles are carefully manipulated, they can be ordered into a regular structure. Scientists hope to accomplish this using nanomachines called “assemblers,” which can be programmed to organize the particles into ordered structures as complex as computers. This technology, known as “molecular manufacturing,” may soon become a reality.

While nanotechnology has some people dreaming of a futuristic world, it comes with its drawbacks.

Particles have very different properties when they are in bulk or in a large cluster compared to when they are separated into nano-sized particles. Scientists fear that some molecules which we know to be harmless may actually be harmful when they are nano-sized. Making clothing or drug delivery devices out of such materials may therefore be extremely dangerous.

Another concern is that since nanoparticles can have atomic physical and chemical properties, they may be used to create potentially disastrous weapons. If used in the right way, though, nanotechnology can definitely prove to be an asset to mankind.

As for college students, what was once a dead weight on their shoulders may eventually be merely tiny lumps in their pockets.