http://education.mrsec.wisc.edu/35.htm
What is Nanotechnology?
Greta Zenner Petersen explains what exactly Nanotechnology is and why it's getting so much buzz.
Defining Nanotechnology
The term "nanotechnology" has been getting a lot of attention in the media in the past few years. News
stories have heralded nanotechnology as the next scientific revolution--with promises of faster
computers, cures for cancer and solutions to the energy crisis, to name a few. But what exactly is
"nanotechnology"? And, can it fulfill all these promises?
The formal definition of nanotechnology from the National Nanotechnology Initiative (NNI) is:
Nanotechnology is the understanding and control of matter at dimensions between approximately 1 and
100 nanometers, where unique phenomena enable novel applications.
Encompassing nanoscale science, engineering, and technology, nanotechnology involves imaging,
measuring, modeling, and manipulating matter at this small scale.
The NNI definition can be distilled to three basic concepts:
1. Nanotechnology is very, very small.
When something is on the nanoscale, it measures between 1 - 100 nanometers (nm) in at least one of its
dimensions. When things are this small, they are much too small to see with our eyes, or even with a
typical light microscope. Scientists have had to develop special tools, like scanning probe microscopes to
see materials that are on the nanometer size scale.
Some materials have ALWAYS been on the nanoscale-like water molecules or silicon atoms. However,
recently scientists have been able to use new tools and processes to synthesize and manipulate
materials common at the macroscale to this size, like particles of TiO2 (titanium dioxide).
2. At the nanoscale, materials may behave in different and unexpected ways.
At the nanoscale, many common materials exhibit unusual properties, such as remarkably lower
resistance to electricity, lower melting points or faster chemical reactions.
For example, at the macroscale, gold (Au) is shiny and yellow. However, when the gold particles are 25
nm in size, they appear red. The smaller particles interact differently with light, so the gold particles
appear a different color. Depending on the size and shape of the particles, gold can appear red, yellow
or blue.
Gold coin
Nanoparticles of gold in solution
Another example of nanoparticles appearing different than the corresponding macroscale material is
found in sunscreens. Titanium Dioxide (TiO2) has been used in sun screens and sun blocks for a long
time. It is one of the ingredients that make the creams appear white in color. Manufacturers are now
using nanoparticles to create creams and gels that are clear-because nanoparticles of TiO2 appear
transparent.
Other properties can change when materials are on the nanoscale, too. For example, aluminum (Al) is
the shiny pliable metal used to make soda cans. At the nanoscale, aluminum particles are extremely
reactive and will explode. Nanoparticles are more reactive because they have more surface area than
macroscale particles.
3. Researchers want to harness these different and unexpected behaviors to make new
technologies.
By harnessing these new behaviors, researchers in many different disciplines hope to create many new
things ranging from everyday products such as antimicrobial socks and lighter tennis rackets to state of
the art solar cells, faster and smaller computers or medical treatments that selectively treat the disease.
Many scientists and engineers think that the possibilities are endless.
Is the iPod Nano an example of Nanotechnolgy?
Nanotechnology-enhanced products are already finding their way to the market. However, not every
product labeled "nano" really utilizes nanotechnolgy. Some manufacturers are using the prefix "nano"to communicate the relative small size of their specific products to potential buyers. In addition, they
hope to capitalize the buzz and excitement that has surrounded nanotechnology.
For example, Indian car makers recently introduced the Tata Nano:
image taken from http://en.wikipedia.org/wiki/Tata_Nano
This car is definitely not on the nanoscale, but the designers chose to name it "Nano" to communicate to
potential buyers its use of "high technology" and its small size. This isn't the only example on the market
today.
A more common example is the iPod Nano:
image taken from http://www.apple.com/ipodnano/
Again, this music player is not "nano-sized" but it is much smaller than the orginal iPod. However, it does
utilize nanotechnology in the chips and circuitry that make it work--the same way your laptop does!
There are some products out there that do use nanotechnology, even if it is not contained in the name!
One of the most common instances is the use silver nanoparticles in consumer products. Silver is
inherently anti-microbial and has been used to control bacteria since ancient times. By incorporating
nanoscale silver into textiles, plastics, and household appliances, manufacturers can make materials that
use a small amount of silver to kill bacteria without affecting other properties of the products.
"Benny the Bear" plush toy
Silver Seal computer keyboard Sports Jersey from Sinotextiles Co,Ltd
All images taken from http://www.nanotechproject.org/inventories/consumer/
However, there is concern that increased use of silver in this manner may pose an environmental risk or
lead to the development of silver-antibiotic-resistant bacteria.
The Project on Emerging Nanotechnologies has created an inventory of consumer products that they
believe actually utilize nanotechnology in some way. However, due to the proprietary nature of these
products, a definitive decision on exactly how the product is utilizing nanotechnology can often not be
made.
Can nanotechnology live up to the hype?
Nanotechnology has been dubbed "the next big thing". It is being heralded as the key to new cancer
treatments, energy independence, improved electronics and bringing clean water to third world
countries. With such a diverse range of possible applications, nanotechnology has the capacity to
change the world we live in, in the same way that computers have changed society over the last 30
years. But to accomplish these feats, scientists and engineers that work on nanoscale materials still have
to better understand how nanoscale materials behave and how to synthesize them reliably.
Some applications are closer to market than others. For instance, researchers, like Prof. Naomi Halas
and Jennifer West at Rice University have collaborated to develop a cancer treatment using gold nano
shells. The treatment is still under development, but may find its way to clinical trials in the near future.