Nanotechnology Applications

A Definition

You're probably aware that nanotechnology deals with the science of the very small. But just how small? A quick review of prefixes will illustrate. You may recall that "milli-" means "one thousandth." A millimeter, then, is one one-thousandth of a meter (a meter is roughly the length of a grown person's arm), a milliliter is one one-thousandth of a liter, a milligram is one one-thousandth of a gram, etc. Moving further down the line of prefixes we come to "micro-", which means "one millionth." Hence, a micrometer, sometimes referred to as a "micron," is one one-millionth of a meter (or one one-thousandth of a millimeter). Still smaller is the nanometer. "Nano-" means one billionth. It takes one billion nanometers to make one meter. This is smaller than most of us can imagine. To illustrate this small scale, consider the following:

• It takes roughly 80,000 nanometers to stretch across the width of a human hair.
• A six foot tall person could also be labeled a 1.83 billion nanometer tall person.
• Viruses are typically 75 times bigger than a nanometer.
• A molecule of DNA is roughly 2.5 nanometers wide.
• There are roughly 25 million nanometers in an inch.
• A nanometer is to a foot what one foot is to 4,800 miles.

Click here for an interactive "powers of ten" tutorial and check out the figure below to gain a greater appreciation of where "nano" fits in.

Why Nano?

But why stop at the nano- scale? Why not move on to the pico- or femto- scales? Well, maybe one day there will be justification for going that small, but right now sceintists and engineers are interested in the nanoscale because that it is the scale of atoms and molecules. This brings us to our definition of nanotechnology. Nanotechnology is the creation, observation, and application of structures that are on the scale of atoms and molecules. It is the arrangement and manipulation of matter on an atom-by-atom or molecule-by-molecule basis. Again, this scale happens to be on the order of nanometers (typically fewer than 1,000 nanometers), hence "nanotechnology" (as opposed to, say, "femtotechnology"). Click here for wikipedia's defnition/page on nanotechnology.

A point that should be made about the term "nanotechnology" is that it does not apply to just one discipline. Asking what nanotechnology is is like asking what technology is. One needs to be more specific, as there is technology (and nanotechnology) in every discipline and in every aspect of our lives. While "technology" is generally defined as the improvement of a certain process, procedure or product, nanotechnology is the improvement of those things via an extremely small scale.

Just as there is the latest in automotive technology, there is the latest in automotive nanotechnology- the manupulation of matter at the nanoscale toward the improvement of automobiles. Likewise, there is the latest in computer nanotechnology, healthcare nanotechnology, clothing nanotechnology, etc. So, although it may seem that the majority of the nanotechnology research being done has to do with electrical engineering and computer science, nanotechnology is by no means restricted to those disciplines. Indeed, this is why there is such a buzz about nanotechnology (or, more appropriately, "nanotechnologies"); it represents a whole new frontier for improvement in every aspect of our lives.

Brief History

People will point to various moments in history as the birth of nanotechnology. Some point to a 1974 paper on ion-sputtering written by Norio Taniguchi at the University of Tokyo. In that paper a top-down approach to engineering (working from the large scale and getting smaller, essentially "scaling down" to an extreme extent) was espoused and the term "nano-technology" was first coined. Others point to 1986, when K. Eric Drexler wrote Engines of Creation: The Coming Era of Nanotechnology and described the ultimate in bottom-up approaches: the manipulation of matter in an atom-by-atom manner to synthesize materials.

Properties of matter change as one approaches the nanoscale. For example, gold, typically thought to be a rich yellow color, can actually display colors or orange, red, purple and green, depending on the size of the gold nanoparticles in question (this slideshow explains these properties of gold further). For this reason, still others point to medieval glass workers as the first of the nanotechnologists because they were responsible for providing, unbeknowst to them, the nanoparticles that gave stained glass and glazes their colors.

However, the most popular argument as to the start of the nanotechnology age seems to be December of 1959, in which Richard Feynman gave a talk entitled "There's Plenty of Room at the Bottom". In true Feynman form, this is an enjoyable and accessible lecture and it's recommended that you read it should you get the chance. The figure below comes from that lecture. The Feynman Prize in Nanotechnology is now awarded to those researchers that most advance Feynman's goal of nanotechnology: molecular manufacturing, or the construction of atomically-precise structures through the use of molecular machine systems.

(click on image for a larger view)

Some Current Applications

Again, the following can by no means be considered comprehensive because new advances in nanotechnology are continually being made in a plethora of disciplines. The following chart, created by Technolytics, illustrates this. Click on the graphic to link to the webpage.

The list below is only meant to give you a sense of some of the current arenas in which nanotechnology has grabbed hold. It is adapted from Ratner & Ratner's Nanotechnology: A Gentle Introduction to the Next Big Idea, cited on the Review of Literature page of this site. To get a better sense of the vast breadth of disciplines being affected by nanotechnology, visit azonano.com/applications.

Biomedical- One of the major promises in this field is the detection of cancer tumors and the subsequent delivery of target-specific drugs. It is a large enough discipline to warrant its own journal, the Journal of Biomedical Nanotechnology.

Electronics- This is arguably the field that would most benefit from advances in nanotechnology, as limits in miniaturization (a top-down approach) are being neared and Moore's Law is becoming harder and harder to maintain. IBM has successfully used a molecular self-assembly technique toward the creation of nanochips and nano-induced magnetic fields may increase the speed of computers by a factor of 500.

Energy Uses- This is a truly exciting domain of nanoscience as nanostructures are being used to make solar energy more efficient. Photovoltaics are expected to play an increasingly important role in the production of the world's energy via the utilization of nanowires.

Optics- This domain of nanotechnology has broad reach, from high density optical data storage to nanolithography. The website of the Nano-optics Group at the University of Rochester provides a nice overview.

Programmable Materials- Any material that's been engineered via the nanoscale to perform an environment-dependent task. An example might be sunglasses that use nanotechnology to change the level of tint as dictated by the amount of light incident upon it (see Nanofilm website). Another example could be clothing that changes thermal properties depending on what the air temperature is (NPR article on nanotech in fashion).

Sensors- Somewhat similar to programmable materials, sensors respond to the presence of somethign we want to detect. One exciting prospect involves growing nanowires to act as artificial cilia in the hope that they may one day be used in cochlear implants. Also, there are hopes of creating dynamic armor; bullet-proof vests that change structure as a bullet strikes them.