What is Nanotechnology?

You most likely have heard nanotechnology mentioned in the news, movies, or books (fiction and non-fiction). There are many different opinions about where nanotechnology will have the most profound impact, but everyone agrees that it has the potential to transform our world.

As one of the world’s leading institutions in the field, the International Institute for Nanotechnology at Northwestern University has developed this information to help you understand what nanotechnology is — and what it isn’t.

What is nanotechnology and how is it impacting our world? Watch this short insightful video to find out!

First, it’s about size.

A nanometer is a unit of length in the metric system.

The prefix “nano” comes from the Greek word for “dwarf” and simply means one billionth. So, while one centimeter (about ½ an inch) is 1/100 of a meter, a nanometer (1 nm) is one-billionth of a meter — or 1/1,000,000,000 of a meter, the size of a single small molecule.

To get an idea of how small this is, atoms which make up all matter, range from 0.1 to 0.5 nanometers in width, and a single strand of a DNA molecule is about 2.5 nanometers wide.

In another example, one nanometer is the length your beard grows between the time you pick up your razor to the time you touch it to your face.

Here's an illustration of scale. Let's start with a flea: 1 millimeter.
Going smaller now. One strand of human hair: 80,000-100,000 nanometers wide.
A red blood cell: 7,000 nanometers across.
The virus that causes COVID-19: 20 to 500 nanometers across.
A strand of DNA: 2.5 nanometers wide.

Why is this small scale important?

What scientists discovered in the latter part of the 20th century is that when materials are at the nanoscale (meaning they have at least one dimension [height, length, or depth] that measures between 1-100 nanometers) their physical and chemical properties are different from the same material with macroscale dimensions.

Imagine breaking a piece of gold into smaller and smaller pieces, each piece will still have the same fundamental properties as the original. For example, each piece will still have the same color, melting and boiling points, density, electrical conductivity, and ability to catalyze chemical reactions.

But at the nanoscale, the properties of materials change depending on their size, shape, and composition, in a way that they don’t at any other length scale.

So, the nanoscale is a different kind of small.

It is difficult to predict at what size a particular material’s properties will change, and this threshold is different for each material and each property.

For example, nanoscale gold exhibits different colors throughout the nanoscale size range (green at 50 nanometers, orange at 100 nanometers), but the size-dependent catalytic properties do not dramatically change until gold particles are smaller than 5 nanometers

In nanoscience, composition, size, and shape play a critical role. The nanoparticles above display different colors depending on their size, shape, and composition. Courtesy Chad A. Mirkin © Northwestern University

How do we know this?

While nanometer-sized materials have always existed, it wasn’t until the relatively recent development of specialized tools that scientists were able to both observe nanoparticles and manipulate them.

The invention of the optical microscope in the 17th century opened the world of small biological organisms never before seen by the human eye. But the magnification of an optical microscope is limited to the wavelength of visible light, which is between 400 and 750 nanometers – much larger than many nanoscale objects.

In 1931, the first microscope was invented that proved you could use electrons instead of visible light to see tiny objects. Over the decades since, the electron microscope has been continuously improved. Then in 1981, the first scanning tunneling microscope was invented that allowed scientists to not only see nanoscale objects, but to manipulate them in order to harness their unique size-, shape-, and composition-dependent qualities.

Today, electron microscopes and scanning tunneling microscopes are a staple of nanoscience research laboratories and allow scientists to see features as small as 0.05 nanometers and manipulate nanoscale particles, atoms, and small molecules.

It is these advanced instruments that enable the field of nanotechnology.

A field that is not just about working with exceptionally small objects, but about capitalizing on the unique and changing properties of nanoscale materials to create solutions to the problems we face today.

This is an example of an image from a transmission electron microscope (TEM). It shows imine-linked covalent organic framework nanocrystals on a lacey carbon TEM grid. Courtesy of Leslie Hamachi and William Dichtel.

Bringing it all together

As you can see, nanotechnology gives us an entirely new way to study and make new materials and devices.

It’s important to note that nanotechnology is not a product like a microchip or an automobile. It is a process that harnesses the unique properties of materials at the 1-100 nanometer scale to develop new materials and devices.

The social impact of nanotechnology has been compared to the implementation of the moving assembly line by Henry Ford in 1908. Ford’s streamlined manufacturing process dramatically lowered the cost of production and made automobiles affordable for most Americans. These manufacturing processes were implemented across the country and helped to fuel the industrial revolution.

With the potential to make a similar impact on medicine, energy, the environment, and beyond, nanotechnology has been called “the next industrial revolution.”

Peptide amphiphiles are a unique class of molecules that can be used as structural and bioactive building blocks for a variety of biomedical applications. Here, cells were cultured on thin film coatings of peptide amphiphile supramolecular assemblies. The interaction between the cells and peptide amphiphile material significantly promoted cell growth and motility, indicating enhanced cellular signaling. These materials hold exceptional promise as regenerative solutions to treat devastating tissue degeneration, including musculoskeletal and neurological injuries. Courtesy of Shelby C. Yuan and Samuel I. Stupp.

Now that you have a basic understanding of the field, you may want to:

Or read on to dispel a few common myths.

What nanotechnology isn't

From “grey goo” caused by runaway nanotechnology to “nanobots” capable of self-replicating and destroying the planet (like those seen in Michael Crichton’s Prey), nanotechnology concepts have often been sensationalized, generating a great deal of fear – not to mention subject matter for a number of science fiction writers.

In reality, such scenarios are not possible given everything researchers have learned about nano-manufacturing. Although the ideas in those stories may be loosely connected to actual research, and there may be just enough scientific facts sprinkled into the plot to make it sound somewhat believable, it is important not to let the hype divert attention from the rigorous nanoscience and technology research and development that is focused on important issues in medicine, energy, the environment, and other areas.

Actual nanotechnology research is primarily focused on the design of new materials with properties that derive from their size, shape, and composition, which can be used to make a positive impact on science and society.

Are nanoparticles harmful?

Nanoparticles are part of nature; many types are in the air we breathe. Whether they are harmful or not depends upon the chemical composition and can only be assessed on a case-by-case basis. Just like all other chemicals, their properties will vary.

The nanoparticles that are currently used in a number of different consumer products are harmless. Clay nanoparticles have made their way into composite materials for cars and packaging materials, where they offer transparency and increased strength. Sunscreens utilize nanoparticulate zinc oxide, and new anti-aging skin creams are being developed with nanoparticles.

Nanoparticles are also being used in antiseptics, as abrasives, in paints, in new coatings for spectacles (making them scratchproof and unbreakable), for tiles, and in electrochromic or self-cleaning coatings for windows. Nanoparticles are the basis for new anti-graffiti coatings for walls and improved ski waxes and ceramic coatings for solar cells. Glues containing nanoparticles have optical properties that give rise to uses in optoelectronics. Casings containing nanoparticles are being developed that shield against electromagnetic interference.

In the laboratory, researchers working with unknown or new nanoparticles employ laboratory safety measures and systems to minimize risk just as they would when working with any other unknown chemical or substance.