Imagine something so small that it’s a million times smaller than the length of an ant. Then consider the ability to manipulate something that small to solve problems and create new products. Welcome to the world of nanotechnology.
What It Is and How It Works
Nanotechnology is the understanding and control of matter at the nanoscale, 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 length scale.
Matter such as gases, liquids, and solids can exhibit unusual physical, chemical, and biological properties at the nanoscale, differing in important ways from the properties of bulk materials and single atoms or molecules. Some nanostructured materials are stronger or have different magnetic properties compared to other forms or sizes or the same material. Others are better at conducting heat or electricity. They may become more chemically reactive or reflect light better or change color as their size or structure is altered.
Learn about the beginning of the science of studying the extremely small and its fundamental concepts.
A nanometer is one-billionth of a meter. Find out just how tiny that actually is.
Special high-powered microscopes have been developed to allow scientists to see and manipulate nanoscale materials. Learn about those microscopes here.
Size of the Nano Scale
Just how small is “nano?” In the International System of Units, the prefix “nano” means one-billionth, or 10-9; therefore one nanometer is one-billionth of a meter. It’s difficult to imagine just how small that is, so here are some examples:
- A sheet of paper is about 100,000 nanometers thick
- A strand of human DNA is 2.5 nanometers in diameter
- There are 25,400,000 nanometers in one inch
- A human hair is approximately 80,000- 100,000 nanometers wide
- A single gold atom is about a third of a nanometer in diameter
- On a comparative scale, if the diameter of a marble was one nanometer, then diameter of the Earth would be about one meter
- One nanometer is about as long as your fingernail grows in one second
The illustration below has three visual examples of the size and the scale of nanotechnology, showing just how small things at the nanoscale actually are.
Working at the Nanoscale
Nanotechnology is more than just mixing nanoscale materials together; it requires the ability to understand and to precisely manipulate and control those materials in a useful way.
Nanotechnology involves a new and broad science where diverse fields such as physics, chemistry, biology, materials science, and engineering converge at the nanoscale.
It is also important to understand that nanoscale materials are found in nature. For instance, hemoglobin, the oxygen-transporting protein found in red blood cells, is 5.5 nanometers in diameter. Naturally occurring nanomaterials exist all around us, such as in smoke from fire, volcanic ash, and sea spray. Some nanomaterials are a byproduct of human activity, such as bus and automobile exhaust and welding fumes.
Working at the nanoscale requires an understanding of the various types and dimensions of nanoscale materials. Different types of nanomaterials are named for their individual shapes and dimensions. Think of these simply as particles, tubes, wires, films, flakes, or shells that have one or more nanometer-sized dimension. For example, carbon nanotubes have a diameter in the nanoscale, but can be several hundred nanometers long or even longer. Nanofilms or nanoplates have a thickness in the nanoscale, but their other two dimensions can be much larger.
The key is to be able to both see and manipulate nanomaterials in order to take advantage of their special properties. As mentioned earlier, the invention of special microscopes gave scientists the ability to work at the nanoscale. The first of these new discoveries was the scanning tunneling microscope. While it’s mainly designed to measure objects, it can also move tiny objects such as carbon nanotubes.
The earliest example of this type of process was accomplished by IBM on November 11, 1989, when researcher Don Eigler and colleagues spelled the company logo in atoms. He and his team were able to literally move 35 xenon atoms on a background of copper atoms to spell out IBM.
More recently a team of Stanford University researchers led by Hari Manoharan were able to encode 35 bits of information per electron and write letters so small they are composed of subatomic bits of matter only 0.3 nanometers wide, or roughly one third of a billionth of a meter. In other words, they beat the record set by IBM, writing Stanford’s initials in letters smaller than atoms. These exercises demonstrated the precision with which it is possible to manipulate matter.
Today, research scientists in universities and companies around the world are manufacturing nanomaterials to make new products and applications, from medical devices and drugs that may treat disease, to strong and lightweight materials that reduce fuel costs for cars and planes. For more information about these discoveries and inventions, see Benefits and Applications here on the Nano.gov website.
Manufacturing at Nanoscale
Manufacturing at the nanoscale is known as nanomanufacturing. Nanomanufacturing involves scaled-up, reliable, and cost-effective manufacturing of nanoscale materials, structures, devices, and systems. It also includes research, development, and integration of top-down processes and increasingly complex bottom-up or self-assembly processes.
In more simple terms, nanomanufacturing leads to the production of improved materials and new products. As mentioned above, there are two basic approaches to nanomanufacturing, either top-down or bottom-up. Top-down fabrication reduces large pieces of materials all the way down to the nanoscale, like someone carving a model airplane out of a block of wood. This approach requires larger amounts of materials and can lead to waste if excess material is discarded. The bottom-up approach to nanomanufacturing creates products by building them up from atomic- and molecular-scale components, which can be time-consuming. Scientists are exploring the concept of placing certain molecular-scale components together that will spontaneously “self-assemble,” from the bottom up into ordered structures.
Within the top-down and bottom-up categories of nanomanufacturing, there are a growing number of new processes that enable nanomanufacturing. Among these are:
- Chemical vapor deposition is a process in which chemicals react to produce very pure, high-performance films
- Molecular beam epitaxyis one method for depositing highly controlled thin films
- Atomic layer epitaxyis a process for depositing one-atom-thick layers on a surface
- Dip pen lithography is a process in which the tip of an atomic force microscope is “dipped” into a chemical fluid and then used to “write” on a surface, like an old fashioned ink pen onto paper
- Nanoimprint lithography is a process for creating nanoscale features by “stamping” or “printing” them onto a surface
- Roll-to-roll processing is a high-volume process to produce nanoscale devices on a roll of ultrathin plastic or metal
- Self-assembly describes the process in which a group of components come together to form an ordered structure without outside direction
Structures and properties of materials can be improved through these nanomanufacturing processes. Such nanomaterials can be stronger, lighter, more durable, water-repellent, anti-reflective, self-cleaning, ultraviolet- or infrared-resistant, antifog, antimicrobial, scratch-resistant, or electrically conductive, among other traits. Taking advantage of these properties, today’s nanotechnology-enabled products range from baseball bats and tennis rackets to catalysts for refining crude oil and ultrasensitive detection and identification of biological and chemical toxins.
Nanoscale transistors may someday lead to computers that are faster, more powerful, and more energy efficient than those used today. Nanotechnology also holds the potential to exponentially increase information storage capacity; soon your computer’s entire memory will be able to be stored on a single tiny chip. In the energy arena, nanotechnology will enable high-efficiency, low-cost batteries and solar cells.
Nanotechnology R&D, and the eventual nanomanufacturing of products, requires advanced and often very expensive equipment and facilities. In order to realize the potential of nanotechnology.