What is Nanotechnology? History, Examples, and Applications
Nanotechnology is the science that deals with the study and application of things at an extremely small scale called the nanoscale.
What makes nanotechnology interesting is the fact that properties of a material change with the change in size at a nanoscale. The changes take place at the atomic and molecular level of a material.
Though the concepts of nanotechnology were introduced by Richard Feynman in 1959, materials at a nanoscale were used centuries ago.
What is the nanoscale?
In the International System of Units, nano means one-billionth of a meter, and it is represented by the standard symbol nm.
A cm is 1/100th of a meter
A millimeter is 1/1000th of a meter
A micrometer is 1/1,000,000th of a meter (one millionth of a meter)
A nanometer is 1/ 1,000,000,000th of a meter one-billionth of a meter.
Here are examples of how small a nanometer can be –
- one inch is about 25.4 million nanometers
- a single water molecule is about 1.5 nanometers
- a sheet of paper is about 100,000 nanometers thick
- a human hair measures about 80,000 to 100,000 nanometers in diameter
- a strand of human DNA is 2.5 nanometers in diameter
A nanometer is used to measure tiny things. For example, the tiniest part of any material is the atom. This atom is measured in nanometers.
History of Nanotechnology
Nanotechnology has been around since the fourth century. The craftsmen who used such techniques did not know about the concept of nanotechnology in scientific terms.
But what they did to create artefacts was similar to the nanotechnology that we are aware of today.
Examples of Nanotechnology in Ancient Times
The Lycurgus Cup made in the 4th century in Rome appeared to be of two different colors depending upon the angle of the light rays.
The Lycurgus Cup seemed to be green when lit from the outside and red when lit from the inside.
The glassmakers in those days achieved this effect by using nanoparticles of gold and silver that were dispersed in colloidal form.
Another example of Nanotechnology in ancient times is the vibrant stained glass windows used in the cathedrals of Europe.
The stained glasses used in the construction of the cathedrals had rich, vibrant colors that were achieved by using nanoparticles of gold, metal oxides and other chlorides.
The south rose window of Notre Dame Cathedral is an example of such an effect.
Early Stages of Nanotechnology
In the year 1981, Gerd Binnig and Heinrich Rohrer at IBM’s Zurich Lab invented the Scanning Tunneling Microscope.
Using the Scanning Tunnelling Microscope scientists were able to work at the atomic level of any material. Scientists were able to manipulate the atoms of material and come up with new materials that had better properties when compared to the original material.
In the year 1986, Gerd Binnig Calvin Quate and Christopher Gerber invented the atomic force microscope. Scientists were able to view, measure and rearrange atoms to fractions of nanometers using the atomic force microscope.
In the year 1989, Don Eigler and Erhard Schweizer at the IBM’s Almaden Research Center worked with 35 individual Xenon atoms to spell out the IBM logo. The creation of the IBM logo proved that atoms could be manipulated with precision.
Change in Color of Gold with the Change in Size
The advance in the field of microscopy has lead to the invention of powerful microscopes that helped scientists to manipulate materials at a nanoscale.
The original properties of a material change as the size of the particles become smaller and smaller. Properties such as melting point, fluorescence, electrical conductivity, magnetic permeability and chemical reactivity of a material change with the change in size at the nanoscale.
For example, gold has a yellow color but at the nanoscale gold particles can appear in different colors.
The change in color is because the gold particles at a nanoscale react with light in a different manner when compared to gold particles on a larger scale.
Nanoparticles of gold can be manipulated to accumulate selectively in tumor cells. This selective accumulation can help in imaging the tumor and targeting the tumor cells without destroying the healthy cells.
Why do properties of a material change with the change in size?
The change in properties of the nanoparticles is also because of the increase in the surface area as the particle size decreases.
As a particle reduces in size, more atoms are exposed and come to the surface thereby increasing the surface area.
For example, one gram of nanoparticles would have thousands of times greater surface area when compared to one gram of a bulk material.
The increase in the surface area at a nanoscale offers room for many improvements on the original material.
Applications of Nanotechnology
Field of Medicine
Nanotechnology in the field of medicine helps to target diseased cells and administer medicine directly to these cells without destroying healthy cells.
Nanoparticles are being engineered to deliver medicines directly to cancer cells. Companies such as CytImmune and Bind Biosciences have conducted clinical trials of such medicines.
Researchers at the University of Illinois have shown that gelatin nanoparticles can be used to deliver medicines directly to the damaged brain tissue.
Researchers at MIT are working to come up with nanoparticles to deliver vaccines. Another research aims at developing nanoparticles to prevent the reproduction of viruses in a patient’s blood.
Research is still going on to develop effective methods to control and treat diseases in the field of medicine.
Field of Electronics
Hard drives used for storing data in computers need more power than a solid-state memory device (also known as the flash drive) and has higher chances of a breakdown. The solid state computer memory device occupies less space and uses less power and are ideal to fit in small computers.
Nanolithography technique has lead to the manufacture of memory chips with sizes as small as 20 nm. Magnetic nanowires made of iron and nickel alloy are being used to create memory devices with greater capacities.
Researchers at North Carolina State University are growing nanodots which are about 6 nm in diameter. A memory device storage capacity can increase phenomenally by using billions of the 6 nm diameter dots.
Carbon nanotubes are being used to make lightweight, millimeter thick nano emissive display panels.
These are some of the examples of nanotechnology in the field of electronics.
More Applications of Nanotechnology
Nanotechnology is being researched to come up with better materials and apply them across fields to improve existing products and come up with new products.
A few examples of ongoing research in nanotechnology -
- The increased surface area of nanoparticles is used to filter water in remote villages where clean drinking water is difficult to access.
- Production of eco-friendly fuel from raw materials to overcome fuel shortages.
- Improve the present catalysts that transform poisonous vapors escaping from industries and automobiles into the harmless breathable air.
- To make fabrics that are water, stain and odor resistant, to make shoe inserts that provide warmth for cold weather.
- Nanotechnology is also being researched in the food industry on how to grow better crops with greater health benefits, improve food safety and the packaging of goods.
Nanotechnology deals with things at a nanoscale. As the size of a particle decreases the properties of the particle changes exponentially.
By manipulating particles at a nanoscale, scientists can come up with ideas to improve the properties of existing products and synthesize new products with better features that can be used across many fields of application.