What exactly is nano?
Extraordinary things happen in nanoscale, but what is this nanoscale? When we say nano, we enter the world, where at least one dimension is between 1-100 nm (nm – nanometer, 10-9 m). 100 nm is ten thousand times less than 1 mm, whereas 1 nm is the length of few atoms (basic particles, which the world is built of) laid one after another.
A world between 1 and 100 nm is the world connecting a world of big things (macroscopic) and world of atoms. In the nanoscale we can see features of both worlds, so let’s introduce them:
Macroscopic world (classical): This is our scale. We express measure of most things in millimeters, centimeters, meters or kilometers. Classical physical laws apply here, such as Newton dynamic laws. When we are looking at the mug on the table, we are certain that it is really standing there. When we throw a basketball, we can predict whether it makes a basket. This is the world we know well and which rarely surprises us.
Atomic world: on the contrary. Atom is a very small object (0,1 – 0,5 nm) and it is beyond classical laws of physics. Only quantum physics laws apply to atoms. These laws are completely different from laws which apply to macroscopic world. Consequently phenomena in the atomic world are different from “ours”. The most visible quantum phenomenon is the variety of colors we see. Some objects are blue and other are red because of specific interaction between light and atoms. We can explain this interaction only using quantum laws (but the explanation goes beyond the scope of this text).
These are two worlds which have to get on well together in the nanoworld. One world is well-organized, where we live in, ruled by classical laws. The other world of atoms seems to be chaotic, but is also ruled by (quantum) laws of physics. What can we expect on the border of these worlds? In some cases we see the first world, in other cases the second one, but sometimes we will observe absolutely surprising and new phenomena. These phenomena are the result of some kind of agreement between two worlds. Nanoscale is on the border of classical physics and quantum physics and this is why it is so intriguing.
What is nanotechnology then?
Nanotechnology deals with making products, which have something in nanoscale (1-100 nm). It doesn’t mean, that you should look for these products under microscope. These products can have normal sizes. You can take them up with your hands, rotate them and look at them from each side.
To explain this, let’s imagine a sand castle. The castle itself can be of a size several dozens of centimeters, but it is built of minute grains of sand with size less than a millimeter. Similarly, each metal is built of minute grains connected together. What if we made these grains 100 times smaller? Then these grains will be in the nanoscale. The chunk of metal itself could be heavy and inconvenient, but it would still be a product of nanotechnology. That’s because it is built of nanograins of metal.
What are the advantages of smaller grains? Why should we bother with making metals with nanosized grains? Let’s get back to our sand castle. It is possible to make a similar castle with gravel? It is at least much harder than making a sand castle. Let’s think, what difference there is between sand and gravel. The only thing which differs these two materials is grain size. Sand consists of microscopic grains whereas gravel has much larger grains.
What’s the conclusion? Using the material with smaller grains (sand) we get better ability to build sand castles than using the material with bigger grains (gravel). Similarly building metal with smaller grains we can change its properties. In case of metal we enhance its mechanical properties – metal with nanosized grains is more resistant to stretching than traditionally made. In nanotechnology there are many more examples like this one. Applications of nanotechnology impacts many aspects of people’s lives. This blog is, among other things, devoted to these applications.
To sum up, the nanoscale world is on the border of atomic world (ruled by quantum physics) and macroscopic world (ruled by classical physics). In this world we can see new phenomena, which haven’t been observed in both the atomic scale and macroscopic scale. Nanotechnology deals with making exclusive products, which have building blocks with dimensions between 1-100 nm.