Graphite in a pencil and a diamond… These two materials look nothing alike! Diamonds are clear, sparkly, and extremely hard — diamond is one of the hardest materials on Earth. Graphite, on the other hand, is opaque, dark grey, and soft enough to leave marks on paper as you use it to draw or write. Physically, their characteristics are very different. And yet, diamond and graphite are made of the exact same type of atom - carbon.
How can that be? It has to do with how the atoms of carbon are arranged inside these two materials. In diamond, the atoms form a pyramid-shaped structure with strong bonds in all directions. In graphite, atoms form layers of connected hexagons. The bonds between those layers are rather weak, so the layers of carbon atoms peel off easily when you run the pencil against a sheet of paper.
The arrangement of atoms changes the properties of the material. The entire world around you is made of atoms. The way these atoms are arranged and combined determines how things look, how they behave under different conditions, and how they interact with each other. If we were able to manipulate the arrangement of atoms, we could re-design the things around us, create entirely new materials, and change their properties! This is where a branch of science and technology known as nanotechnology comes into play.
Nanotechnology deals with objects that are incredibly small — between 1 and 100 nanometres in size. Just how small is that? 1 nanometre is one billionth of a metre. That’s about a hundred thousand times smaller than the width of a human hair. It’s about as much as ten hydrogen atoms laid side by side.
A human red blood cell is about seven thousand nanometres across, and a pinhead, about one million nanometres wide. To manipulate atoms and particles on such a small scale, you need special equipment and processes. A device called a scanning tunnelling microscope is one basic piece of equipment used in nanotechnology. It allows us to produce images at an atomic scale and manipulate individual atoms to build completely new structures. Studying objects at the nanoscale helps us better understand the larger objects around us.
But as it turns out, materials can have different physical or chemical properties at the nanoscale, even though they're still the same materials. For example, gold, which is normally unreactive, becomes chemically very active at the nanoscale. Nanogold particles don’t even have the characteristic gold colour — instead, they can have many different colours depending on their size and shape. With the help of nanotechnology, engineers can create entirely new materials, or improve existing ones. One example would be carbon nanotubes and graphene.
Both are made out of carbon atoms, and arranged in ways that make them the strongest materials known. And it’s not just materials — even whole devices can be built on the nanoscale! Transistors, for instance, are some of the building blocks of all modern electronics, including smartphones and computers. Thanks to nanotechnology, they have been reduced to the size of barely a few nanometres. Billions of transistors can now fit easily into a smartphone processor, making it possible to surf the Internet, take, store, and upload pictures, and much more!
Nanotechnology can be applied in many industrial sectors: medicine, food technology, sports equipment, textiles, and beauty products! What uses for nanotechnology can you think of?