The Origin of Pencils
Before talking about space elevators, please know about pencil leads.
The pencil lead is made from a raw material called “graphite”.
Graphite is a Greek word meaning “to write”.
This substance was discovered in England in the first half of the 16th century and began to be used as a writing instrument.
This is the origin of pencils.
However, graphite turned out to be suitable for writing in the mid-20th century.
This is because the development of X-ray technology has made it possible to investigate the atomic structure of matter.
In other words, for about 400 years, people have used graphite as a writing instrument without knowing the detailed mechanism.
Graphite is made up of thin sheets of carbon atoms stacked on top of each other.
This sheet alone is called “graphene”.
The bonds between the carbon atoms of graphene are very strong, but the overlapping force of graphene is relatively weak.
So, if you rub it on the paper, the sheet will come off and stick to the paper.
This is a technique used for pencils and mechanical pencils.
Some people had struggled for many years because it was so difficult to remove just one piece of this thin substance.
In 2004, British physicists Geim and Novoselov succeeded in separating graphene for the first time.
- It was a method of sticking and peeling cellophane tape on the pencil lead.
- Next, attach the peeled tape on the glass substrate and peel it off again.
- Then, graphite moves onto the glass substrate.
- Apply new tape to the graphite on the substrate again and peel it off.
- Repeating this will eventually leave one graphene on the board.
This “how to extract graphene from graphite” was highly evaluated, and the two won the Nobel Prize.