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  • Picture this:

  • You were thrown into a dingy room and told "You can't leave until you have created the

  • thinnest material known

  • to man."

  • Not only that, it must also be the strongest,

  • the best thermal conductor,

  • and as good at conducting electricity as copper.

  • I know, it sounds hopeless.

  • But luckily,

  • you know something about nanotechnology.

  • You know, really really tiny devices and materials that are less than a hundred nanometres

  • in size.

  • Of course, I don't have to tell you a nanometre is a billionth of a meter.

  • That's roughly the size of ten atoms.

  • But how do you create something that tiny?

  • It's time to embrace your inner MacGyver.

  • You're gonna need a pencil, some scotch tape

  • and a healthy dose of elbow grease.

  • A pencil contains not lead but graphite, which consists of sheets of carbon in a

  • hexagonal lattice.

  • When you write, layers of graphite slide off the tip of the pencil and stick to the

  • paper.

  • Usually, many layers are stacked on top of each other

  • but once in a while you get a single layer of carbon atoms.

  • And this is called

  • 'graphene'.

  • In 2004, Andre Geim and Konstantin Novoselov created

  • graphene using nothing but graphite and scotch tape.

  • They placed a graphite flake onto the tape,

  • folded it in two and then cleaved the flake in half.

  • They repeated this procedure a number of times and then studied the resulting fragments.

  • To their astonishment

  • they found some of the pieces were only a single atom thick.

  • This was particularly unexpected because it was thought a single layer of

  • graphite would not be chemically stable,

  • especially at room temperature.

  • Graphene conducts electrons faster than any other substance at room temperature.

  • This is because of the extraordinarily high quality of the graphene lattice.

  • Scientists are yet to find a single atom out of place in graphene.

  • Since the electrons aren't scattered by defects in the lattice,

  • they go so fast

  • that Einstein's relativity must be used to understand their motion.

  • And this perfect lattice is created by the very strong yet flexible bonds between

  • carbon atoms -

  • making the substance bendable

  • but harder than diamond.

  • Graphene is incredibly strong -

  • if you could balance an elephant on a pencil and

  • support the pencil on graphene,

  • the graphene wouldn't break.

  • Of course the pencil would.

  • For their discovery, Geim and Novoselov were awarded the Nobel Prize

  • for physics in 2010.

  • And this is only the beginning for Graphene.

  • Scientists are hard at work exploiting its unique properties to create:

  • Thin, transparent, flexible touch screens;

  • Smaller, faster, more energy efficient computers;

  • Tough composite materials;

  • And more efficient solar cells.

  • And now consider: this is only one aspect of nanotechnology,

  • so in order to think big

  • you need first consider

  • the very small.

Picture this:


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B2 中高級

可能的任務:石墨烯。 (MISSION POSSIBLE: Graphene)

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    BH 發佈於 2021 年 01 月 14 日