单选题
Graphene"s Superstrength
Big technology comes in tiny packages. New cell phones and personal computers get smaller every year, which means these electronics require even smaller components on the inside. Engineers are looking for creative ways to build these components, and they"ve turned their eyes to graphene, a superthin material, made of carbon, that could change the future of electronics.
This year"s Nobel Prize for Physics has been awarded to Andre Geim and Kostya Novoselov from the University of Manchester, UK. for the discovery of graphene. Graphene isn"t just small, it"s "the thinnest possible material in this world," says Novoselov. He calls it a "wonder material." It"s so thin that you would need to stack about 25,000 sheets just to make a pile as thick as a piece of ordinary white paper. If you were to hold a sheet of graphene in your fingers, you"d have no idea because you wouldn"t be able to see it.
Carbon is one of the most abundant elements in the universe. Every known kind of life contains carbon. Graphene is a sheet of carbon, but only one atom thick. You don"t have to look far to find graphene—it"s all around you.
If you want this high-tech wonderstuff, all you need is a pencil, paper and a little adhesive tape. Use the pencil to shade a small area on the paper, and then apply a small piece of adhesive tape over the area. When you pull up the tape, you"ll see that it pulls up a thin layer of some of the shading from your pencil. That layer is called graphite, one of the softest minerals in the world.
Now stick the same piece of tape on another sheet of paper and pull the tape up—there should be an even thinner layer, this time left on the paper. Now imagine that you do this over and over, until you get the thinnest possible layer of material on the paper. This layer would be only one atom thick, and you wouldn"t be able to see it. Graphite is made of layers of graphene, so when you get to the thinnest possible layer, you"ve found graphene.