Graphene rips follow rules

Mike Williams
713-348-6728
mikewilliams@rice.edu

Graphene rips follow rules
Rice University simulations show carbon sheets tear along energetically favorable lines

Research from Rice University and the University of California at Berkeley may give science and industry a new way to manipulate graphene, the wonder material expected to play a role in advanced electronic, mechanical and thermal applications.

When graphene – a one-atom thick sheet of carbon – rips under stress, it does so in a unique way that puzzled scientists who first observed the phenomenon. Instead of tearing randomly like a piece of paper would, it seeks the path of least resistance and creates new edges that give the material desirable qualities.

Because graphene’s edges determine its electrical properties, finding a way to control them will be significant, said Boris Yakobson, Rice’s Karl F. Hasselmann Professor of Mechanical Engineering and Materials Science and professor of chemistry.

It’s rare that Yakobson’s work as a theoretical physicist appears in the same paper with experimental evidence, but the recent submission in Nano Letters titled “Ripping Graphene: Preferred Directions” is a notable exception, he said.

Yakobson and Vasilii Artyukhov, a postdoctoral researcher at Rice, recreated in computer simulations the kind of ripping observed through an electron microscope by researchers at Berkeley.

The California team noticed that cracks in flakes of graphene followed armchair or zigzag configurations, terms that refer to the shape of the edges created. It seemed that molecular forces were dictating how graphene handles stress.

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