Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Emerging Technology from the arXiv

A View from Emerging Technology from the arXiv

Graphene Repairs Holes By Knitting Itself Back Together, Say Physicists

Make a hole in graphene and the material will heal itself, say materials scientists who have watched the process in action

  • July 10, 2012

The graphene revolution is upon us. If the visionaries are to be believed, the next generation of more or less everything is going to be based on this wonder material–sensors, actuators, transistors and information processors and so on. There seems little that graphene can’t do. 

But there’s one fly in the ointment. Nobody has yet worked out how to make graphene in large, reliable quantities or how to carve and grow it into the shapes necessary for the next generation of devices. 

That’s largely because it’s tricky growing anything into a layer only a single atom thick. But for carbon, it’s all the more difficult because of this element’s affinity to other atoms, including itself. A carbon sheet will happily curl up and form a tube or a ball or some more exotic shape. It will also react with other atoms nearby, which prevents growth and can even tear graphene apart.

So a better understanding of the way a graphene sheet interacts with itself and its environment is crucial if physicists are ever going to tame this stuff.     

Enter Konstantin Novoselov at the University of Manchester and a few pals who have spent more than a few hours staring at graphene sheets through an electron microscope to see how it behaves. 

Today, these guys say they’ve discovered why graphene appears so unpredictable. It turns out that if you make a hole in graphene, the material automatically knits itself back together again. 

Novoselov and co made their discovery by etching tiny holes into a graphene sheet using an electron beam and watching what happens next using an electron microscope. They also added a few atoms of palladium or nickel, which catalyse the dissociation of carbon bonds and bind to the edges of the holes making them stable. 

They found that the size of the holes depended on the number of metal atoms they added–more metal atoms can stabilise bigger holes.

But here’s the curious thing. If they also added extra carbon atoms to the mix, these displaced the the metal atoms and reknitted the holes back together again.

Novoselov and co say the structure of the repaired area depends on the form in which the carbon is available. So when available as a hydrocarbon, the repairs tend to contain non-hexagonal defects where foreign atoms have entered the structure.

But when the carbon is available in pure form, the repairs are perfect and form pristine graphene.

That’s important because it immediately suggests a way to grow graphene into almost any shape using the careful injection of metal and carbon atoms. 

But there are significant challenges ahead. One important question is how quickly these processes occur and whether they can be controlled with the precision and reliability necessary for device manufacture.

Novoselov is a world leader in this area and the joint recipient of the Nobel Prize for physics in 2010 for his early work on graphene. He and his team are well set up to solve this and various related questions. 

But with the future of computing (and almost everything else) at stake, there’s bound to be plenty of competitors snapping at their heels.  

Ref: arxiv.org/abs/1207.1487: Graphene Re-Knits Its Holes

Be the leader your company needs. Implement ethical AI.
Join us at EmTech Digital 2019.

Register now
Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.