Physicists have observed a new behaviour in graphene sheets that causes them to spontaneously grow, tear and peel like self-folding origami. Carbon is a versatile element and can form many types of bonds with different elements – including itself. Diamond, bucky-balls and #graphene are all allotropes of carbon – they are all made out of carbon but have different structures. Graphene was discovered in 2004 and was hailed as a “miracle material” in the news. Under the microscope, graphene looks like chicken wire. Its arrangement gives it interesting properties that scientists are still discovering. The paper, published in Nature, shows that thermal activation magically causes layers of graphene to slide, fold, peel and tear strips within itself. The process happens at room temperature but is accelerated at higher temperatures. “Graphene has been used in research for over ten years. This process has been probably been happening before people’s eyes but nobody has been noticing. They probably just didn’t realise that this happens intrinsically,” Graham Cross, co-author of the paper and professor at the School of Physics and CRANN at Trinity College Dublin, told The Register. To observe the phenomenon, the physicists first isolated layers of graphite to produce graphene. Thin two-dimensional ribbons measuring between 300 and 2,000 nanometres in width and up to five micrometres in length were produced from large graphene sheets. The ribbons were placed on a silicon wafer. Next, a diamond tip was used to puncture the ribbons to form tiny indentations. Thin strands of graphene spontaneously peeled, folded backwards and grew from the edges of the indents.
http://www.theregister.co.uk/2016/07/14/graphene_self_folding_origami/
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