Post by williamplayer on Jan 16, 2015 12:00:13 GMT
Japanese Paper Cuts make Graphene Extra Stretchy
06 August 2014 by Rachel Ehrenberg, writing for the New Scientist Magazine
The world's strongest material becomes a softie when cut in just the right places. Computer simulations show that making patterned cuts in superstrong graphene yields flexible sheets that stretch to more than 160 per cent of their original size.
The approach, which mimics the Japanese paper-cutting technique kirigami, should have a host of uses, such as flexible sensors for the body or foldable TV screens.
Graphene is a chicken wire-like layer of carbon just a single atom thick, yet it is more than 100 times stronger than steel. "It's very counter-intuitive," says Harold Park of Boston University. "Graphene is the thinnest possible material, but it's the strongest material."
Experiments have shown that cutting graphene into patterned sheets, akin to cutting paper into intricate snowflakes or flowers, makes the material stretchable.
Park's colleague Zenan Qi made various simulated cuts, and found a pattern involving numerous overlapping rectangles had the most effect on the stretchiness of the sheets. While ordinary graphene tears haphazardly when stretched less than 30 per cent, the kirigami graphene elongated roughly 65 per cent before tears began to form at the interior of the cuts.
Figuring out where, how and when graphene rips is important for using the material, says Paul McEuen of Cornell University in New York, who is using graphene kirigami to make electrodes that could wrap around cells and eavesdrop on them. "These are questions you can't answer by playing with a sheet of paper."
Journal reference: www.arxiv.org/abs/1407.8113
06 August 2014 by Rachel Ehrenberg, writing for the New Scientist Magazine
The world's strongest material becomes a softie when cut in just the right places. Computer simulations show that making patterned cuts in superstrong graphene yields flexible sheets that stretch to more than 160 per cent of their original size.
The approach, which mimics the Japanese paper-cutting technique kirigami, should have a host of uses, such as flexible sensors for the body or foldable TV screens.
Graphene is a chicken wire-like layer of carbon just a single atom thick, yet it is more than 100 times stronger than steel. "It's very counter-intuitive," says Harold Park of Boston University. "Graphene is the thinnest possible material, but it's the strongest material."
Experiments have shown that cutting graphene into patterned sheets, akin to cutting paper into intricate snowflakes or flowers, makes the material stretchable.
Park's colleague Zenan Qi made various simulated cuts, and found a pattern involving numerous overlapping rectangles had the most effect on the stretchiness of the sheets. While ordinary graphene tears haphazardly when stretched less than 30 per cent, the kirigami graphene elongated roughly 65 per cent before tears began to form at the interior of the cuts.
Figuring out where, how and when graphene rips is important for using the material, says Paul McEuen of Cornell University in New York, who is using graphene kirigami to make electrodes that could wrap around cells and eavesdrop on them. "These are questions you can't answer by playing with a sheet of paper."
Journal reference: www.arxiv.org/abs/1407.8113