YOU won鈥檛 find it at any office supplies shop. But silicon paper may be the key to building bendy versions of traditional microchips.
Nearly all modern gadgets, from smartphones to washing machines, use microprocessors based on silicon wafers. These have a crystal structure that stops them from bending easily, and slicing into thin wafers means they are brittle. That creates a problem for future bendable electronics, which could include roll-up displays and wearable devices.
Chengxin Wang and colleagues at Sun Yat-sen University in Guangzhou, China, wondered if they could coax silicon into a more flexible form. They put silicon monoxide powder inside a crucible and vaporised it by heating it to 1600 掳C.
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The team then used a stream of argon gas to push the vapour to the top of the crucible, where it cooled to form particles of silicon and silicon dioxide. Some of the silicon stuck together and grew into a sheet of nanowires entwined like fibres inside paper.
The nanowires have a rigid crystal structure, but the papery network will easily bend. It is also transparent, as tiny gaps between the wires let optical wavelengths pass through ().
There are other ways to incorporate silicon circuits into bendy materials, says Mark Baxendale of Queen Mary, University of London, but he still expects the nanowire paper to be well received. 鈥淧eople want to see silicon in technology because it is well understood,鈥� he says.