World of computers becomes a big deal smaller Someday we may look back on today's smartphones and laptops as huge, clunky devices with outdated chips made of silicon that was long ago replaced by carbon nanotubes. Tens of thousands of the tiny tube-like structures can fit inside a human hair, and now scientists have created the first carbon nanotube computer - a big step towards miniaturising our electronics even further. While it pales in comparison with today's computers, the bare-bones machine works. It runs a basic operating system and can freely switch between two programs - one that counts in a loop and another that sorts numbers. "This is not a computer you would buy off the shelf," lead author and Stanford electrical engineering graduate student Max Shulaker said. But the functionality is still a complete computer. The study was published online on Wednesday in the journal Nature. Mr Shulaker gave the computer the pet name Cedric, a rough acronym for "carbon nanotube digital integrated circuit." The achievement by Stanford engineers marks the most complex electronic device ever built from carbon nanotubes, a man-made tube-like structure created from one-atom-thick, rolled-up sheets of carbon. Silicon is now the standard material for manufacturing the chips used in computers and phones. But as our devices keep shrinking, silicon circuits are reaching their limit. Silicon is great. It's very hard to beat," senior author and Stanford electrical engineer Subhasish Mitra said. But when everything gets so small, it's not clear you can get high performance and energy efficiency from silicon transistors. Using the minuscule carbon nanotube instead of silicon could mean smaller, faster and more efficient transistors. Carbon nanotubes can be a single nanometre wide in diameter. In comparison, a strand of human DNA is 2.5 nanometres in diameter and your fingernail grows about one nanometre every second. Ever since the first carbon nanotube transistor was built in 1998, "there was a dream in people's minds that we would have a new era of digital electronics using these carbon nanotubes," Professor Mitra said. But researchers found it extremely difficult to manufacture nanotubes without glaring imperfections. Professor Mitra's team had their breakthrough when they stopped trying to make flawless batches of parallel nanotubes and instead focused on designing computer circuits immune to imperfections. Using algorithms, they arranged their circuit in such a way that their computer would still function even if a few nanotubes were misaligned. The computer contains 178 transistors in total, each composed of 10 to 200 nanotubes. Its footprint is only 6.5 square millimetres, meaning you could fit about 40 on a 5¢ coin. Washington Post