Carbon nanotubes are drinking-straw-like structures of pure carbon with walls that can be just one atom thick. Like graphene, which is a flat carbon sheet, carbon nanotubes have a range of useful electronic properties that makes them potential building blocks for computers and other electronic devices. Indeed, carbon nanotubes, which can behave as semiconductors, have already been used to create transistors and other electronic devices that could be smaller, faster and more energy-efficient than silicon-based devices.
Researchers have also used nanotubes to create some of the components used in a computer – such as oscillators and half-adders – but integrating carbon-nanotube devices into a full-blown programmable computer that can run stored programs is far from easy. The problem is that these tubes are only a few nanometres in diameter and tens or even hundreds of them have to be placed with great precision on a substrate to create just one transistor.
Researchers have also used nanotubes to create some of the components used in a computer – such as oscillators and half-adders – but integrating carbon-nanotube devices into a full-blown programmable computer that can run stored programs is far from easy. The problem is that these tubes are only a few nanometres in diameter and tens or even hundreds of them have to be placed with great precision on a substrate to create just one transistor.