Researchers create first carbon nanotube computer

Researchers from Stanford University on Wednesday announced the creation of the first-ever working carbon nanotube computer, a rare breakthrough in nanotechnology.

Max Shulaker, doctoral student in electrical engineering at Stanford University, holds a wafer filled with carbon nanotube computers (CNTs). To his left, a basic CNT computer utilizing this technology is sandwiched beneath a probe card to input and output signals.  (Norbert von der Groeben)

A team of Stanford engineers led by professors Subhasish Mitra and HS Philip Wong built a basic computer using carbon nanotubes, a semiconductor material that has the potential to launch a new generation of electronic devices that run faster, while using less energy, than those made from silicon chips.

The findings of the project, called `CEDRIC,' a loosely derived acronym for carbon nanotube digital integrated circuit, were published in this week's edition of the scientific journal Nature.

The development signals a shift from further research in silicon transistor computing, a technology that has already been stretched to its limit with transistors shrinked to the smallest possible. Carbon nanotube transistors, however, are now a more realistic solution for future generations of computers because they conduct electricity better than silicon, and can scale smaller.

"People have been talking about a new era of carbon nanotube electronics moving beyond silicon," said Mitra, an electrical engineer and computer scientist and Chambers Faculty Scholar of Engineering. "But there have been few demonstrations of complete digital systems using this exciting technology. Here is the proof."

Experts say the Stanford achievement will galvanize efforts to find successors to silicon chips, which could soon encounter physical limits that might prevent them from delivering smaller, faster, cheaper electronic devices.

CNTs are long chains of carbon atoms that are extremely efficient at conducting and controlling electricity. They are so thin – thousands of CNTs could fit side by side in a human hair – that it takes very little energy to switch them off, according to Wong, co-author of the paper and the Williard R and Inez Kerr Bell Professor at Stanford.

"Carbon nanotubes (CNTs) have long been considered as a potential successor to the silicon transistor," said Professor Jan Rabaey, a world expert on electronic circuits and systems at UC Berkeley.

However, the carbon-nanotube technology is still new, and poses many problems.

The Stanford team's solution addresses some of the key issues. Their system can switch off defective carbon nanotubes, and they developed an algorithm to address misalignments of the carbon nanotubes that could result in short-circuiting of the system.

CEDRIC, as it exists now, is not capable of carrying out immediate, complex computations like a desktop computer.

Yet, the Stanford prototype represents the first step toward more robust examples of carbon-nanotube computing in the future, perhaps in the next 10 to 12 years

(Read more: Stanford engineers build first computer based on carbon nanotube technology)