Stanford Develops Carbon Nanotubes

Researchers at Stanford University have demonstrated the first functional computer constructed using only carbon nanotube transistors.

Scientists have been experimenting with transistors based on carbon nanotubes, or CNTs, as substitutes for silicon transistors, which may soon hit their physical limits.

The rudimentary CNT computer is said to run a simple operating system capable of multitasking, according to a synopsis of an article published in the journal Nature.

Made of 178 transistors, each containing between 10 and 200 carbon nanotubes, the computer can do four tasks summarized as instruction fetch, data fetch, arithmetic operation and write-back, and run two different programs concurrently.

The research team was led by Stanford professors Subhasish Mitra and H.S. Philip Wong.

“People have been talking about a new era of carbon nanotube electronics moving beyond silicon,” Mitra said in a statement. “But there have been few demonstrations of complete digital systems using [the] technology. Here is the proof.”

IBM last October said its scientists had placed more than 10,000 transistors made of nano-size tubes of carbon on a single chip. Previous efforts had yielded chips with just a few hundred carbon nanotubes.

Source

IBM’s Next-gen Transistors Mimick Human Brain

IBM has discovered a way to make transistors that could be turned into virtual circuitry that mimics how the human brain operates.

The new transistors would be made from strongly correlated materials, such as metal oxides, which researchers say can be used to build more powerful — but less power-hungry — computation circuitry.

“The scaling of conventional-based transistors is nearing an end, after a fantastic run of 50 years,” said Stuart Parkin, an IBM fellow at IBM Research. “We need to consider alternative devices and materials that operate entirely differently.”

Researchers have been trying to find ways of changing conductivity states in strongly correlated materials for years. Parkin’s team is the first to convert metal oxides from an insulated to conductive state by applying oxygen ions to the material. The team recently published details of the work in the journal Science.

In theory, such transistors could mimic how the human brain operates in that “liquids and currents of ions [would be used] to change materials,” Parkin said, noting that “brains can carry out computing operations a million times more efficiently than silicon-based computers.”

Source