Computers of the future could be even smaller, faster, and more efficient — all by doing away with the very material that currently comprises their core.
In a finding that builds on earlier work from several institutions, including IBM, a team of electrical engineers at Stanford University recently announced the creation of the first-ever computer based on carbon nanotubes. The nanotubes are used to create a novel kind of transistor, one that doesn’t rely on conventional silicon.
“This is the most complex electronic ever built with carbon nanotubes,” said Max Shulaker, a co-author on the paper announcing the progress, which is published in latest issue of Nature magazine. Carbon nanotubes, or CNTs, are infinitesimally small cylinders made from sheets of carbon atoms. When arrayed into transistors, the nanotubes are small enough that engineers can fit many more of them onto a single chip compared to silicon transistors.
Their size, combined with other properties of the nanotubes — including high conductivity and rapid on-off ability — would mean enhanced speed and energy efficiency. That is particularly important given the inherent limits of silicon-based transistors: researchers have been doubling the number of transistors on a chip approximately every two years (a process known as Moore’s Law) but that progress will within decades reach an end.
Despite the exciting progress, Shulaker is also realistic about the prospects of electronics running on carbon nanotubes anytime soon. Additional research will be necessary to yield more sophisticated CNT-based computers, and the nanotubes are only one of several emerging technologies with the potential to replace silicon. Not to mention that any major disruption to the silicon-based electronics industry would be a formidable challenge.
“I’d be naive to think that one fine morning, the industry will just wake up and toss silicon out the window,” he said. “But I like to think that, maybe one day, Silicon Valley will become Carbon Valley.”