Scientists at MIT built a 16-bit microprocessor out of carbon nanotubes and even ran a program on it, a new paper reports.
Silicon-based computer processors seem to be approaching a limit to how small they can be scaled, so researchers are looking for other materials that might make for useful processors. It appears that transistors made from tubes of rolled-up, single-atom-thick sheets of carbon, called carbon nanotubes, could one day have more computational power while requiring less energy than silicon.
the MIT group, led by Gage Hills and Christian Lau, has now debuted a functional 16-bit processor called RV16X-NANO that uses carbon nanotubes, rather than silicon, for its transistors. The processor was constructed using the same industry-standard processes behind silicon chips—Shulaker explained that it’s basically just a silicon microprocessor with carbon nanotubes instead of silicon.
The processor works well enough to run HELLO WORLD, a program that simply outputs the phrase “HELLO WORLD” and is the first program that most coding students learn. Shulaker compared its performance to a processor you’d buy at hobby shop to control a small robot.
A small but notable fraction of carbon nanotubes act like conductors instead of semiconductors. Shulaker explained that study author Hills devised a technique called DREAM, where the circuits were specifically designed to work despite the presence of metallic nanotubes. And of course, the effort relied on the contribution of every member of the relatively small team. The researchers published their results in the journal Nature today.
Ultimately, the goal isn’t to erase the decades of progress made by silicon microchips—perhaps companies can integrate carbon nanotube pieces into existing architectures.
This is still a proof-of-concept. The team still hasn’t calculated the chip’s performance or whether it’s actually more energy efficient than silicon—the gains are based on projections. But Shulaker hopes that the team’s work will serve as a roadmap toward incorporating carbon nanotubes in computers for the future.