A microprocessor has been created built around the “wonder material” carbon nanotubes. The processor built by researchers over at MIT and Analog Devices is fabricated on industry-standard processes, and is comprised of 14,000 transistors. That’s still a long way off the billions of transistors used in today’s silicon chips, but it’s a start.
Carbon nanotubes have been touted as the answer to silicon in semiconductors for years, although has rarely proven itself useful outside of a lab environment. It is expected that these one-atom thick sheets, rolled up into tiny tubes, will be more power-efficient and faster than silicon alternatives. One of the researchers involved, Max Sculaker, believes these transistors could one day operate on one-third of the energy, and three times faster, than silicon (via Science News), but that won’t be for some time.
The team of researchers have managed to corral this new-age material into CNTFETs, or carbon nanotube field-effect transistors, which now somewhat resemble a modern-day CPU. However, this tricky task often leads to unwanted outcomes. Reportedly one of the issues facing this silicon replacement is the distribution of carbon nanotubes during the fabrication process, and this can lead to them bunching together and leading to non-operational transistors. The answer for the MIT team? Give the wafer a good shake, apparently.
And the resulting 16-bit processor from this research does indeed overcome some of the preliminary challenges facing CNT CPUs. It’s based on the RISC-V instruction set, an open standard hoping to spurn on a less license-heavy hardware scene, and is rather capable compared to previous attempts at carbon nanotube CPUs. It even managed to spit out the phrase “Hello, world!”
But we’re still very far off CNTFETs replacing MOSFETs, and even the best nanotubes can offer today is far slower and less scalable than even client desktop chips from Intel and AMD running our PCs today.
You can read all about the intricate carbon nanotube process in the team’s paper, published in Nature (PDF warning).