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A microchip made with carbon nanotubes can outperform modern chips when it comes to energy efficiency. If it can be scaled down, it could be used in many different devices and save a vast amount of energy.

In the past, computing performance could be improved by simply making silicon electronics smaller and smaller, but that process is now slowing down, says Max Shulaker at the Massachusetts Institute of Technology (MIT).

He and his team created a microprocessor that sits atop a silicon wafer but is made with carbon nanotubes. If you made a computer chip with the same architecture as modern silicon chips, but used carbon nanotubes, it would be 10 times as efficient, says Shulaker.

Carbon nanotubes are only a nanometre thin, which means they can be turned on using very little energy. They are also good conductors of electricity.

The team has so far used the chip to run a simple program called “Hello, World” which outputs that message, and is commonly the first program written by people learning to code.

“With silicon, the fabrication temperature is 1000°C or higher, but these carbon nanotube transistors can be made at essentially room temperature,” says team-member Christian Lau, also at MIT.

The next step would be to scale down the components, says Franz Kreupl at the Technical University of Munich in Germany. This would allow them to charge and discharge more quickly, but would require more precise alignment of the nanotubes, he says.