Stanford Researchers Create the World's First Working Carbon Nanotube Computer
This is the news we have all been waiting for; researchers at Stanford University have created the first basic computer made of carbon nanotubes. The invention could make electronic devices faster and more energy -efficient than those that have conventional silicon chips.
The working carbon nanotube computer is slow and simple; it runs with a speed similar to that of the Intel 4004 and uses a simple software instruction set called MIPS. However, researchers are optimistic that this computer could be the first of the Next-Gen computing devices that we have been anticipating.
According to an MIT review, the computer processor is capable of switching between multiple tasks and even fetching and sending data back to an external memory. The device has 178 transistors as the researchers developed the machine in a lab, rather than using an industrial-scale chipmaking facility.
"People have been talking about a new era of carbon nanotube electronics moving beyond silicon," said Mitra, an electrical engineer and computer scientist. "But there have been few demonstrations of complete digital systems using this exciting technology. Here is the proof."
What are these Carbon nanotubes?
Carbon nanotubes are very thin tubes made of carbon that have diameter in nanometers. A nanometer is one-billionth of a meter, or in other words is about one ten-thousandth of a human hair. A prominent feature of the nanotube is that it is an unbroken, hexagonal mesh.
For long, scientistists have been trying to develop a computer made of these nanotubes. Experts say that the latest development will push computing to a whole new level.
"Carbon nanotubes [CNTs] have long been considered as a potential successor to the silicon transistor," said Professor Jan Rabaey, an expert on electronic circuits and systems at the University of California-Berkeley.
The journey has been a long and frustrating one as carbon nanotubes are awfully complicated to use. Experts had created the first CNT transistor about 15 years back. Transistors are the basic on and off switches in digital devices. But, nobody could build a complete circuit of CNTs. The current study even shows that researchers can now move from trying to shrink size of a transistor and build new devices using nanotechnology.
End of Moore's law?
Gordon Moore, Intel Corp co-founder predicted in 1965 that density of transistors would double every two years. Getting more transistors on a chip means getting more work done, which is visible in today's devices. We have been trying to build smaller transistors in order to shrink size and price of devices.
But, a major problem with this approach is that we have devices that waste power and dissipate a lot of energy.
The study has shown that individual carbon nanotube transistors (smaller than 10 nanometers) are both faster and energy efficient than silicon transistors.
"CNTs could take us at least an order of magnitude in performance beyond where you can project silicon could take us," H.-S. Philip Wong, lead author of the study said in a news release.
The major problems with Carbon Nanotubes
Yes, carbon nanotubes are the future of computing, but first researchers would have to work around certain limitations. CNT's are essentially long chains of carbon atoms and grow as a tangled mess. Other researchers have tried to make straight carbon nanotubes, but a typical circuit requires billions of nanotubes and even one crooked tube could cause major error.
Also about a third of the carbon nanotubes behave like metals (conduct electricity). But, we'd want a nanotube that is semiconducting so that it could be switched off.
To eliminate the problem of misaligned CNTs, Stanford researchers developed a powerful algorithm that works regardless of the CNTs alignment.
They worked-out the next problem by switching off the good CNTs and pumping all electricity in the semiconductor. Remember, these tubes were metallic, so they heat-up and eventually disintegrate, MIT said.
"This 'imperfections-immune design' [technique] makes this discovery truly exemplary," said Sankar Basu, a program director at the National Science Foundation.
Of course, it would take years for researchers to develop a way to make carbon nanotubes-based computers on an industrial scale. However, the find is a major step forward towards next-gen computers.
The study is published in the journal Nature.