Carbon Nanotubes for fastest communication of computer and mobile networks

[June 10th 2005]

Nanotechnology Scientist at University of California Irvine demonstrated the fastest propagation of Electrical signals with the help of Carbon Nanotubes. Nanotubes can achieve speed as fast as 10 GHz which is much faster than traditional channels of Aluminium or copper wires. This breakthrough will lead to more faster and efficient network for computers, cell phone systems and wireless networks.

These carbon nanotubes can channelize the signal flow between nanodevices at very high speed compare to copper and aluminium wires. "From now on, any time a nanotube device is used anywhere in the world in a high-speed electronic device, computer, wireless network or telephone system, people will benefit from this technology," said peter bruke, one of the research Scientist who developed the technology for nanotubes and nanotube transistors.

"Our prior research showed that nanotube transistors can operate at extremely high frequencies, but the connections between the transistors were made out of somewhat slower copper, thus forming a bottleneck for the electrical signals," said Peter Burke, assistant professor of electrical engineering and computer science. "In this technology we show that nanotubes can also quickly route electronic signals from one transistor to another, thus removing the bottleneck."

"From now on, any time a nanotube device is used anywhere in the world in a high-speed electronic device, computer, wireless network or telephone system, people will benefit from this technology," Burke added.

Before this discovery peter Brooke's, nanotechnology scientist from University of California along with his team demonstrated that few millimetre channel made up of carbon nanotubes can carry electrical signals faster than that of aluminium or copper wires, but could not measure the scale. Current demonstration is first ever to conclude nanotubes are much faster than traditional aluminium or copper wires.Brukes team earlier developed and demonstrated nanotube transistor technology which can scale up to theoretical frequency upto Terahertz (1024 Giga Heartz). So nanotube transistors interconnected with nanotube channels can build up ultra fast all nanotube electronic circuit, which can be faster than any existing semiconductor technology, adding yet another advance and enthusiastic step in electronics.

What is Nanotube ?

A nanotube is commonly made from carbon and consists of a graphite sheet seamlessly wrapped into a cylinder only a few nanometers wide. Carbon Nanotubes are tiny tubes about 10,000 times thinner than a human hair, consist of rolled up sheets of Carbon Hexagons. A nanometer is a unit of measurement that is 10 raised to -9 meter, or one billionth of a meter. nanotubes are Discovered in 1991 by researchers at NEC Laboratories, They have then proven their potential use in ultrasmall electronic devices. But then Practically to build these devices carbon nanotubes needed to be manuevered with engineering precision. IBM researchers using an atomic force microscope (AFM), an instrument whose tip can apply accurately measured forces to atoms and molecules, had devised a means of changing a nanotube's position, shape and orientation, as well as cutting it. Atomic Force Microscope (AFM) works on the principle that carbon nanotubes Stick to the surface by van der waals forces this helps in bending the nanotubes by bending surfaces.

WHERE IT BEGAN - Onion Rings to Nanotubes

After Nec developed their first high resolution electron microscope in 1971, there research team analyzed all kinds of surfaces with carbon materials. In 1980 researchers discovers onion shaped rings in spherical graphite later identified as Carbon 60 (C60). There were also needle shaped material appeared nearby, now known as nanotubes, this is the first time nanotubes ever been seen by anybody. Nearly decade after that in April 2001 IBM researchers have built the world's first array of transistors out of carbon nanotubes 500 times smaller than today's silicon-based transistors and are 1,000 times stronger than steel.
In the same year American Chemical Society, world's largest scientific society published a report in there nanotechnoloy newsletter called nanoletter saying "Scientists have demonstrated, for the first time, that transistors made from single-walled carbon nanotubes can operate at extremely fast microwave frequencies, opening up the potential for better cell phones and much faster computers, perhaps as much as 1,000 times faster.", a similar but more proof oriented step towards significant development in nanotechnology based electronics.
As Electrons can move without losing energy inside nanotubes, makes them perfect candidates for connections in electrical devices. A semiconducting carbon nanotube can act as a transistor, which can be be switched on and off. Electrons move inside a tube leaving a hole (-ve charge) behind, effectively transmitting a positive charge in one direction and negative charge in another direction. All this is happening without loosing energy proving superior to silicon technology which slows down due to energy loss.
This discovery of Nanotube transistors shown a very high potential in development of very high quality microwave filters that can separate out many different phone conversations more efficiently than current filters, and at lower cost. Currently this one function requires a separate chip inside a cell phone. With nanotube transistors this filter could be integrated with the other processing parts, and the entire radio system can be on one chip leading to more efficiency in cost.
After almost over 2 decades of theoretical drafts and scientific demonstrations of nanotechnology, world of electronics can promisingly predict the next big shift in semiconductor electronics since vaccum tubes to transistors.
Before such a shift could occur, however, nanotube technology would need to be economical to manufacture and require precise assembly, a project Burke is currently working on. The Army Research Office, the Office of Naval Research, and the Defence Advanced Research Projects Agency provided funding for this research.

Future

Moore's Law : "Number of transistors that can be packed on a chip doubles every 18 months". So within 10-20 years silicon will reach its physical limits, to pack more transistors on a chip. Today, chip makers are constantly struggling to reduce the channel length in transistors. The channel is the path where data travels from one place to another inside chips, silver / golden lines we see on Printed circuit boards. Nonotubes Channels to reduce channel length in Transistors allowing more transistors to fit in on a chip. We should not confuse Nanotechnology with Quantum Technology which is still far distant; the authors of quantum technology may not be able to witness it. Quantum technology is based on the superpositions of quantum states, so in a computer / electronic circuit based on quantum technology we will be able to use 1, 0 and superpositions of 1 and 0 together, exponentially increasing the width of the data transfer, sounds physics. Nanotechnology on the other hand is science of very small things, so small that we can use a single electron system as a single transistor.
Nanotube channels and Transistors holds the promise of building next generation electronic devices, which will allow us to continue proving Moore's law true beyond limits of silicon technology.

Original News can be found at ACS Newsletter, Nano letters June 2005