Record breaking nanotube

Scientists in the US have synthesised the world’s longest electrically conducting nanotubes, a development that could lead to improved power transmission lines and extremely strong, lightweight materials.

University of California, Irvine announced yesterday that scientists at The Henry Samueli School of Engineering have synthesised the world’s longest electrically conducting nanotubes.

The 0.4 cm nanotubes are 10 times longer than previously created electrically conducting nanotubes. The discovery may lead to the development of extremely strong, lightweight materials and ultradense nano-memory arrays for extremely powerful computers, ultralow-loss power transmission lines, and nano-biosensors for use in health care applications.

Peter Burke, assistant professor of electrical engineering and computer science, conducted the research along with graduate students Shengdong Li, Christopher Rutherglen and Zhen Yu.

“We are extremely excited about this discovery,” said Burke. “Recently there have been several key advances around the world in synthesising very long carbon nanotubes.

“Our research has taken a significant step forward by showing we can pass electricity through these long nanotubes. Significantly, we have found that our nanotubes have electrical properties superior to copper. This clearly shows for the first time that long nanotubes have outstanding electrical properties, just like short ones.”

According to a UC Irvine statement, the researchers grew the carbon nanotubes using a simple procedure. Burke allowed natural gas to react chemically with tiny iron particles (nanoparticles) inside a small furnace.

By placing a small amount of gold under the iron, Burke’s group found that ultralong nanotubes grow; whereas without the gold, only short nanotubes grow. Because nanotubes are so small, it is difficult to connect regular wires to them. Using gold in the growth process, Burke solved this problem by growing nanotubes that come out already attached to gold wires.

An added scientific benefit is that Burke was able to accurately determine how the electrical resistance of a nanotube depends on its length. The relationship between resistance and physical size (length) is a key property of any new material. Burke’s finding is said to indicate that the electrical conductivity is greater than for copper wires of the same size, a world record for any nano-material of this length.