Self-aligning carbon nanotubes could be key to next generation of devices

Feb 25, 2009
This is a black-and-white image of a micrograph from a scanning electron microscope of the electrodes (inset) and the single-walled carbon nanotube bridge structure. A colorized version of the micrograph of the electrodes was the cover photo for the Jan. 14 issue of Nanotechnology.

(PhysOrg.com) -- Scientists and engineers the world over have thought for years that the next generation of smaller, more-efficient electronic and photonic devices could be based on the use of carbon nanotubes, structures 10,000 times thinner than a human hair but with tremendous potential.

Laboratories are able to create millions of the structures using a process called chemical vapor deposition. The problem has always been finding a way to manipulate something that small so they'll line up in a way that might be useful.

Now, however, a discovery by a team of researchers at the University of Nebraska-Lincoln, led by professor Yongfeng Lu and postdoctoral researcher Yunshen Zhou, may provide a pathway to a solution, and with little or no manipulation necessary.

Using a process based on optical near-field effects, Lu and his team in UNL's Laser Assisted Nano-Engineering Lab created nanoscale devices based on connecting sharp-tipped electrodes with individually self-aligned carbon nanotubes.

Previous efforts in this area by other research groups tried to use advanced instrumentation to manipulate carbon nanotubes after growth. But Lu said that approach is only good for research purposes because it's time consuming and expensive.

"With our method, there's no requirement for expensive instrumentation and no requirement for tedious processes. It's a one-step process," he said. "We call it 'self-aligning growth.' The carbon nanotubes 'know' where to start growth.

"In previous efforts, they could only manipulate carbon nanotubes one piece at a time, so they had to align the carbon nanotubes one by one. For our approach using optical near-field effects, all locations with sharp tips can accommodate carbon nanotube growth. That means we can make multiple carbon nanotubes at a time and all of them will be self-aligned."

Nevertheless, the UNL team has not yet been able to produce large numbers self-aligned carbon nanotubes, but Lu said he and his team see potential for significant expansion that could lead to new applications in devices such as biosensors, light emitters, photon sensors, tiny molecular motors and memory cells.

"We have shown that we can use optical near-field effects to control growth for a small amount of carbon nanotubes," said Lu, Lott professor of electrical engineering at UNL. "We want to make this process scalable so it can be used to make large numbers at a time so we can make a circuit or a system by this approach."

The research was the cover story for the Jan. 14 issue of Nanotechnology, a leading international journal published by the Institute of Physics in the United Kingdom. The research was supported by a grant from the National Science Foundation. Initial funding was provided by the Nebraska Research Initiative.

Provided by University of Nebraska-Lincoln

Explore further: Thinnest feasible nano-membrane produced

add to favorites email to friend print save as pdf

Related Stories

Building better soybeans for a hot, dry, hungry world

14 hours ago

(Phys.org) —A new study shows that soybean plants can be redesigned to increase crop yields while requiring less water and helping to offset greenhouse gas warming. The study is the first to demonstrate ...

Scientists see urgent need for reducing emissions

Apr 15, 2014

(Phys.org) —The bad news: a major transformation of our current energy supply system is needed in order to avoid a dangerous increase in global temperatures. The good news: the technologies needed to get ...

Warm US West, cold East: A 4,000-year pattern

16 hours ago

Last winter's curvy jet stream pattern brought mild temperatures to western North America and harsh cold to the East. A University of Utah-led study shows that pattern became more pronounced 4,000 years ago, ...

Recommended for you

Thinnest feasible nano-membrane produced

14 hours ago

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

17 hours ago

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Making 'bucky-balls' in spin-out's sights

Apr 16, 2014

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...

User comments : 0

More news stories

Thinnest feasible nano-membrane produced

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Six Nepalese dead, six missing in Everest avalanche

At least six Nepalese climbing guides have been killed and six others are missing after an avalanche struck Mount Everest early Friday in one of the deadliest accidents on the world's highest peak, officials ...

White House updating online privacy policy

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...