Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Gecko's lessons transfer well

Forests of nanotubes grown via chemical vapor deposition are treated with hydrogen gas and water to loosen their bonds with a catalyst. They can then be transferred to another surface, just like a rubber stamp.
Forests of nanotubes grown via chemical vapor deposition are treated with hydrogen gas and water to loosen their bonds with a catalyst. They can then be transferred to another surface, just like a rubber stamp.

Abstract:
Dry printing of nanotube patterns to any surface could revolutionize microelectronics and more

Gecko's lessons transfer well

Houston, TX | Posted on January 23rd, 2010

Watch a gecko walk up a wall. It defies gravity as it sticks to the surface no matter how smooth it appears to be.

What's happening isn't magic. The gecko stays put because of the electrical attraction - the van der Waals force - between millions of microscopic hairs on its feet and the surface.

The principle applies to new research at Rice University reported this week in the online version of the journal ACS Nano. But in this case, the hairs figuratively come off the gecko and plant themselves on the wall.

Rice graduate student Cary Pint has come up with a way to transfer forests of strongly aligned, single-walled carbon nanotubes (SWNTs) from one surface to another - any surface - in a matter of minutes. The template used to grow the nanotubes, with its catalyst particles still intact, can be used repeatedly to grow more nanotubes, almost like inking a rubber stamp.

Pint is primary author of the research paper, which also details a way to quickly and easily determine the range of diameters in a batch of nanotubes grown through chemical vapor deposition (CVD). Common spectroscopic techniques are poor at seeing tubes bigger than two nanometers in diameter - or most of the nanotubes in the CVD "supergrowth" process.

"This is important since all of the properties of the nanotubes - electrical, thermal and mechanical - change with diameter," he said. "The best thing is that nearly every university has an FTIR (Fourier transform infrared) spectrometer sitting around that can do these measurements, and that should make the process of synthesis and application development from carbon nanotubes much more precise."

Pint and other students and colleagues of Robert Hauge, a Rice distinguished faculty fellow in chemistry, are also investigating ways to take printed films of SWNTs and make them all-conducting or all-semiconducting - a process Hauge refers to as "Fermi-level engineering" for its ability to manipulate electron movement at the nanoscale.

Combined, the techniques represent a huge step toward a nearly limitless number of practical applications that include sensors, highly efficient solar panels and electronic components.

"A big frontier for the field of nanoscience is in finding ways to make what we can do on the nanoscale impact our everyday activities," Hauge said. "For the use of carbon nanotubes in devices that can change the way we do things, a straightforward and scalable way of patterning aligned carbon nanotubes over any surface and in any pattern is a major advance."

Pint said an afternoon of "experimenting with creative ideas" as a first-year graduate student turned into a project that held his interest through his time at Rice. "I realized early on it may be useful to transfer carbon nanotubes to other surfaces," he said.

"I started playing around with water vapor to clean up the amorphous carbons on the nanotubes. When I pulled out a sample, I noticed the nanotubes actually stuck to the tweezers.

"I thought to myself, 'That's really interesting ...'"

Water turns out to be the key. After growing the nanotubes, Pint etches them with a mix of hydrogen gas and water vapor, which weakens the chemical bonds between the tubes and the metal catalyst. When stamped, the nanotubes lie down and adhere, via van der Waals, to the new surface, leaving all traces of the catalyst behind.

Pint, who hopes to defend his dissertation in August, developed a steady enough hand to deposit nanotubes on a range of surfaces - "anything I could lay my hands on" - in patterns that could easily be replicated and certainly enhanced by industrial processes. A striking example of his work is a crisscross film of nanotubes made by stamping one set of lines onto a surface and then reusing the catalyst to grow more tubes and stamping them again over the first pattern at a 90-degree angle. The process took no more than 15 minutes.

"I'll be honest - that was a little bit of luck, combined with the skill of having done this for a few years," he said of the miniature work of art. "But if I were in industry, I would make a machine to do this for me."

Pint believes industries will take a hard look at the technique, which he said could be scaled up easily, for embedding nanotube circuitry into electronic devices.

His own goal is to develop the process to make a range of highly efficient sensing devices. He's also investigating doping techniques that will take the guesswork out of growing metallic (conducting) or semiconducting SWNTs.

Pint and Hauge co-authored the paper with Junichiro Kono, a Rice professor in electrical and computer engineering and in physics and astronomy; Matteo Pasquali, a professor in chemical and biomolecular engineering; former Rice graduate students Ya-Qiong Xu, now an assistant professor of electrical engineering and physics at Vanderbilt University, and Tonya Cherukuri; graduate students Noe Alvarez and Erik Haroz; undergraduate students Sharief Moghazy and Salma Mahzooni; and Stephen Doorn, a researcher at Los Alamos National Laboratory.

The Rice-based Lockheed Martin LANCER program supported the research.

####

For more information, please click here

Contacts:
Jade Boyd
Associate Director /Science Editor
713-348-6778

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Possible Futures

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Chip Technology

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Scientists discover new 'boat' form of promising semiconductor: GeSe Uncommon form attenuates semiconductor's band gap size March 23rd, 2017

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 2017

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

Nanotubes/Buckyballs/Fullerenes

Intertronics introduce new nanoparticle deagglomeration technology March 15th, 2017

Boron atoms stretch out, gain new powers: Rice University simulations demonstrate 1-D material's stiffness, electrical versatility January 26th, 2017

New stem cell technique shows promise for bone repair January 25th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Sensors

UC researchers use gold coating to control luminescence of nanowires: University of Cincinnati physicists manipulate nanowire semiconductors in pursuit of making electronics smaller, faster and cheaper March 17th, 2017

Optical fingerprint can reveal pollutants in the air: Researchers at Chalmers University of Technology have proposed a new, sophisticated method of detecting molecules with sensors based on ultra-thin nanomaterials March 15th, 2017

New optical nanosensor improves brain mapping accuracy, opens way for more applications: Potassium-sensitive fluorescence-imaging method shines light on chemical activity within the brain March 3rd, 2017

Smart multi-layered magnetic material acts as an electric switch: New study reveals characteristic of islands of magnetic metals between vacuum gaps, displaying tunnelling electric current March 1st, 2017

Nanoelectronics

Scientists discover new 'boat' form of promising semiconductor: GeSe Uncommon form attenuates semiconductor's band gap size March 23rd, 2017

UC researchers use gold coating to control luminescence of nanowires: University of Cincinnati physicists manipulate nanowire semiconductors in pursuit of making electronics smaller, faster and cheaper March 17th, 2017

A SOI wafer is a suitable substrate for gallium nitride crystals: Improved characteristics in power electronics and radio applications can be achieved by using a SOI wafer for gallium nitride growth March 4th, 2017

Smart multi-layered magnetic material acts as an electric switch: New study reveals characteristic of islands of magnetic metals between vacuum gaps, displaying tunnelling electric current March 1st, 2017

Discoveries

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Announcements

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Solar/Photovoltaic

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

New nanofiber marks important step in next generation battery development March 14th, 2017

Perovskite edges can be tuned for optoelectronic performance: Layered 2D material improves efficiency for solar cells and LEDs March 10th, 2017

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project