Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unexpected adhesion properties of graphene may lead to new nanotechnology devices

24.08.2011
Graphene, considered the most exciting new material under study in the world of nanotechnology, just got even more interesting, according to a new study by a group of researchers at the University of Colorado Boulder.

The new findings -- that graphene has surprisingly powerful adhesion qualities -- are expected to help guide the development of graphene manufacturing and of graphene-based mechanical devices such as resonators and gas separation membranes, according to the CU-Boulder team. The experimentsshowed that the extreme flexibility of graphene allows it to conform to the topography of even the smoothest substrates.

Graphene consists of a single layer of carbon atoms chemically bonded in a hexagonal chicken wire lattice. Its unique atomic structure could some day replace silicon as the basis of electronic devices and integrated circuits because of its remarkable electrical, mechanical and thermal properties, said Assistant Professor Scott Bunch of the CU-Boulder mechanical engineering department and lead study author.

A paper on the subject was published online in the Aug. 14 issue of Nature Nanotechnology. Co-authors on the study included CU-Boulder graduate students Steven Koenig and NarasimhaBoddeti and Professor Martin Dunn of the mechanical engineering department.

"The real excitement for me is the possibility of creating new applications that exploit the remarkable flexibility and adhesive characteristics of graphene and devising unique experiments that can teach us more about the nanoscale properties of this amazing material," Bunch said.

Not only does graphene have the highest electrical and thermal conductivity among all materials known, but this "wonder material" has been shown to be the thinnest, stiffest and strongest material in the world, as well as being impermeable to all standard gases. It's newly discovered adhesion properties can now be added to the list of the material's seemingly contradictory qualities, said Bunch.

The CU-Boulder team measured the adhesion energy of graphene sheets, ranging from one to five atomic layers, with a glass substrate, using a pressurized "blister test" to quantify the adhesion between graphene and glass plates.

Adhesion energy describes how "sticky" two things are when placed together. Scotch tape is one example of a material with high adhesion; the gecko lizard, which seemingly defies gravity by scaling up vertical walls using adhesion between its feet and the wall, is another. Adhesion also canplay a detrimental role, as in suspended micromechanical structures where adhesion can cause device failure or prolong the development of a technology, said Bunch.

The CU research, the first direct experimental measurements of the adhesion of graphene nanostructures, showed that so-called "van der Waals forces" -- the sum of the attractive or repulsive forces between molecules -- clamp the graphene samples to the substrates and also hold together the individual graphene sheets in multilayer samples.

The researchers found the adhesion energies between graphene and the glass substrate were several orders of magnitude larger than adhesion energies in typical micromechanical structures, an interaction they described as more liquid-like than solid-like, said Bunch.

The CU-Boulder study was funded primarily by the National Science Foundation and the Defense Advanced Research Projects Agency.

The importance of graphene in the scientific world was illustrated by the 2010 Nobel Prize in physics that honored two scientists at Manchester University in England, Andre K. Geim and Konstantin Novoselov, for producing, isolating, identifying and characterizing graphene.

There is interest in exploiting graphene's incredible mechanical properties to create ultrathin membranes for energy-efficient separations such as those needed for natural gas processing or water purification, while graphene's superior electrical properties promise to revolutionize the microelectronics industry, said Bunch.

In all of these applications, including any large-scale graphene manufacturing, the interaction that graphene has with a surface is of critical importance and a scientific understanding will help push the technology forward, he said.

Contact:
Scott Bunch, 303-492-6802, joseph.bunch@colorado.edu
Carol Rowe, 303-492-7426, carol.rowe@colorado.edu

Scott Bunch | EurekAlert!
Further information:
http://www.colorado.edu

More articles from Materials Sciences:

nachricht New value added to the ICSD (Inorganic Crystal Structure Database)
27.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Argon is not the 'dope' for metallic hydrogen
24.03.2017 | Carnegie Institution for Science

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers create artificial materials atom-by-atom

28.03.2017 | Physics and Astronomy

Researchers show p300 protein may suppress leukemia in MDS patients

28.03.2017 | Health and Medicine

Asian dust providing key nutrients for California's giant sequoias

28.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>