Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanotribology: Tubular probes

29.11.2011
Short, capped single-walled carbon nanotubes may serve as ideal probing tips to study friction, lubrication and wear at the microscale

Studying microscopic interactions at single asperities is vital for the understanding of friction and lubrication at the macroscale. Surface probe instruments with carbon nanotube tips may enable such investigations, as now demonstrated in a theoretical study led by Ping Liu and Yong-Wei Zhang at the A*STAR Institute of High Performance Computing1. The researchers showed that short, single-walled, capped carbon nanotubes are able to capture the frictional characteristics of graphene with atomic resolution.


Atomistic simulations show that short, capped single-walled carbon nanotubes (red) can elucidate the tribological properties of graphene surfaces. Copyright : 2011 Elsevier

“For an ideal probing tip, its dimension should be as small as possible, its rigidity should be as large as possible, its geometry should be well-defined, and it should be chemically inert,” explains Liu. The combination of such characteristics would allow surface characterization with atomic resolution while ensuring a long lifetime and geometrical, chemical and physical stability of the tip.

Carbon nanotubes, in particular short ones, are of great interest due to their inherent strong carbon–carbon bonds, which allows them to withstand buckling and bending deformation and recover to their original shape after deformation. Capped tubes in turn offer improved chemical stability and stiffness in comparison to non-capped tubes. These considerations indicate that short, capped single-walled carbon nanotubes may be ideal imaging probe tips.

As it is not yet possible to use such tips in experimental setups, to test this hypothesis Liu and Zhang performed large-scale atomistic simulations focusing on the interaction between such nanotube probing tips and graphene (see image)—a carbon material that is ideal for surface coating lubrication. “Because of advances in the development of accurate atomic potentials and massive parallel computing algorithms, atomistic simulations not only enable us to determine the probing characteristics of such tips, but also to investigate the frictional and defect characteristics of graphene with atomic resolution,” says Liu.

The simulations could capture the dependence of the friction and average normal forces on tip-to-surface distance and number of graphene layers. The researchers analyzed and interpreted the observed characteristics in terms of different types of sliding motions of the tip across the surface, as well as energy dissipation mechanisms between the tip and underlying graphene layers. They could further identify clear signatures that distinguish the motion of a tip across a point defect or the so-called Stone-Thrower-Wales defect, which is thought to be responsible for nanoscale plasticity and brittle–ductile transitions in the graphene carbon lattice. “Our simulations provide insight into nanoscale friction and may provide guidelines on how to control it,” says Liu.

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing

Lee Swee Heng | Research asia research news
Further information:
http://www.a-star.edu.sg/
http://www.researchsea.com

More articles from Information Technology:

nachricht New epidemic management system combats monkeypox outbreak in Nigeria
15.12.2017 | Helmholtz-Zentrum für Infektionsforschung

nachricht Gecko adhesion technology moves closer to industrial uses
13.12.2017 | Georgia Institute of Technology

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>