Navigation Links
Slippery when stacked: NIST theorists quantify the friction of graphene
Date:1/11/2012

Similar to the way pavement, softened by a hot sun, will slow down a car, graphenea one-atom-thick sheet of carbon with wondrous propertiesslows down an object sliding across its surface. But stack the sheets and graphene gets more slippery, say theorists at the National Institute of Standards and Technology (NIST), who developed new software to quantify the material's friction.

"I don't think anyone expects graphene to behave like a surface of a three-dimensional material, but our simulation for the first time explains the differences at an atomic scale," says NIST postdoctoral researcher Alex Smolyanitsky, who wrote the modeling program and co-authored a new paper* about the study. "If people want to use graphene as a solid-state lubricant or even as a part of flexible electrodes, this is important work."

With the capacity to be folded, rolled or stacked, graphene is super-strong and has unusual electronic and optical properties. The material might be used in applications ranging from electronic circuits to solar cells to "greasing" moving parts in nanoscale devices.

Friction is the force that resists the sliding of two surfaces against each other. Studying friction at the atomic scale is a challenge, surmountable in only the past few years. The NIST software simulates atomic force microscopy (AFM) using a molecular dynamics technique. The program was used to measure what happens when a simulated AFM tip moves across a stack of one to four graphene sheets (see image) at different scanning rates.

The researchers found that graphene deflects under and around the AFM tip. The localized, temporary warping creates rolling friction or resistance, the force that exerts drag on a circular object rolling along a surface. Smolyanitsky compares the effect to the sun melting and softening pavement in the state where he got his doctoral degree, Arizona, causing car tires to sink in slightly and slow down. The NIST results are consistent with those of recent graphene experiments by other research groups but provide new quantitative data.

Most significantly, the NIST study shows why friction falls with each sheet of graphene added to the stack (fast scanning also has an effect on the friction). With fewer layers, the top layer deflects more, and the friction per unit of AFM contact force rises. The top surface of the stack becomes less yielding and more slippery as graphene layers are added. By contrast, the friction of three-dimensional graphite-like material is virtually unaffected by deformation and rolling friction, and is due instead to heat created by the moving tip.


'/>"/>

Contact: Laura Ost
laura.ost@nist.gov
303-497-4880
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology technology :

1. Slippery slope:Researchers take advice from a carnivorous plant
2. Diagenode Releases Two New Epigenetic Monoclonal 5-hmC Antibodies for Quantifying Global Hydroxymethylation
3. Bruker Introduces HyperQuant™, a Unique Bench-Top NMR Reader to Quantify Hyperpolarization
4. Penn and Brown researchers demonstrate earthquake friction effect at the nanoscale
5. Nanotechnologists reveal the frictional characteristics of atomically thin sheets
6. Nanotechnologists from Penn collaborate to form near-frictionless diamond material
7. Metamaterials could reduce friction in nanomachines
8. Friction force differences could offer a new means for sorting and assembling nanotubes
9. Models present new view of nanoscale friction
10. Graphene reveals its magnetic personality
11. Graphene rips follow rules
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Slippery when stacked: NIST theorists quantify the friction of graphene
(Date:6/23/2016)... 23, 2016  The Biodesign Challenge (BDC), a university ... to harness living systems and biotechnology, announced its winning ... New York City . ... showcased projects at MoMA,s Celeste Bartos Theater during the ... MoMA,s senior curator of architecture and design, and ...
(Date:6/23/2016)... ... June 23, 2016 , ... Supplyframe, the Industry Network for ... Design Lab . Located in Pasadena, Calif., the Design Lab’s mission is to ... are designed, built and brought to market. , The Design Lab is Supplyframe’s ...
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report published today ... a patient who developed lymphedema after being treated for breast cancer benefitted from an ... paradigm for dealing with this debilitating, frequent side effect of cancer treatment. ...
(Date:6/23/2016)... June 23, 2016  Blueprint Bio, a company dedicated ... the medical community, has closed its Series A funding ... . "We have received a commitment from ... we need to meet our current goals," stated ... the runway to complete validation on the current projects ...
Breaking Biology Technology:
(Date:4/15/2016)... , April 15, 2016  A new ... make more accurate underwriting decisions in a fraction ... timely, competitively priced and high-value life insurance policies ... screenings. With Force Diagnostics, rapid testing ... lifestyle data readings (blood pressure, weight, pulse, BMI, ...
(Date:4/13/2016)... CHICAGO , April 13, 2016  IMPOWER physicians ... are setting a new clinical standard in telehealth ... By leveraging the higi platform, IMPOWER patients can ... weight, pulse and body mass index, and, when they ... quick and convenient visit to a local retail location ...
(Date:3/29/2016)... 2016 LegacyXChange, Inc. (OTC: ... SelectaDNA/CSI Protect are pleased to announce our successful effort ... variety of writing instruments, ensuring athletes signatures against counterfeiting ... from athletes on LegacyXChange will be assured of ongoing ... Bill Bollander , CEO states, "By ...
Breaking Biology News(10 mins):