Shear stiffness and friction mechanics of single-layer graphene measured for the first time

February 14, 2012
Artistic impression of graphene molecules. Credit: University of Manchester

Researchers from the University of Bristol have measured and identified for the first time the stress and strain shear modulus and internal friction of graphene sheets. Graphene is a material that has many potential groundbreaking uses in the electronics and composites industry.

The research, in collaboration with the US Office of Naval Research, is published in Nano Letters.

Graphene is made up of a single layer of carbon atoms arranged in a . It is a promising material for the production of next-generation displays or solar cells because it is flexible, transparent and conductive.

For graphene to be used as nanoelectromechanical resonators or nanosensors, it is essential to know its structural behaviour and limitations as a mechanical material.

Fabrizio Scarpa, Professor of in the University of Bristol's Centre for Innovation and Science (ACCIS), said: "To improve the design of graphene nanosensors it is important to understand the mechanical behaviour and the natural intrinsic damping and internal friction of graphene. Our findings indicate that graphene produced using could be a vital alternative for nanomechanical sensor applications."

The researchers, using a technique called (CVD), grew graphene films on copper foil in a furnace at 1030 oC using a mixture of methane and hydrogen.

The research established some of the elastic properties of CVD-grown, single-layer graphene films on copper. The results revealed a striking difference between single- and multilayered graphene films in both shear modulus and internal friction. This difference may be due to the transition of the shear restoring force from chemical bonding within a layer to interlayer interactions.

The average shear modulus of the films studied compared well with most of the theoretical calculations based on single-layer pristine graphene structures. The high shear modulus and low internal friction point to a low defect density structure approaching that of the pristine graphene.

The findings suggest the use of CVD material in nanomechanical sensor applications could be a vital alternative.

Explore further: Producing graphene layers using crystallization

More information: Shear Modulus of Monolayer Graphene Prepared by Chemical Vapor Deposition, Xiao Liu, Thomas H Metcalf, Jeremy T Robinson, Brian H Houston, and Fabrizio Scarpa, Nano Letters, published online ahead of print 03 January 2012.

Related Stories

Producing graphene layers using crystallization

March 2, 2010

( -- Ever since it's relatively recent discovery, graphene has generated a great deal of interest. Graphene is extracted from graphite in many cases, and consists of a sheet of carbon atoms bound together in a ...

Seeing an atomic thickness

May 19, 2011

Scientists from NPL, in collaboration with Linkoping University, Sweden, have shown that regions of graphene of different thickness can be easily identified in ambient conditions using Electrostatic Force Microscopy (EFM).

STM of individual grains in CVD-grown graphene

June 24, 2011

Users from Purdue University, working collaboratively with staff in the CNM Electronic & Magnetic Materials & Devices Group, studied CVD-grown graphene on polycrystalline copper foil for the first time at the atomic-scale. ...

Hydrogen may be key to growth of high-quality graphene

July 18, 2011

A new approach to growing graphene greatly reduces problems that have plagued researchers in the past and clears a path to the crystalline form of graphite's use in sophisticated electronic devices of tomorrow.

Flaky graphene makes reliable chemical sensors

January 17, 2012

Scientists from the University of Illinois at Urbana-Champaign and the company Dioxide Materials have demonstrated that randomly stacked graphene flakes can make an effective chemical sensor.

Recommended for you

Mathematicians identify limits to heat flow at the nanoscale

November 24, 2015

How much heat can two bodies exchange without touching? For over a century, scientists have been able to answer this question for virtually any pair of objects in the macroscopic world, from the rate at which a campfire can ...

New sensor sends electronic signal when estrogen is detected

November 24, 2015

Estrogen is a tiny molecule, but it can have big effects on humans and other animals. Estrogen is one of the main hormones that regulates the female reproductive system - it can be monitored to track human fertility and is ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.