Navigation Links
Straintronics: Engineers create piezoelectric graphene
Date:3/17/2012

In what became known as the 'Scotch tape technique," researchers first extracted graphene with a piece of adhesive in 2004. Graphene is a single layer of carbon atoms arranged in a honeycomb, hexagonal pattern. It looks like chicken wire.

Graphene is a wonder material. It is one-hundred-times better at conducting electricity than silicon. It is stronger than diamond. And, at just one atom thick, it is so thin as to be essentially a two-dimensional material. Such promising physics have made graphene the most studied substance of the last decade, particularly in nanotechnology. In 2010, the researchers who first isolated it shared the Nobel Prize.

Yet, while graphene is many things, it is not piezoelectric. Piezoelectricity is the property of some materials to produce electric charge when bent, squeezed or twisted. Perhaps more importantly, piezoelectricity is reversible. When an electric field is applied, piezoelectric materials change shape, yielding a remarkable level of engineering control.

Piezoelectrics have found application in countless devices from watches, radios and ultrasound to the push-button starters on propane grills, but these uses all require relatively large, three-dimensional quantities of piezoelectric materials.

Now, in a paper published in the journal ACS Nano, two materials engineers at Stanford have described how they have engineered piezoelectrics into graphene, extending for the first time such fine physical control to the nanoscale.

Straintronics

"The physical deformations we can create are directly proportional to the electrical field applied and this represents a fundamentally new way to control electronics at the nanoscale," said Evan Reed, head of the Materials Computation and Theory Group at Stanford and senior author of the study. "This phenomenon brings new dimension to the concept of 'straintronics' for the way the electrical field strains or deforms the lattice of carbon, causing it to change shape in predictable ways."

"Piezoelectric graphene could provide an unparalleled degree of electrical, optical or mechanical control for applications ranging from touchscreens to nanoscale transistors," said Mitchell Ong, a post-doctoral scholar in Reed's lab and first author of the paper.

AUDIO: Listen to Stanford engineers Evan Reed and Mitchell Ong discuss their piezoelectric graphene.

Click here for more information.

Using a sophisticated modeling application running on high-performance supercomputers, the engineers simulated the deposition of atoms on one side of a graphene lattice a process known as doping and measured the piezoelectric effect.

They modeled graphene doped with lithium, hydrogen, potassium and fluorine, as well as combinations of hydrogen and fluorine and lithium and fluorine on either side of the lattice. Doping just one side of the graphene, or doping both sides with different atoms, is key to the process as it breaks graphene's perfect physical symmetry, which otherwise cancels the piezoelectric effect.

The results surprised both engineers.

"We thought the piezoelectric effect would be present, but relatively small. Yet, we were able to achieve piezoelectric levels comparable to traditional three-dimensional materials," said Reed. "It was pretty significant."

Designer piezoelectricity

"We were further able to fine tune the effect by pattern doping the grapheneselectively placing atoms in specific sections and not others," said Ong. "We call it designer piezoelectricity because it allows us to strategically control where, when and how much the graphene is deformed by an applied electrical field with promising implications for engineering."

While the results in creating piezoelectric graphene are encouraging, the researchers believe that their technique might further be used to engineer piezoelectricity in nanotubes and other nanomaterials with applications ranging from electronics, photonics, and energy harvesting to chemical sensing and high-frequency acoustics.

"We're already looking now at new piezoelectric devices based on other 2D and low-dimensional materials hoping they might open new and dramatic possibilities in nanotechnology," said Reed.


'/>"/>

Contact: Andrew Myers
admyers@stanford.edu
650-736-2245
Stanford School of Engineering
Source:Eurekalert  

Related biology technology :

1. Online Systems Engineering Master's Program Attracts Engineers from Fortune 500 Firms
2. NC State engineers discover nanoparticles can break on through
3. Engineers aim to solve burning computer problem
4. Virginia Tech engineers identify conditions that initiate erosion
5. Techstreet Launches BuildingBlocks Utility for Industry Standards Saving Time and Increasing Productivity for Engineers
6. Virginia Tech engineers investigate energy independent monitoring system for bridges
7. New Educational Website Celebrates the Accomplishments of Engineers
8. Engineers tune a nanoscale grating structure to trap and release a variety of light waves
9. UB engineers prove that carbon nanotubes are superior to metals for electronics
10. Siemens Offers Life Science Solutions Design Guide for Consulting Engineers
11. Connecting Materials Science With Biology, K-State Engineers Create DNA Sensors That Could Identify Cancer Using Material Only One Atom Thick
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Straintronics: Engineers create piezoelectric graphene
(Date:12/7/2016)... December 7, 2016 Regen BioPharma Inc. ... Journal of Molecular Sciences a team of scientists in ... have demonstrated that expression of NR2F6 in patients with ... for NR2F6 in patient,s cervical cancer tissue as well as ... "This is an interesting study and the first that ...
(Date:12/7/2016)... , ... December 07, 2016 , ... ... pathology, announced today a new service to enable rapid migration of large pathology ... has remained one of the factors limiting adoption of digital pathology. Proscia’s free ...
(Date:12/7/2016)... ... December 07, 2016 , ... ... to an early access program for SmartBiome -- a novel metagenomic deep-sequencing ... simultaneous specific enrichment and detection of hundreds of different genes. The selective ...
(Date:12/6/2016)... AUSTIN, Texas , Dec. 6, 2016 ... Naturopathica for its adoption of arnica ( Arnica ... provides support to ABC,s HerbMedPro database, ... to important scientific and clinical research data on ... 250 popular herbs. Naturopathica, a wellness ...
Breaking Biology Technology:
(Date:11/28/2016)... "The biometric system market ... The biometric system market is in the growth stage ... future. The biometric system market is expected to be ... CAGR of 16.79% between 2016 and 2022. Government initiative ... in smartphones, rising use of biometric technology in financial ...
(Date:11/21/2016)... Lithuania , Nov. 21, 2016   ... and object recognition technologies, today announced that the ... smart cards was submitted for the NIST ... successfully passed all the mandatory steps of the ... evaluation is a continuing test of fingerprint templates ...
(Date:11/16/2016)... , Nov. 16, 2016 Sensory ... experience and security for consumer electronics, and ... financial and retail industry, today announced a global ... convenient way to authenticate users of mobile banking ... TrulySecure™ software which requires no specialized ...
Breaking Biology News(10 mins):