Nanite News
Recent News |  Archives |  Tags |  About |  Newsletter |  Submit News |  Links |  Subscribe to NaniteNews.com RSS Feed Subscribe


More Articles
The economic territory of Upper Palaeolithic groups is specified by flintThe economic territory of Upper Palaeolithic groups is specified by flint

Flower development in 3D: Timing is the keyFlower development in 3D: Timing is the key

Wisconsin scientists find genetic recipe to turn stem cells to bloodWisconsin scientists find genetic recipe to turn stem cells to blood

PIWI proteins and piRNAs regulate genes in the germline and beyondPIWI proteins and piRNAs regulate genes in the germline and beyond

Potent spider toxin 'electrocutes' German, not American, cockroachesPotent spider toxin 'electrocutes' German, not American, cockroaches

Speedy computation enables scientists to reconstruct an animal's development cell by cellSpeedy computation enables scientists to reconstruct an animal's development cell by cell

Large twin study suggests that language delay due more to nature than nurtureLarge twin study suggests that language delay due more to nature than nurture

NRL reveals new meteorological insight into mid-level cloudsNRL reveals new meteorological insight into mid-level clouds

Ancient genetic material from caries bacterium obtained for the first timeAncient genetic material from caries bacterium obtained for the first time

Law of physics governs airplane evolutionLaw of physics governs airplane evolution

Running for life: How speed restricts evolutionary change of the vertebral columnRunning for life: How speed restricts evolutionary change of the vertebral column

Brain waves show learning to read does not end in 4th grade, contrary to popular theory

Asteroid Vesta to reshape theories of planet formationAsteroid Vesta to reshape theories of planet formation

Is the universe a bubble? Let's checkIs the universe a bubble? Let's check

Postcards from the photosynthetic edgePostcards from the photosynthetic edge

Getting a grip on robotic graspGetting a grip on robotic grasp

The bend in the Appalachian mountain chain is finally explainedThe bend in the Appalachian mountain chain is finally explained

Sophisticated radiation detector designed for broad public useSophisticated radiation detector designed for broad public use

Cooperation among humans, a question of ageCooperation among humans, a question of age

Protein's 'hands' enable bacteria to establish infection, research findsProtein's 'hands' enable bacteria to establish infection, research finds

Less exercise, not more calories, responsible for expanding waistlinesLess exercise, not more calories, responsible for expanding waistlines

High earners in a stock market game have brain patterns that can predict market bubblesHigh earners in a stock market game have brain patterns that can predict market bubbles

A healthy lifestyle adds years to lifeA healthy lifestyle adds years to life

Platonic solids generate their 4-dimensional analoguesPlatonic solids generate their 4-dimensional analogues

Study of animal urination could lead to better-engineered productsStudy of animal urination could lead to better-engineered products

Do probiotics help kids with stomach bugs?Do probiotics help kids with stomach bugs?

Strict diet suspends development, doubles lifespan of wormsStrict diet suspends development, doubles lifespan of worms

Identified for the first time what kind of explosive has been used after the detonationIdentified for the first time what kind of explosive has been used after the detonation

Copied from nature: Detecting software errors via genetic algorithmsCopied from nature: Detecting software errors via genetic algorithms

Lou's clues lead to nano revelation (2/21/2010)

Tags:
nanowires, welding, gold
Two gold nanowires weld when their tips touch. -  Jun Lou/Rice University
Two gold nanowires weld when their tips touch. - Jun Lou/Rice University

Welding uses heat to join pieces of metal in everything from circuits to skyscrapers. But Rice University researchers have found a way to beat the heat on the nanoscale.

Jun Lou, an assistant professor in mechanical engineering and materials science, and his group have discovered that gold wires between three-billionths and 10-billionths of a meter wide weld themselves together quite nicely - without heat.

They report in today's online edition of the journal Nature Nanotechnology that clean gold nanowires with identical atomic structures will merge into a single wire that loses none of its electrical and mechanical properties. The process works just as well with silver nanowires, which bond with each other or with gold.

This cold-welding process has been observed on the macro scale for decades, Lou said. Clean, flat pieces of similar metals can be made to bond under high pressure and in a vacuum. But only Lou and his colleagues have seen the process happen on the nanoscale, under an electron microscope.

As so often happens in basic research, that's not what they were looking for at all. Lou and Rice graduate student Yang Lu, with collaborators at Sandia National Laboratories and Brown University, were trying to determine the tensile strength of gold nanowires by attaching one end of a wire to a probe in a transmission electron microscope (TEM) and the other to a tiny cantilever spring called an atomic force microscopy (AFM) probe.

Pulling the wire apart gave the team a measurement of its strength. What they didn't expect to see was the broken wire mending itself when its ends or sides touched. Measurements showed the reconnected wire was as strong as before.

"Before you can actually stretch something, you need to clamp it well," said Lou, who received a Young Investigators Research Program grant from the Air Force Office of Sponsored Research last year. "During the manipulation process, we observed this type of welding behavior all the time.

"Initially, we didn't pay attention to it because it didn't seem significant. But after doing a little research on the field, I realized we discovered something that may be useful."

In testing, Lou found the nanowires could be snapped and welded many times. Mended wires never broke again at the same spot; this attests to the strength of the new bond.

The wire's electrical properties also seemed unaffected by repeated breaking and welding. "We'd break a wire and reweld it 11 times and check the electrical properties every time. All the numbers were very close," he said.

The keys to a successful weld are the nanowire's single crystalline structure and matching orientation. "There are a lot of surface atoms, very active, that participate in the diffusion at the nanoscale," Lou said. "We tried gold and silver, and they weld in the same way as long as you satisfy the crystalline-orientation requirement."

Lou sees the discovery opening new paths for researchers looking at molecular-scale electronics. He said teams at Harvard and Northwestern are working on ways to pattern arrays of nanowires, and incorporating cold welding could simplify their processes. "If you're building high-density electronic devices, these kinds of phenomena will be very useful," he said, noting that heat-induced welds on the nanoscale run the risk of damaging the materials' strength or conductivity.

Lou said the discovery has caused a stir among the few he's told. "Different people see different aspects: Electrical engineers see the application side. Theory people see some interesting physics behind this behavior. We hope this paper will encourage more fundamental study."

Note: This story has been adapted from a news release issued by the Rice University

Post Comments:

Search
New Articles
Understanding graphene's electrical properties on an atomic levelUnderstanding graphene's electrical properties on an atomic level

Cost-effective, solvothermal synthesis of heteroatom (S or N)-doped graphene developed

'Nanocamera' takes pictures at distances smaller than light's own wavelength'Nanocamera' takes pictures at distances smaller than light's own wavelength

Researchers demonstrate novel, tunable nanoantennasResearchers demonstrate novel, tunable nanoantennas

Smallest Swiss cross -- Made of 20 single atomsSmallest Swiss cross -- Made of 20 single atoms

Researchers discover boron 'buckyball'Researchers discover boron 'buckyball'

3-D nanostructure could benefit nanoelectronics, gas storage

Nanophotonics experts create powerful molecular sensor

Study advances limits for ultrafast nano-devicesStudy advances limits for ultrafast nano-devices

Projecting a 3-dimensional future

'Nano-pixels' promise thin, flexible, high resolution displays'Nano-pixels' promise thin, flexible, high resolution displays

'Nanojuice' could improve how doctors examine the gut'Nanojuice' could improve how doctors examine the gut

Making dreams come true: Making graphene from plastic?Making dreams come true: Making graphene from plastic?

A new method to detect infrared energy using a nanoporous ZnO/n-Si photodetectorA new method to detect infrared energy using a nanoporous ZnO/n-Si photodetector

Engineers envision an electronic switch just 3 atoms thickEngineers envision an electronic switch just 3 atoms thick



Archives
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007


Science Friends
Agricultural Science
Astronomy News
Biology News
Biomimicry Science
Cognitive Research
Chemistry News
Tissue Engineering
Cancer Research
Cybernetics Research
Electonics Research
Forensics Report
Fossil News
Genetic Archaeology
Genetics News
Geology News
Microbiology Research
Parenting News
Physics News


  Archives |  Submit News |  Advertise With Us |  Contact Us |  Links
Use of this site constitutes acceptance of our Terms of Service and Privacy Policy. All contents © 2000 - 2015 Web Doodle, LLC. All rights reserved.