Navigation Links
Stanford engineers weld nanowires with light
Date:2/6/2012

One area of intensive research at the nanoscale is the creation of electrically conductive meshes made of metal nanowires. Promising exceptional electrical throughput, low cost and easy processing, engineers foresee a day when such meshes are common in new generations of touch-screens, video displays, light-emitting diodes and thin-film solar cells.

Standing in the way, however, is a major engineering hurdle: In processing, these delicate meshes must be heated or pressed to unite the crisscross pattern of nanowires that form the mesh, damaging them in the process.

In a paper just published in the journal Nature Materials, a team of engineers at Stanford has demonstrated a promising new nanowire welding technique that harnesses plasmonics to fuse the wires with a simple blast of light.

Self-limiting

At the heart of the technique is the physics of plasmonics, the interaction of light and metal in which the light flows across the surface of the metal in waves, like water on the beach.

"When two nanowires lay crisscrossed, we know that light will generate plasmon waves at the place where the two nanowires meet, creating a hot spot. The beauty is that the hot spots exist only when the nanowires touch, not after they have fused. The welding stops itself. It's self-limiting," explained Mark Brongersma, an associate professor of materials science engineering at Stanford and an expert in plasmonics. Brongersma is one of the study's senior authors.

"The rest of the wires and, just as importantly, the underlying material are unaffected," noted Michael McGehee, a materials engineer and senior author of the paper. "This ability to heat with precision greatly increases the control, speed and energy efficiency of nanoscale welding."

In before-and-after electron-microscope images, individual nanowires are visually distinct prior to illumination. They lay atop one another, like two fallen trees in the forest. When illuminated, the top nanowire acts like an antenna of sorts, directing the plasmon waves of light into the bottom wire and creating heat that welds the wires together. Post-illumination images show X-like nanowires lying flat against the substrate with fused joints.

Transparency

In addition to making it easier to produce stronger and better performing nanowire meshes, the researchers say that the new technique could open the possibility of mesh electrodes bound to flexible or transparent plastics and polymers.

To demonstrate the possibilities, they applied their mesh on Saran wrap. They sprayed a solution containing silver nanowires in suspension on the plastic and dried it. After illumination, what was left was an ultrathin layer of welded nanowires.

"Then we balled it up like a piece of paper. When we unfurled the wrap, it maintained its electrical properties," said co-author Yi Cui, an associate professor materials science and engineering. "And when you hold it up, it's virtually transparent."

This could lead to inexpensive window coatings that generate solar power while reducing glare for those inside, the researchers said.

"In previous welding techniques that used a hotplate, this would never have been possible," said lead author, Erik C. Garnett, PhD, a post-doctoral scholar in materials science who works with Brongersma, McGehee and Cui. "The Saran wrap would have melted far sooner than the silver, destroying the device instantly."

"There are many possible applications that would not even be possible in older annealing techniques," said Brongersma. "This opens some interesting, simple and large-area processing schemes for electronic devices solar, LEDs and touch-screen displays, especially."


'/>"/>

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

Related biology technology :

1. Vermillion and Stanford Scientists Receive Best Research Award From the PAD Coalition
2. Stanford: Quantum computing spins closer
3. Cell Biosciences Delivers Next Generation System to Stanford University
4. Artemis Health Licenses Prenatal Cell-Free DNA Analysis Technology from Stanford University
5. Stanford writes in worlds smallest letters
6. Kornberg Associates Architects Selected to Develop Design for New Stanford University Imaging Center
7. Stanford researchers find a quicker, cheaper way to sort isotopes
8. Eiger BioPharmaceuticals Acquires Exclusive License to Novel Hepatitis C Virus (HCV) Technology From Stanford University
9. LASIK Expert Edward Manche, M.D., of the Stanford Eye Laser Center Joins Top Surgeons Listed at the Trusted LASIK Surgeons Directory
10. New technique reinforces immune cells that seek and destroy cancer, says Stanford researcher
11. Stanford scientists develop new way to grow adult stem cells in culture
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Stanford engineers weld nanowires with light
(Date:10/12/2017)... ... October 12, 2017 , ... ... multicenter, prospective clinical study that demonstrates the accuracy of the FebriDx® test, ... clinically significant acute bacterial and viral respiratory tract infections by testing the ...
(Date:10/12/2017)... ... 12, 2017 , ... AMRI, a global contract research, development ... patient outcomes and quality of life, will now be offering its impurity solutions ... new regulatory requirements for all new drug products, including the finalization of ICH ...
(Date:10/11/2017)... ... October 11, 2017 , ... ... Andi Purple announced Dr. Suneel I. Sheikh, the co-founder, CEO and chief research ... Inc. has been selected for membership in ARCS Alumni Hall of Fame ...
(Date:10/11/2017)... , ... October 11, 2017 , ... Personal eye wash is a basic first aid ... at a time. So which eye do you rinse first if a dangerous substance enters ... Plum Duo Eye Wash with its unique dual eye piece. , “Whether its dirt ...
Breaking Biology Technology:
(Date:4/5/2017)... , April 4, 2017 KEY FINDINGS ... to expand at a CAGR of 25.76% during the ... is the primary factor for the growth of the ... https://www.reportbuyer.com/product/4807905/ MARKET INSIGHTS The global stem ... technology, application, and geography. The stem cell market of ...
(Date:3/30/2017)... March 30, 2017 Trends, opportunities and forecast ... behavioral), by technology (fingerprint, AFIS, iris recognition, facial recognition, ... others), by end use industry (government and law enforcement, ... and banking, and others), and by region ( ... Asia Pacific , and the Rest ...
(Date:3/24/2017)... Research and Markets has announced the addition of the ... Industry Forecast to 2025" report to their offering. ... The Global Biometric Vehicle Access ... 15.1% over the next decade to reach approximately $1,580 million by ... and forecasts for all the given segments on global as well ...
Breaking Biology News(10 mins):