Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Stretched Rubber Offers Simpler Method For Assembling Nanowires

Abstract:
Researchers at North Carolina State University have developed a cheap and easy method for assembling nanowires, controlling their alignment and density. The researchers hope the findings will foster additional research into a range of device applications using nanowires, from nanoelectronics to nanosensors, especially on unconventional substrates such as rubber, plastic and paper.

Stretched Rubber Offers Simpler Method For Assembling Nanowires

Raleigh, NC | Posted on February 28th, 2011

"Alignment is a critical first step for developing devices that use nanowires," says Dr. Yong Zhu, an assistant professor of mechanical and aerospace engineering at NC State and co-author of a paper describing the research. "Hopefully our simple and cost-effective method will facilitate research in this field."

Aligning nanowires is challenging because, when they are created, the user is faced with a profusion of randomly oriented nanoscale wires that are, by definition, incredibly small. For example, the nanowires are between 10 and 100 nanometers in diameter, whereas a white blood cell is approximately 10,000 nanometers in diameter. Before any practical applications can be pursued, the user must assemble the nanowires in an orderly way. Specifically, users need to align the nanowires in a common direction and define their density - meaning the number of nanowires in a given area. Controlling both alignment and density is commonly called "assembling" the nanowires.

In the new method, Zhu's team deposited the nanowires on a stretched rubber substrate, and then released the tension on the substrate. When the nanowires settled, they aligned at a right angle to where the tension was coming from. Picture a rubber band being stretched to the east and west. If nanowires were placed on the rubber band, and the band was allowed to snap back to its original shape, the nanowires would be oriented to the north and south. The more the rubber substrate is stretched, the more aligned the nanowires will be, and the greater the nanowire density will be.

Previous research has presented a number of other methods for assembling nanowires. But the new method offers a number of distinct advantages. "Our method is cost-effective," says Feng Xu, a Ph.D. student working on this project, "because it is so simple. It can also be used for nanowires synthesized by different methods or processed in different conditions, for instance, silver nanowires synthesized in solution and silicon nanowires synthesized by the vapor-liquid-solid method, as demonstrated in our work." In addition, the new method can be used in conjunction with previous methods to achieve even better nanowire assembly.

The use of a rubber substrate in this method facilitates broad research and manufacturing sectors. For example, a key element of research into stretchable nanoelectronics involves aligning nanowires on a stretchable rubber substrate. Similarly, rubber is also the material used as "stamps" in transfer printing - a critical fabrication method used in manufacturing nanodevices on diverse substrates ranging from silicon to glass to plastic.

Zhu notes that the initial step of the method, when the nanowires are first deposited on stretched rubber, sometimes yields an inconsistent degree of nanowire alignment. The team is currently working to understand the fundamental interface mechanics -including adhesion and static friction -between nanowires and rubber substrates, which is expected to lead to a better control of the assembly process and hence a higher yield of the nanowire assembly.

The paper, "Strain-Release Assembly of Nanowires on Stretchable Substrates," was published Feb. 22 in ACS Nano. The paper was co-authored by Zhu, Xu, NC State Ph.D. student John Durham, and Dr. Benjamin Wiley, an assistant professor at Duke University. The research was funded by the National Science Foundation.

NC State's Department of Mechanical and Aerospace Engineering is part of the university's College of Engineering.

"Strain-Release Assembly of Nanowires on Stretchable Substrates"

Authors: Feng Xu, John W. Durham, III, Yong Zhu, North Carolina State University; Benjamin J. Wiley, Duke University

Published: Feb. 22, 2011, ACS Nano

Abstract: A simple yet effective method for assembly of highly aligned nanowires (NWs) on stretchable substrates is reported. In this method, NWs were first transferred to a strained stretchable substrate. After the strain was released, the NWs aligned in the transverse direction and the area coverage of the NWs on the substrate increased. This method can be applied to any NWs deposited on a stretchable film and can be repeated multiple times to increase the alignment and density of the NWs. For silver (Ag) and silicon (Si) NWs on poly(dimethylsiloxane) (PDMS) substrates, the probability of NW alignment increased from 29% to 90% for Ag NWs, and from 25% to 88% for Si NWs after two assembly steps; the density increased by 60% and 75% for the Ag and Si NWs, respectively. The large-strain elasticity of the substrate and the static friction between the NWs and the substrate play key roles in this assembly method. We find that a model that takes into account the volume incompressibility of PDMS reliably predicts the degree of NW alignment and NW density. The utility of this assembly method was demonstrated by fabricating a strain sensor array composed of aligned Si NWs on a PDMS substrate, with a device yield of 95%.

####

For more information, please click here

Contacts:
Matt Shipman | News Services | 919.515.6386

Dr. Yong Zhu | 919.513.7735

Copyright © North Carolina State University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Why Is Google Making Synthetic Arms? February 1st, 2015

Nanomaterials Used to Reduce Heat Generated by LED Panels February 1st, 2015

Leader Describes Iran's Independence as Root Cause of Bullying Powers' Enmity February 1st, 2015

Performance Drop in Solar Cells Prevented by Nanotechnology February 1st, 2015

Govt.-Legislation/Regulation/Funding/Policy

Leader Describes Iran's Independence as Root Cause of Bullying Powers' Enmity February 1st, 2015

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Nanoscale Mirrored Cavities Amplify, Connect Quantum Memories: Advance could lead to quantum computing and the secure transfer of information over long-distance fiber optic networks January 28th, 2015

Detecting chemical weapons with a color-changing film January 28th, 2015

Possible Futures

Leader Describes Iran's Independence as Root Cause of Bullying Powers' Enmity February 1st, 2015

GS7 Graphene Sensor maybe Solution in Fight Against Cancer January 25th, 2015

Nanotechnology in Energy Applications Market Research Report 2014-2018: Radiant Insights, Inc January 15th, 2015

'Mind the gap' between atomically thin materials December 23rd, 2014

Academic/Education

Rice's Naomi Halas to direct Smalley Institute: Optics pioneer will lead Rice's multidisciplinary science institute January 15th, 2015

SUNY Board Appoints Dr. Alain Kaloyeros as Founding President of SUNY Polytechnic Institute January 13th, 2015

CNSE's Smart System Technology & Commercialization Center Successfully Recertifies as ISO 9001:2008 January 12th, 2015

SUNY Poly Now Accepting Applications to the Colleges of Nanoscale Science and Engineering for Fall 2015: Full Scholarships Available to Incoming CNSE Students January 7th, 2015

Sensors

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

GS7 Graphene Sensor maybe Solution in Fight Against Cancer January 25th, 2015

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

Iranian Scientists Produce Graphene-Based Oxygen Sensor January 23rd, 2015

Nanoelectronics

Electronic circuits with reconfigurable pathways closer to reality January 26th, 2015

Rice-sized laser, powered one electron at a time, bodes well for quantum computing January 15th, 2015

Rapid journey through a crystal lattice: Researchers measure how fast electrons move through single atomic layers January 14th, 2015

A new step towards using graphene in electronic applications January 14th, 2015

Discoveries

Nanomaterials Used to Reduce Heat Generated by LED Panels February 1st, 2015

Performance Drop in Solar Cells Prevented by Nanotechnology February 1st, 2015

Pinholes are Pitfalls for High Performance Solar Cells February 1st, 2015

New method allows for greater variation in band gap tunability: The method can change a material's electronic band gap by up to 200 percent January 31st, 2015

Announcements

Why Is Google Making Synthetic Arms? February 1st, 2015

Nanomaterials Used to Reduce Heat Generated by LED Panels February 1st, 2015

Leader Describes Iran's Independence as Root Cause of Bullying Powers' Enmity February 1st, 2015

Performance Drop in Solar Cells Prevented by Nanotechnology February 1st, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE