Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > A giant step toward tiny functional nanowires

Abstract:
OWL able to produce gaps as small as 2.5 nanometers wide

A giant step toward tiny functional nanowires

Evanston, IL | June 30, 2005

Carving a telephone pole is easy if you have the right tools, say a power saw and some large chisels. And with some much tinier tools you could even carve a design into a paper clip if you wanted to. But shrink your sights down to the nanoscale, to a nanowire that is 1,000 times smaller than the diameter of a paper clip, and you find there are no physical tools to do the job properly.

So a team of Northwestern University scientists turned to chemistry and developed a new method that can routinely and cheaply produce nanowires with gaps as small as five nanometers wide -- a feat that is unattainable using conventional lithographic techniques. The results will be published in the July 1 issue of the journal Science.

Carved gaps are essential to a nanowire's function, and controlling those gaps would allow scientists and engineers to design with precision devices ranging from tiny integrated circuits to gene chips and protein arrays for diagnostics and drug discovery.

"With miniaturization happening across so many fields, our existing tools -- our chisels of a sort -- can't control the shapes and spacing of these small structures," said Chad A. Mirkin, director of Northwestern's Institute for Nanotechnology, who led the research team. "Our method allows us to selectively introduce gaps into the wires. These gaps can be filled with molecules, making them components for building small electronic and photonic devices or chemical and biological sensors."

The development of sophisticated nanoelectronics, said Mirkin, depends on the ability to fabricate and functionalize electrode gaps less than 20 nanometers wide for precise electrical measurements on nanomaterials and even individual molecules. While conventional techniques can't make gaps much smaller than 20 nanometers wide, Mirkin's method, called on-wire lithography, or OWL, has been able to produce gaps as small as 2.5 nanometers wide.

Mirkin and his team made the notched structures by first depositing into a porous template segmented nanowires made of two materials, one that is resistant to wet-chemical etching (gold) and one that is susceptible (nickel). The template is then dissolved, releasing the nanowires. Next, the wires are dispersed on a flat substrate, and a thin layer of glass is deposited onto their exposed faces. They are then suspended in solution, and a selective wet-chemical etching removes the nickel, leaving gold nanowires with well-defined gaps where the nickel used to be. (The glass is used as a bridging material, to hold the nanowire together.)

Using the OWL method, the researchers prepared nanowires with designed gaps of 5, 25, 40, 50, 70, 100, 140 and 210 nanometers wide. (A nanometer is one billionth of a meter or roughly the length of three atoms side by side. A DNA molecule is 2.5 nanometers wide.) In recent days, they have refined the technique to be able to make gaps as small as 2.5 nanometers wide.

"With dip-pen nanolithography, we can then drop into these gaps many different molecules, depending on what function we want the structure to have," said Mirkin, also George B. Rathmann Professor of Chemistry. "This really opens up the possibility of using molecules as components for a variety of nanoscale devices."

In addition to Mirkin, other authors on the Science paper are Lidong Qin (lead author), Sungho Park and Ling Huang of Northwestern University.


####

About Northwestern University:
Northwestern University is a private institution founded in 1851 to serve the Northwest Territory, an area that now includes the states of Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota. In 1853 the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University's founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.

For more information, please visit www.northwestern.edu


Copyright © Northwestern 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

Possible Futures

European roadmap for graphene science and technology published February 25th, 2015

Quantum research past, present and future for discussion at AAAS February 16th, 2015

World’s first compact rotary 3D printer-cum-scanner unveiled at AAAS by NTU Singapore start-up: With production funded by crowdsourcing, the first unit will be delivered to the United States in March February 16th, 2015

Nanotechnology Electric Vehicle (EV) Market Analysis Report 2015: According to Radiant Insights, Inc February 13th, 2015

Sensors

Penn researchers develop new technique for making molybdenum disulfide: Extra control over monolayer material with advantages over graphene February 19th, 2015

Researchers build atomically thin gas and chemical sensors: Sensors made of molybdenum disulfide are small, thin and have a high level of selectivity when detecting gases and chemicals February 19th, 2015

Production of Biosensor in Iran to Detect Oxalic Acid February 18th, 2015

Improved fire detection with new ultra-sensitive, ultraviolet light sensor February 17th, 2015

Nanoelectronics

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Ultra-thin nanowires can trap electron 'twisters' that disrupt superconductors February 24th, 2015

Improved fire detection with new ultra-sensitive, ultraviolet light sensor February 17th, 2015

Nanotechnology facility planned in Lund, Sweden: A production facility for start-ups in the field of nanotechnology may be built in the Science Village in Lund, a world-class research and innovation village that is also home to ESS, the European Spallation Source February 15th, 2015

Announcements

International research partnership tricks the light fantastic March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Tools

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Mass spectrometers with optimised hydrogen pumping March 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