Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

Regulation of two-dimensional nanomaterials: New driving force for lithium-ion batteries July 26th, 2017

Liquid electrolyte contacts for advanced characterization of resistive switching memories July 26th, 2017

Graduate Students from Across the Country Attend Hands-on NanoCamp: Prominent scientists Warren Oliver, Ph.D., and George Pharr, Ph.D., presented a weeklong NanoCamp for hand-picked graduate students across the United States July 26th, 2017

Shining rings: A new material emits white light when exposed to electricity: New synthetic approach could spark development of other dynamic materials July 24th, 2017

Sensors

Giant enhancement of electromagnetic waves revealed within small dielectric particles: Scientists have done for the first time direct measurements of giant electromagnetic fields July 8th, 2017

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Letiís Autonomous-Vehicle System Embedded in Infineonís AURIX Platform: Letiís Low-Power, Multi-Sensor System that Transforms Distance Data into Clear Information About the Driving Environment Will Be Demonstrated at ITS Meeting in Strasbourg, June 19-22 June 20th, 2017

New diode features optically controlled capacitance: Israeli researchers have developed a new optically tunable capacitor with embedded metal nanoparticles, creating a metal-insulator-semiconductor diode that is tunable by illumination. June 8th, 2017

Nanoelectronics

Tokyo Institute of Technology research: Antiaromatic molecule displays record electrical conductance July 19th, 2017

A firefly's flash inspires new nanolaser light July 18th, 2017

GLOBALFOUNDRIES and VeriSilicon To Enable Single-Chip Solution for Next-Gen IoT Networks: Integrated solution leverages GFís 22FDXģ technology to decrease power, area, and cost for NB-IoT and LTE-M applications July 14th, 2017

Thinking thin brings new layering and thermal abilities to the semiconductor industry: In a breakthrough for the semiconductor industry, researchers demonstrate a new layer transfer technique called "controlled spalling" that creates many thin layers from a single gallium nitride July 11th, 2017

Announcements

Regulation of two-dimensional nanomaterials: New driving force for lithium-ion batteries July 26th, 2017

Liquid electrolyte contacts for advanced characterization of resistive switching memories July 26th, 2017

Phenom-World Launches Phenom Pro and ProX Generation 5 SEMs at Microscopy & Microanalysis Conference USA: The excellent performance in a wide range of applications offers a serious alternative to floor model SEMs July 26th, 2017

Graduate Students from Across the Country Attend Hands-on NanoCamp: Prominent scientists Warren Oliver, Ph.D., and George Pharr, Ph.D., presented a weeklong NanoCamp for hand-picked graduate students across the United States July 26th, 2017

Tools

Phenom-World Launches Phenom Pro and ProX Generation 5 SEMs at Microscopy & Microanalysis Conference USA: The excellent performance in a wide range of applications offers a serious alternative to floor model SEMs July 26th, 2017

The School of Materials at the University of Manchester utilise Debenís mechanical stages to characterise structure and behaviour at the micro- and nano- scale July 25th, 2017

Scientists announce the quest for high-index materials: All-dielectric nanophotonics: The quest for better materials and fabrication techniques July 22nd, 2017

Coupling a nano-trumpet with a quantum dot enables precise position determination July 14th, 2017

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