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

Harris & Harris Group Portfolio Company D-Wave Systems Announces 1,000 Qubit Processor and is Discussed in the Economist June 23rd, 2015

Global Nanoclays Market Analysis, Size, Growth, Trends And Segment Forecasts, 2015 To 2022: Grand View Research, Inc June 15th, 2015

Healthcare Nanotechnology (Nanomedicine) Market Size To 2020 June 5th, 2015

Environmental Issues to Hamper Growth of Global Nanocomposites Market June 4th, 2015

Sensors

Visible Light-Sensitive Photocatalysts Used for Purification of Contaminated Water in Iran June 30th, 2015

Graphene breakthrough as Bosch creates magnetic sensor 100 times more sensitive than silicon equivalent June 28th, 2015

The peaks and valleys of silicon: Team of USC Viterbi School of Engineering Researchers introduce new layered semiconducting materials as silicon alternative June 27th, 2015

Green Chemistry Methods Used in Iran to Produce Zinc Oxide Nanoparticles June 27th, 2015

Nanoelectronics

Exagan Raises €5.7 Million to Produce High-efficiency GaN-on-Silicon Power-switching Devices on 200mm Wafers: Leti-and-Soitec Spinout Focused on Becoming Leading European Source Of GaN Devices for Solar, Automotive, Telecoms and Infrastructure June 25th, 2015

Nanowires could be the LEDs of the future June 25th, 2015

Leti to Present Solutions to New Applications Using 3D Technologies at SEMICON West LetiDay Event, July 14: Leti Experts also Will Speak at TechXPOT Session on MEMS and STS Session on Lithography Cost-and-Productivity Issues Below 14nm June 22nd, 2015

Graphene heat-transfer riddle unraveled June 17th, 2015

Announcements

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Oxford Instruments’ TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

Tools

Oxford Instruments’ TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

How Graphene–based Nanomaterials and Films Revolutionize Science Explained in July 9 Webinar Hosted by Park Systems June 29th, 2015

Keysight Technologies Introduces Ultrafast-Scanning 9500 Atomic Force Microscope: New Integrated Software, Hardware Delivers Unmatched Scan Rates June 29th, 2015

Rice University boots up powerful microscopes: New electron microscopes will capture images at subnanometer resolution June 29th, 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