Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > 2-d blueprint into novel 3-d nanostructures

Abstract:
Self-assembling block copolymers extend photolithography to three dimensions

From 2-d blueprint, material assembles into novel 3-d nanostructures

Madison, WI | Posted on January 27, 2006

An international team of scientists affiliated with the University of Wisconsin-Madison Nanoscale Science and Engineering Center has coaxed a self-assembling material into forming never-before-seen, three-dimensional nanoscale structures, with potential applications ranging from catalysis and chemical separation to semiconductor manufacturing.

Led by UW-Madison chemical and biological engineering professors Paul Nealey and Juan de Pablo and colleagues at Georg-August University in Germany and the Paul Scherrer Institute in Switzerland, the team has discovered that materials known as block copolymers will spontaneously assemble into intricate 3-D shapes when deposited onto particular 2-D surface patterns created with photolithography.

The result, published in the Jan. 27 issue of Physical Review Letters, demonstrates a promising strategy for building complex, 3-D nanostructures by using standard tools of the semiconductor industry, says Nealey. Those tools, particularly lithography, already allow the making of devices with dimensions substantially smaller than 100 nanometers, or a hundred-thousandth of a centimeter.

But photolithography is also limited, he says, because as practiced today it is essentially a two-dimensional process.

"What we've done by using self-assembling block copolymers is to extend photolithography to three dimensions," says Nealey. "And the structures we've fabricated are completely different from the same block copolymer materials in the bulk."

Also important to manufacturing, the new 3-D nanostructures are stable, well defined and nearly defect-free over large areas. They also align perfectly with the underlying lithographic pattern-a key requirement for any device or application based on them.

"This research shows that lithography combined with block copolymers is more versatile and powerful than we thought. We can now create completely new structures that will no doubt have new properties and new applications," says de Pablo. "Exactly what those structures will be is anybody's guess; here we demonstrate a complicated one. But the important thing is they open up a new field of exploration, both for these materials and this technology."

The specific structures the team produced were composed of two tightly interwoven, yet completely independent, networks of channels and passages-all at the scale of atoms. "What we have are two interpenetrating meshes, both of which are completely continuous. And yet you could travel through one from end to end without ever entering the other," says de Pablo.

The networks are also in perfect register with the photolithographic pattern underneath, which tells scientists exactly where each channel ends and gives them ready access to channel openings. A gas, for example, might be introduced through the openings to react with a catalyst deposited on the walls of the network. Nanoscale materials have massive surface areas compared to their volumes; thus, catalysis would be extremely efficient.

Another use would be chemical separation of substances of different sizes. "This process gives us exquisite control over the dimensions of pores," says de Pablo. "So, we could easily make membranes that are permeable to substances smaller than the length scale of the material."

The researchers study specific block copolymers consisting of long chains of two different types of molecules, which alternate with each other in blocks. At high temperature, block copolymers are molten and randomly mixed. But when cooled down, the material spontaneously assembles into alternating layers of molecules.

This work was supported by the National Science Foundation Nanoscale Science and Engineering Center at the University of Wisconsin and the Semiconductor Research Corporation.

####
Contact:
Paul Nealey
(608) 265-8171
nealey@engr.wisc.edu

Copyright University of Wisconsin-Madison

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

Self Assembly

Berkeley Lab researchers create nanoparticle thin films that self-assemble in 1 minute June 9th, 2014

Design of self-assembling protein nanomachines starts to click: A nanocage builds itself from engineered components June 5th, 2014

Molecular self-assembly scales up from nanometers to millimeters June 5th, 2014

Nano world: Where towers construct themselves: How physicists get control on the self-assembly process June 2nd, 2014

Materials/Metamaterials

From Narrow to Broad July 30th, 2014

Nature inspires a greener way to make colorful plastics July 30th, 2014

Tough foam from tiny sheets: Rice University lab uses atom-thick materials to make ultralight foam July 29th, 2014

A new way to make microstructured surfaces: Method can produce strong, lightweight materials with specific surface properties July 29th, 2014

Announcements

University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014

Nature inspires a greener way to make colorful plastics July 30th, 2014

Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials July 30th, 2014

FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research July 30th, 2014

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 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE