Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

30.01.2006


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.

Paul Nealey | EurekAlert!
Further information:
http://wisc.edu

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>