Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Just-For-Fun Experiment Creates Self-Assembly Method

14.12.2001


An experiment that University of Chicago physicists conducted just for fun has unexpectedly led them to a new technique for producing nanoscale structures.
The Chicago physicists have built simple electronic devices using the new technique, which precisely controls the growth of metal wires along tiny scaffolds that automatically assemble themselves following nature’s own tendencies.

"This is perhaps the first time that it has been possible to assemble large numbers of parallel, continuous wires that are truly nanometer scale in cross-section," said Heinrich Jaeger, Professor in Physics at the University of Chicago. Jaeger and Ward Lopes of Arryx Inc. in Chicago describe the technique in today’s issue of the journal Nature.


Self-assembly is a hot research field today because of the promise it holds for producing new technology at the nanoscale, the scale of atoms and molecules. Conventional methods for building smaller, faster computer components involves chiseling ever-finer structures out of a larger piece of material. Self-assembly, in contrast, builds up larger structures from smaller building blocks.

The nanowires that Lopes fabricated during the course of his Ph.D. research at the University measure 30 nanometers by 10 nanometers in diameter. A nanometer is a billionth of a meter, or the width of a double strand of DNA. Lopes also fabricated "nanochains," tiny strings of metal beads of similar size that could serve as switches.

The most perfect wirelike structures are formed with silver, Jaeger said. "Silver is unique in that it forms the wires. Essentially all other metals -- gold, copper, tin, lead, bismuth -- form nanochains under normal conditions.

"We can also form nanochains with silver, but the exciting advance of Ward’s research is that he was able to combine experimental results with computer simulations to get a feeling of what it is about a particular metal that makes it behave in a wirelike fashion or the chainlike fashion."

This productive line of research started on a lark.

"In Heinrich’s lab we had a tradition on Friday afternoons of doing experiments that you couldn’t justify spending time on, that you would only do because you wanted to have fun and try things out," Lopes said.

In his experiment, Lopes attempted to see if silver would chemically react to certain copolymers -- synthetic compounds -- the way gold did, as would be expected. But Lopes noticed that the silver exhibited strange behavior. All other metals formed balls on the copolymers and, if he added too much metal the balls would bond to each other and ignore the template. When he added enough silver he expected the silver to ignore the copolymer template, but the silver spheres had become long and thin.

"I just followed my nose and said, how long can I get these things to be?"

Potential applications for the technique include the production of high-density computer disks, and to make lenses for X-ray lithography, a process for transferring ultrasmall patterns to silicon computer chips.

The Chicago physicists used commonly available copolymers and simple methods with an eye toward easing the transfer of their results to potential applications.

"The plastics in the copolymer we used are standard, everyday plastics," Lopes said. "One was polystyrene, which is used to make Styrofoam, and the other, polymethylmethacrylate, is familiar from Plexiglas."

Steve Koppes | International Science News
Further information:
http://unisci.com/stories/20014/1213015.htm

More articles from Materials Sciences:

nachricht Materials scientist creates fabric alternative to batteries for wearable devices
12.11.2018 | University of Massachusetts at Amherst

nachricht A new path through the looking-glass
12.11.2018 | Deutsches Elektronen-Synchrotron DESY

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection

13.11.2018 | Life Sciences

Fish recognize their prey by electric colors

13.11.2018 | Life Sciences

Ultrasound Connects

13.11.2018 | Awards Funding

VideoLinks
Science & Research
Overview of more VideoLinks >>>