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 Nagoya University researchers break down plastic waste
29.05.2017 | Nagoya University

nachricht A new tool for discovering nanoporous materials
23.05.2017 | Ecole Polytechnique Fédérale de Lausanne

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New Method of Characterizing Graphene

Scientists have developed a new method of characterizing graphene’s properties without applying disruptive electrical contacts, allowing them to investigate both the resistance and quantum capacitance of graphene and other two-dimensional materials. Researchers from the Swiss Nanoscience Institute and the University of Basel’s Department of Physics reported their findings in the journal Physical Review Applied.

Graphene consists of a single layer of carbon atoms. It is transparent, harder than diamond and stronger than steel, yet flexible, and a significantly better...

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

3D printer inks from the woods

30.05.2017 | Life Sciences

How circadian clocks communicate with each other

30.05.2017 | Life Sciences

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible

30.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>