Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

KIT Researchers Succeed in Realizing a New Material Class

09.05.2012
Metafluids for Transformation Acoustics

A research team lead by Professor Martin Wegener at the Karlsruhe Institute of Technology (KIT) has succeeded in realizing a new material class through the manufacturing of a stable crystalline metafluid, a pentamode metamaterial.


Pentamode metamaterials almost behave like fluids. Their manufacture opens new possibilities in transformation acoustics. (Source: CFN, KIT)


The stable four-leg structure (shown in orange) is the basic element of the pentamode metamaterial. It is arranged in the form of a three-dimensional adamantine crystal such that the resulting material as a whole can be formed. (Source: CFN, KIT)

Using new nanostructuring methods, these materials can now be realized for the first time with any conceivable mechanical properties. The researchers will present their results in the cover story of the May issue of Applied Physics Letters. (DOI 10.1063/1.4709436)

The Rubicon was crossed, so to speak, at the DFG Center for Functional Nanostructures (CFN) and at the Institute of Applied Physics (AP) in Karlsruhe during the past few months. Eventually, numerous three-dimensional transformation acoustics ideas, for example inaudibility cloaks, acoustic prisms or new loudspeaker concepts, could become reality in the near future.

So far, pentamodes, proposed in 1995 by Graeme Milton and Andrej Cherkaev, have been purely theoretical: The mechanical behavior of materials such as gold or water is expressed in terms of compression and shear parameters. Whereas the phenomenon that water, for example, can hardly be compressed in a cylinder is described through the compression parameter, the fact that it can be stirred in all directions using a spoon is expressed through the shear parameters.

The word penta is derived from ancient Greek and means “five”. In the case of water, the five shear parameters equal zero, and only one parameter, compression, differs from that value. In terms of parameters, the ideal state of a pentamode metamaterial corresponds to the state of water, which is why that material is referred to as a metafluid. Theoretically, any conceivable mechanical properties whatsoever can be obtained by varying the relevant parameters.

“Realizing a pentamode metamaterial is about as difficult as trying to build a scaffold from pins that must not touch but at their tips,” first author Dr. Muamer Kadic explains. “The Karlsruhe prototype has been manufactured from a polymer. The mechanical behavior of the material is determined by the acuteness and length of the individual “sugar loaves”. On the one hand, we must be capable of designing small sugar loaves in the nanometer range and connect them to one another at the right angle. On the other hand, the entire structure must eventually become as large as possible. Since the material itself contributes only little more than one percent to the respective volume, the composite obtained is extremely light.

“To obtain similar 3D results, as in transformation optics, transformation acoustics is exclusively dependent on metamaterials. In view of this, this first manufacture of our pentamode metamaterial is a quite significant success,” adds Tiemo Bückmann, who is about to receive his diploma at the Institute of Applied Physics and is responsible for realizing the structures of the new material by means of dip-in laser writing, a method that has been derived from direct laser writing developed by the Nanoscribe company.

In recent years, a Professor at the Institute of Applied Physics and CFN coordinator, Martin Wegener and his collaborators, have developed direct laser writing and, based on that method, established optical lithography of three-dimensional nanostructures. Numerous achievements of Wegener’s group in transformation optics e.g., the first three-dimensional cloak of invisibility in the range of visible light have been due to that technique.

About the DFG Center for Functional Nanostructures (CFN)
The DFG Center for Functional Nanostructures (CFN) focuses on an important area of nanotechnology: Functional nanostructures. Excellent interdisciplinary and international research is aimed at representing nanostructures with new technical functions and at making the first step from fundamental research to application. Presently, more than 250 scientists and technicians in Karlsruhe cooperate in more than 80 partial projects coordinated by the CFN. The focus lies on nanophotonics, nanoelectronics, molecular nanostructures, nanobiology, and nanoenergy.

Karlsruhe Institute of Technology (KIT) is a public corporation according to the legislation of the state of Baden-Württemberg. It fulfills the mission of a university and the mission of a national research center of the Helmholtz Association. KIT focuses on a knowledge triangle that links the tasks of research, teaching, and innovation.

For further information, please contact:

Tatjana Erkert DFG-Centrum für Funktionelle Nanostrukturen (CFN) www.cfn.kit.edu Tel.: +49 721 608-43409 Fax: +49 721 608-48496 E-Mail: tatjana erkert∂kit.edu

Monika Landgraf | EurekAlert!
Further information:
http://www.kit.edu

More articles from Materials Sciences:

nachricht Strange but true: Turning a material upside down can sometimes make it softer
20.10.2017 | Universitat Autonoma de Barcelona

nachricht Metallic nanoparticles will help to determine the percentage of volatile compounds
20.10.2017 | Lomonosov Moscow State University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>