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 Proteins imaged in graphene liquid cell have higher radiation tolerance
10.12.2018 | INM - Leibniz-Institut für Neue Materialien gGmbH

nachricht High-temperature electronics? That's hot
07.12.2018 | Purdue 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: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Some brain tumors may respond to immunotherapy, new study suggests

11.12.2018 | Studies and Analyses

Researchers image atomic structure of important immune regulator

11.12.2018 | Health and Medicine

Physicists edge closer to controlling chemical reactions

11.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>