Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Invisibility cloak' could protect against earthquakes

22.07.2009
Research at the University of Liverpool has shown it is possible to develop an 'invisibility cloak' to protect buildings from earthquakes.

The seismic waves produced by earthquakes include body waves which travel through the earth and surface waves which travel across it. The new technology controls the path of surface waves which are the most damaging and responsible for much of the destruction which follows earthquakes.

The technology involves the use of concentric rings of plastic which could be fitted to the Earth's surface to divert surface waves. By controlling the stiffness and elasticity of the rings, waves travelling through the 'cloak' pass smoothly into the material and are compressed into small fluctuations in pressure and density. The path of the surface waves can be made into an arc that directs the waves outside the protective cloak. The technique could be applied to buildings by installing the rings into foundations.

Sebastien Guenneau, from the University's Department of Mathematics, who developed the technology with Stefan Enoch and Mohamed Farhat from the Fresnel Institute (CNRS) in Marseilles, France, explained: "We are able to 'tune' the cloak to the differing frequencies of incoming waves which means we can divert waves of a variety of frequencies. For each small frequency range, there is a pair of rings which does most of the work and these move about a lot – bending up and down – when they are hit by a wave at their frequency.

"The waves are then directed outside the cloak where they return to their previous size. The cloak does not reflect waves – they continue to travel behind it with the same intensity. At this stage, therefore, we can only transfer the risk from one area to another, rather than eliminate it completely."

He added: "This work has enormous potential in offering protection for densely populated areas of the world at risk from earthquakes. The challenge now is to turn our theories into real applications that can save lives – small scale experiments are underway."

Seismic waves also include coupled pressure and shear body waves which are less destructive than surface waves. Sebastien Guenneau and Sasha Movchan at the University of Liverpool, together with Michele Brun at Cagliari University, have designed an 'elastic' cloak to protect against these particularseismic waves and the team is currently seeking a suitable material to accommodate the elastic parameters of the cloak.

The new research to protect against earthquakes is published in Applied Physics Letters and Physical Review Letters.

Kate Spark | EurekAlert!
Further information:
http://www.liv.ac.uk

More articles from Physics and Astronomy:

nachricht New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

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: 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 >>>