Liverpool scientists create invisibility cloak to protect coastlines

Oct 6 2008

A PIONEERING method to protect coastlines from flooding is being tested by scientists at Liverpool University.

Mathematicians at the University of Liverpool, together with physicists at the Centre National de la Recherche Scientifique (CNRS) and Aix-Marseille Universite in France, have discovered a structure that could reduce the risk of tidal waves and coastal floods.

The structure has been dubbed the “invisibility cloak” because it is made of metamaterial (a term used by electromagnetics researchers for materials which exhibit negative refraction) which can bend electromagnetic radiation such as radar, microwaves and light around spherical space, making an object within this space appear invisible.

The unique structure is cylindrical and has rigid pillars which help guide water along the corridors of the pillars and increase the speed of water flow as it nears the structure’s centre – very similar to that of a whirlpool. However, the waves are never broken up and therefore leave the structure as though they had never been disturbed.

Dr Sebastien Guenneau, from Liverpool University’s department of mathematical science, said: “Defending land against flooding and tidal waves is a big issue for scientists and engineers all over the world.

“Coastal defences have to withstand great forces and there is always a risk of water overtopping or penetrating these structures.

“Water crashes against these defences, breaking the wave and causing a lot of damage to roads and property hidden behind them.”