Ultrabroadband Elastic Cloaking in Thin Plates

This paper made the cover of PRL and gave rise to numerous press articles, including in Popular Science Magazine (USA), New Scientist (UK), Pour La Science and La Recherche. As a result of the discovery of cloaking of seismic waves, a patent on anti-earthquake systems in perforated plates is being filed between the CNRS and the University of Liverpool (UK).International audienceControl of waves with metamaterials is of great topical interest, and is fueled by rapid progress in broadband acoustic and electromagnetic cloaks. We propose a design for a cloak to control bending waves propagating in isotropic heterogeneous thin plates. This is achieved through homogenization of a multilayered concentric coating filled with piecewise constant isotropic elastic material. Significantly, our cloak displays no phase shift for both backward and forward scattering. To foster experimental efforts, we provide a simplified design of the cloak which is shown to work in a more than two-octave frequency range (30 Hz to 150 Hz) when it consists of 10 layers using only 6 different materials overall. This metamaterial should be easy to manufacture, with potential applications ranging from car industry to antiearthquake passive systems for smart buildings, depending upon the plate dimensions and wavelengths