Rémi Marchal
Jeudi 11 juillet 2013 à 14h - Barre 22-32, salle 201, 2e étage.
Acoustic metamaterials are heterostructures designed to control the propagation of elastic waves. They are generally constituted by an arrangement of local resonators. Effective mass density and compressibility can be both negative when resonators are vibrated on their eigenmodes out-of-phase with respect to the elastic wave that propagates in the matrix. Moreover, to produce macroscopic effect as negative reflexion, resonators have to be smaller than the wavelength of the incident wave. As a result, we need to find resonators with minimum one eigenfrequency corresponding to a wavelength of the Lamb wave minimum ten times bigger than the typical size of the resonator (homogenous criteria).
This presentation will describe recent measurements on passive and resonant scattering field produce by holes and silicon stubs in silicon plate as potential « good » resonators to doing this kind of material.