Laboratory: Institut d’Alembert , Université Pierre et Marie Curie, Paris
Contact : Pr. Régis Wunenburger (regis.wunenburger @ upmc.fr)
Description : Acoustic metamaterials are composite materials which are designed so that the propagation of acoustic waves exhibits remarkable properties in specific frequency ranges like band gaps or negative effective refractive index. These unique properties allow to foresee original strategies of control of the propagation of acoustic waves with potential applications to guiding, filtering, imaging, non destructive control, isolation, cloaking… In the frame of the ANR funded Metakoustik project (2012---2015), which gathers 4 research teams from CRPP (Bordeaux), I2M (Bordeaux), LoF (Bordeaux), and d’Alembert Institute (Paris), we work on the design, the synthesis by physico--- chemistry and microfluidics, and the acoustic characterization of so---called locally resonant acoustic metamaterials, i.e. whose microstructure is made of mechanical resonators: drops, bubbles, hard core---soft shells particles, with the aim of obtaining these non usual propagation properties in the ultrasonic frequency range.
Two realistic designs of metamaterials supposed to work in the ultrasonic frequency range could be indentified: a dispersion of dense spheres in a hard matrix, and more promisingly, a dispersion of dense spheres coated with a thin polymer shell . These materials are presently being produced in LoF. In close collaboration with the postdoc in charge with their synthesis, the postdoc working in Institut d’Alembert will be in charge of :
 L. Bos, L. Lukyanova, R. Wunenburger, Constraints on the design of core---shell resonators of locally resonant acoustic metamaterials, Phys. Rev. B 86, 184107 (2012).
 R. Tadmouri, et al., Millifluidic production of metallic microparticles, Soft Matter 8, 10704 (2012).
Salary: net 24 400€ / year (gross 30 000€ / year) (CNRS---Solvay postdoctoral grant)