Phononic crystals (PnC) are periodic structures that have an ability to forbid the propagation of elastic waves in certain frequency. This region is known as Phononic Band Gap (PnBg) and can be used as guiding or filtering for elastic or acoustic wave. This ability has attracted many researchers around the world and many applications can be found from it such as in sensor, multiplexer, acoustic lens and acoustic cloaking. Furthermore, defects in the periodicity can be used to confine acoustic waves to follow complicated routes on a wavelength scale. In this presentation, we will show that phononic crystals based on resonant inclusions, could be used to strongly confine elastic waves and more specifically elastic waves propagating at the surface of a semi-infinite substrate exploiting the rich physics offered by the different coupling mechanisms in view of designing resonator systems capable to confine, control and transport the elastic energy. The potential application of this mechanism will be illustrated in micro-fluidics, sensors and telecommunications.
Abdelkrim Khelif is a senior researcher at CNRS (centre national de la recherche scientifique). He received in 1998, the Ph.D. degree in materials science from the Universite de Lille I, Lille, France. His dissertation was dedicated to the theory of vibrations of and acoustic scattering by supported wires on a surface. In 2002, he joined the Centre National de la Recherche Scientifique in Besancon, France and FEMTO-ST institute as researcher. In 2007, he was awarded with Medaille de Bronze from CNRS that acknowledges the first years of research of a talented young scientist. He has authored or co-authored more than 100 papers. His work focuses on phononic crystals, periodically structured materials that display astonishing acoustic properties, such as complete band gap, cavities mode and a phononic waveguides. He is also active to extract the potential application of phononic crystal as a new acoustic device for signal processing, and sensing applications.