Hypersonic Phononic Crystals

Probing Thermomechanics at the Nanoscale: Impulsively Excited Pseudosurface Acoustic Waves in Hypersonic Phononic Crystals

High-frequency surface acoustic waves can be generated by ultrafast laser excitation of nanoscale patterned surfaces. Here we study this phenomenon in the hypersonic frequency limit. By modeling the thermomechanics from first-principles, we calculate the system's initial heat-driven impulsive response and follow its time evolution. A scheme is introduced to quantitatively access frequencies and...

A new class of tunable hypersonic phononic crystals based on polymer-tethered colloids

The design and engineering of hybrid materials exhibiting tailored phononic band gaps are fundamentally relevant to innovative material technologies in areas ranging from acoustics to thermo-optic devices. Phononic hybridization gaps, originating from the anti-crossing between local resonant and propagating modes, have attracted particular interest because of their relative robustness to struct...

Tunable magnetoelastic phononic crystals

J.-F. Robillard, O. Bou Matar, J. O. Vasseur, P. A. Deymier, M. Stippinger, A.-C. Hladky-Hennion, Y. Pennec, and B. Djafari-Rouhani Joint European Laboratory LEMAC, Ecole Centrale de Lille, 59651 Villeneuve d’Ascq, France Institut d’Électronique, de Microélectronique et de Nanotechnologie, UMR CNRS 8520, Cité Scientifique, 59652 Villeneuve d’Ascq Cedex, France Department of Materials Science an...

Magnetic-Sphere-Based Phononic Crystals

Periodic arrays in one, two, and three dimensions, made of magnetic spheres embedded in a fluid matrix, are considered in this study and utilized as phononic structures. The propagation of acoustic waves through these structures is analyzed experimentally, in lowand high-frequency region, via laser vibrometry, as well as standard underwater acoustic measurements. A first comparison to theoretic...

Design and characterization of bubble phononic crystals