A bubble metascreen, i.e., a single layer of gas inclusions in soft solid, can be modeled as an acoustic open resonator, whose behavior is well captured by simple analytical expression. We show that tuning the parameters superabsorption achieved over broad frequency range, which confirmed finite element simulations and experiments. Bubble metascreens thus used ultrathin coatings for turning reflectors into perfect absorbers.Received 6 October 2014Revised 3 December...

Thanks to a multiple-scattering theory algorithm, we present way focus energy at the deep subwavelength scale, from far field, inside cubic disordered bubble cloud by using broadband time reversal (TR). We show that analytical calculation of an effective wavenumber performing independant scattering approximation (ISA) matches numerical results for focal extension. Subwavelength focusings $\ensuremath{\lambda}/100$ are reported simulations with perfect bubbles (no loss). A more realistic...

To produce sounds, we adjust the tension of our vocal folds to shape their properties and control pitch. This efficient mechanism offers inspiration for designing reconfigurable materials adaptable soft robots. However, understanding how flexible structures respond a significant static strain is not straightforward. complexity also limits precision medical imaging when applied tensioned organs like muscles, tendons, ligaments blood vessels among others. In this article, experimentally...

Significance We monitor the propagation of in-plane elastic waves in an incompressible thin strip and observe a Dirac cone soft material. Additional remarkable wave features such as negative phase velocities, pseudo-zero group velocity, one-way chiral selection are highlighted. These results universal: Any made any elastomer will display same behavior. cones have inspired many developments condensed-matter field over last decade. Our findings enable search for analogs realm matter, leading...

We investigate the interaction between Bragg and hybridization effects on band gap properties of bubble phononic crystals. These latter consist air cavities periodically arranged in an elastomer matrix are fabricated using soft-lithography techniques. Their transmission affected by due to periodicity structure as well propagating mode embedding medium resonance. The survives disorder while requires a periodic distribution bubbles. distance two layers can be tuned make gaps overlap or create peak gap.

A bubble meta-screen is an exceptionally effective and low frequency resonator which can be optimized in order to exactly balance the energy provided by radiative process lost under a viscous mechanism (critical coupling). Under this condition, one absorb 99.9% of carried two phase-matched counter propagating acoustic beams. This phenomenon, called coherent perfect absorption, here observed with bubbles 75 times smaller than incident wavelength shown remarkably broadband. Finally, tuning...

Using a Multiple Scattering Theory algorithm, we investigate numerically the transmission of ultrasonic waves through disordered locally resonant metamaterial containing only monopolar resonators. By comparing cases perfectly random medium with its pair correlated counterpart, show that introduction short range correlation can substantially impact effective parameters sample. We report, notably, opening an acoustic transparency window in region hybridization band gap. Interestingly, is found...

Gas bubbles in a sound field are submitted to radiative force, known as the secondary Bjerknes force. We propose an original experimental setup that allows us investigate detail this force between two bubbles, function of sonication frequency, well radii and distance. report observation both attractive and, more interestingly, repulsive when driven antiphase. Our experiments show importance taking multiple scatterings into account, which leads strong acoustic coupling their similar....

The interaction between waves and evolving media challenges traditional conservation laws. We experimentally investigate the behavior of elastic wave packets crossing a moving interface that separates two with distinct propagation properties, observing noninvariance wavelength frequency. Our experimental setup employs an strip whose local stretching can be dynamically altered by pulling one end at constant velocity. By demonstrating this dynamic configuration creates spatiotemporal traveling...

Gas bubbles in a sound field are submitted to radiative force, known as the secondary Bjerknes force. In this presentation, we propose an original experimental setup that allowed us investigate details force between two neighboring bubbles. The dependance with sonication frequency, well radii and distance, was examined. We report observation of both attractive and, more interestingly, repulsive when have different can thus be driven antiphase. On contrary, our results also show importance...

Mechanical waves propagating in soft materials play an important role physiology. They can be natural, such as the cochlear wave inner ear of mammalians, or controlled, elastography context medical imaging. In a recent study, Lanoy, Lemoult, Eddi, and Prada [Proc. Natl. Acad. Sci. U.S.A. 117(48), 30186–30190 (2020)] implemented experimental tabletop platform that allows direct observation in-plane guided strip. Here, detailed description setup signal processing steps is presented well...

Dynamic Mechanical Analysis (DMA) allows for the measurement of complex shear modulus an elastomer. Measurements at frequencies above frequency range device can be reached thanks to Time–Temperature Equivalence principle. Yet, higher than a few kHz are not attainable. Here, we propose method exploiting physics bubble phononic crystals measure tens kHz. The idea is fabricate crystal by creating period arrangement bubbles in elastomer interest, here PolyDiMethylSiloxane (PDMS), and its...

A sound wave travelling in water is scattered by a periodic assembly of air bubbles. The local structure matters even the low frequency regime. If bubbles are arranged face-centered cubic (fcc) lattice, total band gap opens near Minnaert resonance frequency. they diamond structure, which one obtains simply adding second bubble to unit cell, finds an additional branch with negative slope (optical branch). For single specific frequency, medium behaves as if its refractive index (relative...

This study examines the potential of elongated periodic three-dimensional lattice structures for design vibration filters using so-called absolute band gaps. These are generally obtained by modifying total stiffness structure, which decreases propagation velocity all wave polarisations. With a view to optimisation, we implementing an original structure consisting interconnected 3D beams with sinusoidal accordion shape control speed longitudinal waves. In addition, central junction in...

Thanks to their particularly efficient, low frequency Minnaert resonance, air bubbles are known be excellent candidates for the realization of acoustic metamaterials. Here, we demonstrate that introduction pair-wise spatial correlations between can result in double negativity. This occur when bubble pairs arranged either random or periodic configurations. Predictions both types structure will presented and influence dissipation on doubly negative behaviour discussed.

A bubble in water exhibits a low-frequency monopolar acoustic resonance, the so-called Minnaert which makes an assembly of such bubbles ideal system to study multiple scattering ultrasound. Following Foldy’s seminal work, various approaches, as ones by Keller or Waterman and Truell, have been developed infer effective properties cloud. Here, we confront predictions these different approaches with numerical results obtained theory (MST) code that fully incorporates effects. Based on this...

To produce sounds, we adjust the tension of our vocal folds to shape their properties and control pitch. This efficient mechanism offers inspiration for designing reconfigurable materials adaptable soft robots. However, understanding how flexible structures respond a significant static strain is not straightforward. complexity also limits precision medical imaging when applied tensioned organs like muscles, tendons, ligaments blood vessels among others. In this article, experimentally...

The particularly efficient and low frequency Minnaert resonances of air bubbles in fluids or soft solids make them excellent candidates for the realization acoustic metamaterials. Here, we study transmission a plane wave through single meta-layer consisting periodic arrangement trapped viscoelastic matrix show how perfect coherent absorber can be realized.

Having a material that is matched in acoustic impedance with the surrounding medium considerable asset for many underwater applications. In this work, matching achieved by dispersing small, deeply subwavelength sized particles soft matrix, and appropriate concentration determined help of Coherent Potential Approximation Waterman & Truell models. We show experimentally validity models using mixtures Polydimethylsiloxane (PDMS) TiO2 particles. The optimized composite has same longitudinal as...