V. Romero-García

V. Romero-García
Université du Maine · Acoustical Laboratory of the Université du Maine (LAUM)

PhD. Applied Physics
Wave propagation in complex media. Acoustic Metamaterials. Phononic Crystals. Hyperuniform materials. Disordered media.

About

197
Publications
49,856
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,173
Citations
Introduction
V. Romero-García currently works at the Acoustical Laboratory of the Le Mans University (LAUM). V. Romero-García does research in Acoustics, Condensed Matter Physics and Applied Physics. Their current project is 'Acoustic Metamaterials in the Audible Regime [MetAudible]'.
Additional affiliations
September 2014 - present
Université du Maine
Position
  • CNRS Researcher
September 2013 - September 2014
Université du Maine
Position
  • PostDoc Position
July 2011 - July 2013
Universitat Politècnica de València
Position
  • PostDoc Position

Publications

Publications (197)
Article
Full-text available
This work deals with wave absorption in reciprocal asymmetric scattering problem by addressing the acoustic problem of compact absorbers for perfect unidirectional absorption, flush mounted to the walls of wide ducts. These absorbers are composed of several side‑by‑side resonators that are usually of different geometry and thus detuned to yield an...
Data
Supplementary Material for 'Underwater metamaterial absorber with impedance-matched composite' that was published on Science Advances 8, eabm4206 (2022).
Article
Full-text available
By using a structured tungsten-polyurethane composite that is impedance matched to water while simultaneously having a much slower longitudinal sound speed, we have theoretically designed and experimentally realized an underwater acoustic absorber exhibiting high absorption from 4 to 20 kHz, measured in a 5.6 m by 3.6 m water pool with the time-dom...
Article
The perfect absorption of bending waves by thermally tunable subwavelength absorbers is analytically and experimentally demonstrated in this work for a reflection problem in beams. These absorbers are local resonators located at the end of a semi-infinite beam and consist of thin blades covered with a layer of Shape Memory Polymer (SMP), the stiffn...
Article
The closed form expressions of the effective properties in periodic fluid laminates are derived thanks to the Padé approximation of the transfer matrix. A second-order Taylor expansion of the transfer matrix elements exhibits Willis coupling. This coupling is the sum of a local term and a nonlocal term. The nonlocal term arises from the apparent bu...
Article
This article explores, theoretically and experimentally, asymmetric absorbers made of detuned and folded quarter wavelength resonators filled with air or porous materials. When used as acoustic lining in ducts, their thickness can be sub-wavelength and they can be designed for perfect absorption in broad target frequency bandwidth. The considered f...
Preprint
Full-text available
Two-dimensional stealthy hyperuniform distributions of rigid scatterers embedded in a waveguide are experimentally characterized the wave transport properties for scalar waves in airborne audible acoustics. The non resonant nature of the scatterers allows us to directly links the these properties to the geometric distribution of points through the...
Article
Thermoacoustic amplifiers are analyzed in the framework of nonreciprocal Willis coupling. The closed form expressions of the effective properties are derived, showing that an applied temperature gradient causes the appearance of a nonreciprocal Willis coupling. Even and nonreciprocal Willis couplings are exhibited already in the first-order Taylor...
Chapter
Motivated by the analogous photonic crystals acting on electromagnetic waves, periodic distribution of solid materials, i.e., phononic crystals, have been exploited during the last decades to control elastic and acoustic waves. This Chapter reviews phononic crystals in which the background medium is a fluid and the scatterers are rigid solids, i.e....
Chapter
The transfer matrix method is a simple but powerful analytical tool used to model acoustic wave propagation in a wide range of one-dimensional problems. In this chapter, we present the method and summarize the most common building blocks encountered in one-dimensional acoustic systems. These include layers of fluids and porous media, ducts and wave...
Chapter
Porous and fibrous materials provide effective and broadband acoustic absorption at mid/high audible frequencies. However, these traditional treatments result in thick and heavy layers when designed for low frequency audible sound. To overcome these limitations, in the recent years metamaterials have been proposed as an alternative to design sub-wa...
Preprint
By using a structured tungsten-polyurethane composite that is impedance-matched to water while simultaneously having a much slower longitudinal sound speed, we have theoretically designed, and experimentally realized, an underwater acoustic absorber exhibiting high absorption from 4 to 20 kHz, measured in a 5.6m times 3.6m water pool with the time-...
Article
Stealthy hyperuniform point patterns are characterized by a vanishing spatial Fourier transform around the origin of the reciprocal vector space. The long-range point density fluctuations are suppressed as well in materials consisting of such distribution of scatterers, opening up opportunities to control waves. Beside wave transport in such struct...
Conference Paper
Full-text available
This presentation introduces an asymmetric metaporous treatment for sound absorption, i.e., simultaneous cancellation of reflection and transmission, in a lined duct. The treatment is 3D printed and composed of folded and detuned quarter-wavelength resonators filled by air or by porous media. The asymmetry of the treatment, i.e., the use of pairs o...
Article
Full-text available
Most simulations involving metamaterials often require complex physics to be solvedthrough refined meshing grids. However, it can prove challenging to simulate the effect of localphysical conditions created by said metamaterials into much wider computing sceneries due to theincreased meshing load. We thus present in this work a framework for simula...
Article
Light and thin structures exhibiting high sound insulation over a wide frequency range are a major industrial concern, especially in the transport and building sectors. Phononic crystals constitute promising solutions to solve this issue due to their particular dispersion properties. In this work, we build a system consisting of a well-known sandwi...
Conference Paper
Full-text available
Open-cell materials are well-known for their low price, low weight, and broadband acoustic behavior. They form one of the most used class of acoustic treatments but suffer from a lack of versatility when made by conventional manufacturing processes. Recent advances in additive manufacturing allow to produce porous materials having a controlled micr...
Article
Full-text available
Sound diffusion refers to the ability of a surface to evenly scatter sound energy in both time and space. However, omni-directional radiation of sound, or perfect diffusion, can be impractical or difficult to reach under traditional means. This is due to the considerable size required, and the lack of tunability, of typical quarter-wavelength scatt...
Article
We report a procedure to design two-dimensional acoustic structures with prescribed scattering properties. The structures are designed from targeted properties in the reciprocal space so that their structure factors, i.e. their scattering patterns under the Born approximation, exactly follow the desired scattering properties for a set of wavelength...
Article
Full-text available
The optimal absorption of flexural energy by the critical coupling of a locally resonant grating embedded in a thin plate is reported in this work for the reflection and transmission problems. The grating is made of a 1D-periodic array of local resonators. A viscoelastic coating is also placed on top of each resonator to control the intrinsic losse...
Article
Full-text available
In this work, we show that scattered acoustic vortices generated by metasurfaces with chiral symmetry present broadband unusual properties in the far-field. These metasurfaces are designed to encode the holographic field of an acoustical vortex, resulting in structures with spiral geometry. In the near field, phase dislocations with tuned topologic...
Article
Full-text available
Acoustic vortices with subwavelength dimensions and tunable topological charge are theoretically and experimentally synthesized at distances far beyond the Rayleigh diffraction length of the source, using self-demodulation. A dual helical acoustic source is used to generate two primary confocal vortex beams at different frequencies and different to...
Article
Full-text available
As building blocks of acoustic metamaterials, resonant scatterers have demonstrated their ability to modulate the effective fluid parameters, which subsequently possess extreme properties such as negative bulk modulus or negative mass density. Promising applications have been shown such as extraordinary absorption, focusing, and abnormal refraction...
Article
This paper examines the feasibility of cloaking an obstacle using Plate-type Acoustic Metamaterials (PAMs). We present two distinct strategies to cloak this obstacle, using either the near-zero-density regime of a periodic arrangement of plates or the acoustic doping phenomenon to achieve simultaneous zero-phase propagation and impedance matching....
Article
Full-text available
Porous materials and metamaterials play a key role in sound absorbing and insulation solutions in acoustics. With the growing interest in additive manufacturing techniques, recent work has focused on the printing of porous and resonant structures for acoustic purposes. Usual metaporous surfaces/interfaces are generally built by periodically inserti...
Article
We report experiments on high-amplitude sound wave propagation in an acoustic metamaterial composed of an air-filled waveguide periodically side-loaded by holes. In addition to the linear viscothermal and radiation losses, high amplitude sound waves at the locations of the side holes introduce nonlinear losses. The latter result in an amplitude-dep...
Article
Full-text available
In this review, we present the results on sub-wavelength perfect acoustic absorption using acoustic metamaterials made of Helmholtz resonators with different setups. Low frequency perfect absorption requires to increase the number of states at low frequencies and finding the good conditions for impedance matching with the background medium. If, in...
Article
Full-text available
We present a 3-dimensional fully natural sonic crystal composed of spherical aggregates of fibers (called Aegagropilae) resulting from the decomposition of Posidonia Oceanica. The fiber network is first acoustically characterized, providing insights on this natural fiber entanglement due to turbulent flow. The Aegagropilae are then arranged on a pr...
Article
Full-text available
This Letter reports a folded metaporous surface optimized to achieve sub-wavelength and broadband perfect absorption. Its unit cell is composed of four different helicoidal cavities filled by porous media, which are structured and quasi-isotropic micro-lattices with a variable lattice constant. The effective thickness and intrinsic losses of each h...
Article
Full-text available
Mirror-symmetric acoustic metascreens producing perfect absorption independently of the incidence side are theoretically and experimentally reported in this work. The mirror-symmetric resonant building blocks of the metascreen support symmetric and antisymmetric resonances that can be tuned to be at the same frequency (degenerate resonances). The g...
Conference Paper
Full-text available
Sound diffusers are structured surfaces designed to control the scattering of acoustic waves, mainly used in room acoustics to improve sound quality. However, as they are mainly based on quarter-wavelength resonators, phase-grating diffusers result in heavy and thick structures. We present a novel approach to design deep-subwavelength sound diffuse...
Article
Full-text available
The design of graded and anisotropic materials has been of significant interest, especially for sound absorption purposes. Together with the rise of additive manufacturing techniques, new possibilities are emerging from engineered porous micro-structures. In this work, we present a theoretical and numerical study of graded and anisotropic porous ma...
Preprint
Full-text available
We report a procedure to design 2-dimensional acoustic structures with prescribed scattering properties. The structures are designed from targeted properties in the reciprocal space so that their structure factors, i.e., their scattering patterns under the Born approximation, exactly follow the desired scattering properties for a set of wavelengths...
Article
We theoretically, numerically, and experimentally investigate the feasibility of acoustic doping, i.e., changing one of the effective properties of a medium by adding an impurity, to achieve supersqueezing. This effect, characterized by perfect and zero-phase transmission, can be obtained with zero index media. In acoustics, zero-phase propagation...
Preprint
Full-text available
Mirror-symmetric acoustic metascreens producing perfect absorption independently of the incidence side are theoretically and experimentally reported in this work. The mirror-symmetric resonant building blocks of the metascreen support symmetric and antisymmetric resonances that can be tuned to be at the same frequency (degenerate resonances). The g...
Article
An Acoustic Black Hole (ABH) in a one-dimensional (1D) beam is a passive vibration damping device based on a local reduction of the beam thickness attached to a thin layer of attenuating material. This work aims at revisiting the ABH effect by analysing the ABH trapped modes in the complex frequency plane. This analysis relies on an analytical mode...
Article
Full-text available
We report a theoretical and experimental study of an array of Helmholtz resonators optimized to achieve both efficient sound absorption and diffusion. The analysis starts with a simplified 1D model where the plane wave approximation is used to design an array of resonators showing perfect absorption for a targeted range of frequencies. The absorpti...
Article
Full-text available
The acoustic behavior of 3D printed micro-lattices is investigated to assess the impact of defects induced by the Fused Deposition Modeling technique on the parameters of the equivalent fluid medium. It is shown that the manufacturing process leads to three types of non-trivial defects: elliptical filament section , filament section shrinkage and f...
Article
Full-text available
This article presents a numerical optimization procedure of continuous gradient porous layer properties to achieve perfect absorption under normal incidence. This design tool is applied on a graded porous medium composed of a periodic arrangement of ordered unit cells allowing one to link the effective acoustic properties to its geometry. The best...
Article
Full-text available
This work deals with the sound wave propagation modeling in anisotropic and heterogeneous media. The considered scattering problem involves an infinite layer of finite thickness containing an anisotropic fluid whose properties can vary along the layer depth. The specular transmission and reflection of an acoustic plane wave by such a layer is model...
Article
We theoretically, numerically, and experimentally analyze the Density-Near-Zero (DNZ) regime of a one-dimensional acoustic metamaterial. This acoustic metamaterial is composed of thin elastic plates periodically clamped in an air-filled waveguide, and the effective dynamic zero mass density is obtained from the strong dispersion around the bandgaps...
Article
Full-text available
An acoustic metadiffuser is a subwavelength locally resonant surface relying on slow sound propagation. Its design consists of rigidly backed slotted panels, with each slit being loaded by an array of Helmholtz resonators. Due to the slow sound properties, the effective thickness of the panel can therefore be dramatically reduced when compared to t...
Chapter
Acoustics metamaterials have recently revolutionized the field of acoustics and mechanics due to their extraordinary functionalities giving rise to breakthroughs in the material design strategy. This chapter discusses two types of acoustic metamaterial, both based on slow sound and critical coupling conditions, showing efficient absorption and diff...
Article
This paper presents a 3D printing technique based on stereolithography and direct light processing for the fabrication of low resonance frequency thin plates suitable for acoustic metamaterials applications. It was possible to achieve a better resolution with respect to other 3D printing methods such as fusion deposition modeling and to obtain plat...
Article
Full-text available
The unusual viscoelastic properties of silica aerogel plates are efficiently used to design subwavelength perfect sound absorbers. We theoretically, numerically, and experimentally report a perfect absorbing metamaterial panel made of periodically arranged resonant building blocks consisting of a slit loaded by a clamped aerogel plate backed by a c...
Article
Full-text available
Matrices are introduced in mathematical subjects in connection with vector spaces and linear algebra, being disconnected from their applications in other fields of science and engineering studies. The transmission of this knowledge is done, in many occasions, in a purely theoretical manner and posing problems to students that are disconnected from...
Article
Full-text available
Used as building biomaterials for centuries, cereal straws are known for their remarkable acoustic performances in sound absorption. Yet, their use as fibrous media disregards their internal structure made of nodes partitioning stems. Here, we show that such nodes can impart negative acoustic bulk modulus to straw balls when straws are cut on eithe...
Preprint
Full-text available
The unusual viscoelastic properties of silica aerogel plates are efficiently used to design subwavelength perfect sound absorbers. We theoretically, numerically and experimentally report a perfect absorbing metamaterial panel made of periodically arranged resonant building blocks consisting of a slit loaded by a clamped aerogel plate backed by a cl...
Article
Full-text available
We report the experimental design of a one-dimensional stealth acoustic material, namely a material that suppresses the acoustic scattering for a given set of incident wave vectors. The material consists of multiple scatterers, rigid diaphragms, located in an air-filled acoustic waveguide. The position of the scatterers has been chosen such that in...
Article
The finite-element time-domain method for elastic band-structure calculations is presented in this paper. The method is based on discretizing the appropriate equations of motion by finite elements, applying Bloch boundary conditions to reduce the analysis to a single unit cell, and conducting a simulation using a standard time-integration scheme. T...
Article
Full-text available
The limits of flexural wave absorption by open lossy resonators are analytically and numerically reported in this work for both the reflection and transmission problems. An experimental validation for the reflection problem is presented. The reflection and transmission of flexural waves in 1D resonant thin beams are analyzed by means of the transfe...
Preprint
Full-text available
We report the experimental design of a 1D stealth acoustic material, namely a material that suppresses the acoustic scattering for a given set of incident wave vectors. The material consists of multiple scatterers, rigid diaphragms, located in an air-filled acoustic waveguide. The position of the scatterers has been chosen such that in the Born app...
Preprint
Full-text available
The limits of flexural wave absorption by open lossy resonators are analytically and numerically reported in this work for both the reflection and transmission problems. An experimental validation for the reflection problem is presented. The reflection and transmission of flexural waves in 1D resonant thin beams are analyzed by means of the transfe...
Article
Full-text available
Broadband acoustic attenuation produced by a three dimensional (3D) locally resonant sonic crystal (LRSC), exploiting both the multiple coupled resonances and the Bragg band gaps, is numerically and experimentally reported in this work. The LRSC is made of square cross-section scatterers arranged on a square lattice and periodically incorporating b...
Article
The ability of a single piezoelectric patch with a single negative capacitance shunt for the multimodal vibration damping is used in this work to drastically reduce the acoustic radiation of a vibrating plate. With a geometry fixed, the elastic properties can be controlled using the resistance and the negative capacitance of the shunt: using a valu...
Article
Full-text available
The complex dispersion relations along the main symmetry directions of two-dimensional finite size periodic arrangements of resonant or non-resonant scatterers are recovered by using an extension of the SLaTCoW (Spatial LAplace Transform for COmplex Wavenumber) method. This method relies on the analysis of the spatial Laplace transform instead of t...