Imperial College London

Professor Sébastien Guenneau

Faculty of Natural SciencesDepartment of Mathematics

Research Associate
 
 
 
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Contact

 

s.guenneau Website

 
 
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Location

 

6m13Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

247 results found

Meng Y, Hao Y, Guenneau S, Wang S, Li Jet al., 2021, Willis coupling in water waves, NEW JOURNAL OF PHYSICS, Vol: 23, ISSN: 1367-2630

Journal article

Farhat M, Guenneau S, Chen P-Y, Alu A, Salama KNet al., 2021, Reply to "Comment on 'Scattering Cancellation-Based Cloaking for the Maxwell-Cattaneo Heat Waves'", PHYSICAL REVIEW APPLIED, Vol: 15, ISSN: 2331-7019

Journal article

Cassier M, Degiovanni T, Guenneau S, Guevara Vasquez Fet al., 2021, Active thermal cloaking and mimicking, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol: 477, ISSN: 1364-5021

We present an active cloaking method for the parabolic heat (and mass or light diffusion) equation that can hide both objects and sources. By active, we mean that it relies on designing monopole and dipole heat source distributions on the boundary of the region to be cloaked. The same technique can be used to make a source or an object look like a different one to an observer outside the cloaked region, from the perspective of thermal measurements. Our results assume a homogeneous isotropic bulk medium and require knowledge of the source to cloak or mimic, but are in most cases independent of the object to cloak.

Journal article

Guenneau S, Lombard B, Bellis C, 2021, Time-domain investigation of an external cloak for antiplane elastic waves, APPLIED PHYSICS LETTERS, Vol: 118, ISSN: 0003-6951

Journal article

Farhat M, Chen P-Y, Guenneau S, Wu Yet al., 2021, Self-dual singularity through lasing and antilasing in thin elastic plates, PHYSICAL REVIEW B, Vol: 103, ISSN: 2469-9950

Journal article

Ji Q, Chen X, Liang J, Laude V, Guenneau S, Fang G, Kadic Met al., 2021, Designing thermal energy harvesting devices with natural materials through optimized microstructures, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, Vol: 169, ISSN: 0017-9310

Journal article

Tang K, Xu C, Guenneau S, Sebbah Pet al., 2021, Pulse Dynamics of Flexural Waves in Transformed Plates, ADVANCED FUNCTIONAL MATERIALS, Vol: 31, ISSN: 1616-301X

Journal article

Gralak B, Guenneau S, 2021, Foreword, Comptes Rendus Physique, Vol: 21, Pages: 619-623, ISSN: 1631-0705

Journal article

Gralak B, Guenneau S, 2021, Foreword, Comptes Rendus Physique, Vol: 21, Pages: 311-341, ISSN: 1631-0705

Journal article

Brûlé S, Guenneau S, 2021, Past, present and future of seismic metamaterials: Experiments on soil dynamics, cloaking, large scale analogue computer and space–time modulations, Comptes Rendus Physique, Vol: 21, Pages: 767-785, ISSN: 1631-0705

Some properties of electromagnetic metamaterials have been translated, using some wave analogies, to surface seismic wave control in sedimentary soils structured at the meter scale. Two large scale experiments performed in 2012 near the French cities of Grenoble [1] and Lyon [2] have confirmed the usefulness of this methodology and its potential influence on soil-structure interaction. We present here a new perspective on the in-situ experiment near Lyon, which unveils energy corridors in the seismic lens. We further introduce a concept of time-modulated seismic metamaterial underpined by an effective model based on Willis’s equations. As a first application, we propose that ambient seismic noise time-modulates structured soils that can be viewed as moving media. In the same spirit, a design of an analogous seismic computer is proposed making use of ambient seismic noise. We recall that ancient Roman theaters and forests of trees are two examples of large scale structures that behave in a way similar to electromagnetic metamaterials: invisibility cloaks and rainbows, respectively. Seismic metamaterials can thus not only be implemented for shielding, lensing and cloaking of potentially deleterious Rayleigh waves, but they also have potential applications in energy harvesting and analogous computations using ambient seismic noise, and this opens new vistas in seismic energy harvesting and conversion through the use of natural or artificial soil structuring.

Journal article

Craster R, Diatta A, Guenneau S, Hutridurga Het al., 2021, On near-cloaking for linear elasticity, Multiscale Modeling & Simulation, Vol: 19, Pages: 633-664, ISSN: 1540-3459

We make precise some results on the cloaking of displacement fields in linear elasticity. In the spirit of transformation media theory, the transformed governing equations in Cosseratand Willis frameworks are shown to be equivalent to certain high-contrast small defect problems forthe usual Navier equations. We discuss near-cloaking for elasticity systems via a regularized transform and perform numerical experiments to illustrate our near-cloaking results. We also study thesharpness of the estimates from [H. Ammari, H. Kang, K. Kim, and H. Lee, J. Differential Equations,254 (2013), pp. 4446--4464], wherein the convergence of the solutions to the transmission problems isinvestigated, when the Lam\'e parameters in the inclusion tend to extreme values. Both soft and hardinclusion limits are studied and we also touch upon the finite frequency case. Finally, we propose anapproximate isotropic cloak algorithm for a symmetrized Cosserat cloak.

Journal article

Farhat M, Guenneau S, Chen P-Y, Wu Yet al., 2020, Parity-Time Symmetry and Exceptional Points for Flexural-Gravity Waves in Buoyant Thin-Plates, CRYSTALS, Vol: 10, ISSN: 2073-4352

Journal article

Marigo JJ, Pham K, Maurel A, Guenneau Set al., 2020, Effective model for elastic waves propagating in a substrate supporting a dense array of plates/beams with flexural resonances, Journal of the Mechanics and Physics of Solids, Vol: 143, ISSN: 0022-5096

We consider the effect of an array of plates or beams over a semi-infinite elastic ground on the propagation of elastic waves hitting the interface. The plates/beams are slender bodies with flexural resonances at low frequencies able to perturb significantly the propagation of waves in the ground. An effective model is obtained using asymptotic analysis and homogenization techniques, which can be expressed in terms of the ground alone with effective dynamic (frequency-dependent) boundary conditions of the Robin's type. For an incident plane wave at oblique incidence, the displacement fields and the reflection coefficients are obtained in closed forms and their validity is inspected by comparison with direct numerics in a two-dimensional setting.

Journal article

Makwana M, Wiltshaw R, Guenneau S, Craster Ret al., 2020, Hybrid topological guiding mechanisms for photonic crystal fibers, Optics Express, Vol: 28, Pages: 30871-30888, ISSN: 1094-4087

We create hybrid topological-photonic localisation of light by introducing concepts from the field of topological matter to that of photonic crystal fiber arrays. S-polarized obliquely propagating electromagnetic waves are guided by hexagonal, and square, lattice topological systems along an array of infinitely conducting fibers. The theory utilises perfectly periodic arrays that, in frequency space, have gapped Dirac cones producing band gaps demarcated by pronounced valleys locally imbued with a nonzero local topological quantity. These broken symmetry-induced stop-bands allow for localised guidance of electromagnetic edge-waves along the crystal fiber axis. Finite element simulations, complemented by asymptotic techniques, demonstrate the effectiveness of the proposed designs for localising energy in finite arrays in a robust manner.

Journal article

Guenneau S, Zolla F, Cherkaev E, Wellander Net al., 2020, Multiple scale method applied to homogenization of irrational metamaterials, Pages: 162-164

We adapt the multiple scale method introduced over 40 years ago for the homogenization of periodic structures [1], to the quasiperiodic (cut-and-projection) setting. We make use of partial differential operators (gradient, divergence and curl) acting on periodic functions of m variables in a higher-dimensional space that are projected onto operators acting on quasiperiodic functions in the n-dimensional physical space (mn). We replace heterogeneous quasiperiodic structures, coined irrational metamaterials in [2], by homogeneous media with anisotropic permittivity and permeability tensors, obtained from the solution of annex problems of electrostatic type in a periodic cell in higher dimensional space. This approach is valid when the wavelength is much larger than the period of the higher dimensional elementary cell.

Conference paper

Varma TV, Ungureanu B, Sarkar S, Craster R, Guenneau S, Brule Set al., 2020, The influence of structure geometry and material on seismic metamaterial performance, Publisher: arXiv

Diverting, and controlling, elastic vibrations impacting upon infrastructureis a major challenge for seismic hazard mitigation, and for the reduction ofmachine noise and vehicle vibration in the urban environment. Seismicmetamaterials (SMs), with their inherent ability to manipulate wavepropagation, provide a key route for overcoming the technological hurdlesinvolved in this challenge. Engineering the structure of the SM serves as abasis to tune and enhance its functionality, and inspired by split rings,swiss-rolls, notch-shaped and labyrinthine designs of elementary cells inelectromagnetic and mechanical metamaterials, we investigate altering thestructure geometries of SMs with the aim of creating large bandgaps\textcolor{black}{in a subwavelength regime}. We show that square stiffinclusions, perform better in comparison to circular ones, whilst keeping thesame filling fraction. En route to enhancing the bandgap, we have also studiedthe performance of SMs with different constituent materials; we find that steelcolumns, as inclusions, show large bandgaps, however, the columns are too largefor steel to be a feasible material in practical or financial terms.Non-reinforced concrete would be preferable for industry level scaling up ofthe technology because, concrete is cost-effective, easy to cast directly atthe construction site and easy to provide arbitrary geometry of the structure.As a part of this study, we show that concrete columns can also be designed toexhibit bandgaps if we cast them within a soft soil coating surrounding theprotected area for various civil structures like a bridge, building, oilpipelines etc.

Working paper

Chen Y, Kadic M, Guenneau S, Wegener Met al., 2020, Isotropic Chiral Acoustic Phonons in 3D Quasicrystalline Metamaterials, PHYSICAL REVIEW LETTERS, Vol: 124, ISSN: 0031-9007

Journal article

Farhat M, Guenneau S, Alu A, Wu Yet al., 2020, Scattering cancellation technique for acoustic spinning objects, PHYSICAL REVIEW B, Vol: 101, ISSN: 2469-9950

Journal article

Makwana M, Laforge N, Craster R, Dupont G, Guenneau S, Laude V, Kadic Met al., 2020, Experimental observations of topologically guided water waves within non-hexagonal structures, Applied Physics Letters, Vol: 116, Pages: 131603-1-131603-5, ISSN: 0003-6951

We investigate symmetry-protected topological water waves within a strategically engineered square lattice system. Thus far, symmetry-protected topological modes in hexagonal systems have primarily been studied in electromagnetism and acoustics, i.e. dispersionless media. Herein, we show experimentally how crucial geometrical properties of square structures allow for topological transport that is ordinarily forbidden within conventional hexagonal structures. We perform numerical simulations that take into account the inherent dispersion within water waves and devise a topological insulator that supports symmetry-protected transport along the domain walls. Our measurements, viewed with a high-speed camera under stroboscopic illumination, unambiguously demonstrate the valley-locked transport of water waves within a non-hexagonal structure. Due to the tunability of the energy's directionality by geometry, our results could be used for developing highly-efficient energy harvesters, filters and beam-splitters within dispersive media.

Journal article

Pham K, Maurel A, Félix S, Guenneau Set al., 2020, Hybridized love waves in a guiding layer supporting an array of plates with decorative endings, Materials, Vol: 13, Pages: 1-27

This study follows from Maurel et al., Phys. Rev. B 98, 134311 (2018), where we reported on direct numerical observations of out-of-plane shear surface waves propagating along an array of plates atop a guiding layer, as a model for a forest of trees. We derived closed form dispersion relations using the homogenization procedure and investigated the effect of heterogeneities at the top of the plates (the foliage of trees). Here, we extend the study to the derivation of a homogenized model accounting for heterogeneities at both endings of the plates. The derivation is presented in the time domain, which allows for an energetic analysis of the effective problem. The effect of these heterogeneous endings on the properties of the surface waves is inspected for hard heterogeneities. It is shown that top heterogeneities affect the resonances of the plates, hence modifying the cut-off frequencies of a wave mathematically similar to the so-called Spoof Plasmon Polariton (SPP) wave, while the bottom heterogeneities affect the behavior of the layer, hence modifying the dispersion relation of the Love waves. The complete system simply mixes these two ingredients, resulting in hybrid surface waves accurately described by our model.

Journal article

Chen Y, Frenzel T, Guenneau S, Kadic M, Wegener Met al., 2020, Mapping acoustical activity in 3D chiral mechanical metamaterials onto micropolar continuum elasticity, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, Vol: 137, ISSN: 0022-5096

Journal article

Ungureanu B, Makwana M, Craster R, Guenneau Set al., 2020, Localising symmetry protected edge waves via the topological rainbow effect, Publisher: arXiv

We combine two different fields, topological physics and metamaterials to design a topological metasurface tocontrol and redirect elastic waves. We strategically design a two-dimensional crystalline perforated elastic platethat hosts symmetry-induced topological edge states. By concurrently allowing the elastic substrate to spatiallyvary in depth, we are able to convert the incident slow wave into a series of robust modes, with differing envelopemodulations. This adiabatic transition localises the incoming energy into a concentrated region where it can thenbe damped or extracted. For larger transitions, different behaviour is observed; the incoming energy propagatesalong the interface before being partitioned into two disparate chiral beams. This “topological rainbow” effectleverages two main concepts, namely the quantum valley-Hall effect and the rainbow effect usually associatedwith electromagnetic metamaterials. The topological rainbow effect transcends specific physical systems, hence,the phenomena we describe can be transposed to other wave physics. Due to the directional tunability of theelastic energy by geometry our results have far-reaching implications for applications such as switches, filtersand energy-harvesters.

Working paper

Farhat M, Chen PY, Bagci H, Salama KN, Alù A, Guenneau Set al., 2020, Scattering theory and cancellation of gravity-flexural waves of floating plates, Physical Review B, Vol: 101, ISSN: 2469-9950

We combine theories of scattering for linearized water waves and flexural waves in thin elastic plates to characterize and achieve control of water wave scattering using floating plates. This requires manipulating a sixth-order partial differential equation with appropriate boundary conditions of the velocity potential. Making use of multipole expansions, we reduce the scattering problem to a linear algebraic system. The response of a floating plate in the quasistatic limit simplifies, considering a distinct behavior for water and flexural waves. Unlike for similar studies in electromagnetics and acoustics, scattering of gravity-flexural waves results in a nonvanishing scattering cross-section in the zero-frequency limit, dominated by its zeroth-order multipole. Potential applications lie in floating structures manipulating ocean water waves.

Journal article

Brule S, Enoch S, Guenneau S, 2020, Emergence of seismic metamaterials: Current state and future perspectives, PHYSICS LETTERS A, Vol: 384, ISSN: 0375-9601

Journal article

Kadic M, Wegener M, Nicolet A, Zolla F, Guenneau S, Diatta Aet al., 2020, Elastodynamic behavior of mechanical cloaks designed by direct lattice transformations, Wave Motion, Vol: 92, ISSN: 0165-2125

Steering waves in elastic solids is more demanding than steering waves in electromagnetism or acoustics. As a result, designing material distributions which are the counterpart of optical invisibility cloaks in elasticity poses a major challenge. Waves of all polarizations should be guided around an obstacle to emerge on the downstream side as though no obstacle were there. Recently, we have introduced the direct-lattice-transformation approach. This simple and explicit construction procedure led to extremely good cloaking results in the static case. Here, we transfer this approach to the dynamic case, i.e., to elastic waves or phonons. We demonstrate broadband reduction of scattering, with best suppressions exceeding a factor of five when using cubic coordinate transformations instead of linear ones. To reliably and quantitatively test these cloaks efficiency, we use an effective-medium approach.

Journal article

Pomot L, Payan C, Remillieux M, Guenneau Set al., 2020, Acoustic cloaking: Geometric transform, homogenization and a genetic algorithm, Wave Motion, Vol: 92, ISSN: 0165-2125

A general process is proposed to experimentally design anisotropic inhomogeneous metamaterials obtained through a change of coordinates in the Helmholtz equation. The method is applied to the case of a cylindrical transformation that allows cloaking to be performed. To approximate such complex metamaterials we apply results of the theory of homogenization and combine them with a genetic algorithm. To illustrate the power of our approach, we design three types of cloaks composed of isotropic concentric layers structured with three types of perforations: curved rectangles, split rings and crosses. These cloaks have parameters compatible with existing technology and they mimic the behavior of the transformed material. Numerical simulations have been performed to qualitatively and quantitatively study the cloaking efficiency of these metamaterials.

Journal article

Achaoui Y, Diatta A, Kadic M, Guenneau Set al., 2020, Cloaking in-plane elastic waves with swiss rolls, Materials, Vol: 13

We propose a design of cylindrical cloak for coupled in-plane shear waves consisting of concentric layers of sub-wavelength resonant stress-free inclusions shaped as Swiss rolls. The scaling factor between inclusions' sizes is according to Pendry's transform. Unlike the hitherto known situations, the present geometric transform starts from a Willis medium and further assumes that displacement fields u in original medium and u' in transformed medium remain unaffected (u' = u). This breaks the minor symmetries of the rank-4 and rank-3 tensors in theWillis equation that describe the transformed effective medium. We achieve some cloaking for a shear polarized source at specific, resonant sub-wavelength, frequencies, when it is located in close proximity to a clamped obstacle surrounded by the structured cloak. The structured medium approximating the effective medium allows for strong Willis coupling, notwithstanding potential chiral elastic effects, and thus mitigates roles ofWillis and Cosserat media in the achieved elastodynamic cloaking.

Journal article

Brule S, Enoch S, Guenneau S, 2019, Role of nanophotonics in the birth of seismic megastructures, NANOPHOTONICS, Vol: 8, Pages: 1591-1605, ISSN: 2192-8606

Journal article

Brûlé S, Enoch S, Guenneau S, 2019, Role of nanophotonics in the birth of seismic megastructures, Nanophotonics, Vol: 8, Pages: 1591-1605

The discovery of photonic crystals 30 years ago in conjunction with research advances in plasmonics and metamaterials, has inspired the concept of decameter scale metasurfaces, coined seismic metamaterials for an enhanced control of surface (Love and Rayleigh) and bulk (shear and pressure) elastodynamic waves. These powerful mathematical tools of coordinate transforms, effective medium and Floquet-Bloch theories which have revolutionized nanophotonics, can be translated in the language of civil engineering and geophysics. Experiments on seismic metamaterials made of buried elements in the soil demonstrate that the fore mentioned tools make a possible novel description of complex phenomena of soil-structure interaction during a seismic disturbance. But the concepts are already moving to more futuristic concepts and the same notions developed for structured soils are now used to examine the effects of buildings viewed as above surface resonators in megastructures such as metacities. But this perspective of future should not make us forget the heritage of the ancient peoples. Indeed, we finally point out the striking similarity between an invisible cloak design and the architecture of some ancient megastructures as the antique Gallo-Roman theaters and amphitheatres.

Journal article

Cherkaev E, Guenneau S, Hutridurga H, Wellander Net al., 2019, Quasiperiodic composites: Multiscale reiterated homogenization, Pages: X086-X088

With recent technological advances, quasiperiodic and aperiodic materials present a novel class of metamaterials that possess very unusual, extraordinary properties such as superconductivity, unusual mechanical properties and diffraction patterns, extremely low thermal conductivity, etc. As all these properties critically depend on the microgeometry of the media, the methods that allow characterizing the effective properties of such materials are of paramount importance. In this paper, we analyze the effective properties of a class of multiscale composites consisting of periodic and quasiperiodic phases appearing at different scales. We derive homogenized equations for the effective behavior of the composite and discover a variety of new effects which could have interesting applications in the control of wave and diffusion phenomena.

Conference paper

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