METACLOAK · Broadband cloaking and shielding of elastic waves in solids.
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2015-11-01 → 2017-10-31
- EU contribution
- €183,455
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Broadband cloaking and shielding of elastic waves in solids.
This project dealt with the control of elastic waves in solid media using the metamaterial design concepts. Metamaterials are a particular type of structured media, usually artificial, whose properties are controlled less by the microscopic structure and more by the macroscopic arrangement of resonating elements characterizing the material. Those resonators are typically sub-wavelength, i.e. of size smaller than the propagating wavelength and they are arranged over a distance that allows coupling between each other. The effective properties emerge due to specific interactions with wave fields. When this project started two years ago, it had the main goal of extending the cloaking concept (invisibility) in the field of seismic waves to conceal structures from destructive seismic waves. This was meant to be done with metamaterials, whose extraordinary wave control capacities only could deliver the correct property to build a cloak. Practically I went much further extending metamaterial wave control capacities to both large scale (seismic metamaterials) and small scale (mechanical vibrations metamaterials). From 2015, as a Marie Curie Fellow in Prof Craster’s group at Imperial College London I have developed the metamaterial concept to make practical devices to control mechanical waves across a wide range of scales from very low frequencies to very high frequencies; from: seismic waves (earthquakes) and ground vibrations (windfarms, trains, traffic and construction) all the way to nanostructures used in electronics, photonics and phononics. My research has combined theoretical and numerical modelling and state of the art supercomputing with experiments in the laboratory and in the field (for seismic waves this has been literally in a field!). In these three years, I have validated prototypes that can be further developed and applied in research, industry and the environment. This can be applied in a wide range of areas, for instance: a meta forest (a plantation of trees) that can reduce ground borne vibrations, acoustic black holes (for absorbing unwanted sound, vibrations and resonances) and resonant nano-antenna which can be used as high sensitive nano detectors.
Data: CORDIS, © European Union
Project objective
In this project we aim to develop the theory to underpin the optimal design of metamaterial devices. We will test the theory by building a metamaterial cloak which surpasses current models in its combination of elastic wave protection and cloaking capacities at frequency band much larger (~1 kHz).The design of the cloak is based on a novel metamaterial that I have co-developed, consisting of a cluster of closely spaced sub-wavelength resonators fixed to a thin plate where flexural waves propagate. The effective properties of this cloak are generated by local resonance effects and they include, besides large band gaps, negative diffraction (refraction) index, sub-wavelength energy focusing and broad scalability in the sound and infrasound frequency range. Contrary to other studies, it does not require an unrealistic composite material to be realised, or a periodic arrangement of resonant elements and hence it should have real practical impact. Two innovative applications concerning control of mechanical vibrations, and seismology are proposed. To refine the modelling, detailed numerical simulations and development of optimisation schemes are required: this will benefit enormously from interaction with several groupings at Imperial College (in Physics, Mathematics and Mechanical Engineering), highly active in elastic waves and metamaterials, that have very relevant expertise. 3D numerical simulations giving quantitative analysis of the cloak properties and performance will guide the construction of laboratory models for experimental validation. The distribution and the structure of the resonators (vertical beams with nominal section much smaller than the wavelength) are the main parameters governing the performances of the cloak. The optimisation strategies that will be implemented will fine tune the cloak within a given frequency band and/or simplify the cloak design maintaining the same performance level.
Original text from CORDIS.
Participants
- IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE · LondonCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union