Periodic Reporting for period 3 - BOHEME (Bio-Inspired Hierarchical MetaMaterials)
Reporting period: 2023-01-01 to 2024-06-30
BOHEME’s ambitious goal is to design and realise a new class of bioinspired mechanical metamaterials for novel applicative tools in diverse technological fields. Metamaterials exhibit exotic vibrational properties currently unavailable in Nature, and numerous important applications are emerging. However, universally valid design criteria are currently lacking, and their effectiveness is presently restricted to limited frequency ranges. BOHEME starts from an innovative assumption, increasingly supported by experimental evidence, that the working principle behind metamaterials is already exploited in Nature, and that through evolution, this has given rise to optimised designs for impact damping and other wave manipulation purposes.
From the perspective of basic science, the project aims to explore biological structural materials for evidence of this, to investigate novel optimised bio inspired designs (e.g. porous hierarchical structures spanning various length scales,cochlea-inspired spirals that select sound frequencies, spider web-inspired frames that attenuate vibrations) using state-of-the-art analytical and numerical approaches, to design and manufacture vibrationally effective structures, and to experimentally verify their performance over wide frequency ranges.
From the point of view of applications, BOHEME has addressed technological sectors over various wavelength scales, from low-frequency vibration control (such as vibrations generated by trains), to noise abatement (e.g. in MRI scanners), to nondestructive testing using “acoustic lenses”, to resonating floater arrays to protect against coastal erosion from ocean waves. Industrial partners have been involved in proof of principle experiments and development of prototypes, which will hopefully be further developed and brought to the commercialization stage.
From the perspective of basic science, the project aims to explore biological structural materials for evidence of this, to investigate novel optimised bio inspired designs (e.g. porous hierarchical structures spanning various length scales,cochlea-inspired spirals that select sound frequencies, spider web-inspired frames that attenuate vibrations) using state-of-the-art analytical and numerical approaches, to design and manufacture vibrationally effective structures, and to experimentally verify their performance over wide frequency ranges.
From the point of view of applications, BOHEME has addressed technological sectors over various wavelength scales, from low-frequency vibration control (such as vibrations generated by trains), to noise abatement (e.g. in MRI scanners), to nondestructive testing using “acoustic lenses”, to resonating floater arrays to protect against coastal erosion from ocean waves. Industrial partners have been involved in proof of principle experiments and development of prototypes, which will hopefully be further developed and brought to the commercialization stage.
In the final 18 months, the project has exploited theoretical and numerical tools and bioinspired design developed in the first 36 monts to implement them in the selected application areas.
In large scale applications, the main result has been the design, fabrication and in-field validation of a buried metamaterial-based barrier for low frequency vibration attenuation (e.g. vibrations from railways). This demonstrator has been tested and good attenuation results have been achieved in the 20-50 Hz range. An EIC Transition proposal based on the FET Innovation Launchpad “BIOMETARAIL” project has been submitted based on these results (unsuccessfully), and a modified version will be resubmitted at the end of BOHEME project.
In acoustics, the main results have been the realization of full-scale demonstrators for efficient sound absorption based on hierarchical metamaterials, proving their potential to inhibit acoustic wave propagation. The first is a a sound absorption panel based on a hierarchical labyrinthine rainbow design aimed at low frequency noise ; the second is a prototype for a metamaterial-based noise insulating layer to be installed in MRI scanners. An EIC transition proposal based on this prototype and on its commercialization strategy, outlined in the FET Innovation Launchpad (“SILENCE”), is under preparation.
In terms of sernsing applications, spider-web or cochlea-inspired metasensors emerging from numerical optimization procedures have been fabricated and tested. Also, novel defect or impact localization procedures for NDT, based on spider-web inspired structures or on modal analysis have been developed.
In water wave applications, extensive numerical studies and testing in a wave tank facility have proved the effectiveness of an array of submerged inverted pendula (“Metareef”), which has been patented by some of the project participants. .
Overall, results have led to about 118 publications in international journals, including Nature Communications and Advanced Functional Materials, which have been disseminated in various seminars and presentations. A patent application has already been submitted by one of the industrial partners on a related application.
In large scale applications, the main result has been the design, fabrication and in-field validation of a buried metamaterial-based barrier for low frequency vibration attenuation (e.g. vibrations from railways). This demonstrator has been tested and good attenuation results have been achieved in the 20-50 Hz range. An EIC Transition proposal based on the FET Innovation Launchpad “BIOMETARAIL” project has been submitted based on these results (unsuccessfully), and a modified version will be resubmitted at the end of BOHEME project.
In acoustics, the main results have been the realization of full-scale demonstrators for efficient sound absorption based on hierarchical metamaterials, proving their potential to inhibit acoustic wave propagation. The first is a a sound absorption panel based on a hierarchical labyrinthine rainbow design aimed at low frequency noise ; the second is a prototype for a metamaterial-based noise insulating layer to be installed in MRI scanners. An EIC transition proposal based on this prototype and on its commercialization strategy, outlined in the FET Innovation Launchpad (“SILENCE”), is under preparation.
In terms of sernsing applications, spider-web or cochlea-inspired metasensors emerging from numerical optimization procedures have been fabricated and tested. Also, novel defect or impact localization procedures for NDT, based on spider-web inspired structures or on modal analysis have been developed.
In water wave applications, extensive numerical studies and testing in a wave tank facility have proved the effectiveness of an array of submerged inverted pendula (“Metareef”), which has been patented by some of the project participants. .
Overall, results have led to about 118 publications in international journals, including Nature Communications and Advanced Functional Materials, which have been disseminated in various seminars and presentations. A patent application has already been submitted by one of the industrial partners on a related application.
Progress beyond the state of the art in BOHEME has been the generation of optimised metamaterials that are effective in multiple frequency ranges, include multifunctionality (e.g. useful static as well as dynamic properties), additional functionality such as tunability, and are based on systematic bioinspired design criteria, which can be exploited in applications at multiple size scales. Impacts include designs enabling improved low-frequency vibration control (including from transport infrastructure like trains), noise abatement (focusing on the caser of MRI scanners), nondestructive testing, coastal protection from ocean waves. Exploitation of the project results will be delivered by the two participating SMEs, in future commercial projects, contributing also to the EU sustainable development goals 9 (Innovation and Infrastructure) and 11 (Sustainable cities and communities).