In recent years, the study and design of novel materials with unconventional and advanced vibrational properties, often referred to as mechanical metamaterials, has opened up new research roadmaps in the field of phononics due to their unique possibilities to control elastic waves. In a broad sense, these materials are heterogeneous media with various types of periodicity at different structural organization levels (from nano- to macro-scale). The structural periodicity, rather than material composition, governs the overall dynamic properties, leading to exotic physical properties, such as negative refraction, stop-band filtering, cloaking, energy harvesting etc., unachievable using continuous materials or traditional composites. In parallel, recent advances in material science and technology have allowed the realization of a huge variety of metamaterials operating at very different frequency scales, leading to novel application proposals in the field of wave control, focusing and collimation, environmental noise reduction, or even earthquake protection. The fast growth of the topic and expanded interest in the field from researchers with expertise in the areas of acoustic and elastic waves, composite materials, material science, and related fields, provide the main motive for the publication of a Research Topic of Frontiers of Materials on the topic. Contributions will address the dynamics of mechanical metamaterials, comprising phononic crystals with direction-dependent frequency bands caused by Bragg scattering and acoustic/elastic metamaterials with the additional feature of local resonance giving rise to sub-wavelength phenomena. This Research Topic is intended to provide a platform for researchers working in the field of metamaterials to disseminate their ideas on the design and characterization of new configurations, highlighting novel dynamic phenomena and exploring additional promising applications. The Research Topic should also stimulate a cross-fertilization between researchers of the field with other readers of the journal, providing a rapidly growing discipline with an opportunity to find new potential fields of application.
In recent years, the study and design of novel materials with unconventional and advanced vibrational properties, often referred to as mechanical metamaterials, has opened up new research roadmaps in the field of phononics due to their unique possibilities to control elastic waves. In a broad sense, these materials are heterogeneous media with various types of periodicity at different structural organization levels (from nano- to macro-scale). The structural periodicity, rather than material composition, governs the overall dynamic properties, leading to exotic physical properties, such as negative refraction, stop-band filtering, cloaking, energy harvesting etc., unachievable using continuous materials or traditional composites. In parallel, recent advances in material science and technology have allowed the realization of a huge variety of metamaterials operating at very different frequency scales, leading to novel application proposals in the field of wave control, focusing and collimation, environmental noise reduction, or even earthquake protection. The fast growth of the topic and expanded interest in the field from researchers with expertise in the areas of acoustic and elastic waves, composite materials, material science, and related fields, provide the main motive for the publication of a Research Topic of Frontiers of Materials on the topic. Contributions will address the dynamics of mechanical metamaterials, comprising phononic crystals with direction-dependent frequency bands caused by Bragg scattering and acoustic/elastic metamaterials with the additional feature of local resonance giving rise to sub-wavelength phenomena. This Research Topic is intended to provide a platform for researchers working in the field of metamaterials to disseminate their ideas on the design and characterization of new configurations, highlighting novel dynamic phenomena and exploring additional promising applications. The Research Topic should also stimulate a cross-fertilization between researchers of the field with other readers of the journal, providing a rapidly growing discipline with an opportunity to find new potential fields of application.
