High contrast biphasic mechanical metamaterials for acoustic and elastic vibration mitigation

Humans are sensitive to vibrations below 20 kHz, driving the development of silencers and dampers in this range. Phononic crystals (PnCs), with periodic arrays of inclusions in a base matrix, are a promising passive control strategy. Their design focuses on achieving wide stopbands by optimizing phase contrast and geometry. The role of intra-phase connections in modifying spectral properties remains an open field of investigation. This research line focuses on the influence of material contrast and intra-phase connectivity on bandgap formation in 2D PnCs. Spectral properties are analyzed using semi-analytical finite element methods. Results show stopband width is strongly influenced by impedance contrast, and intra-phase connectivity can extend damping and silencing functionalities. These findings highlight the potential of combining material contrast and connectivity for PnC-based metadevices.