Ultrabroadband Acoustic Ventilation Barriers via Hybrid-Functional Metasurfaces

Ventilation barriers allowing simultaneous sound blocking and free airflow passage are a great chal-lenge but are necessary for particular scenarios calling for soundproofing ventilation. Previous studies using local resonance or Fano-like interference consider a narrow working range around the resonant or destructive-interference frequency. Efforts made with regard to broadband designs show a limited band-width typically smaller than half an octave. Here we conceptually propose an ultrabroadband ventilation barrier via hybridization of dissipation and interference. Confirmed by experiments, our hybrid-functional metasurface, empowered by its synergistic effect, significantly expands the range of the operating frequen-cies, enabling an effective blocking of more than 90% of incident energy in the range from 650 to 2000 Hz, while its structural thickness is only 53 mm (approximately ?/10). Our design showcases the great flex-ibility of customizing the broadband and is capable of tackling sound coming from various directions, which has potential in air-permeable yet soundproofing applications.

Automated summary

The study introduces an ultrabroadband ventilation barrier design that can effectively block over 90% of incident energy in the range of 650 to 2000 Hz with a thickness of only 53 mm. This design has the potential to handle sound coming from various directions and is capable of functioning in air-permeable yet soundproofing applications.