Reconfigurable and Phase-Engineered Acoustic Metasurfaces for Broadband Wavefront Manipulation

A novel type of phase-engineered acoustic metasurfaces with reconfigurable properties is reported, enabling the flexible broadband manipulation of reflected wavefronts. The participants of the metasurface are elements conceived to possess even-distributed reflected phases covering 2 pi span with linearity and small acoustic energy loss. The reconfigurable property of the metasurface is implemented by rearranging the fixed meta-elements based on the phase profile, which is related to the characteristic of a specific wavefront shape. The metasurface's capability is successfully demonstrated to achieve acoustic focusing and bending within the frequency range of 2300-2800 Hz, showcasing its feasibility and adaptability. To enhance its practical applications, porous materials are incorporated, leveraging the robustness of phase differences among the meta-elements to achieve high acoustic energy cancellation. Effective sound attenuation occurs within the frequency range of 1300-3100 Hz, even under wide-angle incidences ranging from -80 degrees to 80 degrees. The work paves the way for further research on reconfigurable acoustic metasurfaces in broad frequency regions and exerts favorable implications for generally applicable structures applied in multi-fields including biomedical acoustics, noise control, and so on. A novel type of phase-engineered acoustic metasurfaces composed of meta-elements with a robust phase difference is reported, enabling the flexible broadband manipulation of reflected wavefronts. This work exerts favorable implications for generally applicable structures applied in multiple scenarios including biomedical acoustics, noise control, and so on. image