Programmable Elastic Wave Control Via Mechanical-Acoustic Interaction in Bistable Metamaterials

Conventional elastic wave metamaterials are typically constrained by fixed structural configurations, which limits their ability to achieve reconfigurable and application-specific wave manipulation. To address this challenge, this work propose a mechanical-acoustic interaction (MAI) paradigm for mechanically programmable elastic wave control, in which acoustic functionalities are reconfigured through reversible switching between bistable mechanical states. The proposed acoustic dome metamaterial (ADM) consists of modular bistable units, where the peak and valley configurations serve as two mechanically programmable states without relying on electrical, magnetic, or thermal stimuli. By spatially encoding these bistable states, the band structure and transmission characteristics of the metamaterial can be reconfigured, enabling programmable control of elastic wave propagation, attenuation, and energy localization. Numerical and experimental results demonstrate low-frequency vibration suppression, reconfigurable waveguiding, and defect-state-enabled energy localization governed by mechanically encoded state patterns. Moreover, a one-press programming strategy is introduced to improve programming efficiency and reproducibility at the system level. These findings establish MAI as a physically intuitive and scalable mechanism for elastic wave programming, offering new opportunities for reconfigurable acoustic metamaterials and intelligent acoustic devices.