LAUSR

Abstract Industrial sound barriers are designed to reduce the sound pressure (dB) on the other side of the barriers while maintaining the structural strength. Conventionally, the noise barriers are made of concrete, steel, vinyl, wood or earth mounds. In this article, alternatively, a metamaterial wall (MetaWall) is proposed for the industrial sound isolation walls. Proposed MetaWall is to achieve three principal objectives, (1) provide enhanced sound isolation capability, higher than the state of the art technologies, (2) maintain the required structural strength by design and (3) potentially use the isolated abundant noise by transforming the acoustic energy into usable electrical energy, simultaneously. Acoustic metamaterials are traditionally reported for guiding and isolating acoustic and elastic waves. In a recent report, energy harvesting using Acousto-Elastic Sonic Crystal (AESC) is proposed by trapping the wave energy inside the crystal. In this article, wave isolation and energy harvesting capabilities are fused to propose MetaWall unit bricks as an industrial building material, which is made of rubber-metal-concrete composite. A prototype of the MetaWall is designed, built, tested and analyzed by accommodating 16-unit AESC cells in a MetaWall brick. It has been found that around 60% of original acoustic energy can be filtered using the proposed MetaWall, which is higher than the state of the art methods. Next, a pair of smart materials is methodically placed in the AESC to recover/transfer the filtered acoustic energy into electric potential. A numerical study shows that the designed MetaWall prototype is capable of generating up to ∼2 mW of power against 10KΩ resistive load depending on the type of smart material used in the AESC composite while maintaining compressive strength greater than the minimum required strength 5 MPa.