Acoustic metamaterials: towards practical realisations

Human exposure to noise has increased over centuries and is recognized as the second largest environmental cause of ill health in today’s Western Europe. Common sound sources - e.g. traffic and machinery noise - are low frequent (< 2 000 Hz) and the thick sound absorbing panels, which are required to efficiently absorb these sound waves, conflict with the strive towards compact and lightweight design.
Acoustic metamaterials (AMs) that target high absorption coefficients at low frequencies are omnipresent in today's academic literature. These structures are based on conventional acoustic resonators, but are geometrically modified to obtain thin and performant solutions. However, due to their complexity, AM designs are often only theoretically studied, using a variety of prediction models, or validated using small-scale samples, typically produced by additive manufacturing. To bring AMs to industrial practice, there is thus a clear need for (i) performant absorber designs, which are manufacturable by high-throughput production processes, and (ii) supporting design tools.
This project will therefore develop a versatile and computationally efficient modelling framework to predict the AMs’ performance, whilst accounting for production related limitations. Using this framework, design trade-offs will be evaluated and compact absorbing structures will be optimized, manufactured and validated. The potential of these structures will be demonstrated in selected real life applications, e.g. thin sound absorption panels for landscape offices.