Practical Guidance on the Additive Manufacturing of Acoustic Materials

This study draws on experiences and knowledge gained from the additive manufacturing of acoustic materials to provide a best practice guide to their design and manufacture. The emphasis is primarily on porous materials and metamaterials. 3D printing technologies enabled the creation of complex structures that otherwise could not be produced using traditional subtractive methods. Additively manufactured components are subject to various production defects which primarily originate from: layer-by-layer fabrication, the influence of post-processing and properties of the build material. These include surface roughness, poor geometric tolerances and micro-porosity of the built material. Thus, produced parts differ from the computer-aided design geometries on which they are based. These issues must be well understood and considered during the development of novel acoustic materials to provide a good match between numerical and experimental results and achieve the designed performance. Here three distinct 3D printing technologies are examined: extrusion-based FDM, resin-based MSLA and powder-based SLM. Our findings offer insights into the impact of additive manufacturing on the acoustic performance of novel materials and provide recommendations for acoustic material development.