Additive manufacturing of membrane-type acoustic metamaterials

Traditional membrane-type acoustic metamaterials have been proven to act as effective lightweight sound insulation materials. However, their geometries cannot be easily incorporated into other acoustic designs in a single workflow. Here, we leverage the enhanced customizability that additive manufacturing provides by introducing 3D printed membrane-type metamaterials that can one day be seamlessly incorporated into a variety of acoustic designs without the need for post-processing. In this study, we present the fabrication workflow to 3D print membranes of varying thicknesses and offer an analysis on print quality. Using a four-microphone normal-incidence impedance tube, we provide preliminary results on the sound transmission loss behavior of these membrane-type metamaterials. Our results show the membranes are fabricated without any significant holes or gaps, and their thicknesses can be reliably controlled.