Acoustic band structures of Architectured Materials based on Triply Periodic Minimal Surfaces

Acoustic metamaterials with unusual properties have attracted much attention owing to their capability in controlling sound propagation. In this work, the acoustic properties of polymethyl methacrylate (PMMA) material based triply periodic minimal surfaces (TPMS), including Schoen’s F-RD, Gyroid, and Fischer-Koch S surfaces are numerically studied. The simulation results show that these three different TPMS lattices have multiple bandgaps in the frequency range between 200 and 2000 Hz. In the sub-700 Hz frequency range, they commonly have a bandgap with a central frequency of nearly 500 Hz and a bandwidth of nearly 400 Hz. However, in the higher frequency range between 800 Hz and 2000 Hz, the bandwidths of bandgaps are much different from one structure to the other. For example, the Fischer-Koch S-TPMS lattice shows the widest bandgap with a bandwidth of more than 200-Hz, but the F-RD TPMS lattice shows the narrowest bandgaps with a bandwidth of less than 50-Hz. This study is potentially applicable for low-frequency sound attenuation applications.