A fundamental study on the sound insulation characteristic of gyroid

Gyroid is a micro-periodic structure that has been observed in biological structural coloration such as butterfly wind scale. It reflects and interferes with light, producing vivid and complex colors. This study aims to apply this property to control sound waves. In this paper, we focused on its sound insulation characteristics, and performed a basic study through the numerical analysis and experiments. The main findings are as follows: (1) The gyroid has a significant sound insulation performance in a specific frequency range depending on its size. (2) Compressing gyroid in the incident direction further improves the performance. The gyroid samples were fabricated by additive manufacturing and their insertion loss were measured in an anechoic chamber. This result experimentally confirmed the findings explained above.