MEMS approach to low-frequency broadband acoustic metamaterials

We experimentally demonstrate a simple micro-electro-mechnical systems (MEMS) approach to acoustic metamaterials and have observed the average increase of nearly 6 dB beyond the classic law for sound attenuation at low frequencies from 200 Hz to 1200 Hz. Here, we have also found that the MEMS metastructure, especially the cavity-backed micromembrane, contributes to 22.3% gain of sound transmission loss (STL) with a fill factor of perforation of less than 7.6%.