Acoustic metamaterials that combine high load-bearing capacity with excellent sound absorption are urgently needed in automotive, defence, and aerospace engineering. However, integrating acoustic and mechanical performance within a single structural unit remains challenging, limiting practical applications. Inspired by the lightweight and high-strength architecture of cuttlebone, we developed a bioinspired labyrinthine metamaterial (BLM) with asymmetric walls and space-coiling channels that combines superior compressive properties with designable sound absorption. An analytical acoustic-impedance model was employed to guide the geometric optimization of the BLM. Numerical simulations and experiments confirmed a sound absorption coefficient exceeding 0.99 at 258.5 Hz with a subwavelength thickness of λ/45. The BLM also exhibited an experimental specific compressive strength of 32.97 MPa·cm³·g⁻¹, approximately 3.26 times that of a conventional labyrinthine metamaterial (CLM). Furthermore, a compact broadband design strategy was developed by partitioning the labyrinthine channel into length-graded cavities with a dual-pore configuration, achieving average sound absorption coefficients of 0.80 over 490–660 Hz and 620–810 Hz. This work provides a versatile approach to acoustic metastructures that combine high specific compressive strength with tunable low-frequency and broadband sound absorption.

Bionic Design,Acoustic Metamaterials,Low Frequency Sound Absorption,Mechanical Strength