Today, acoustic metamaterials form a core area of metamaterial research. They offer bespoke wave control, achievable through their rationally designed structure and are at the forefront of metamaterial applications and commercialisation. They find purpose across science and defence sectors in wave filtering, sensing, communications, energy harvesting, thermal emission control, and aeroacoustics, to name but a few. They enjoy success in metropolitan environments with designer audio and noise mitigation falling within their remit; acoustic metamaterial technologies are already penetrating the market across audio and healthcare sectors.

The landscape of acoustic metamaterial research is continually expanding, now incorporating several wave regimes under a broader definition that we adopt here. The diversity of acoustic metamaterial research displays how they exist not only to translate electromagnetic phenomena, but also to provide a unique platform for exploring all metamaterial physics, and for solving key societal challenges.

The aim of this Roadmap is to present a summary of the state of acoustic metamaterial research and innovation in 2024, with opinions on the challenges and future opportunities from a group of renown experts, covering key interdisciplinary areas from fundamental acoustics to device implementation.