Temperature-dependent sound absorption characteristics of geometrically regular microlattice materials

With the development of micro and nanotechnology, multilayer microlattice plates with geometrical regularity can be precisely designed and fabricated and have demonstrated applications in sound absorption as novel acoustic metamaterials. In this paper, temperature-dependent sound absorption characteristics of microlattice materials were studied through theory, simulation, and experiment. A semi-theoretical model based on our improved transfer matrix method was developed and validated by numerical simulation and experimental implementation. The results indicate that the microlattice materials could provide enhanced sound absorption performance in both low and broadband frequency ranges compared to conventional irregular porous absorbers. Furthermore, the sound absorption mechanism and temperature effect by the distributions of sound pressure, particle velocity, temperature change, and thermal-viscous power dissipation density were investigated. Finally, the effect of geometric parameters of microlattice materials was studied, and the configuration for optimal sound absorption was found. Importantly, in contrast to conventional absorbers whose sound absorption degrades with temperature, that of microlattice materials at high temperatures is not reduced but rather enhanced by appropriately tuning the geometrical configuration, and thus better meets the requirements of high-temperature applications. This work is helpful for the design and development of acoustic metamaterials for high-temperature purposes.