Thermal transport in 2D nanophononic metamaterials embedded with cylindrical arrays

The development of nanophononic metamaterials presents new opportunities for controlling thermal conduction. Using the theory of elasticity and the finite element method, we systematically investigated the thermal conductance of two-dimensional nanophononic metamaterials embedded with cylindrical arrays. When the sound speed of the embedded material is higher than matrix, there is a weak correlation between structural parameters and thermal conductance. However, when the nanophononic metamaterials are embedded with lower sound speed materials, they exhibit clear local resonances. The local resonance frequency can move to a higher or lower range depending on the filler radius. Local resonances reduce group velocity but greatly increase the phonon density of states, contributing to an increase in thermal conductance. Furthermore, this conclusion applies to nanophononic metamaterials with different matrix materials.