Heat flux concentrators based on nanoscale phononic metastructures.

In recent years, nanoscale heat flux regulation has been at the forefront of research. Nanoscale heat flux concentration is of potential importance in various applications, but no research has been conducted on local heat flux concentration. In this paper, we designed two heat flux concentrators using patterned amorphous and nanomesh structures, respectively. Using molecular dynamics simulation, we find that the heat flux in the central regions is much higher than that in the adjacent regions, with the concentration ratio arriving at 9-fold. Thus a heat flux concentrator is realized using these nanophononic metastructures. The phonon localization theory was used to explain the underlying mechanism. This work provides a direct design strategy for thermal concentrators using practical nanofabrication technologies.