Inverse design of rotating metadevice for adaptive thermal cloaking

Thermal metamaterials have been extensively studied due to their extraordinary properties beyond natural materials and offered great flexibilities to tune heat flow for desired thermal functionalities, like thermal cloaking, concentrating, rotating, etc. Whereas, the thermal properties of thermal metamaterials are usually fixed once the configuration and the constituent materials are designed and fabricated. For instance, the thermal cloaking effect may be deteriorated when background changes, which limits its practical application significantly. By deducing the effective thermal conductivities of rotating objects, we propose an adaptive thermal cloaking metadevice that is composed by three rotating layers with different roles. The joint effect of three rotating layers makes the effective thermal conductivity a real number on the reciprocity line for feasible implementation. When background changes, we only need change the angular velocities rather than change the configuration or the constituent materials to restore the cloaking effect, which is much more convenient and real-time for practical applications. The underlying physics of the rotating thermal cloak is discussed to identify the key parameters and upper and lower limits of the effective thermal conductivity for further improving the cloaking effect. The present study can trigger more rotating metadevices for novel applications beyond thermal cloaking. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Thermal metamaterials with adaptive thermal cloaking effects have been studied, allowing for changes in thermal conductivity by adjusting the angular velocities of rotating layers rather than the configuration or constituent materials. This approach improves practicality and real-time application while providing insights for enhancing thermal cloaking effects in the future.