Temperature-dependent switchable thermal bifunctions in different diamond-shaped devices

The different temperature-dependent switchable thermal devices are designed in this paper, which can automatically realize the switchable thermal concentrating or cloaking functions at different temperature intervals. Based on the temperature-dependent transformation thermotics, we first theoretically derive the material parameters of the diamond-shaped switchable thermal concentrators and cloaks in the transformed space, thus achieving the construction of the mathematical models of temperature-dependent switchable thermal concentrators and cloaks. Then, we further integrate the switchable thermal concentrating and cloaking functions described above into a single device to construct the path-dependent switchable devices, which can intelligently control the thermal concentrating and cloaking functions along different axes simultaneously as the temperature changes. Finally, the temperature-dependent properties of the switchable thermal concentrators, cloaks and path-dependent devices are validated numerically. The results show that the switchable thermal concentrators, cloaks, and path-dependent devices can perfectly realize the thermal concentrating, cloaking, and x-directional concentrating and y-directional cloaking functions at specific different temperature intervals, respectively. Once the specific temperature intervals have changed, the thermal bifunctions described above are turned off automatically. The temperature-dependent switchable properties can also be extended to other physical fields to design the intelligent multi-physical metadevices.