Black-hole-inspired thermal trapping with graded heat-conduction metadevices

Liujun Xu; Jinrong Liu; Peng Jin; Guoqiang Xu; Jiaxin Li; Xiaoping Ouyang; Ying Li; Cheng-Wei Qiu; Jiping Huang

doi:10.1093/nsr/nwac159

Black-hole-inspired thermal trapping with graded heat-conduction metadevices

Natl Sci Rev. 2022 Aug 16;10(2):nwac159. doi: 10.1093/nsr/nwac159. eCollection 2023 Feb.

Authors

Liujun Xu^{1

2

3}, Jinrong Liu¹, Peng Jin¹, Guoqiang Xu², Jiaxin Li², Xiaoping Ouyang⁴, Ying Li^{5

6}, Cheng-Wei Qiu², Jiping Huang¹

Affiliations

¹ Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai 200438, China.
² Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore.
³ Graduate School of China Academy of Engineering Physics, Beijing 100193, China.
⁴ School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
⁵ Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310027, China.
⁶ International Joint Innovation Center, Key Laboratory of Advanced Micro/Nano Electronic Devices and Smart Systems of Zhejiang, The Electromagnetics Academy of Zhejiang University, Zhejiang University, Haining 314400, China.

Abstract

The curved space-time produced by black holes leads to the intriguing trapping effect. So far, metadevices have enabled analogous black holes to trap light or sound in laboratory spacetime. However, trapping heat in a conductive environment is still challenging because diffusive behaviors are directionless. Inspired by black holes, we construct graded heat-conduction metadevices to achieve thermal trapping, resorting to the imitated advection produced by graded thermal conductivities rather than the trivial solution of using insulation materials to confine thermal diffusion. We experimentally demonstrate thermal trapping for guiding hot spots to diffuse towards the center. Graded heat-conduction metadevices have advantages in energy-efficient thermal regulation because the imitated advection has a similar temperature field effect to the realistic advection that is usually driven by external energy sources. These results also provide an insight into correlating transformation thermotics with other disciplines, such as cosmology, for emerging heat control schemes.

Keywords: graded metadevices; imitated advection; thermal trapping.