Macroscopic thermal diode with stable rectification ratio by thermal null medium
Hongtao Dai, Fei Sun, Hanchuan Chen, Yichao Liu, Yibiao Yang, Zhihui Chen, Shaowei Liang, Zheng Wang
Abstract
Thermal diode can achieve a unidirectional and irreversible thermal transport, which can be used for direction-selective thermal management. Here we demonstrate a macroscopic thermal diode by asymmetrically embedding staggered structure of copper and expanded polystyrene sheets in stainless steel background, which can achieve a stable high thermal rectification ratio at room temperature. For the fabricated samples measured here, we observe a nearly constant thermal rectification ratio ∼1.6 at room temperature, when the temperature bias applied on both sides changes from 25 K to 50 K or the input heat power changes from 10 W to 15 W. In contrast to the conventional methods, this approach provides a new way to design macroscopic thermal diode with a stable thermal rectification effect at room temperature, which opens up new possibilities for macroscopic heat preservation, energy-saving buildings, and direction-selective thermal camouflages.