Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
Nano Lett. 2015 Feb 11;15(2):1217-21. doi: 10.1021/nl504332t. Epub 2015 Jan 28.
Although blackbody radiation described by Planck's law is commonly regarded as the maximum of thermal radiation, thermal energy transfer in the near-field can exceed the blackbody limit due to the contribution from evanescent waves. Here, we demonstrate experimentally a broadband thermal energy extraction device based on hyperbolic metamaterials that can significantly enhance near-field thermal energy transfer. The thermal extractor made from hyperbolic metamaterials does not absorb or emit any radiation but serves as a transparent pipe guiding the radiative energy from the emitter. At the same gap between an emitter and an absorber, we observe that near-field thermal energy transfer with thermal extraction can be enhanced by around 1 order of magnitude, compared to the case without thermal extraction. The novel thermal extraction scheme has important practical implications in a variety of technologies, e.g., thermophotovoltaic energy conversion, radiative cooling, thermal infrared imaging, and heat assisted magnetic recording.
尽管普朗克定律描述的黑体辐射通常被认为是热辐射的最大值，但由于消逝波的贡献，近场中的热能传递可以超过黑体极限。在这里，我们通过实验展示了一种基于双曲超材料的宽带热能量提取装置，它可以显著增强近场热能量传递。由双曲超材料制成的热提取器不吸收或发射任何辐射，而是作为一个透明的管道，从发射器引导辐射能。在发射器和吸收器之间相同的间隙下，我们观察到，与没有热提取的情况相比，带有热提取的近场热能量传递可以增强约 1 个数量级。这种新颖的热提取方案在各种技术中具有重要的实际意义，例如，热光伏能量转换、辐射冷却、热红外成像和热辅助磁记录。
