Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling.
Passive radiative cooling draws heat from surfaces and radiates it into space as infrared radiation to which the atmosphere is transparent. However, the energy density mismatch between solar irradiance and the low infrared radiation flux from a near-ambient-temperature surface requires materials that strongly emit thermal energy and barely absorb sunlight. We embedded resonant polar dielectric microspheres randomly in a polymeric matrix, resulting in a metamaterial that is fully transparent to the solar spectrum while having an infrared emissivity greater than 0.93 across the atmospheric window. When backed with a silver coating, the metamaterial shows a noontime radiative cooling power of 93 watts per square meter under direct sunshine. More critically, we demonstrated high-throughput, economical roll-to-roll manufacturing of the metamaterial, which is vital for promoting radiative cooling as a viable energy technology.
Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309, USA.
Yao
0000-0002-0224-0492
Y
Zhai
Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309, USA.
Yaoguang
0000-0002-8091-611X
Y
Ma
Materials Science and Engineering Program, University of Colorado, Boulder, CO 80309, USA.
Sabrina N
SN
David
Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309, USA.
Dongliang
D
Zhao
Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO 80309, USA.
Runnan
R
Lou
Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY 82071, USA.
Gang
G
Tan
Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309, USA. xiaobo.yin@colorado.edu ronggui.yang@colorado.edu.
Ronggui
0000-0002-3602-6945
R
Yang
Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309, USA. xiaobo.yin@colorado.edu ronggui.yang@colorado.edu.|Materials Science and Engineering Program, University of Colorado, Boulder, CO 80309, USA.
Xiaobo
0000-0002-8344-9166
X
Yin