A radiative cooling structural material

Tian Li; Yao Zhai; Shuaiming He; Wentao Gan; Zhiyuan Wei; Mohammad Heidarinejad; Daniel Dalgo; Ruiyu Mi; Xinpeng Zhao; Jianwei Song; Jiaqi Dai; Chaoji Chen; Ablimit Aili; Azhar Vellore; Ashlie Martini; Ronggui Yang; Jelena Srebric; Xiaobo Yin; Liangbing Hu

doi:10.1126/science.aau9101

A radiative cooling structural material

Science. 2019 May 24;364(6442):760-763. doi: 10.1126/science.aau9101.

Authors

Tian Li¹, Yao Zhai², Shuaiming He¹, Wentao Gan¹, Zhiyuan Wei³, Mohammad Heidarinejad⁴, Daniel Dalgo⁴, Ruiyu Mi¹, Xinpeng Zhao², Jianwei Song¹, Jiaqi Dai¹, Chaoji Chen¹, Ablimit Aili², Azhar Vellore⁵, Ashlie Martini⁵, Ronggui Yang^{2

6}, Jelena Srebric⁴, Xiaobo Yin^{7

3}, Liangbing Hu⁸

Affiliations

¹ Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA.
² Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.
³ Materials Sciences and Engineering Program, University of Colorado Boulder, Boulder, CO 80309, USA.
⁴ Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA.
⁵ Department of Mechanical Engineering, University of California, Merced, Merced, CA 95340, USA.
⁶ School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P.R. China.
⁷ Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA. binghu@umd.edu xiaobo.yin@colorado.edu.
⁸ Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA. binghu@umd.edu xiaobo.yin@colorado.edu.

PMID: 31123132
DOI: 10.1126/science.aau9101

Abstract

Reducing human reliance on energy-inefficient cooling methods such as air conditioning would have a large impact on the global energy landscape. By a process of complete delignification and densification of wood, we developed a structural material with a mechanical strength of 404.3 megapascals, more than eight times that of natural wood. The cellulose nanofibers in our engineered material backscatter solar radiation and emit strongly in mid-infrared wavelengths, resulting in continuous subambient cooling during both day and night. We model the potential impact of our cooling wood and find energy savings between 20 and 60%, which is most pronounced in hot and dry climates.