@article{55aded23716b4d968d69b7c858dabc1c,
title = "A dual-mode textile for human body radiative heating and cooling",
abstract = "Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textile without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. Numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast.",
author = "Hsu, {Po Chun} and Chong Liu and Song, {Alex Y.} and Ze Zhang and Yucan Peng and Jin Xie and Kai Liu and Wu, {Chun Lan} and Catrysse, {Peter B.} and Lili Cai and Shang Zhai and Arun Majumdar and Shanhui Fan and Yi Cui",
note = "Funding Information: We thank K. Yan for providing the silicon dioxide powders and Z. Chen and L. Zhu for the valuable advice regarding radiative cooling and heat transfer. Funding: This work was sponsored by the Advanced Research Projects Agency-Energy, U.S. Department of Energy, under award number DE-AR0000533. The authors acknowledge the use of the Stanford Nano Shared Facilities of Stanford University for sample characterization. Author contributions: Y.C. and P.-C.H. conceived the idea. P.-C.H. and C.L. designed and conducted the thermal measurements. P.-C.H., C.L., K.L., and C.-L.W. prepared the dual-mode textile samples. P.-C.H., A.Y.S., Y.P., and L.C. conducted the FTIR spectrometry measurement. P.-C.H., P.B.C., S.Z., and A.M. constructed the heat transport model. P.-C.H., J.X., and Z.Z. performed the data fitting. P.-C.H. conducted the SEM and optical microscopy characterization. Y.C. and S.F. supervised the project. All authors contributed to the writing of the paper. Y.C. and P.-C.H. claim responsibility for all figures in the main text and the Supplementary Materials. Competing interests: Y.C., S.F., P.-C.H., A.Y.S., P.B.C., and Y.P. are authors on a patent application related to this work filed by the Board of Trustees of the Leland Stanford Junior University (application no. PCT/US2017/018420, published 24 August 2017). All other authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors. Publisher Copyright: Copyright {\textcopyright} 2017 The Authors.",
year = "2017",
doi = "10.1126/sciadv.1700895",
language = "English (US)",
volume = "3",
journal = "Science Advances",
issn = "2375-2548",
publisher = "American Association for the Advancement of Science",
number = "11",
}