PerspectiveOptical Metamaterials

Metamaterials for perpetual cooling at large scales

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Science  10 Mar 2017:
Vol. 355, Issue 6329, pp. 1023-1024
DOI: 10.1126/science.aam8566

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  • Cooling power can be much improved
    • Yoshiyasu Takefuji, Professor, Keio University
    • Other Contributors:
      • Takashi Sasaki, CEO, Niigata-Techno

    During the solar radiation peak, Fig.4C shows that cooling power of the proposed method (1) dramatically decreases. It is because the volume of the hybrid metamaterial is not sufficient. Fig.S2A in the supplementary material indicates that the maximum refractive index is about 22 degree (arctangent(80cm/2/100cm)=21.8). Because of 90/21.8=4.1, overlaying five films should make less likely to become hot. Because of 22-(22*5-90)=2 degree, the near-perfect reflection can be achieved.

    1. Yao Zhai, et al., Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling, Science 355, 1062–1066 (2017)

    Competing Interests: None declared.
  • pico or peta?

    Is there a typo in the introduction: picowatts (pW) or petawatts (PW)?

    The last time I checked, there was a whole atmosphere between us and outer space ('the cold universe'), so is it right to say this is where the dumped heat is going?

    Competing Interests: None declared.