MEMS micro-mirror switch for thermal emissivity control
ORAL
Abstract
Controlling infrared (IR) emissivity is of great importance for a range of applications, including radiative cooling, thermal management, and thermophotovoltaics. Future systems would benefit from systems that could allow emissivity switching over a broader spectral range. Here, we demonstrate an active high-contrast switching of emissivity in an ultrabroad 5-14 µm spectral range by combining a metasurface thermal emitter with a micro-mirror array. Upon actuation with an electrical bias the mirrors open or close, switching between low and high emissivity states. To achieve high emissivity, a metasurface multilayer structure consisting of a 70 nm ITO atop 500 µm SiO2 with an Al backreflector is used. Our FTIR measurements show that the average emissivity in the 5 to 14 µm range in ON and OFF states is ~ 0.69 and ~ 0.26, respectively. We further discuss the optical, mechanical and electrical properties of the system. Our micro-mirror integrated metasurface switches could find applications in smart windows, thermal cameras, and radiative cooling.
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Presenters
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Mozakkar Hossain
University of California, Los Angeles (UCLA); Indian Association for the Cultivation of Science, University of California, Los Angeles (UCLA)
Authors
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Mozakkar Hossain
University of California, Los Angeles (UCLA); Indian Association for the Cultivation of Science, University of California, Los Angeles (UCLA)
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Hanseong Jo
UCLA, University of California, Los Angeles (UCLA)
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Pavel Shafirin
University of California, Los Angeles, University of California, Los Angeles (UCLA)
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Artur Davoyan
University of California, Los Angeles, UCLA, University of California Los Angeles, University of California, Los Angeles (UCLA)