Graphene-Based Adaptive Thermal Camouflage

Date
2018
Advisor
Instructor
Source Title
Nano Letters
Print ISSN
1530-6984
Electronic ISSN
Publisher
American Chemical Society
Volume
18
Issue
7
Pages
4541 - 4548
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

In nature, adaptive coloration has been effectively utilized for concealment and signaling. Various biological mechanisms have evolved to tune the reflectivity for visible and ultraviolet light. These examples inspire many artificial systems for mimicking adaptive coloration to match the visual appearance to their surroundings. Thermal camouflage, however, has been an outstanding challenge which requires an ability to control the emitted thermal radiation from the surface. Here we report a new class of active thermal surfaces capable of efficient real-time electrical-control of thermal emission over the full infrared (IR) spectrum without changing the temperature of the surface. Our approach relies on electro-modulation of IR absorptivity and emissivity of multilayer graphene via reversible intercalation of nonvolatile ionic liquids. The demonstrated devices are light (30 g/m2), thin (<50 μm), and ultraflexible, which can conformably coat their environment. In addition, by combining active thermal surfaces with a feedback mechanism, we demonstrate realization of an adaptive thermal camouflage system which can reconfigure its thermal appearance and blend itself with the varying thermal background in a few seconds. Furthermore, we show that these devices can disguise hot objects as cold and cold ones as hot in a thermal imaging system. We anticipate that, the electrical control of thermal radiation would impact on a variety of new technologies ranging from adaptive IR optics to heat management for outer space applications.

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Book Title
Keywords
electrolyte gating, Graphene optoelectronics, Heat management, IR optics, Multilayer graphene, Reconfigurable surface, Thermal camouflage, Thermal emission, Variable emissivity
Citation
Published Version (Please cite this version)