Thermal camouflage based on the phase-changing material GST

Yurui Qu,Meiyan Pan,Min Qiu,Kaikai Du,Lu Cai,Pintu Ghosh,Qiang Li

doi:10.1038/s41377-018-0038-5

Abstract

Camouflage technology has attracted growing interest for many thermal applications. Previous experimental demonstrations of thermal camouflage technology have not adequately explored the ability to continuously camouflage objects either at varying background temperatures or for wide observation angles. In this study, a thermal camouflage device incorporating the phase-changing material Ge2Sb2Te5 (GST) is experimentally demonstrated. It has been shown that near-perfect thermal camouflage can be continuously achieved for background temperatures ranging from 30 °C to 50 °C by tuning the emissivity of the device, which is attained by controlling the GST phase change. The thermal camouflage is robust when the observation angle is changed from 0° to 60°. This demonstration paves the way toward dynamic thermal emission control both within the scientific field and for practical applications in thermal information.

Highlights

Camouflage technology, which has the ability to hide or disguise an object in the background[1], has attracted increasing interest for many thermal applications
Camera, Pobj is the emitted power of the object detected by the IR camera, Iobj is the spectral radiance of the object, εobj is the emissivity of the object, and [λ1, λ2] is the spectral range of the IR camera (FLIR S65: 7.5 μm–13 μm)
The radiation temperature of the object is directly related to the emitted power of the object Pobj, which is determined by the emissivity of the object, the real temperature of the object, and the spectral range of the IR camera

Summary

Introduction

Camouflage technology, which has the ability to hide or disguise an object (a person, an animal, or a piece of equipment) in the background[1], has attracted increasing interest for many thermal applications. Color camouflage is achieved by tuning light reflection or transmission to match the object’s appearance to the background in the visible or near-infrared range[2,3,4]. Many natural creatures such as cephalopods or chameleons can rapidly change their skin color to camouflage in this way[5,6]. The emitted power of the object can be tuned by manipulating the annealing time, and it can thereby be matched with that of the background at different temperatures. The radiation temperatures of the object and the background can be close enough to fool the infrared imagers

Methods

Results

Conclusion