Thermal infrared camouflage technology has attracted increasing attention with the progress of infrared surveillance technologies.Inspired by honeycombs,a thermal infrared camouflage film with honeycomb sandwich structure based on fluid and temperature control is proposed to cloak objects and display false targets in the thermal infrared spectrum.The structure and manufacturing method of the film are introduced,and the fluid and temperature control system is established and tested to explore the thermal infrared characteristics of the film composed of different thermal units.The camouflage performance of the film is intuitively displayed through the temperature frequency histograms of the infrared images photographed by an infrared camera.The temperature control accuracy of the thermal infrared camouflage system and the dynamic camouflage response of the film are evaluated by the temperature distribution map of each pixel in infrared images and the salient degree values.Furthermore,the influential factors on the camouflage responding time are investigated,including the heating and cooling time of the liquid,the flow rate of pumps inside the driving module,and the energy loss along the liquid lines.An application of displaying false target is also introduced and tested.The results show that the camouflage film has a well camouflage effect and a wide adjustment temperature range,showing promise for a broad range of potential applications,such as counter-surveillance,thermal control and heat shielding.
Lujia LiHuanhuan LiGang KouDafeng YangWei HuJinghui PengSongjing Li
Natural organisms have different techniques to avoid enemies,such as chameleon skin with innate camouflage ability to change with the surrounding environment.Inspired by this,a microfluidic biomimetic chameleon skin based on infrared(IR)information processing is proposed for active thermal camouflage in a dynamic infrared background.Microfluidic circulation in microcavities distributed under the skin is controlled by a thermal camouflage system.The structure and working principle of the biomimetic skin are introduced,and the thermal camouflage system is established and tested to explore the heat transfer characteristics between the skin and the fluid.The mechanism of collecting the background infrared information and regulating the skin temperature through the control signal generated by the infrared information processing system is illustrated.Furthermore,the dynamic thermal response of the skin is tested when transitioning between different temperature backgrounds,modeling the ambient temperature of the sand,woodland and lakes where chameleons live.The performance of the skin is evaluated by measuring the camouflage responding time of the skin to an external heat source.The results show that the chameleon biomimetic skin is naturally transitioned and matched by infrared information processing and microfluidics.The limitation that the conventional thermal camouflage technology cannot adapt to the dynamic combat environment is overcome and the weaknesses of a small camouflage band range and a single form of camouflage are resolved in this study,thus effectively improving the target’s survivability in combat.
