WVO-Based Nanocavity for Adaptive Thermal Camouflage with Visual Coloration.

With the rapid advancements in optical and thermal imaging technologies, visible-compatible thermal camouflage technologies are pivotal for the survival of military devices and facilities. However, realizing adaptive thermal camouflage in dynamic scenes where the target temperature varies still remains a huge challenge in existing designs due to the limitation of insufficient ability to regulate radiative heat. Here, we proposed a visible-compatible adaptive infrared camouflage strategy employed by the WVO-based nanocavity structure to operate effectively across a wide temperature range of 30-70 °C. The adaptive camouflage is realized by the switchable selective radiation of the nanocavity structure, in which an environmentally compatible thermal radiation (∼100 W m) within the detection band is achieved, as well as the peak value of spectral emissivity within the nondetection band of 5-8 μm is switched from high (∼0.9) to low (∼0.3) as the temperature increases. With the dynamic couple of nanocavity resonance, outstanding thermal camouflage with negligible contrast (<7%) of radiative temperature between the sample and surroundings has been realized for the long-wave infrared band. Moreover, the designed camouflage coatings also demonstrate colorful appearance compatible to various surroundings. This straightforward WVO-based nanocavity structure offers a competitive strategy for visible-compatible adaptive thermal camouflage in practice.