Flexible active pixel-matrix ultrafast thermal camouflage using square-wave temperature

High-sensitivity, high-resolution, and multi-band fusion detection technologies pose a great threat to military targets. Achieving instant camouflage without being detected on the rapidly changing battlefield still faces enormous challenges. Here, the flexible ultrafast thermal camouflage device with camouflage ranging from visible-to-infrared spectrum was realized using the square-wave temperature formed by the combination of the electrocaloric polymer and flexible conductor heater. The temperature change rate can reach 3.8 × 10−3 s/K, which is three orders of magnitude faster than that of just Joule heating and cooling processes in the air. The active pixel-matrix camouflage device can also achieve the targeted and differential thermal camouflage. Moreover, the flexible thermal camouflage device maintains stable performance under the bending angles ranging from 0° to 120°. The new camouflage device has a faster temperature change rate than existing thermal camouflage technologies, opening a path to using the technology for a variety of practical applications.