Shortwave‐Infrared Electrochromic Covalent Organic Frameworks for Active Dynamic Camouflage and Steganography

Abstract Covalent Organic Frameworks (COFs) have demonstrated significant potential in the precise design and application of stimulus‐responsive materials. Here, the design of two shortwave infrared (SWIR) electrochromic COFs with monomer‐regulated responsive wavelengths is reported for dynamic camouflage and steganography. Upon voltage stimulation, well‐designed 1100‐COF _TPDA‐TPB and 1500‐COF _TPDA‐TFPy exhibit electrochromic effects peaking at ≈1100 and 1500 nm, allowing them to be “seen” by silicon‐based (Si‐based) and InGaAs SWIR sensors, respectively. Leveraging the active modulation capabilities of the SWIR electrochromic COFs, the dynamic camouflage of objects against the SWIR view, adapting to the environmental grayscale. Furthermore, exploiting the inherent concealment and penetrability of SWIR light enables the development of portable and wearable covert information‐conveying steganography devices for discreet communication. This work represents a creative advancement in the construction of wavelength‐modulable SWIR electrochromic COFs and devices, highlighting their immense value in dynamic camouflage and steganography applications.