Multifunctional Hydrogels with Broadband Electromagnetic Interference Shielding and Infrared Stealth Performance in Harsh Environments with Low Conductive Filler Content

within the hydrogel system led to a 3-fold enhancement in mechanical properties, 20-dB improvement in EMI shielding effectiveness, and 40% enhancement in the gauge factor with only 0.12 wt % conductive filler. Benefiting from its high conductivity, efficient thermal insulation, and composite network structure, the double network hydrogels maintain stable EMI shielding and infrared stealth performance under various harsh conditions including repeated stretching, prolonged water evaporation, low-temperature freezing, high-temperature heating, alcohol lamp flame exposure, and high-strain stretching. These findings demonstrate that the hydrogels combine ultra-low filler efficiency, environmental robustness, and multifunctional adaptability, making it a promising candidate for next-generation aerospace, military, and wearable electronic applications.