Lotus leaf-inspired MCMB/MnO2 superhydrophobic composite coating simultaneously boosts thermal dissipation and electromagnetic shielding for aerospace avionics

Avionics equipment often use epoxy resin as encapsulation material. However, epoxy resins have limited performance in terms of heat dissipation, electromagnetic shielding, and resistance to moisture and heat. As the integration of avionics continues to increase, epoxy resins have become more and more difficult to meet the stringent requirements for high reliability of avionics in the aerospace industry. In this study, inspired by the unique structure of lotus leaves, a thin film composite of mesophase carbon microspheres (MCMB) and manganese dioxide (MnO 2 ) was prepared on the surface of a copper foil using a mechanical hybrid spraying method. The film exhibits excellent superhydrophobicity with a water contact angle of 161.1°. This performance was attributed to its micro- and nanoscale roughness structure and low surface energy modification by POTS/stearic acid. In terms of infrared stealth, the composite material effectively suppresses thermal radiation through a trapped air layer and gradient thermal resistance design. In addition, the material’s electromagnetic shielding effectiveness in the 2.4 GHz band reaches −56 dB, originating from the synergistic effect of reflection loss in the copper substrate and dielectric absorption in MnO 2 . At the same time, the three-dimensional network constructed by the MCMBs gives the material high thermal conductivity, which significantly improves the thermal management efficiency. The composite film also has good abrasion resistance, chemical stability and self-cleaning function, which is suitable for avionics and other fields of protection, providing a new solution to solve the problem of avionics packaging.