Roll‑to‑roll micro‑embossed carbonyl‑iron powder doped composite films with large‑area superhydrophobicity and microwave absorption

• A large-area superhydrophobic, wave-absorbing film based on micropatterned CIP doped PDMS was proposed. • The sedimentation of CIP during micro embossing process of the composite resin was explored. • Optimization of the static pre-curing was studied with the aim of improving wave-absorbing performance. • Large-area micropatterned CIP-doped PDMS film was achieved by roll-to-roll micro embossing process. Superhydrophobic, wave-absorbing multifunctional films hold considerable potential in the domains of anti-icing and stealth technology for unmanned aerial vehicles. However, existing multifunctional materials face limitations such as high energy consumption and the challenge of large-scale preparation. To address this problem, a large-area superhydrophobic, wave-absorbing multifunctional film made of carbonyl iron powder (CIP) doped poly(dimethylsiloxane) resin was proposed. The sedimentation behaviour of CIP within the resin during the micro-embossing process was explored, and effect of CIP dispersion on wave-absorbing performance was further studied. Furthermore, the static pre-curing step was optimized to improve CIP dispersion, thereby enhancing the hydrophobic and wave-absorbing performance. A large-area micropatterned CIP-doped composite film was achieved by employing a roll-to-roll micro embossing process. The film was demonstrated to exhibit a peak loss of −12.6 dB, an effective absorption bandwidth of 3.1 GHz, a water contact angle of 150.1°, a sliding angle of 9.6° and also excellent mechanical durability. The findings provide a technically feasible solution for the preparation of large-area superhydrophobic and wave-absorbing films, with application prospects in anti-icing and stealth technology.