Flexible radar-infrared compatible stealth skin metastructure based on multi-scale optimization design

In order to meet the requirements of efficient flight over wide airspace and at high speeds, morphing aircraft have been gradually emerging as a new avenue for innovative developments in aeronautical systems. With the steady progress in multi-target detection capabilities, the development of radar-infrared multi-spectral stealth-compatibility flexible skinning has become essential to ensure optimum flight performance for morphing aircraft. In this context, the study proposes a novel multi-layered design for optimization, integrating micro-structure and macro-structure. Several electromagnetic wave attenuation mechanisms have been developed by embedding nanoparticles in a PDMS matrix combined with frequency selective metasurfaces. This approach has resulted in a flexible sandwich matrix with extraordinary mechanical properties (1.66 MPa tensile strength) and an ultra-wide absorption bandwidth (25.28 GHz, Reflection loss (RL) < −10 dB). In addition, by integrating the infrared shield layer (IRSL), radar-infrared compatible stealth was achieved with an emissivity as low as 0.26. The developed multi-layer composite structure not only solves the incompatibility of radar and infrared stealth, but also demonstrates excellent flexibility in the conformations. This research provides both the theoretical basis and the technical support for the innovative development of high-speed morphing aircraft.