New microwave absorber based on flexible, lightweight and structured composite material

This study introduces a periodic structure composed of silicone foam reinforced with carbon fibers, designed as an electromagnetic absorber for microwave frequencies. This absorber, assimilated to an organic metamaterial, is fabricated using two simple methods. Firstly, the "particle-template" technique employs a sacrificial filler to create a composite with a low density of 0.33 g.cm⁻. Secondly, simple periodic structuring is achieved manually using scissors to form the metamaterial. The resulting absorber prototype, with a total thickness of 16 mm, demonstrates broadband absorption performance, maintaining a reflection coefficient (S11) below −10 dB from 4 to 18 GHz for both normal (0°) and oblique (30°) incidences of electromagnetic waves. These results validate the potential of this structured organic absorber.