A nanocomposite metamaterial with excellent broadband microwave absorption performance and good mechanical property

The microwave absorbers draw great attentions in addressing the electromagnetic pollution issues and the electromagnetic stealth needs. However, it remains a challenge to realize the microwave absorbers with thin thickness, broadband absorption and good mechanical properties simultaneously. Inspired by the special microstructures of papilio palinurus's wing and beetle's elytra, nanocomposite metamaterial with excellent broadband microwave absorption and good mechanical property was designed and fabricated. The Carbonyl iron-Carbon nanotubes-epoxy nanocomposites were firstly synthesized for fabricating the designed metamaterial. Slab made of the synthesized nanocomposites can realize 7.04 GHz effective absorption bandwidth (i.e., EAB, reflection loss (RL) ≤-10 dB) with thickness of 1.28 mm. Unit cell size parameters optimization of designed metamaterial was then conducted with the multi-population genetic algorithms, in which both the microwave absorption bandwidth and microwave absorption intensity were set as the optimized target. The optimized bioinspired nanocomposite metamaterial possesses 31.7 GHz EAB and −47 dB minimum RL value with thickness of only 6 mm, and its compressive strength is 33.78 MPa. The proposed bioinspired metamaterial strategy in this paper provides an efficient way for designing metamaterials with excellent broadband microwave absorption performance and good mechanical properties.