Bamboo-inspired composite metastructure for broadband microwave absorption and load bearing

Microwave absorbing structures that can simultaneously cope with the complex electromagnetic and physical environments have become indispensable in contemporary stealth technology. Herein, a bamboo-inspired composite metastructure with integrated functions of broadband electromagnetic microwave absorption and mechanical load bearing is designed and investigated by 3D printing technology with lossy magnetic composite. By integrating the benefits of gradient structure design in both microwave absorption and mechanical load bearing areas, structural optimization and experimental demonstration are conducted to simultaneously achieve a range of -10 dB microwave absorption from 3.2 GHz to 40 GHz, a -15 dB absorption bandwidth in 4.2-5.23 GHz and 6.9-40 GHz, and an average compressive yield stress of 13.27 MPa. Furthermore, this metastructure also exhibits broadband microwave absorption at wide incident angles for different polarizations of transverse electric and transverse magnetic modes. These results indicate that the integrated functional design facilitates practical engineering applications in severe service environments for stealth technology.