Lightweight, ultra-broadband SiOC-based triply periodic minimal surface meta-structures for electromagnetic absorption

Lightweight wide-band ceramic-based electromagnetic (EM) absorbers have a great application demand in the field of high-temperature EM wave absorption. However, it is difficult for traditional ceramic-based structural EM absorbing materials (EMAMs) to balance the contradiction between broadband absorption and good impedance matching due to resonance effect. Herein, three novel non-resonant SiOC-based triply periodic minimal surface (TPMS) meta-structures named Schoen G (SG), Schwarz D (SD) and Schwarz P (SP) with a density of 0.556 g/cm3 were successfully synthesized by digital light processing (DLP) 3D printing and polymer-derived ceramics (PDCs) method. Through the structural design of multilayer arrays and holes, three metamaterials achieve good impedance matching and broadband EM absorption. The effective absorption bandwidth (EAB) of all three meta-structures reaches 9.80 GHz (8.2–18.0 GHz) in a wide matching thickness range, covering the entire X-Ku band. In addition, the minimum reflection loss (RLmin) of −55.68 dB is obtained at a matching thickness of 3.02 mm for SD meta-structure in X-band. Besides, the SG meta-structure tested by the arch method has an ultra-wide EAB of 11.88 GHz (6.12–18.0 GHz), exhibiting ultra-broadband EM absorption properties. It is significant that the intrinsic relationships between TPMS meta-structures and EM responses are explored by CST simulation. This work provides a new perspective for the design of lightweight, broadband ceramic-based EM metamaterial absorbers under high-temperature, harsh environments.