3D printed lightweight metastructure with microwave absorption and mechanical resistance

Recently, lightweight multifunctional metastructures have attracted significant attention owing to its advantage of integrating microwave absorption and mechanical resistance. However, these features are typically entangled, and a feasible strategy for independently manipulating the microwave absorption and mechanical resistance is still lacking. Herein, a double high-impedance surface-loaded honeycomb (DHHC) is proposed, based on a theoretical analysis, and fabricated using a 3D printing technique. The impedance and surface current distribution of the DHHC were analyzed and investigated to achieve broadband microwave absorption characteristics. The structural parameters and resistances of the high-impedance surface were investigated and optimized to regulate the absorbing bandwidth and reflectivity intensity. Our experimental results indicated that a 4.25 mm thick DHHC metastructure can achieve a -10 dB absorbing bandwidth at a frequency range of 6.73-18 GHz, as well as a -15 dB absorbing band at 8.42-14.75 GHz. Moreover, the structural parameters of the honeycombs were investigated for the adjustment of stress distributions during the compression and flexural processes. Loadbearing tests indicated that the DHHC possessed a mechanical resistance with an equivalent areal density of 2.32 kg/m2. This study provides a promising route for achieving independently manipulated compatibility between microwave absorption and mechanical resistance for practical applications. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).