Research on the Geometry Control and Microwave Absorption Performance of Auxetic Materials

There is great potential for the development of microwave-absorbing materials (MAMs) for structural regulation. Auxetic structures have excellent mechanical properties, which can be applied to multifunctional MAMs in various fields. Here, the microwave absorption performances of the auxetic structures were simulated using the High-Frequency Structure Simulator (HFSS), by regulating the structure, dielectric constant, layer number, and pore size. The simulation results show that increasing the dielectric constant, layer number, or decreasing pore size will lead to a decrease in the frequency of minimum reflection loss (RLmin). The main purpose of this study is to elucidate the influence of structure, dielectric constant, layer number, and pore size on the absorption performance of auxetic structures and obtain practical auxetic MAMs with a performance of RLmin < −30 dB and effective absorption bandwidth (EAB) > 3 GHz. Finally, practical auxetic MAMs between 8 and 18 GHz and MAMs optimized in dielectric constant were obtained, which were proven to have the advantages of lightweight characteristics, high absorption, and wide bandwidth. The four structures exhibit great RLmin values of −51.09, −55.52, −47.09, and −54.98 dB with wide EAB values of 3.25, 3, 4.75, and 4.5 GHz, demonstrating the strong electromagnetic wave absorption performance of auxetic structures. This work provides theoretical guidance for the study of auxetic structures in the field of microwave absorption and provides an effective approach for multi-disciplinary research on MAMs.