3D-Printed Lightweight Metamaterial Absorber Using Rectangular Perforations

Metamaterial absorbers (MMAs) are designed to achieve near-total absorption of electromagnetic radiation. In radio-frequency fields, MMAs exhibit absorption behavior that stems from RF resonance. Thus, MMAs are useful in fields such as stealth coatings. However, the use of MMA unit cells for stealth applications is limited due to their heavy weight. In this paper, we demonstrate that a weight reduction of up to 61.31% and a 66.22% decrease in PLA volume can be achieved in a Jerusalem Cross MMA unit cell, with minimal impact on key absorptive properties such as resonant frequency and absorptivity. This was accomplished by selectively removing material from the corners and near-edge regions of the dielectric layer within the unit cell. The simulation results were verified with an array consisting of $12\times 12$ MMA unit cells, where resonant behavior was observed at 10.33 GHz with an absorptivity of 99.84%. Polylactic acid was used as the dielectric material for 3D printing, and the conductive surfaces were fabricated using silver paste. The results of this study demonstrate the feasibility of lightweight MMA designs for real-life applications.