A novel elastic dome array structure for precise pressure regulation toward tunable microwave absorption

The rapid advancements in communication technology and robotic intelligence have introduced new demands of intelligent responsiveness and proactive regulation for microwave absorbing materials. Nonetheless, the investigation into the precise regulation of the operational range for microwave absorption continues to pose a significant challenge at the present stage. To address this issue with precision, an elastic microwave absorber featuring dome array structures is meticulously fabricated in this work, which utilizes platinum-catalyzed silicone rubber (Ecoflex) as the flexible substrates and self-developed NiCo chains/CNTs-OH composites with a broad absorption bandwidth of 5.16 GHz at 1.55 mm as the fillers, respectively. As the compressive deformation increases, the macro-dome structures gradually flatten out, leading to an obvious alteration in the propagation direction of reflected microwaves. Simultaneously, the reduction in distance between the independent micro-conductive network layers facilitates the formation of new conductive pathways, which is accompanied by an enhancement in the equivalent electromagnetic parameters. Ultimately, the reflection loss peak frequency consistently shifts from 11.8 GHz to 9.4 GHz as deformation increases from 0 % to 25 %. The radar cross-section (RCS) values demonstrate a conspicuous decrease on the side equipped with the dome array structure, particularly showing further reductions within the angular ranges of 0–20°, 45–75°, 285–315° and 340–360° after experiencing compressive deformation at approximately 9.4 GHz. This research presents a novel approach to achieving finely tunable intelligent absorbing materials via pressure stimulation. This method can serve as an effective smart radar stealth solution for military equipment, such as high-speed vehicles exposed to various aerodynamic pressures.