Bioinspired hollow heterostructure fillers for enhanced electromagnetic interference shielding in polyimide aerogels

Heterostructure fillers are crucial for enhancing the electromagnetic interference (EMI) shielding performance of composites, and the core lies in the regulation of their morphology. Inspired by the radial structures on marimo surfaces during growth, we propose a bioinspired heterostructure assembly strategy to fabricate novel marimo-like hollow spherical reduced graphene oxide (hs-rGO)@nickel-catalyzed nitrogen-doped carbon nanotubes (Ni-NCNTs) and their corresponding polyimide aerogels. Benefiting from the synergistic design of multilevel porous architectures formed by the hollow microspheres in combination with the aerogel matrix, as well as radially aligned Ni-NCNTs epitaxially grown on hs-rGO surfaces, the resulting aerogels exhibit exceptional EMI shielding effectiveness, reaching up to 68 dB. Finite element simulations further elucidate the shielding mechanisms. Additionally, these aerogels exhibit rapid, durable pressure-sensing performance due to their excellent resilience and conductivity. The multifunctional combination of high-efficiency EMI shielding and mechanical sensing highlights their promising potential in next-generation intelligent electronics, aerospace systems, and advanced communication technologies. (Figure presented.).