3D-Printed Biomimetic Sponge-Based Broadband and Highly Efficient Terahertz Absorber

With the rapid advancement of terahertz technology, electromagnetic interference has become a critical issue that compromises device performance, creating an urgent demand for high-performance terahertz absorbers. Three-dimensional (3D) printing, characterized by flexible structural design, monolithic fabrication, and mold-free processing, has emerged as a promising technique for producing terahertz absorbers. In this work, inspired by the structural and functional characteristics of deep-sea sponges, we propose a bioinspired absorber design that integrates a porous topology with 3D printing. By optimizing the rotation angle and the hollowed array, the absorber establishes multiple internal reflection paths, which, combined with the structural matrix and the graphene conductive coating, enable highly efficient dissipation of electromagnetic energy. Experimental results show that the fabricated sample achieves an absorptivity exceeding 99% over the 0.5–2.0 THz frequency range, while also exhibiting wide-angle absorption and polarization-insensitive performance. The influence of pore size and graphene concentration on the absorption properties is systematically revealed. This work further enhances the performance of 3D-printed terahertz absorbers and provides a novel technical pathway for the design and fabrication of high-performance terahertz absorbers.