A multi-materials 3D-printed continuous conductive fibre-based metamaterial for broadband microwave absorption

Electromagnetic pollution and military stealth technique have raised tremendous interest in high-performance microwave-absorbing structures. However, an ultra-broadband absorbing functional structure is still in urgent demand. Herein, a novel continuous conductive fibre-based absorbing metamaterial was successfully designed and fabricated by multi-materials hybrid 3D printing technique. Benefitting from the highly symmetric structured design of a super unit cell and appropriate conductive property of continuous fibre, the absorbing metamaterial is demonstrated to have an ultra-wide band microwave absorption and polarisation insensitivity. Furthermore, the thickness of the proposed metamaterial is only 3.2 mm of 0.085λmax. In the wave absorption test, the metamaterial shows a broadband absorption of 8–18.1 GHz (greater than 90%) and maintains a good absorption effect at an incident angle of 40°. The design and fabrication method of the continuous fibre-absorbing metamaterial provides a new idea for the realisation of the integrated bearing and absorbing metamaterial, which will greatly promote the practical application of absorbing metamaterial.