Spider web-inspired continuous fibre floating 3D printing for large lightweight mesh structures

Large-scale lightweight mesh structures offer high-performance with minimal material usage, but their 3D printing is hindered by support waste and structural instability. Inspired by the suspended weaving of spider webs, we present a continuous fibre floating 3D printing (CFF-3DP) method for fabricating large-span lightweight meshes. Utilising shear-induced tension and optimised printing parameters, this approach enables unsupported fabrication with precise control over filament morphology and mechanical properties. Experimental and theoretical results show that moderate printing speeds and temperatures optimise tension and fibre-matrix impregnation, producing filaments with a breaking force of 64.45 N and a root mean square error (RMSE) of 0.233 mm over a 100 mm span. Compared to single-layer printing, multilayer staggered deposition reduces vertical deviation by 40.7%, achieving a surface RMSE of 0.128 mm. The resulting meshes retain 72.2% of the tensile strength (7.24 kN·m−1) and 65.8% of the tensile secant stiffness (329.67 kN·m−1) of conventional platform-based prints, while exhibiting good structural continuity at the nodes. Electromagnetic (EM) reflection tests confirm the meshes’ functionality as lightweight reflectors, with return losses below 0.46 dB across the 2.6–3.95 GHz range. Demonstrations including parabolic antennas and scalable EM metasurfaces underscore the method’s potential for constructing large-scale functional structures.