Researchers at Seoul National University (SNU), South Korea, have developed a new method for manufacturing strong yet lightweight carbon fibre structures without the need for layered assembly or joints.

Carbon fibre composites are typically manufactured by stacking thin layers of material or assembling multiple components. Even newer approaches, such as 3D printing, rely on layer-by-layer fabrication. 

The challenge is that these methods introduce weaknesses where layers or parts meet, and create internal boundaries that can disrupt load transfer.

To overcome this, SNU researchers explored whether they could build a structure by placing a single continuous fibre directly in three-dimensional space. 

Their process begins with a temporary scaffold that defines nodal geometry. A long carbon fibre is then wound across these nodes, forming a spatial lattice network. Once the geometry is established, the structure is consolidated through resin impregnation, producing a solid composite.

As the fibre remains continuous throughout the structure, forces are transmitted without interruption, avoiding the stress concentrations and failure points commonly associated with joints and interfaces in typical carbon fibre lattice structures.

To validate their approach in the real world, the researchers applied the structure to a drone frame. This redesigned frame reduced structural weight by approximately 79% compared to conventional designs. This directly resulted in a 33% increase in flight time under the same operating conditions.

According to the researchers, this shows that structural weight reduction directly translates into improved system-level performance, particularly in applications where mass is a primary constraint.

They say that scaled manufacturing can also be achieved using robotic, toolpath-driven fabrication systems, where complex fibre trajectories are generated and executed directly from digital designs. 

Dr Jun Young Choi and Professor Sung-Hoon Ahn in the department of mechanical engineering at SNU said: “The spatial complexity of continuous fibre architectures has limited their scalability in conventional manufacturing.

“With advances in robotic and AI-driven fabrication, these structures can now be produced at scale, and this work provides a roadmap for their practical realisation.”

Their study – ‘Mesoscale carbon fibre lattices with foam-like weight and bulk strength’ – has been published in the journal Nature Communications.