Enhancing performance and reusability of multi-material honeycomb metamaterials via blended FDM

• Introduce b-FDM as a new route to enhance bonding strength in multimaterial prints. • b-FDM integrates PETG strength and TPU toughness for 4D reusable honeycombs. • Blended honeycombs dissipate up to 490% more energy than TPU ones after 12 cycles. • b-FDM yields 121% higher final energy dissipation than conventional m-FDM. • b-FDM delivers 8-fold mechanical tunability with 27% material savings. A blended fused deposition modeling (b-FDM) method is introduced as a novel route for fabricating high-performance multi-material honeycomb metamaterials. Conventional multi-material FDM (m-FDM) directly deposits discrete polymers. In contrast, b-FDM blends materials into a single filament, enabling continuous deposition of the desired multi-material structures with robust interfacial bonding. Following the concept of 4D printing, two shape memory polymers, polyethylene terephthalate glycol (PETG) and thermoplastic polyurethane (TPU), are blended via b-FDM to integrate PETG’s high strength and TPU’s high toughness into honeycomb structures with reusable functionality. By optimizing printing parameters and blend ratios, honeycombs that demonstrate both excellent one-off and cyclic performance are produced. Mechanical testing revealed that, after twelve loading cycles, a honeycomb with a 50%TPU blend dissipated 49% and 490% more energy than its 100%PETG and 100%TPU counterparts, respectively. Crucially, the b-FDM process enhanced interfacial bonding through continuous deposition, leading to significant improvements in structural performance. For example, a 33%TPU honeycomb fabricated by b-FDM dissipated 61% and 121% more energy compared to the m-FDM counterpart in the first and final cycle, respectively, providing a 13% improvement in the final performance retention. Additionally, b-FDM achieved an 8-fold range of one-off mechanical tunability in honeycomb structures while reducing material consumption by 27% relative to m-FDM, highlighting its potential for tunable and cost-effective multi-material manufacturing. This work provides valuable insights and a practical framework for developing high-performance, reusable, multi-material mechanical metamaterials tailored for energy dissipation applications.