Single step 3D printing of bioinspired structures via metal reinforced thermoplastic and highly stretchable elastomer

摘要

Multimaterial additive manufacturing technique is a great alternative approach for fabrication of complex structures with diverse mechanical properties compared to traditional assembly process. Fused deposition modeling is a simple, popular and affordable technique, which is available in numerous desktop 3D printers nowadays. However, this technology is not developed considerably to co-fabricate highly stretchable (800% strain) elastomer materials with low stiffness and high strength parts in one single build platform. In this paper, a single step fabrication of a novel bioinspired joint system, consisting of dissimilar materials with high strength and high strain elements is developed by an inexpensive 3D printer. The joint consists of continuous metal fibers reinforced thermoplastic part that resembles bones and soft elastomer that mimics soft tissues. Tensile test results of the 3D printed reinforced thermoplastic part showed a 78% increase in strength, which can be competed with natural bone. Highly stretchable elastomer is used for the soft parts that was directly 3D printed and simultaneously cured by heating. Overall, a simple and cost effective heterogeneous material manufacturing technique is developed that maintained high mechanical strength and sufficient elasticity, to produce a bioinspired joint that composed of a rigid skeleton covered by a very soft elastomer.