AUXETIC LATTICE STRUCTURES FABRICATED BY 3D PRINTING USING FUSED DEPOSITION MODELING AND LCD-SLA PHOTOPOLYMERIZATION

Abstract

The paper presents a study of auxetic lattice structures fabricated by additive manufacturing using fused deposition modeling (FDM) and liquid crystal display stereolithography (LCD-SLA). The investigated samples were produced from TPU filament and ABS-like photopolymer resin. Particular attention was paid to the influence of printing technology on the accuracy of reproducing thin ribs, nodes, and repeating auxetic cells. It was shown that LCD-SLA provides higher geometric accuracy, better surface quality, and more precise reproduction of small structural elements, which is especially important for research and demonstration samples. At the same time, FDM printing with flexible thermoplastics, particularly TPU, may be more suitable for functional auxetic structures subjected to repeated deformation or impact loading. The main technological difficulties of both methods are discussed, including shrinkage and increased stiffness of photopolymer samples, as well as first-layer adhesion problems, layer shifting, and stringing during FDM printing. The results confirm that the choice of 3D printing technology and material is critical for obtaining auxetic lattice structures with the required geometry and deformation behavior.