The world of 3D printing is constantly evolving, and researchers are always pushing the boundaries of what's possible. A recent study from Jiangnan University and Jiangda Vibration Isolator Co., Ltd. showcases an innovative approach to 3D printing that combines antifungal resistance with vibration isolation. The result is a 3D-printed silicone rubber lattice that can resist fungal growth while absorbing vibration and repeated compression in marine environments. This development addresses a critical materials trade-off: surface coatings can lose their antimicrobial effectiveness over time, while higher filler loadings can improve fungal resistance but reduce the flexibility needed for cushioning applications. The researchers used additive manufacturing to control both the composition and internal geometry of the material, which is a significant advantage over conventional foaming methods that produce pores with irregular size and distribution. They formulated a printable composite ink using silicone rubber and hexagonal boron nitride (hBN), then deposited it through a custom gantry-type 3D printing system fitted with a 250 μm nozzle. The result was a lattice with ordered filaments, stable interlayer bonding, and preserved architecture, as confirmed by optical microscopy and micro-CT images. The processing limit was also established: inks containing more than 5 wt% hBN became too viscous for reliable extrusion, making 1-5 wt% the workable composition range. This processing window is crucial because it shows that the balance between printability and antifungal performance was part of the design problem, not an afterthought. Antifungal testing revealed the clearest performance contrast. Under ASTM G21 conditions using five fungal species, hBN-free silicone lattices developed visible colonization after 28 days, while lattices containing hBN inhibited growth more effectively as filler content increased. At 5 wt% hBN, fungal coverage fell below 0.8%, and the material achieved a rating of 0, meaning no observable fungal growth under the standard. Geometry also influenced performance, with larger filament spacing increasing fungal coverage at lower filler loadings due to more exposed surface area. In a second test using carbon-rich peptone-dextrose-agar to accelerate growth, the hBN-free lattice degraded rapidly, while the 5 wt% hBN version retained its white appearance and showed no internal fungal penetration over seven days. The paper links fungal resistance to two measurable effects. First, hBN increased surface hydrophobicity, making the surface more water-repellent and reducing fungal spore penetration. Second, microscopy data indicated biochemical and physical damage at the fungus-material interface, with reactive oxygen species detected at the interface between fungi and the hBN-filled composite. The lattice architecture also functioned as a cushioning structure, with compression curves showing an initial elastic region, an extended stress plateau, and a final stage of rapidly increasing stress. The authors attributed this to elastic buckling in the ordered lattice cells, creating a near-zero-stiffness region associated with energy absorption. Finite element simulations and in situ observations supported this mechanism, and durability remained high under repeated loading. Vibration tests extended these results beyond compression, showing that the lattice shifted the isolation frequency leftward compared to a solid reference, widening the effective vibration-isolation range. Random vibration tests produced direction-dependent results, with the EL-3-0.6 configuration delivering higher efficiency than its solid counterpart under two test conditions. Additional tests at different temperatures and humidity levels showed isolation efficiencies above 80% across all three directions tested. Even after fungal exposure, vibration-isolation performance changed only marginally over the test period. This study describes a 3D-printed elastomer lattice that combines antifungal resistance with mechanical performance, addressing a materials trade-off by using controlled architecture to manage the balance between fungal resistance and flexibility needed for cushioning and vibration isolation. The authors, Zhenyu Wang, Xinyu Song, Tao Zhang, Peng Chen, Chenxi Hua, Yu Liu, and Changli Cheng, have developed a material that could have significant implications for shipborne equipment and other systems exposed to humidity, temperature variation, and persistent vibration. The study's findings are a testament to the power of additive manufacturing in creating innovative solutions to complex problems. As the 3D printing industry continues to evolve, we can expect to see more groundbreaking developments like this one, pushing the boundaries of what's possible and shaping the future of manufacturing.
