Department of Mechanical and Materials Engineering, Western University, London, Ontario, N6A 5B9, Canada.
Nanotechnology. 2018 Dec 14;29(50):505704. doi: 10.1088/1361-6528/aae283. Epub 2018 Sep 19.
Metamaterials with artificially designed architectures can achieve unique and even unprecedented physical properties, which show promising applications in actuators, amplifiers and micromechanical controls. An initiator-integrated 3D printing technology (i3DP) was applied in this study to create scalable, metal/polymer meta-mechanical materials, which can gradually achieve negative Poisson's ratio, high strength and ultralow density, as well as high compressive and super-elastic behavior. The i3DP was enabled by integrating an atomic-transfer radical polymerization (ATRP) initiator with UV-curable resin, followed by polyelectrolyte brushes (PMETAC) grafting via surface-initiated ATRP and thereafter electroless plating to form metal coatings. Compared with polymer structures, the compressive stress of metal-polymer structure can be doubled when deposited with a 190 nm copper layer. The hollow metallic materials possess a tunable Poisson's ratio, and the highest average recoverability, which can recover nearly completely to their original shape after over 30% compression. Overall, this i3DP approach provides meta-structures with substantial benefits from the hierarchical design and fabrication flexibility.
具有人工设计结构的超材料可以实现独特的，甚至是前所未有的物理特性，在驱动器、放大器和微机械控制方面显示出了很有前景的应用。本研究应用了一种集成引发剂的 3D 打印技术（i3DP）来制造可扩展的金属/聚合物超机械材料，这些材料可以逐渐实现负泊松比、高强度和超低密度，以及高压缩性和超弹性。该 i3DP 通过将原子转移自由基聚合（ATRP）引发剂与紫外光可固化树脂集成，然后通过表面引发 ATRP 接枝聚电解质刷（PMETAC），再进行化学镀来形成金属涂层。与聚合物结构相比，当沉积 190nm 铜层时，金属-聚合物结构的压缩应力可以增加一倍。中空金属材料具有可调节的泊松比，平均恢复能力最高，在超过 30%的压缩后几乎可以完全恢复到原来的形状。总的来说，这种 i3DP 方法为分层设计和制造灵活性提供了具有显著优势的超结构。
