Voxelated meniscus-confined electrodeposition of 3D metallic microstructures

Additive manufacturing is a rapidly evolving technology for the fabrication of 3D metallic microstructures. However, the production of complex 3D metallic micro/nanoscale structures with satisfactory mechanical properties is challenging for existing additive manufacturing technologies. In this study, a voxelated meniscus-confined electrodeposition 3D printing technology was developed to fabricate 3D metallic structures in an ambient environment at the microscale and nanoscale with high stiffness and stability. The proposed method changes the continuous meniscus-confined electrodeposition process to a discrete process, which facilitates the fabrication of 3D metallic microstructures and strengthens the stiffness of meniscus-confined electrodeposition. To verify the newly proposed method, a single-voxel deposition, micropillars, a micropillar array, tilt micropillars, and multi-pillar supporting microstructures were fabricated. In-situ microscale compression tests under scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were conducted to compare the mechanical performances of the fabricated metallic microstructures obtained using the continuous and the voxelated meniscus-confined electrodeposition methods. Our results demonstrate that micropillars fabricated via the voxelated meniscus-confined electrodeposition method could have much smaller nanograined structures and have higher stiffness than those structures fabricated via the continuous method. We discussed the formation process of nanograins fabricated by the voxelated method and it is found that the superior mechanical property of the structures fabricated by the voxelated method was owing to its high current density and discrete voltage supply in the electrodeposition process.