With the rapid development of three-dimensional (3D) printing technology, the field of multi-material fabrication, particularly in the production of functionally graded materials, has achieved revolutionary advancements. However, the structures of micromixers, which are central to this technology, have not been sufficiently studied. This study introduces an optimized passive micromixer design based on a 3D Tesla valve, specifically engineered for the efficient mixing of Fe3O4 particles within an epoxy resin E51 matrix. The micromixer leverages the fluid dynamics of the Tesla valve, where sudden changes in flow direction generate secondary flows that enhance mixing performance by disrupting laminar flow and inducing chaotic advection, thereby increasing the interfacial area between different material components. This process significantly improves mixing efficiency in the fabrication of gradient materials. Through theoretical analysis and computational simulations, the study identifies optimal configurations for the Tesla valve system, emphasizing mixing dynamics that enhance material gradient formation. The findings reveal that optimal mixing efficiency is achieved with a configuration comprising three Tesla valves. This optimal setup includes a 0.5-mm opening width at the turning point, an immediate transition from the turning point to the straight pipe (0 mm length), a 0.25-mm structural height for the Tesla valve, and an outlet distance of 0.25 mm from the curved pipe. Hopefully, this study can provide a robust reference for the significant potential of future applications in the realm of multi-material 3D printing, thereby fostering its substantial growth prospects.

High aspect ratio tungsten nanowires have been prepared by selective dissolution of Nickel-aluminum-tungsten (NiAl−W) alloys which were directionally solidified at growth rates varying from 2 to 25 μm/s with a temperature gradient of 300 K·cm⁻¹. Young’s modulus and electrical resistivity of tungsten nanowires were measured by metallic mask template method. The results show that the tungsten nanowires with uniform diameter and high aspect ratio are well aligned. The length of tungsten nanowires increases with prolongation of etching time, and their length reaches 300 μm at 14 h. Young’s modulus of tungsten nanowires is estimated by Hertz and Sneddon models. The Sneddon model is proper for estimating the Young’s modulus, and the value of calculating Young’s modulus are 260–460 GPa which approach the value of bulk tungsten. The resistivity of tungsten nanowires is measured and fitted with Fuchs−Sondheimer (FS) + Mayadas−Shatzkes (MS) model. The fitting results show that the specific resistivity of W nanowires is a litter bigger than the bulk W, and its value decreases with decreasing diameter.