Micromixers present essential roles in providing homogeneous mixtures in microfluidic systems. It is of critical importance to introduce strategies to increase the mixing efficiency of passive micromixers, capable of operating at high efficiency levels over a wide range of Reynolds (Re) numbers. To this end, a novel design of twisted microstructure for enhancing mixing performance in a wide range of Reynolds numbers was introduced. Incorporating this microstructure with straight and serpentine micromixers was numerically and experimentally investigated. Micromixers with twisted microstructures were fabricated in Poly(methyl methacrylate) (PMMA) using high-precision micromilling. The effects of Reynolds number, pitch number, and channel hydraulic diameter on mixing efficiency and pressure drop were analyzed. Results revealed that the twist architecture could increase mixing efficiency significantly with very low pressure drop of up to 0.89 kPa. The twisted serpentine micromixer could narrow the disparity of mixing efficiency from 87% (Re = 10) to 98% (Re = 400). High mixing efficiency could be achieved within a length of 4.8 mm in the twisted serpentine micromixer with a hydraulic diameter of 300 $\mu m$. Taken together, the twisted structure could be incorporated with various geometries to create compact and high efficiency micromixers for operation in a wide range of Re numbers.

微型混合器在微流体系统中提供均质混合物方面起着至关重要的作用。引入提高无源微型混合器混合效率的策略至关重要，该策略能够在各种雷诺数（Re）范围内以高效率运行。为此，介绍了一种新颖的扭曲微结构设计，用于增强各种雷诺数下的混合性能。在数值上和实验上研究了将这种微观结构与直线型和蛇形微型混合器结合在一起。使用高精度微铣削在聚甲基丙烯酸甲酯（PMMA）中制造具有扭曲微结构的微混合器。分析了雷诺数，螺距数和通道水力直径对混合效率和压降的影响。结果表明，扭曲结构可在高达0.89 kPa的极低压降下显着提高混合效率。扭曲的蛇形微混合器可以将混合效率的差异从87％（Re = 10）缩小到98％（Re = 400）。在水力直径为300的扭曲蛇形微混合器中，可以在4.8毫米的长度内实现高混合效率$\mu 米$。总而言之，扭曲的结构可以与各种几何形状结合在一起，以创建紧凑且高效的微型混合器，以便在各种Re数下运行。