【摘要】 为了在雷诺数条件不定的小尺寸的芯片内部集成高效的混合功能，根据菲克定律和布朗运动的爱因斯坦关系式提出了一种通过匹配接触面提高浓度差的策略来设计微混合器，对科恩达效应进行了扩展，分析了流体在通道表面的流动方向，从特定微通道模块中抽象出4种具体功能。通过模块的功能来预测和调控浓度梯度并构建微混合器。使用4种功能模块来旋转并匹配流体界面，设计了两种三维结构的被动式微混合器。采用三维Navier-Stokes方程组进行了数值分析，并通过软光刻工艺制作微混合器进行了实验验证。实验和仿真结果表明，在雷诺数为0.1～100内，设计的微混合器在3.3 mm，即22倍水力直径长度处能稳定提供94%～99%的混合效率，在等水力直径条件下具有明显的优势，而且结构易于在芯片上集成，证明了模块化设计的优越性。更多还原

【Abstract】 To integrate efficient mixing functions inside small chips with variable Reynolds numbers, this study developed a strategy for designing micromixers by increasing the concentration difference through matching contact surfaces based on Fick’s law and Einstein’s equation for Brownian motion. Subsequently, the Coanda effect was extended by analyzing the flow direction of the fluid over the channel surface and abstracting four functions from specific microchannel modules. These functions were used to predict and modulate the concentration gradient and construct the micromixer. Two three-dimensional structures of passive micromixers were designed using four functional modules to rotate and adjust the fluid interface. A three-dimensional Navier-Stokes system of equations was used for numerical analysis, and a micromixer was constructed via soft lithography for experimental verification. The experimental and simulation results showed that the designed micromixer consistently exhibits a mixing efficiency of 94%-99% at 3. 3 mm, which is 22 times the hydraulic diameter length, for Reynolds numbers ranging from 0. 1 to 100. This demonstrates a clear advantage over existing methods at an equal hydraulic diameter. Furthermore, the structure is easy to integrate on a chip, indicating the superiority of the modular design.更多还原