Mixing of fluids flowing through channels and chambers is a crucial step in chemical and biochemical reactions inside microfluidic devices due to laminar flow because of small size channel and chamber dimensions. Mixing can be enhanced by passive or active mechanism which makes convection dominant over diffusion. To address this challenge, the study proposes three novel mixing designs: passive mixer, active mixer and a combination of active and passive mixing. These designs mixing performance has been studied by numerical simulation using COMSOL 5.3. According to the preliminary results of the study, pure active micromixer design has superior mixing ability. The mixing ability was proved by concentration line plots, concentration contours and videos. In order to further optimize the mixing index of the pure active micromixer, Taguchi method is applied against various input parametric values for micromixer such as frequency, voltage and velocity. The velocity is required for two fluids to flow, while frequency and voltages are for providing an external energy for active mixing. A total of nine cases were analyzed; the two best cases out of nine were selected for comparing mixing index line plots. The result of the study conclude that pure active micro-mixer at an optimal set of parameters, frequency of 10 Hz, velocity of 0.05 mm s–1 and voltage of 0.5 V achieved 99.6% mixing index at t = 0.2 s.

中文翻译：

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使用田口法的主动和被动微混合器的最佳参数混合分析

由于通道和腔室尺寸小，流经通道和腔室的流体混合是微流体装置内部化学和生化反应的关键步骤，因为层流。混合可以通过被动或主动机制增强，这使得对流优于扩散。为了应对这一挑战，该研究提出了三种新颖的混频设计：无源混频器、有源混频器以及有源和无源混频的组合。这些设计的混合性能已使用 COMSOL 5.3 通过数值模拟进行了研究。根据研究的初步结果，纯活性微混合器设计具有优越的混合能力。通过浓度线图、浓度等高线和视频证明了混合能力。为了进一步优化纯活性微混合器的混合指标，田口方法适用于微混合器的各种输入参数值，如频率、电压和速度。两种流体流动需要速度，而频率和电压则为主动混合提供外部能量。共分析了九个案例；选择了九个最佳案例中的两个来比较混合指数线图。研究结果得出结论，纯有源微混合器在一组最佳参数、10 Hz 频率、0.05 mm s-1 速度和 0.5 V 电压下在 t = 0.2 s 时实现了 99.6% 的混合指数。选择了九个最佳案例中的两个来比较混合指数线图。研究结果得出结论，纯有源微混合器在一组最佳参数、10 Hz 频率、0.05 mm s-1 速度和 0.5 V 电压下在 t = 0.2 s 时实现了 99.6% 的混合指数。选择了九个最佳案例中的两个来比较混合指数线图。研究结果得出结论，纯有源微混合器在一组最佳参数、10 Hz 频率、0.05 mm s-1 速度和 0.5 V 电压下在 t = 0.2 s 时实现了 99.6% 的混合指数。