To date, a comprehensive systematic optimization framework, capable of accurately predicting an efficient electrode geometry, is not available. Here, different geometries, including 3D step electrodes, have been designed in order to fabricate AC electroosmosis micropumps. It is essential to optimize both geometrical parameters of electrode, such as width and height of steps on each base electrode and their location in one pair, the size of each base electrode (symmetric or asymmetric), the gap of electrode pairs, and nongeometrical parameters such as fluid flow in a channel and electrical characteristics (e.g., frequency and voltage). The governing equations comprising of electric domain and fluid domain have been coupled using finite element method. The developed model was employed to investigate the effect of electrode geometric parameters on electroosmotic slip velocity and its subsequent effect on pressure and flow rate. Numerical simulation indicates that the optimal performance can be achieved using a design with varying step height and displacement, at a given voltage (2.5 V) and frequency (1 kHz). Finally, in order to validate the numerical simulation, the optimal microchip was fabricated using a combination of photolithography, electroplating, and a polydimethylsiloxane microchannel. Our results indicate that our micropump is capable of generating a pressure, velocity, and flow rate of 74.2 Pa, 1.76 mm/s, and 14.8 µl/min, respectively. This result reveals that our proposed geometry outperforms the state-of-the-art micropumps previously reported in the literature by improving the fluid velocity by 32%, with 80% less electrodes per unit length, and whereas the channel length is ∼80% shorter.

中文翻译：

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新型交流电渗微泵中 3D 电极排列的影响：数值建模和实验验证

迄今为止，还没有能够准确预测有效电极几何形状的综合系统优化框架。在这里，设计了不同的几何形状，包括 3D 阶梯电极，以制造交流电渗微泵。必须优化电极的几何参数，例如每个基电极上台阶的宽度和高度及其在一对中的位置、每个基电极的尺寸（对称或不对称）、电极对的间隙和非几何参数例如通道中的流体流动和电气特性（例如，频率和电压）。由电域和流体域组成的控制方程已使用有限元方法耦合。所开发的模型用于研究电极几何参数对电渗滑移速度的影响及其对压力和流速的后续影响。数值模拟表明，在给定电压 (2.5 V) 和频率 (1 kHz) 下，使用具有不同步高和位移的设计可以实现最佳性能。最后，为了验证数值模拟，使用光刻、电镀和聚二甲基硅氧烷微通道的组合制造了最佳微芯片。我们的结果表明，我们的微型泵能够分别产生 74.2 Pa、1.76 mm/s 和 14.8 µl/min 的压力、速度和流速。