Gao Shang, Rui Xichuan, Zeng Xiangyu, Zhou Jia
School of Microelectronics, Fudan University, Shanghai 200433, China.
Department of Micro/Nano Electronics State Key Laboratory of Radio Frequency Heterogeneous Integration, Shanghai Jiao Tong University, Shanghai 200433, China.
Sensors (Basel). 2023 Aug 11;23(16):7102. doi: 10.3390/s23167102.
Digital microfluidic platforms have been extensively studied in biology. However, achieving efficient mixing of macromolecules in microscale, low Reynolds number fluids remains a major challenge. To address this challenge, this study presents a novel design solution based on dielectric electro-wetting (EWOD) by optimizing the geometry of the transport electrode. The new design integrates micro-barriers on the electrodes to generate vortex currents that promote mixing during droplet transport. This design solution requires only two activation signals, minimizing the number of pins required. The mixing performance of the new design was evaluated by analyzing the degree of mixing inside the droplet and quantifying the motion of the internal particles. In addition, the rapid mixing capability of the new platform was demonstrated by successfully mixing the sorbitol solution with the detection solution and detecting the resulting reaction products. The experimental results show that the transfer electrode with a micro-barrier enables rapid mixing of liquids with a six-fold increase in mixing efficiency, making it ideal for the development of EWOD devices.
数字微流控平台在生物学领域已得到广泛研究。然而，在微尺度、低雷诺数流体中实现大分子的高效混合仍然是一项重大挑战。为应对这一挑战，本研究提出了一种基于介电电润湿（EWOD）的新颖设计方案，通过优化传输电极的几何形状来实现。新设计在电极上集成了微屏障，以产生涡电流，在液滴传输过程中促进混合。该设计方案仅需两个激活信号，将所需引脚数量减至最少。通过分析液滴内部的混合程度并量化内部粒子的运动，对新设计的混合性能进行了评估。此外，通过成功将山梨醇溶液与检测溶液混合并检测产生的反应产物，证明了新平台的快速混合能力。实验结果表明，带有微屏障的传输电极能够实现液体的快速混合，混合效率提高了六倍，使其成为EWOD设备开发的理想选择。
