Kim Taeyung, Kim Jaewook, Kang Jeon Woong, Kwon Sun Beom, Hong Jiwoo
School of Mechanical Engineering, Soongsil University, 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Republic of Korea.
Langmuir. 2022 May 10;38(18):5759-5764. doi: 10.1021/acs.langmuir.2c00360. Epub 2022 Apr 28.
Digital microfluidics (DMF) has garnered considerable interest as a straightforward, rapid, and programmable technique for controlling microdroplets in various biological, chemical, and medicinal research disciplines. This study details the construction of compact and low-cost 3D DMF platforms with programmable contact charge electrophoresis (CCEP) actuations by employing electrode arrays composed of a small commercial pin socket and a 3D-printed housing. We demonstrate basic 3D droplet manipulation on the platform, including horizontal and vertical transport via lifting and climbing techniques, and droplet merging. Furthermore, phenolphthalein reaction and precipitation process are evaluated using the proposed 3D DMF manipulations as a proof of concept for chemical reaction-based analysis and synthesis. The threshold voltage (or electrical field) and maximum vertical transport velocity are quantified as a function of applied voltage and electrode distance to determine the CCEP actuation conditions for 3D droplet manipulations. The ease of manufacturing and flexibility of the proposed 3D DMF platform may provide an effective technique for programmable 3D manipulation of droplets in biochemical and medical applications, such as biochemical analysis and medical diagnostics.
数字微流控（DMF）作为一种简单、快速且可编程的技术，用于在各种生物、化学和医学研究领域中控制微滴，已引起了广泛关注。本研究详细介绍了通过采用由小型商用引脚插座和3D打印外壳组成的电极阵列，构建具有可编程接触电荷电泳（CCEP）驱动的紧凑型低成本3D DMF平台。我们展示了该平台上的基本3D液滴操作，包括通过提升和攀爬技术进行水平和垂直传输以及液滴合并。此外，使用所提出的3D DMF操作评估酚酞反应和沉淀过程，作为基于化学反应的分析和合成概念验证。量化阈值电压（或电场）和最大垂直传输速度作为施加电压和电极距离的函数，以确定3D液滴操作的CCEP驱动条件。所提出的3D DMF平台的易于制造和灵活性可为生化和医学应用（如生化分析和医学诊断）中液滴的可编程3D操作提供有效技术。
