To improve tools for controlling and optimizing miniaturized chemistry, a novel oil extraction architecture, designated as the Counter-Current Continuous Phase Extraction (C³PE) module, was developed to enable precise control over reaction incubation in water-in-oil droplet microfluidic reactors. Using a symmetric pillar array coupled to adjustable oil flows prevented sample loss and droplet breakup, even at high final volume fractions, and cross-flow added novel stabilization of oil extraction against instability in control pressures. By integrating this dynamic functionality, C³PE enabled rational selection of the oil extraction magnitude across a range of achievable final droplet volume fractions (up to 85%) when processing droplets at 40–200 Hz. Further, this versatile device handled many droplet sizes (70–500 pL demonstrated here). Next, this approach to controlling droplet volume fraction enabled incubation time monitoring and optimization when coupled to a K-channel direct injection feature to label selected droplets. In profiling system characteristics like volume fraction, channel geometry, and continuous phase viscosity, this technique provided a powerful tool to control, measure, and improve incubation performance. Finally, applying C³PE principles to an in-droplet β-galactosidase enzyme reaction (useful in immunoassay systems) increased product formation while significantly decreasing variance in product yield among droplets relative to a non-extracted comparison. We envision that this method will inform future design and implementation of high precision in-droplet chemistry while being of general interest in the study of emulsion fluid dynamics.

为了改进控制和优化微型化学的工具，开发了一种新型的油萃取体系结构，称为逆流连续相萃取（C ³ PE）模块，可以精确控制油包水微滴反应器中的反应孵育。使用对称的柱阵列与可调节的油流量相结合，即使在最终体积分数很高的情况下，也能防止样品损失和液滴破裂，并且错流为控制压力的不稳定增加了采油的新稳定性。通过集成此动态功能，C ³当以40–200 Hz的频率处理油滴时，PE可以在可实现的最终油滴体积分数范围内（高达85％）合理选择油的提取量。此外，这种多功能设备可处理多种液滴尺寸（此处显示70–500 pL）。接下来，这种控制液滴体积分数的方法在与K通道直接注入功能结合以标记选定的液滴时，可进行孵育时间监控和优化。在分析系统特征（例如体积分数，通道几何形状和连续相粘度）时，此技术提供了一个强大的工具来控制，测量和改善孵育性能。最后，应用C ³相对于未提取的比较，液滴内β-半乳糖苷酶反应的PE原理（在免疫测定系统中有用）增加了产物的形成，同时显着降低了液滴间产物收率的差异。我们设想，该方法将为高精度液滴化学的未来设计和实现提供参考，同时在乳液流体动力学研究中也将引起广泛关注。