Step emulsification for monodisperse droplet creation using a connection-free PDMS microchip

IF 4.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Colloids and Surfaces A: Physicochemical and Engineering Aspects Pub Date : 2024-11-15 DOI:10.1016/j.colsurfa.2024.135725

Kazutaka Ota, Masahiko Hashimoto

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引用次数: 0

Abstract

Microfluidic technology for generating monodisperse droplets has significantly advanced various scientific and industrial applications. However, reliance on complex infrastructure, such as external pumps and intricate connections, limits its widespread adoption. In this study, we focused on passive droplet formation through step emulsification (SE) using a connection-free polydimethylsiloxane (PDMS) microchip. Our microchip design enabled droplet formation without the need for external pumps for active flow control, instead utilizing the pressure differential created between inlet reservoirs and a shared sealed-outlet space when degassed PDMS was exposed to atmospheric pressure. We began with a simple design and through progressive refinement of the microchip geometry, we achieved a more advanced design that facilitated detailed analysis of droplet formation dynamics. This design allowed for real-time observation of the droplet formation process, including time-dependent variations in droplet formation rate and the associated gentle changes in droplet size, which were intrinsic characteristics of connection-free PDMS microchips. Experiments demonstrated that a triangular nozzle design significantly improved droplet size uniformity, with a coefficient of variation in droplet diameter below 2 % under optimal conditions. These results highlighted the potential of connection-free SE microchips for generating highly uniform droplets in a simplified and efficient manner.

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使用无连接 PDMS 微芯片进行阶跃乳化以产生单分散液滴

用于产生单分散液滴的微流体技术极大地推动了各种科学和工业应用。然而，由于依赖于复杂的基础设施，如外部泵和复杂的连接，限制了其广泛应用。在本研究中，我们利用无连接的聚二甲基硅氧烷（PDMS）微芯片，重点研究了通过阶跃乳化（SE）被动形成液滴的技术。我们的微芯片设计无需外部泵进行主动流量控制，而是利用脱气 PDMS 暴露在大气压力下时在入口储液器和共享密封出口空间之间产生的压差来实现液滴形成。我们从一个简单的设计开始，通过逐步完善微芯片的几何形状，我们实现了一个更先进的设计，便于对液滴形成动力学进行详细分析。这种设计可以实时观察液滴形成过程，包括液滴形成速率随时间的变化以及与之相关的液滴大小的平缓变化，这些都是无连接 PDMS 微芯片的固有特征。实验证明，三角形喷嘴设计大大改善了液滴大小的均匀性，在最佳条件下，液滴直径的变化系数低于 2%。这些结果凸显了无连接 SE 微芯片以简化、高效的方式生成高度均匀液滴的潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Colloids and Surfaces A: Physicochemical and Engineering Aspects 化学-物理化学

CiteScore

8.70

自引率

9.60%

发文量

2421

审稿时长

56 days

期刊介绍： Colloids and Surfaces A: Physicochemical and Engineering Aspects is an international journal devoted to the science underlying applications of colloids and interfacial phenomena. The journal aims at publishing high quality research papers featuring new materials or new insights into the role of colloid and interface science in (for example) food, energy, minerals processing, pharmaceuticals or the environment.