Woo Sung Oh, Oh Myungkeun, Nietfeld Kyle, Boehler Bailey, Choi Yongki
Department of Physics, North Dakota State University, Fargo, North Dakota 58108, USA.
Materials and Nanotechnology Program, North Dakota State University, Fargo, North Dakota 58108, USA.
Biomicrofluidics. 2021 May 21;15(3):034106. doi: 10.1063/5.0051361. eCollection 2021 May.
Integration of microfluidic devices with pressure-driven, self-powered fluid flow propulsion methods has provided a very effective solution for on-chip, droplet blood testing applications. However, precise understanding of the physical process governing fluid dynamics in polydimethylsiloxane (PDMS)-based microfluidic devices remains unclear. Here, we propose a pressure-driven diffusion model using Fick's law and the ideal gas law, the results of which agree well with the experimental fluid dynamics observed in our vacuum pocket-assisted, self-powered microfluidic devices. Notably, this model enables us to precisely tune the flow rate by adjusting two geometrical parameters of the vacuum pocket. By linking the self-powered fluid flow propulsion method to the sedimentation, we also show that direct plasma separation from a drop of whole blood can be achieved using only a simple construction without the need for external power sources, connectors, or a complex operational procedure. Finally, the potential of the vacuum pocket, along with a removable vacuum battery to be integrated with non-PDMS microfluidic devices to drive and control the fluid flow, is demonstrated.
将微流控设备与压力驱动的自供电流体流动推进方法相结合，为芯片上的液滴血液检测应用提供了一种非常有效的解决方案。然而，对于基于聚二甲基硅氧烷（PDMS）的微流控设备中控制流体动力学的物理过程，仍缺乏精确的理解。在此，我们提出了一种基于菲克定律和理想气体定律的压力驱动扩散模型，其结果与我们在真空腔辅助的自供电微流控设备中观察到的实验流体动力学结果吻合良好。值得注意的是，该模型使我们能够通过调整真空腔的两个几何参数来精确调节流速。通过将自供电流体流动推进方法与沉降过程相联系，我们还表明，仅使用简单的结构，无需外部电源、连接器或复杂的操作程序，就可以从一滴全血中直接实现血浆分离。最后，展示了真空腔以及可集成到非PDMS微流控设备中的可移除真空电池在驱动和控制流体流动方面的潜力。
