气动驱动的微流体平台，用于微颗粒浓缩
Summary
本方案描述了一种气动微流体平台，可用于高效的微粒浓缩。
Abstract
本文介绍了一种利用微流体平台制造和操作气动阀以控制颗粒浓度的方法。该平台具有具有弯曲流体通道和三个气动阀的三维（3D）网络，通过与聚二甲基硅氧烷（PDMS）的双相复制来创建网络，通道和空间。该装置根据气动阀控制的流体流速的瞬态响应按以下顺序运行：（1）样品上样，（2）样品阻塞，（3）样品浓度和（4）样品释放。颗粒被筛阀（Vs）板的薄隔膜层变形阻挡并积聚在弯曲的微流体通道中。工作流体通过两个开/关阀的驱动排出。由于该操作，所有各种放大倍率的粒子都被成功拦截并脱离。当应用该技术时，操作压力、浓缩所需的时间和浓缩速率可能会根据设备尺寸和粒度放大倍率而变化。
Introduction
由于生物分析的重要性，微流体和生物医学微机电系统（BioMEMS）技术1，2 用于开发和研究用于纯化和收集微材料的装置2，3，4。粒子捕获分为主动或被动。主动式阱已用于作用于独立粒子的外部介电5、磁吞噬6、听觉7、视觉8或热9 力，从而能够精确控制其运动。然而，粒子和外力之间的相互作用是必需的;因此，吞吐量较低。在微流体系统中，控制流速非常重要，因为外力传递到目标颗粒。
一般来说，无源微流体器件在微通道10，11中具有微柱。颗粒通过与流动流体的相互作用进行过滤，这些设备易于设计且制造成本低廉。然而，它们在微柱中引起颗粒堵塞，因此已经开发出更复杂的装置来防止颗粒堵塞12。具有复杂结构的微流体装置通常适用于管理有限数量的颗粒13，14，15，16，17，18。
本文描述了一种制造和操作气动驱动的大颗粒浓度微流体平台的方法，该平台克服了上述缺点18。该平台可以通过变形和驱动积聚在弯曲微流体通道中的筛阀（Vs）板的薄隔膜层来阻挡和浓缩颗粒。颗粒积聚在弯曲的微流体通道中，并且浓缩的颗粒可以通过两个PDMS密封件的开/关阀18的驱动来排出工作流体来分离。这种方法使得可以处理有限数量的颗粒或浓缩大量小颗粒。诸如流速和压缩空气压力等工作条件可以防止不必要的电池损坏并提高电池捕获效率。
Protocol
1. 颗粒浓缩微流控平台设计 设计气动微流体平台，该平台由一个用于 3D 流网络中流体流动的气动阀和三个用于筛网 （V）、流体 （Vf） 和颗粒 （Vp） 操作的气动阀组成（图 1）。注意：Vs阻挡液体中的浓缩颗粒，Vf和Vp允许浓缩后释放流体和颗粒。三个气动端口提供来自流体/气动供应层（常开）的压缩空气和气动阀灯出口以驱动阀门。微流体通道网络…
Representative Results
图8 显示了四级平台操作的流体速率的流速，如 表2所示。第一阶段是加载状态（状态）。该平台在所有阀门打开的情况下提供流体，并且工作流体（Qf）和颗粒（Qp）几乎相同，因为微流体通道网络表现出结构对称性。在第二阶段（b状态）中，压缩空气被输送到Vs以阻挡颗粒，并且随着Vs隔膜变形，流路变窄，并且通过液压阻力减小了在出口处测量的流速。Qf和Qp…
Discussion
该平台提供了一种纯化和浓缩各种尺寸颗粒的简单方法。颗粒通过气动阀控制积聚和释放，并且没有观察到堵塞，因为没有被动结构。使用该装置，呈现三种尺寸的颗粒的浓度。然而，操作压力、浓缩所需的时间和速率可以根据器件尺寸、粒径放大倍率和Vs 18，20，21处的压力而变化。
当执行步骤3.1时，气?…
Declarações
The authors have nothing to disclose.
Acknowledgements
这项工作得到了韩国国家研究基金会（NRF）的支持，该基金由韩国政府（科学和信息通信技术部）资助。（编号NRF-2021R1A2C1011380）。
Materials
| 1.5 mm puncture | Self procduction | Self procduction | This puncture was made by requesting a mold maker based on the Miltex® Biopsy Punch with Plunger (15110-15) product. |
| 4 inch Silicon Wafer/SU-8 mold | 4science | 29-03573-01 | 4 inch (100) Ptype silicon wafer/SU-8 mold |
| Carboxyl Polystyrene Crosslinked Particle(24.9 μm) | Spherotech | CPX-200-10 | Concentrated bead sample1 |
| Flow meter | Sensirion | SLI-1000 | Flow measurement |
| High-speed camera | Photron | FASTCAM Mini | Observation of concentration |
| Hot plate | As one | HI-1000 | heating plate for curing of liquid PDMS |
| KOVAX-SYRINGE 10 mL/Syringe | Koreavaccine | 22G-10ML | Fill the microfluidic channel with bubble-free demineralized water. |
| Laboratory Conona treater/Atmospheric plasma | Electro-Technic | BD-20AC | Chip bonding/atmospheric plasma |
| Liquid polydimethylsiloxane, PDMS | Dow Corning Inc. | Sylgard 184 | Components of chip |
| Microscope | Olympus | IX-81 | Observation of concentration |
| PEEK Tubes | SAINT-GOBAIN PPL CORP. | AAD04103 | Inject or collect particles |
| Polystyrene Particle(4.16 μm) | Spherotech | PP-40-10 | Concentrated bead sample3 |
| Polystyrene Particle(8.49 μm) | Spherotech | PP-100-10 | Concentrated bead sample2 |
| Pressure controller/μflucon | AMED | μflucon | Control of air pressure |
| Spin coater | iNexus | ACE-200 | spread the liquid PDMS on SU-8 mold |
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Citar este artigo
Choi, H. J., Lee, J. H., Jeong, O. C. Pneumatically Driven Microfluidic Platform for Micro-Particle Concentration. J. Vis. Exp. (180), e63301, doi:10.3791/63301 (2022).