Futai Nobuyuki, Fujita Kenji, Ikuta Wataru
Department of Mechanical Engineering, Shibaura Institute of Technology;
Department of Mechanical Engineering, Shibaura Institute of Technology.
J Vis Exp. 2018 Apr 12(134):57230. doi: 10.3791/57230.
Microfluidic components need to have various shapes to realize different key microfluidic functions such as mixing, separation, particle trapping, or reactions. A microfluidic channel that deforms even after fabrication while retaining the channel shape enables high spatiotemporal reconfigurability. This reconfigurability is required in such key microfluidic functions that are difficult to achieve in existing "reconfigurable" or "integrated" microfluidic systems. We describe a method for the fabrication of a microfluidic channel with a deformable sidewall consisting of a laterally aligned array of the ends of rectangular pins. Actuating the pins in their longitudinal directions changes the pins' end positions, and thus, the shape of discretized channel sidewalls.Pin gaps can cause unwanted leakage or adhesion to adjacent pins caused by meniscus forces. To close the pin gaps, we have introduced hydrocarbon-fluoropolymer suspension-based gap filler accompanied by an elastomeric barrier. This reconfigurable microfluidic device can generate strong temporal in-channel displacement flow, or can stop the flow in any region of the channel. This feature will facilitate, on demand, the handling of cells, viscous liquids, gas bubbles, and non-fluids, even if their existence or behavior is unknown at the time of fabrication.
微流体组件需要具备各种形状，以实现诸如混合、分离、颗粒捕获或反应等不同的关键微流体功能。一种微流体通道，即使在制造后仍会变形，但能保持通道形状，从而实现高时空可重构性。在现有的“可重构”或“集成”微流体系统中难以实现的此类关键微流体功能中，就需要这种可重构性。我们描述了一种制造具有可变形侧壁的微流体通道的方法，该侧壁由矩形销端部的横向对齐阵列组成。沿销的纵向方向驱动销会改变销的端部位置，进而改变离散通道侧壁的形状。销之间的间隙可能会导致不必要的泄漏，或者由于弯月面力而导致与相邻销粘连。为了封闭销间隙，我们引入了基于烃 - 含氟聚合物悬浮液的间隙填充物，并伴有弹性体屏障。这种可重构微流体装置可以在通道内产生强烈的时间依赖性位移流，或者可以在通道的任何区域停止流动。这一特性将有助于根据需要处理细胞、粘性液体、气泡和非流体，即使在制造时它们的存在或行为未知。
