Department of Bioengineering, University of California, Riverside, California 92521, USA.
Langmuir. 2010 Feb 16;26(4):2951-7. doi: 10.1021/la902886d.
Advection driven mixing is essential for microfluidics and poses challenges to the design of microdevices. Force transducers or complex channel configurations provide means for, respectively, active or passive disrupting of laminar flows and for homogenizing the composing fluids. Print-and-peel (PAP) is a nonlithographic fabrication technique that involves direct printing of masters for molding polymer components of microdevices. PAP, hence, allows for facile and expedient preparation of microfluidic devices, without requiring access to specialized microfabrication facilities. We utilized PAP for fabrication of microfluidic devices capable of turning, expanding, and contracting microflows. We examined the mixing capabilities of these devices under flow conditions of small Reynolds numbers (0.2-20) and large Peclet numbers (260-26 000), under which advection is the dominant mode of mass transfer. We focused on mixing channels with arched shapes and examined the dependence of the mixing performance on the turns and the expansions along the direction of the microflows. Three-dimensional expansion and contraction, along with an increase in the modes of twisting of the laminar currents, improved the quality of mixing. The simplicity in the described fabrication of the investigated passive micromixers makes PAP an attractive alternative for expedient device prototyping.
推流式混合对于微流控至关重要，这给微器件的设计带来了挑战。力传感器或复杂的通道结构分别为层流的主动或被动破坏以及组成流体的均匀化提供了手段。打印-剥离（PAP）是一种非光刻制造技术，涉及用于模制微器件的聚合物组件的母版的直接打印。因此，PAP 允许轻松快捷地制备微流控器件，而无需访问专门的微制造设施。我们利用 PAP 制造了能够转弯、扩展和收缩微流的微流控器件。我们在小雷诺数（0.2-20）和大 Peclet 数（260-26000）的流动条件下检查了这些器件的混合能力，在这些条件下，对流是质量传递的主要模式。我们专注于具有弧形形状的混合通道，并研究了混合性能对转弯和沿微流方向扩展的依赖性。三维扩展和收缩，以及层流扭转模式的增加，提高了混合质量。所研究的被动微混合器的这种简单制造方法使得 PAP 成为快速原型设备的有吸引力的替代方案。
