Assessment of mixing in passive microchannels with fractal surface patterning
Assessment of mixing in passive microchannels with fractal surface patterning
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DOI：
10.1051/epjap/2009108
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发表时间：
2009-09-01
影响因子：
1
通讯作者：
Kaufman, M.
中科院分区：
文献类型：
--
作者：
Fodor, P. S.;Itomlenskis, M.;Kaufman, M.
我们探讨了提高微通道的混合能力的可行性，采用维尔斯特拉斯分形函数产生的V形脊的通道地板上的图案。出于实验的局限性，如有限的分辨率（类似于10 μ m）与快速成型通过软光刻技术，我们研究的混合质量的影响，具有有限宽度的脊。研究的设计的混合能力进行了评估，使用熵的措施和设计进行优化：脊之间的距离和它们的尖端沿着通道的宽度的位置范围。结果进行了评估，相对于非常成功的交错人字形（SHB）设计建立的基准。我们发现，使用一个非周期性的协议，以产生的微通道的底面的几何形状可以导致一贯较大的熵混合指数比在循环结构。此外，由于分形微通道的优化曲线（混合指数与几何参数）比其SHB对应物在最大值处更宽，因此使用Weierstrass分形函数的微通道设计对实验不确定性不太敏感。
We explore numerically the feasibility of enhancing the mixing capability of microchannels by employing the Weierstrass fractal function to generate a pattern of V-shaped ridges on the channel floor. Motivated by experimental limitations such as the finite resolution (similar to 10 mu m) associated with rapid prototyping through soft lithography techniques, we study the influence on the quality of mixing of having finite width ridges. The mixing capability of the designs studied is evaluated using an entropic measure and the designs are optimized with respect to: the distances between the ridges and the position range of their tip along the width of the channels. The results are evaluated with respect to the benchmarks established by the very successful staggered herring bone (SHB) design. We find that the use of a non periodic protocol to generate the geometry of the bottom surface of the microchannels can lead to consistently larger entropic mixing indices than in cyclic structures. Furthermore, since the optimization curves (mixing index vs. geometric parameters) are broader at the maximum for fractal microchannels than for their SHB counterparts, the microchannel designs using the Weierstrass fractal function are less sensitive to experimental uncertainties.