Laminar interface

Fig, 7.17. Schematic illustrations of sub-crack propagation along the laminar interface of the composite intermittently bonded with perforated films. After Jea and Felbeck (1980). 

Figure 2. Concq)t of differential manipulation in a single bovine capillary endothelial cell using multiple laminar flows, (a, b). Chip layout 300 x 50 pm channels are used to create laminar interfaces between hquids from different inlets, (c) Fluorescence image of a cell locally exposed to red and green fluorophores in a laminar flow, (d) Migration of fluorophores over time (scale bars, 25 pm). This shows the high potential for accurate spatial control and separation of hquids achievable in microfluidic laminar flows. (Adapted by permission from Macmillan Pubhshers, Ltd Nature [29], copyright 2001.)...

The polymeric catalytic membrane is utilized for biphasic laminar flow synthesis. Uozumi and coworkers developed membrane-installed microflow devices, in which a self-assembled polymeric Pd nanoparticle membrane was installed, for several important chemical transformations. The polymer membrane was precipitated at the laminar interface between the two parallel flows (Scheme 7.5). There is no doubt that the vast interfacial surface of the catalytic membrane with substrates and reactants in the biphasic flows would improve the rate of chemical transformation. 

Overall, the performance of microfluidic cells in terms of power density has already reached or even exceeded the levels of comparable technologies. Performance benchmarks aside, other critical metrics related to utility also need to be addressed in order for this technology to become commercially viable, namely the efflciency/fuel utilization, co-laminar interface stability, and the stacking/scale-up solutions. Although nearly 100 % fuel utilization has been achieved [16], matching this level of efficiency with high power density is a major challenge that has not been realized to date. Further research on recirculation may potentially lead to a... 

Typical failure modes of these materials are caused by voids between layers, unbonds between layers, impurities or foreign material in the laminar interfaces, and significant irregularities (damage) to the geometric core structure. Criteria for acceptability of each part to be evaluated must be established in terms of minimum size of void to be detected, minimum area of disbond that can be said to constitute a defect, and any other void or disbond characteristic that is deemed significant. To start the program, then, it becomes necessary to use samples of known acceptable and known defective parts. Ideally, the defective samples furnished should include known defects of each classification and the minimum sizes required to be detected and identified. When this isn t possible it becomes necessary to synthesize flaws in the samples to simulate the minimum defects. 

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