Microfluidizer disadvantages

Laminar flow is prevalent in microfluidic channels. Describe one advantage and one disadvantage of such a physical phenomenon. (2 marks)... 

Imprinting into plastic materials can help to overcome two main disadvantages of silicon-based microfluidic systems expense of fabrication and brittleness of the material. Imprinting can be carried out at elevated temperatures [6,7] or at room temperature [8]. While heating of the plastic material can result in better feature aspect ratios, it is limited by the breaking of silicon templates during the cooling process due to the different thermal... 

It should be noted that the microfluidization process involves a very high shearing force that can potentially damage the structure of material to be encapsulated (40 5). Another disadvantage of the microfluidization method is material loss, contamination and being relatively difficult to scale-up (44). 

To overcome these limitations imposed on conventional and microfluidic methods for size separation, hydrophoretic methods have been developed. Here we provide a review of the methods for continuous size separation of microparticles, blood cells and cell-cycle synchrony, and for sheathless focusing of cells without external fields and sheath flows in microfluidic devices. We describe details of the separation mechanism and its application to particle and cell manipulation, comparing its advantages and disadvantages with other microfluidic methods. Finally, we present some challenges of the hydrophoretic technology. 

Hydrophoresis offers advantages of a sheathless method, passive operation, and single channel. These advantages can make this separation technique a solution to the challenging problem of conventional separation methods. Here, we provide a detailed review of hydrophoretic methods for particle and cell manipulation, comparing their advantages and disadvantages with other microfluidic methods. 

Table 1 summarizes the advantages and disadvantages of established chemotaxis assays, including microfluidic methods. In the following sections, we discuss methods for developing two new types of microfluidic chemotaxis systems (1) a pPlug model... 

Since then, various methods have been adopted for fabrication of photoresist-based microfluidic devices. The first method shown in Figure 20.9a begins with a spin coating of photoresist onto a substrate and patterning with a photomask." Once the open microchannels are created, a sacrificial material is filled into the space of the microchannel. Subsequently, a second layer of photoresist is spin coated and patterned on top to define the access holes for inlet and outlet. Finally, the sacrificial layer is dissolved to create the closed microchannels. The major disadvantage in this process is the slow dissolution, therefore only short microchannels are applicable. 

Another disadvantage of microfluidic devices is the hmited number of samples that may be assayed at the same time due to the complexity of the assay. Additional modifications are needed to allow the testing multiple... 

Utilization of flow reactors can overcome many of the problems associated with traditional batch reactors. Such reactors often have veiy short path lengths and may have better control of temperature. As demonstrated in many flow chemistry applications, scale-up is only limited by time. Over the past decade there have been many developments in the technology for photochemical reactions in flow, ranging from complex microfluidic devices to simple tubing based reactors, all of which have advantages and disadvantages." ... 

---