Microchannels fabrication using sacrificial materials

FIGURE 51.1 Schematic diagram of the general processing steps involved in the fabrication of microchannel structures using sacrificial materials. 

PCSL microfabrication is an attractive alternative for making robustly enclosed microchannels by solvent bonding, while protecting microchannel integrity using a sacrificial material. This technique does not require sophisticated thin-film deposition instrumentation and should be easy to implement by microfluidics researchers. In the next section, we provide guidelines for the fabrication of polymer microfiuidic systems using PCSLs. 

The final step in PCSL fabrication of microfluidic systems is removal of the sacrificial material to yield clean, smooth microchannel inner surfaces. Paraffin wax PCSL is removed by heating the microdevice to 85°C and applying vacuum to a reservoir in the PMMA cover piece to aspirate the liquid PCSL (Figure 51.2h). Nonpolar organic solvents such as hexane or cyclohexane can be used subsequently to dissolve and remove residual sacrificial material from inside the channel. With... 

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