Poly quartz chip

As glass and quartz exhibit the same surface property as fused-silica capillary, the monolithic materials could be conveniently prepared in a glass- or quartz-based microfluidic device via the same way of monoliths in the capillary. However, glass/quartz devices are rather expensive, and the need for specialized facilities for their fabrication with conventional photolithography technology hinders any rapid modification of the chip architecture. An attractive alternative is using a variety of polymeric materials, such as poly(dimethylsiloxane) (PDMS), poly(methyl methacrylate) (PMMA), polycarbonate (PC), and cyclic olefin copolymer (COC), to fabricate microchips for their mechanical and chemical properties, low cost, ease of fabrication, and high flexibility. 

In a typical microfluidic setting, the most power absorbing material is the liquid sample in the microchannels. The common materials for microfluidic chips are glass, quartz, and thermal plastics such as polydimethylsiloxane (PDMS), poly(methyl methacrylate) (PMMA), and polycarbonate, which usually have very small absorption as compared to liquid materials. The absorption of the liquid medium increases with its ionic content which increases the conductivity and with the operating frequency. Take water as an example. 

Figure 5.6 (a) Schematic illustration of conformation changes of a pH-responsive polymer brush, (b) Response of a poly(methacrylic acid) brush (11 nm thick) modified quartz crystal microbalance chip upon exposure to increasing pH values. 

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