Studies On Metrological Techniques For Basic Physical Parameters Of Microfluidic Systems

The micrometer dimensions of fluidic structures in microfluidic systems produce significant differences in mass-transfer and heat-transfer processes compared with macro systems. The basic physical parameters and their variation under different experimental conditions constitute important information for advanced studies. Hitherto related literature are rather few.Existing metrological techniques for basic parameters such as length, temperature and velocity are either complicated and expensive, or cannot fully meet the requirement of related studies. In this thesis, metrological techniques for three important physical parameters in microfluidic systems were systemically studied, including feature characterization and measurement of chip structure dimensions as well as temperature and velocity of microfluids. The methods are reliable, cheap and simple to be implemented in any analytical laboratory.A new approach for the metrological characterization of microfabricated features on microfluidic chips was developed, based on a combination of poly(dimethylsiloxane) (PDMS) replication and CCD imaging. A PDMS replicate was cast from the original chip sample, and a sample slice was cut from the replica at the cross section to be studied using a special cutting tool. The proposed method was successfully used in the non-destructive characterization of microfluidic chips of various materials. The results obtained using the method agreed well with those using conventional equipment. Depth and width measurements obtained using the method agreed well with those obtained using a stylus profiler and universal measuring microscope, with a deviation of less than 0.9 μm. and a precision better...