Microfluidic Chips With Integrated Mixing And Driving Units

As a-new type of chem/bio-analytical platform, microfluidic chips have some advantages such as miniaturization, integration and so on. It has good prospects in chem/bio-analysis. The mixing and driving of fluid are important for the application of microfluidic chips in the micron or nano-level channel. This thesis focused on investigating the fluid mixing and driving in microfluidic chips. The detection of adenosine triphosphate (ATP) was achieved in microfluidic chips, which utilized the Nucleotide Frag-mentation Sense (NTFS). The main research contents include:1. Y-type microfluidic chip for ATP detection. In order to achieve a better mixing and reaction effiency of reactants in the microfluidic chip, the length of the Y-type glass microfluidic chip channel was extended. This section also developed a method for temperature manipulation in microfluidic chips, utilizing an additional heating device. The ATP detection was accomplished in this microfluidic chip, with a detection limit of about 50 nM. In this study, solution mixing and temperature controlling were achieved simultaneously. The feasibility of using NTFS for detection on the developed microfluidic chip platform was also confirmed.2. Chaotic mixing microfluidic chip combined with beads for ATP detection. The mixing of solution in the Y-type microfluidic chip required a long channel and the mixing efficiency was not high enough, because the predominant flow type in such channel was laminar. To constract a micro-mixing unit, polystyrene beads were filled into the glass microfluidic chip. The laminar mixture can form turbulent mixing when the mixture flows through the beads area, which accelerated the mixing of different kinds of liquids, significantly reduced the channel length and improved the mixing efficiency. The chip was used to detect ATP, in which the length of the channel reduced from 400 mm in Y-type chip to 40 mm and the detection limit was reduced to 20 nM. It indicated that this mixing method was simple, efficient, and no complex structure was needed. Therefore, it is available for integration with other elements of microfluidic chips for further application.3. Micro-driver integrated microfluidic chip for ATP detection. The present micro-drivers have some problems, including complex manufacture and difficulties in miniaturization and integration. The capillary and evaporation action of the "micro-pump" was integrated into the microfluidic chip to solve these problems through designing evaporation holes on the cover of microfluidic chip and filling absorbent membrane. At the same time, the bead-based mixing unit was also integrated into the microfluidic chip, and rapid, sensitive ATP detection was achieved. This drive mode avoids the large external devices on the chip and showed potential for the development of versatile microfluidic chips.