Fabrication And Applications Of Pdms Pneumatic Micropump And Glass-based Micro-nano Chip

Miniaturized Total Analysis System (μTAS) is an important direction in analytical chemistry. Its goal is to integrate biochemistry functions on a microchip, including sampling, reagent addition, reaction, separation, biochemical analysis and manipulation of cell and biological macromolecules. The advantage of μTAS lies in its ability to manipulate reagents from microliters to picoliters, which has significantly reduced the time consumed of the whole process. This thesis focuses mainly on the following two important sub-fields of the microfluidics.1. Polydimethylsiloxane (PDMS)-based pneumatic micropumpFluid flow control is the core technology of microfluidics, because various biological operations should be taken through delicate fluid flow manipulation in microfluidics. Micro valve, micro pump and micro fluid flow sensors are three major components for micro fluid control system. Here, a three-layered PDMS micropump is designed and fabricated. The chip is composed of the upper layer for pneumatic actuation, the middle layer as a diaphragm and the bottom layer as the preloaded reagent reservoir. For the chip to function, the diaphragm is first deformed, which would drive the hydrochloric acid in the fluidic chamber into the solid chamber, where the NaHC03react with acidic fluid and carbon dioxide is produced. Several times greater volume of gas is released compared to the original volume of the liquid. We can flexibly control the volume of the released carbon dioxide by merely changing the concentration of acidic liquid, the volume of the gas is4.4times greater volume of the fluidic chamber when the hydrochloric acid concentration is0.8mol/L.2. Glass-based micro-nano chip and its characterizationIn recent years, the expanding of the microfluidic chip fabrication technologies has enabled rapid development of micro and nanofluidics. Among the available materials for chip fabrication, glass is popular because of its mechanical stability, transparency, hydrophilicity and ease for surface patterning. In our work, the double etching technique was used to fabricate nanofluidic chip which integrated nanochannel with microchannel the same glass substrate. A simplified chip bonding technique is also proposed as follows:etched glass and cover plates were washed sequentially with acetone, detergent and Piranha lotion, subsequently the plates were aligned vertically and brought into close contact under a continuous stream of ultrapure water. The combined plates were then allowed to stand at room temperature for more than3h and the bonding is completed. The bonding technique is heating-free and has higher successful rate than traditional methods. Nanofluidic preconcentration is taken on the chip for fluorescein isothiocyanate (FITC) and Rhodamine6G.