Electro-osmotic Micropump On Glass-based Microfluidic Chip

Microfluidic chip is a micro analysis system based on microscale network channel structure and machining platform of MEMS,which integrates the operation units of sample preparation,separation,detection,reaction onto a centimeter-scale chip.Microfluidic chip has been found widespread application prospect in many fields including clinical diagnostics,drug screening,environmental protection and judicial expertise,owing to the advantages such as miniaturization,integration, robotization,fast-analysis and low-consumption.Microfluidic chip has been known as lab-on-a-chip as well,because the chip was portable and can be employed in the environment outside laboratory,however,few microfluidic chip was successfully used outside laboratory virtually,for complicated system was required to manipulate the chip.Driving liquid by electro-osmotic flow in microfluidic chip was very successful because the flow,including flow rate and flow direction,can be easily controlled,and the electro-osmotic pump can be well and easily integrated on chip,which was one of the most crucial techniques in microfluidic chip.This thesis aims to resolve existing issure of avoiding the damage created by the high electric fields required to drive electro-osmotic flow and hazardous high driving voltage which prevents easy handling.The main work and results are summarized as follow:1.Method for the fabrication of glass-based microfluidic chip was optimized, and the approach of low temperature bonding of glass chip was established and optimized,which has laid the foundation for the future application in glass chip.2.Technique of charge modification selectively in microchannel by the method of layer-by-layer electrostatic self-assembly of polyelectrolyte multilayers was built to create negative and positive channel surface charges respectively,which is very promising for the multi-functionalization of channel surface.3.A Y-shaped field-free electroosmotic micropump consisting of two arms which has small sub-channels in parallel was developed.Two arm-channels were modified with cationic and anionic polyelectrolyte respectively,allowing a field-free flow to be generated in main-channel.4.A novel multistage electro-osmotic micropump was developed with the purpose of lowering applied voltage.Low voltage was achieved by connecting a series of electro-osmotic pump unit.Result showed that pumping pressure was 710 Pa for the pump with 7 stages when applied voltage was 50 V.5.A series of 2D micromixers integrating angles were designed and FITC mixing experiments was carried out to test the mixing performance of the micromixers.