Research ONAC Electroosmotic Flow Micropimp Based On The Technology Of MEMS

Microluidics system is a key part of the Lab-on-a-Chip in the MEMS((Micro Electro Mechanical Systems) field, which has important application in the booming micro total analysis system. It transports the sample with microchannels, which saves time and reduces the material waste, lowers environment pollution. Recently, the driving fashion of flow becomes a key problem in the field of microfluidics system. AC electroosmotic flow micropump which bases on the principle of DC electroosmosis controls the flow in the microchannel by electric field. Recent years, It attracts more and more people's recognition. This paper is on the purpose of practical application. In this paper the theory and experimented of AC electroosmotic flow micropump are researched further deeply which offers the basics of theory and experiment for the application of AC electroosmotic flow micropumps.In the AC electroosmosis system, the pumping speed is effected by the dimension of microelectrodes, property of the fluid, frequency and amplitude of AC signal, which must be considered when designing the micropump. In this paper the main work is to research how these parameters influence the pumping speed when applying small voltage to drivie low conductance fluid.First, this paper introduces the research of AC electroosmosis at home and abroad in detail, then the driving technology of AC electroosmosis is compared with other methods, such as mechanical micropump driving and DC electroosmosis driving. The theory of electric double layer and AC electroosmosis micropump is expatiated. The expression which calculates the velocity of electroosmotic flow on the surfure of asymmetry electrodes is given based on the linear theory of symmetry electrodes. Parameters which influence pumping speed such as dimension of electrodes, property of fluid and AC signal are researched and simulated by Matlab. Partial differential equations and their linear boundary condition in the microchannel which describe voltage, electric field and velocity field are founded, and then distribution of voltage, electric field and velocity field are calculated by finite element analysis.Experiment is done in order to validate correctness of the theories. PDMS is used to designed self-regulating microchannal for AC electroosmotic micropump. Choose the material and dimension to design and manufacture microchip. The flow of fluid in the microchannel is observed, which validate the possibility of driving fluid applied by asymmetry electrodes. The tendency which the main parameters influence the punping speed is checked out by changing the frequency, voltage, conductivity of the solution. It was verified correct by comparing with the theoretical result, that provides the base for further design of AC electroosmotic pump.