Electroosmosis Performance Analysis of Microchip Electrophoresis Fabricated by the Ultra-precision CNC Milling

Ultra precision CNC milling can be used to fabricate the Microchip electrophoresis on the substrate of PMMA which exhibited a better electro-osmosis performance. All micro-channels on the chip are 150μm X 140μm in section area, and the separation micro-channel is 5 cm long. The top chip and the bottom one are packaged with hot embossing technique with the ponder pressing machine at the condition of 80°C 0Pa, 5min. EOF performance is theoretical studied based on the theory of low Reynolds Number, electro-osmotic mobility could be calculated μ_∞ =2.3 × 10^-4 cm²/Vs. While the experiment test EOF with current monitoring method show that the apparent electro-osmosis mobility is μ_∞ = 3.02 × 10^-4 cm²/Vs at pH9.18, 5mmol/L borax buffer solution. The difference between the theory calculation and experiment results could be explained by the XPS test which indicate that the surface valent bonds intensity were strengthened after milling fabrication.