An approach to optimize the design of microfluidic chips for electrophoretic separations

The precise design and operational control of the separation process of liquid matrices is key to the performance of on-chip liquid analysis. Present research attempts from the engineering point of view to investigate of the process occurring in the microfluidic channels for chip design with the best separation efficiency. An one-dimensional model of electrokinetic sample motion was developed to simulate the separation process of sample containing amino acids (tryptophan, tyrosine, proline, methionine) that migrate in a buffer solution through a straight separation channel made of poly(methyl methacrylate) within a microfluidic chip under different conditions. On the basis of the simulations by the finite-difference method the effects of the channel size, the chip material, the applied voltage difference and the test solution pH on separation rate are discussed. It was found that for the channel length of 2 cm the resolution of peaks is optimal and the fastest time of amino acids separation is 4 s.