Reducing Undesired Effects of Turns on Electroosmotic Flow Field in Nanochannels

There has been a growing interest in developing the miniaturized fluidic devices for transportation, separation and detection of bio-samples. In many of these phenomena electrokinetic effects play an important role. Studies show that in fabricating these devices, if long channels are used, separation efficiency can be improved. In these devices, turns must be induced to integrate a long channel within the small area of a single chip. One of the ensuing results of these turns is serious distortion in flow field that named dispersion. Dispersion can result in degraded separation quality. The present study shows that how dispersion after the turns can be reduced by minimum changing in geometry. It is also shown that how using an optimized distribution for ζ-potential near the turns can reduced the magnitude of dispersion without changing the geometry. The optimized distribution of ζ-potential has been found by genetic algorithm technique. Computer code based on the genetic algorithm has been developed to study the effectiveness of purposed methods.