Manipulation of nanoparticles within a microfluidic system based on SU-8 polymer for bio-applications

We present in this paper experimental results regarding the control the fluid flow of aqua solution whit different nanoparticles such as magnetite - Fe(3)O(4), magnetite Fe(3)O(4) - functionalized with silver particles, Fe(3)O(4) - functionalized with gold particles, and gold nanoparticles by an array of Cr/Au electrodes in a microfluidic system. The crystals of magnetite nanoparticles used in this experiment, with particle size in the range of 10 nm, were synthesized by the coprecipitation method from an aqueous Fe(3+)/Fe(2+) solution. The microfluidic system was fabricated using SU-8 polymer and it consist of an inlet, an outlet and a microfluidic channel with width of 200 mu m control and length of 8250 mu m. The electrodes were configured on the bottom of the microchannel. They are used to apply a small voltage on the solution in the microchannel. The microfluidic system was characterized by optical microscopy, white light interferometry and SEM. We simulate the distribution of the fluid velocity in the channel and we study the movement of aqua solutions with different nanoparticles in the microfluidic system under the influence of different voltages were applied, with different polarities. (C) 2010 Elsevier B.V. All rights reserved.