Investigation of Particle Movement Induced by AC Electrokinetics inside Microchannel with Microneedle Array

• Main Authors: Yu-LuenDeng, 鄧宇倫
• Other Authors: Yi-Je Juang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/91229944832227210907

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 98 === In the microfluidic systems, AC electrokinetics has been a common strategy to manipulate the fluid flow and particle motion, which leads to various applications such as separation, sample concentration and so on. From the literature, most of the electrode pair fabricated is two dimensional. Since the dielectrophoretic (DEP) force is proportional to the gradient of the square of electric field, 3-D design could extend the electrodes into the microchannel and provide the electric field inside the entire microchannel. In this study, we used an array of microneedles along with ITO glass to form the 3-D electrode pairs. The results show that, at lower particle concentration, the fluorescent particles aggregate faster at the tips of microneedles and the fluorescent intensity reaches the maximum in 10 seconds when only the tip of microneedles is conductive. AC electro-osmotic flow is observed at the lower frequency. As the particle concentration increases, an array of the pearl chain-like structure can be formed. Although the pearl chain-like structure can be formed when using the plane electrode, the distribution is not uniform.