Studies on Particles Assembly Using Micro-Vortices Driven by Electroosmosis on AC Electrodes
| Autor: | Yung-shun Yang, 楊詠順 |
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| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 In microfluidic systems, fluid is usually driven by an external AC electric field rather than a conventional mechanical pump. In this thesis, AC electrodes were designed to generate micro vortices for the assembly of suspended particles onto stagnation points on the electrodes. Such a design is useful for the transport and assembly of various molecules, proteins, and DNAs. We studied the effects of AC frequencies, voltages, and boundary conditions on the formation of micro vortices and stagnation points. Experimental results demonstrated that the best efficiency of suspended particles assembly occurred at the frequency of 100Hz and the voltage of 2.8Vpp. From the relationship between the applied voltage and the average velocity, it was verified that the flow mechanism was the AC electroosmotic (ACEO) flow. In addition, our specific boundary conditions experiments revealed that pure ACEO flow could give rise to the observed stagnation points. The experimental data are consistent with the simulation results about the position of stagnation points by the FEMLAB software. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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