Manipulation of micro- and nano-particles by electro-osmosis and dielectrophoresis
- 作者：A. Heeren ; C.P. Luo ; W. Henschel ; M. Fleischer ; D.P. Kern
- 关键词：Microfluidics ; Electro-osmosis ; Dielectrophoresis ; Electrodes
- 刊名：Microelectronic Engineering
- 出版年：2007
- 期刊代码：91_01679317
- 类别：cp
- 出版时间：May-August 2007
- 卷：84
- 期：5-8
- 页码：1706-1709
- 文件大小：743 K
摘要
The manipulation of micro- and nano-particles in fluids is one of the challenges for biological applications of microfluidic systems. In this work a method is developed for the local immobilization of particles collected from relatively large volumes. Micro- or nano-particles suspended in a liquid in microfluidic channels can be manipulated both by electro-osmosis (EO) and by dielectrophoresis (DEP) via the use of metallic electrodes. A positive dielectrophoretic force pulls the particles towards the edges of the electrodes. However, dielectrophoresis is a short-range interaction, hence only the particles in the immediate vicinity can be influenced and fixed. In contrast, electro-osmosis can be used to induce a circulation in the channel and thus exert a long-range interaction. In this approach, electro-osmosis and dielectrophoresis are combined for the manipulation of particles in a fluid cell to immobilize most of the particles distributed in the cell on a test-device. To this effect the fluid is locally circulated in the channel by an electro-osmotic flow which is induced by a voltage applied to a set of electrodes (EO-electrodes). Particles that come close to a second set of electrodes (DEP-electrodes) to which appropriate voltages are applied are influenced by the short-range interaction of the dielectrophoresis, whereby they are captured at these electrodes.