Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, South Korea.
Biomicrofluidics. 2010 Jul 14;4(3):034102. doi: 10.1063/1.3463716.
Optoelectrofluidic field separation (OEFS) of particles under light -intensity gradient (LIG) is reported, where the LIG illumination on the photoconductive layer converts the short-ranged dielectrophoresis (DEP) force to the long-ranged one. The long-ranged DEP force can compete with the hydrodynamic force by alternating current electro-osmosis (ACEO) over the entire illumination area for realizing effective field separation of particles. In the OEFS system, the codirectional illumination and observation induce the levitation effect, compensating the attenuation of the DEP force under LIG illumination by slightly floating particles from the surface. Results of the field separation and concentration of diverse particle pairs (0.82-16 mum) are well demonstrated, and conditions determining the critical radius and effective particle manipulation are discussed. The OEFS with codirectional LIG strategy could be a promising particle manipulation method in many applications where a rapid manipulation of biological cells and particles over the entire working area are of interest.
光强梯度（LIG）下的光电流场分离（OEFS），其中光导层上的 LIG 照明将短程介电泳（DEP）力转换为长程力。长程 DEP 力可以通过整个照明区域的交流电渗流（ACEO）与流体动力竞争，从而实现颗粒的有效场分离。在 OEFS 系统中，同向照明和观察会产生悬浮效应，通过将颗粒从表面略微抬起，补偿 LIG 照明下 DEP 力的衰减。不同颗粒对（0.82-16 µm）的场分离和浓缩结果得到了很好的证明，并讨论了确定临界半径和有效颗粒操纵条件。具有同向 LIG 策略的 OEFS 可能是一种很有前途的颗粒操纵方法，在许多应用中，需要在整个工作区域内快速操纵生物细胞和颗粒。
