Particle rotational trapping on a floating electrode by rotating induced-charge electroosmosis

Yukun Ren, Weiyu Liu, Jiangwei Liu, Ye Tao, Yongbo Guo, Hongyuan Jiang
2016 Biomicrofluidics  
We describe a novel rotating trait of induced-charge electroosmotic slip above a planar metal surface, a phenomenon termed "Rotating induced-charge electro-osmosis" (ROT-ICEO), in the context of a new microfluidic technology for tunable particle rotation or rotational trap. ROT-ICEO has a dynamic flow stagnation line (FSL) that rotates synchronously with a background circularly polarized electric field. We reveal that the rotating FSL of ROT-ICEO gives rise to a net hydrodynamic torque that is
more » ... esponsible for rotating fluids or particles in the direction of the applied rotating electric field either synchronously or asynchronously, the magnitude of which is adjusted by a balance between rotation of FSL and amplitude of angular-direction flow component oscillating at twice the field frequency. Supported by experimental observation, our physical demonstration with ROT-ICEO proves invaluable for the design of flexible electrokinetic framework in modern microfluidic system. Published by AIP Publishing. [http://dx.
doi:10.1063/1.4962804 pmid:27703589 pmcid:PMC5035304 fatcat:ikccvor6fncfpncikfy5du3n3m