Particle Catcher Using Induced-Charge Electroosmosis

Abstract

Finding an innovative separation mechanism is a central task in future microfluidic systems. We propose a size-controllable microfluidic catching device that has a face-to-face structure consisting of elastic beams that change the acceptable particle size dynamically by hydrodynamic force due to induced charge electroosmosis (ICEO) in water and numerically examine the novel separation mechanism consisting of catching and releasing motions with size selectivity. By an implicit strongly coupled simulation technique between a fluid and an elastic structure based on the boundary element method, along with the thin double-layer approximation, we find that the catching device works effectively at low applied voltages in a realistic microfluidic channel and shows a wide range dynamic size selectivity. Furthermore, by modeling the ICEO phenomena with elastic motion, we successfully explain the acceptable particle size of the catching device. We believe that our proposed device will contribute to realizing innovat...