Elastic Beating Pump Using Induced-Charge Electro-osmosis

Pumping a viscous liquid in a confined space is essential in microfluidic systems because the pressure-driven flow rate through small channels decreases with the third or fourth power of the channel size. Hence, inspired by a cilium's pumping ability in a confined space, we propose an elastic beating pump using a hydrodynamic force due to induced-charge electro-osmosis (ICEO) and numerically examine the pumping performance. By the multiphysics coupled simulation technique based on the boundary element method along with the thin double-layer approximation, we find that by selecting the optimum rigidity of the elastic beam, the ICEO elastic beating pump functions effectively at high frequencies with low applied voltages and shows a large average flow velocity with a remarkably large peak velocity that may be useful to flow a liquid with unexpectedly high viscosity. Furthermore, we propose a simple model that explains the characteristics of the time response behavior of the ICEO elastic beating pump tosome extent. By this analysis, we can considerably contribute to developments in studies on the artificial cilia having versatile functions.