Flow Visualization Around Actuating Valve of Micro-Vibrating Flow Pump

Abstract

In this paper, we propose a novel micropump, so-called micro vibrating flow pump (micro-VFP). Micro-VFP consists of a microchannel and an actively vibrating valve which has a cantilever like structure fixed on a wall of a microchannel. This valve works as an actuator for liquid flow in the microchannel. Since the valve is made of a flexible material including magnetic particles, it can be deformed by externally applying the magnetic field. After removing the magnetic field, the valve returns back to its original position by its own elasticity. By periodically changing the magnetic field, the valve vibrates and gives kinetic energy to the liquid. Furthermore, we designed sleeves on the side walls of the microchannel in the downstream of the valve. By adding the sleeves, the valve vibrates asymmetrically to generate net flow in one direction. To investigate the basic performance of micro-VFP, a prototype one is fabricated using soft lithography processes. The flow dynamics around the actuating valve is investigated in detail using particle image velocimetry.