Simulation of Flow Control in Microchannels Using Ferrofluid Plugs

Microfluidic devices have acquired an important position in the field of MEMS. While the usage of mechanical components for achieving electroosmosis and electrophoresis effects can prove to be impractical and costly, alternative methods for flow control have to be explored. This paper extends the concept of obtaining a superior flow control in microchannels by using ferrofluid plugs as barriers. These plugs occlude and discharge fluid flow, thereby functioning as valves and rendering the usage of mechanical components unnecessary. A numerical simulation of a ferrofluid plug blocking fluid flow in a microchannel due to the action of a magnetic field is carried out. The relationship between ferrofluid property and the capacity to block fluid flow is studied and analyzed. Thus a new concept of flow control in a microfluidic device by the proper variation of the external magnetic field and positioning of the ferrofluid plugs has been introduced.