Model Gallery

Model ID: 603

Electrokinetic Valve

This model presents an example of pressure driven flow and electrophoresis in a 3D micro channel system. Researchers often use a device similar to the one in this model as an electrokinetic sample injector in biochips to obtain well-defined sample volumes of dissociated acids and salts and to transport these volumes.

Focusing is obtained through pressure driven flow of the sample and buffer solution, which confines the sample in the focusing channel. When steady state has been obtained, the pressure driven flow is turned off and an electric field is applied along the channels.

The electric field drives the dissociated sample ions that are found in the focusing zone at right angles to the focusing channel, through the injection channel. This is solved in the time-domain.

This model requires the Chemical Reaction Engineering Module and either the CFD Module or the Microfluidics Module.

Electrokinetic Valve This view shows the time-dependent transfer of ions during this injection stage. A clean separation of the sample ions is important, and different configurations of the electric field are tested to achieve this.