Selective ion extraction: a separation method for microfluidic devices.

A separation concept, selective ion extraction (SIE), is proposed on the basis of the combination of hydrodynamic and electrokinetic flow controls in microfluidic devices. Using a control system with multiple pressure and voltage sources, the hydrodynamic flow and electric field in any section of the microfluidic network can be set to desired values. Mixtures of compounds sent into a T-junction on a chip can be completely separated into different channels on the basis of their electrophoretic mobilities.

Synchronized cyclic capillary electrophoresis using channels arranged in a triangle and low voltages.

Synchronized cyclic capillary electrophoresis (SCCE) makes use of a closed loop separation channel by which the same sample can be separated during many cycles. This enables the repeated use of the same voltage for separations such that a high total voltage, and thus high efficiency, is obtained for the synchronized components. This can be accomplished by using any type of polygon geometry for the separation channel; and calculations of the available field and number of connections needed for polygons from 3 to 5 sides are presented.

Multiport flow-control system for lab-on-a-chip microfluidic devices.

A multiport system suitable for pressure control on a lab-on-a-chip microfluidic device is described. An algorithm and a strategy for calculating pressures were developed to control the flow from multiple reservoirs for the microfluidic devices. Dye mixing and enzyme assay titration experiments were performed using pressure-driven flow only.