The development of microfluidic free-flow electrophoresis

The free-flow electrophoresis (FFE) was first put forward in last century, and since then it has been widely applied in analysis of bio-organic and inorganic substances. Its continuous sample preparation and mild separation conditions also make it interesting for online monitoring and detection applications. With the developments of micromachining and microsystem, several microfluidic FFE devices had been developed and characterized. Microfluidic FFE (μ-FFE) devices can offer new possibilities that are the rapid separations within several seconds or below and the requirement for the sample volumes in the microliter range. This review is intended to introduce the developments of designs and applications on Microfluidic FFE.