The present disclosure describes a field flow fractionator including (a) a top plate assembly including a top electrically conductive electrode, (b) an o-ring, (c) an electrically insulating frit, (d) an electrically insulating spacer between a bottom surface of the top electrode and the o-ring and the frit, (e) a membrane between the spacer and the frit, and (f) a bottom plate assembly including a bottom electrically conductive electrode.

A micropump that pumps liquid using electrothermally-induced flow is described, along with a corresponding self-regulating pump and infusion pump. The micropump has applications in microfluidic systems, such as biochips. The self-regulating infusion pump is useful for administration of large and small volumes of liquids such as drugs to patients and can be designed for a wide range of flow rates by combining multiple micropumps in one infusion pump system. The micropump uses electrode sequences on opposing surfaces of a flow chamber that are staggered with respect to each other. The opposing surfaces include staggered electrodes that have the same phase and same electrode sequence. As such electrodes with the same phase are staggered and not eclipsed.