Microfluidic mixing using periodically induced secondary potential in electroosmotic flow

This research develops a novel microfluidic mixing in a simple manner: An electrode was installed between two primary electrodes that generate DC fields and induce electroosmotic flow (EOF). While EOF was introduced by DC fields from the two primary electrodes, the active mixing could be achieved if potential was supplied to the secondary anode. Normal EOF was recovered as soon as the supply of potential to the secondary anode was terminated. By periodically repeating the on/off phase of the driving potential to the secondary anode, oscillating and vortex swirling flow patterns occurred and vigorous and efficient mixing was obtained.

► We present a microfluidic mixing method using a periodically induced secondary potential.
► The periodic secondary potential induces fast mixing with low electric fields in a simple manner.
► The mixing performance of a periodic secondary voltage is verified by both experimental and simulation results.