Manipulation of microfluidic flow pattern by optically controlled electroosmosis

Light is used to dynamically control the pattern of electroosmotic flow in a microfluidic channel. One wall of the channel is formed by a photoconductor film in a specific geometry. Illumination of this surface results in an increase of the conductivity that modifies the structure of the electric field inside the channel. A dramatic change of the electroosmotic flow pattern can be achieved. This approach provides useful capabilities for the manipulation of fluids in microfluidic systems like directing flow and mixing.