On chip control of fluids using electrodes

A device for controlling movement of a fluid sample along a flow path comprising:

• a channel defining the flow path, said channel comprising a first surface, an opposite surface including a channel roof, and two sidewalls,
• a working electrode arranged on said first surface to contact the fluid sample when said fluid sample moves along the flow path;
• a reference electrode arranged to directly contact the fluid sample when said fluid sample moves along the flow path;
• and
• a hydrophobic surface portion arranged to directly contact the fluid sample when said fluid sample moves along the flow path;
• wherein at least a portion of said reference electrode is arranged abreast of or downstream at least a portion of said working electrode, and wherein said hydrophobic surface portion is arranged on said opposite surface and abreast of at least a portion of the working electrode and said hydrophobic surface portion covers a portion of the channel roof of the channel and arranged after the reference electrode in the direction of the flow path, and wherein at least another portion of the channel roof is of hydrophilic nature.