Novel electrohydrodynamic (EHD) pump driven micro mixers are fabricated to study fluidic mixing in micro channels experimentally. Microscopic flow visualization experiments are presented to visualize microscale mixing in micro mixers. Mixing is achieved in a laminar flow by perturbing the main flow with EHD pumps in a micro channel. EHD pumps operate in a way to form cross-stream mixing mechanism by using either dc voltage or traveling wave signals. Experimental results show transverse or vortical cross-stream flows are generated within hundreds microns distance in the micro mixers, thereby increasing mixing.