We demonstrate that the coffee ring effect in drying microdroplets is strongly influenced by the topography of the substrate. The fluid motion and particle distribution inside the evaporating droplet were investigated through Particle image Velocimetry (PIV) experiments. Numerical simulations were also performed and the results were compared with the experiments. It was observed that the patterning in the self-assembly can be controlled and is expected to contribute significantly in the fabrication of devices associated with many applications such as sensor, soft lithography and touch screen in smart phones. © 15CBMS-0001.