Uniformity of flow among micro channels in a microscopic structure can have a significant effect on micromanipulators. More uniform flow distribution leads to better performance of devices. In this study, two basic Structures were considered: one, type A structure that has one inlet and two outlets and having flat, convex and concave manifolds, another, trapezoidal structure with different inlet and outlet places and flat, concave and convex manifolds. In this study, numerical modeling to quantitatively study the geometrical and operational parameters’ effect on uniformity and pressure drop have been used. Results show that in basic A type model, inlet manifold angle and outlet manifold angle with respect to the horizontal line, have a significant effect on the distri- bution of flow and increasing in the angle has a negative effect on the uniformity of the flow. In trapezoidal struc- ture, studies show that it is better for the distribution when the inlet flow is aligned with the flow direction in channels and studies on curved inlet and outlet manifolds showed that concave manifold results in better uniformity due to lesser dead volume.
