<p>A microfluidic device for the splitting or sequencing of fluid flow includes a plurality of upstream and/or downstream chambers coupled via microfluidic channels. For splitting fluid, a substrate is provided that includes a main chamber and a plurality of downstream sub-chambers. Each sub-chamber is associated with a sealable vent hole. Fluid is selectively moved into the desired sub-chamber of interest by unsealing its associated vent hole. Fluid is then pumped into the sub-chamber, for example, by rotating the substrate. For flow sequencing, a substrate is provided that includes a plurality of upstream chambers coupled to at least one downstream chamber. Each upstream chamber has an associated vent hole that can be selectively opened. The substrate is then rotated and fluid contained in the upstream chamber with the valve in the unsealed state will then pass to the at least one downstream chamber.</p>