The invention provides a fuel cell stack including a layer of encapsulating material disposed about the separator plate, MEA, and reactant manifold, wherein the reactant manifold is bounded at least in part by the encapsulating material. The fuel cell stack also includes a first opening through the plate body to the first face from the second face, and an open channel in the second face extending from the opening toward a periphery of the plate. The invention also provides a fuel cell stack having a first face including an opening for passage of a reactant therethrough, a first reactant flow field defined thereon, and a first raised surface formed thereon substantially surrounding the opening. The first raised surface is configured and adapted to mate with a second surface on a face of an adjacent plate to create a flow obstruction for encapsulating material.