Patent ID: 7097931

Claim:
A flow field plate for use in a proton exchange membrane fuel cell for delivering fuel or oxidant to and for removing reaction by-products from a side of the proton exchange membrane, the flow field plate being made of an electrically conducting material and comprising: (a) a substantially planar surface; (b) a flow field formed in the substantially planar surface; (c) a fluid supply manifold through which a fuel or an oxidant is introduced to the flow field and a fluid exhaust manifold through which reaction by-products and excess fuel or oxidant are removed from the flow field, wherein the fuel or oxidant and reaction by-products migrate through the flow field in a fluid migration direction oriented from the fluid supply manifold toward the fluid exhaust manifold; (d) a plurality of spaced lands in the flow field, said lands being arranged in rows that are substantially perpendicular to the fluid migration direction, the lands in each row being staggered from the lands of the adjacent row so as to define a network of channels in the flow field, said channels being oriented diagonal to the fluid migration direction, each of said channels intersecting other channels of the network of channels where each channel crosses a row of lands, each intersection of channels occurring at an orifice in the flow field formed between a plurality of lands; whereby streams of fuel or oxidant and reaction by-products are continually separated and diverted into separate channels by the lands as the streams pass each row of lands in the flow field, and the separated streams are then mixed with streams from adjacent channels.