material although shown notionally as having a thick walled structure the individual plates 65 a and 65 b also referred to herein as half plates that make up the assembly 65 preferably employ thin sheet like or foil like structure as will be shown and described in more detail below as such fig2 should not be used to infer the relative assembly 65 thickness simplified opposing surfaces defined by the facingly adjacent half plates 65 a and 65 b are provided to separate each mea 50 and accompanying diffusion layers 55 60 from adjacent meas and layers neither of which are shown in the stack 1 one half plate 65 a engages the anode diffusion layer 55 while a second half plate 65 b engages the cathode diffusion layer 60 the two thin facing metal sheets that make up the half plates 65 a 65 b define u2014 upon suitable compression and related joining techniques u2014 an assembled plate 65 each half plate 65 a and 65 b which upon assembly as a unitary whole would make up the bipolar plate 65 defines numerous reactant gas flow channels 70 along a respective plate face although bipolar plate 65 is shown for stylized purposes defining purely rectangular reactant gas flow channels 70 and surrounding structure it will be appreciated by those skilled in.