The present invention is a proton exchange membrane fuel cell that includes a fuel cell assembly. The fuel cell assembly includes a bipolar separator, which includes an anode separator, a cathode separator and a membrane electrode assembly. The bipolar separator includes a highly porous, electrically conductive, non-metallic interface and a non-porous frame. The highly porous interface includes micro-channels for fluid communication and diffusion. Both the cathodic interface and anodic interface of the bipolar separator contain the highly porous material in a fluid diffusion region that interfaces with the active area of the MEA interposed between two bipolar separators. The highly porous material connects the fluid diffusion regions with their respective external sources of oxidant and fuel. The bipolar separator includes a non-porous frame that seals the highly porous material and isolates the fluids within the proton exchange membrane fuel cell.