US Patent 7169503 Basic fuel cell element limiting methanol crossing through the electrolyte

The PEM (Proton Exchange Membrane) type basic fuel cell element has a high efficient when only the protons migrate towards the cathode, excluding any other species that could react with the cathode. It is composed mainly of a silicon substrate (25) crossed by pipes (26), terminating on the bottom of a dish. The cathode (20) is deposited on the bottom of this dish, covered by a first layer of electrolyte (23). An internal part (32) of the anode is embedded between two layers (23) of electrolyte, while an external part (31) is placed on the upper part of it. The internal part (32) is preferably a grid or a foam such that fuel migrating towards the cathode can be consumed and protons can pass through.