(EP963614-A2)      A separator comprises a gas barrier with an electrically conducting pathway and a porous electroconductive member of expanded metal mesh, metal foam, conducting polymer foam, porous conductive C or their mixtures, in electrical contact with each side of the pathway. Alternatively, a gas impermeable material is placed within a portion of a porous electroconductive sheet.    Also claimed are: (a) a separator comprising two conductive sheets with a conductive gas barrier between the sheets; and (b) a fluid cooled bipolar plate comprising an electroconductive anode and cathode flow field and an electroconductive cooling flow field including fluid impermeable barriers defining a fluid passage.    The pathway is formed from a 2nd porous electroconductive member. The gas barrier is a metal or a polymer, and is parallel with the electroconductive member. A cooling fluid channel is formed within the gas barrier. The gas barrier material is an epoxy, polyether-sulphone, nylon, polycarbonate, perfluorinated sulphonic acid polymer, or Ti, stainless steel, Al, Mg and their alloys, and is formed along one face or within a central portion of the porous sheet. The cooling fluid channels are several fluid tubes, through or in contact with the gas impermeable material.    Cooling fluid inlet and outlet manifolds are connected to the cooling fluid flow field. A frame is positioned around the cooling fluid flow field.    USE -   For fuel cells.    ADVANTAGE -   The separator can be made thinner and can support higher current densities in the fuel cell, as well as having specific reactant gas impermeability, etc.    (US6146780-A)      A separator comprises a gas barrier with an electrically conducting pathway and a porous electroconductive member of expanded metal mesh, metal foam, conducting polymer foam, porous conductive C or their mixtures, in electrical contact with each side of the pathway. Alternatively, a gas impermeable material is placed within a portion of a porous electroconductive sheet.    Also claimed are: (a) a separator comprising two conductive sheets with a conductive gas barrier between the sheets; and (b) a fluid cooled bipolar plate comprising an electroconductive anode and cathode flow field and an electroconductive cooling flow field including fluid impermeable barriers defining a fluid passage.    The pathway is formed from a 2nd porous electroconductive member. The gas barrier is a metal or a polymer, and is parallel with the electroconductive member. A cooling fluid channel is formed within the gas barrier. The gas barrier material is an epoxy, polyether-sulphone, nylon, polycarbonate, perfluorinated sulphonic acid polymer, or Ti, stainless steel, Al, Mg and their alloys, and is formed along one face or within a central portion of the porous sheet. The cooling fluid channels are several fluid tubes, through or in contact with the gas impermeable material.    Cooling fluid inlet and outlet manifolds are connected to the cooling fluid flow field. A frame is positioned around the cooling fluid flow field.    USE -   For fuel cells.    ADVANTAGE -   The separator can be made thinner and can support higher current densities in the fuel cell, as well as having specific reactant gas impermeability, etc.