Patent ID: 8101320

Claim:
A fuel cell assembly comprising: a plurality of fuel cells arranged as a stack, each of said fuel cells comprising: an anode configured to accept a hydrogen-bearing reactant; a cathode configured to accept an oxygen-bearing reactant; and a bipolar plate disposed between said anode and said cathode such that an anode flowpath and a cathode flowpath defined on opposing surfaces of said bipolar plate are configured such that a respective one of said hydrogen-bearing reactant and said oxygen-bearing reactant may be delivered to a corresponding one of said anode and said cathode, said anode flowpath and said cathode flowpath arranged such that at least a portion of a travel distance therealong defines: an active region formed along a portion of a surface of said bipolar plate, said active region adjacent a respective one of said anode and said cathode to facilitate a catalytic reaction therebetween, and an inactive region formed along a portion of said surface of said bipolar plate that is spaced away from said active region, said inactive region configured such that a catalytic reaction does not take place therein; and a water transport unit placed between an adjacently stacked anode and cathode within at least said inactive region such that they are in moisture exchange communication with one another, said water transport unit comprising: a moisture-donating fluid channel configured to receive flow from at least one moisture-rich flowpath in said bipolar plate that corresponds to one of said adjacently stacked anode or cathode; and a moisture-accepting fluid channel configured to deliver flow to the other of said flowpath in said bipolar plate that corresponds to said anode or said cathode, said moisture-accepting fluid channel cooperative with said moisture-donating fluid channel such that upon passage of a moisture-donating fluid through the latter, at least some of the water contained therein passes to the former, wherein said moisture-donating fluid channel and said moisture-accepting fluid channel are separated by a moisture-permeable membrane, and wherein at least one side of said moisture-permeable membrane is substantially covered with a hydrophilic diffusion media.