Patent ID: 7201992

Claim:
A fuel cell ( 12 ) for generating electrical current from first and second reactant streams, comprising: a. a membrane electrode assembly ( 46 ); b. a first reactant flow field ( 80 ) secured adjacent a surface selected from the group consisting of a first surface ( 48 ) and a second surface ( 50 ) of the membrane electrode assembly ( 46 ) for directing flow of a first reactant adjacent the selected surface ( 48 , 50 ) of the assembly ( 46 ); c. wherein the first reactant flow field ( 80 ) defines a plurality of two-pass circuits ( 82 , 84 , 86 , 88 ), each two-pass circuit being in fluid communication with a first reactant inlet ( 90 ) for directing the first reactant into the fuel cell ( 12 ), and in fluid communication with a first reactant outlet ( 92 ) for directing the first reactant out of the fuel cell ( 12 ); and, d. wherein the reactant flow field ( 80 ) defines a common turn-around ( 96 ) in fluid communication with each two-pass circuit ( 82 , 84 , 86 , 88 ), and the common turn-around ( 96 ) being defined between the first reactant inlet ( 90 ) and the first reactant outlet ( 92 ) so that the first reactant flowing from the first reactant inlet ( 90 ) to the first reactant outlet ( 92 ) passes through the common turn-around ( 96 ) and raises within the common turn around ( 96 ) with the first reactant passing through the other of the plurality of two-pass circuits ( 84 , 86 , 88 ).