Patent ID: 7217471

Claim:
A method of making a gasketed fuel cell membrane electrode assembly comprising the steps of: i) selecting a fluid transport layer sheet material: ii) selecting Ct % for said fluid transport layer sheet material, wherein C % is compression in thickness of said fluid transport layer sheet material as a percent of uncompressed thickness and Ct % is the target level of C % during use of said fluid transport layer sheet material in a fuel cell membrane electrode assembly; iii) measuring the pressure Pt for which said fluid transport layer sheet material achieves compression of Ct %; iv) positioning between the platens of a press a membrane electrode assembly comprising: a) a polymer electrolyte membrane having an anode face with an outer edge portion, a cathode face with an outer edge portion, and an outer perimeter; b) An anode catalyst material in contact with at least a portion of the anode face of said polymer electrolyte membrane; c) A cathode catalyst material in contact with at least a portion of the cathode face of said polymer electrolyte membrane; d) an anode-side fluid transport layer comprising said fluid transport layer sheet material, said anode-side fluid transport layer being in contact with said layer of anode catalyst material, said anode-side fluid transport layer not extending over the outer edge portion of the anode side of said polymer electrolyte membrane; e) a cathode-side fluid transport layer comprising said fluid transport layer sheet material, said cathode-side fluid transport layer being in contact with said layer of cathode catalyst material, said cathode-side fluid transport layer not extending over the outer edge portion of the cathode side of said polymer electrolyte membrane; v) depositing a gasket material in the outer edge portions of the anode and cathode faces of said polymer electrolyte membrane; vi) compressing said membrane electrode assembly to a pressing pressure Pp which is between 90% and 110% of Pt; vii) substantially fixing said gasket material so as to form a gasketed fuel cell membrane electrode assembly; and viii) positioning one or two patterning plates, which bear a negative relief of a raised-ridge microstructured contact pattern, between one or both platens of said press and said gasket material, wherein said raised-ridge microstructured contact pattern comprises ridges which meet at joining points, wherein no more than three ridges meet at any one joining point, wherein said raised-ridge microstructured contact pattern is a hexagonal pattern.