PCT No. PCT / US95 / 13325 Sec. 371 Date Sep. 28, 1997 Sec. 102(e) Date Sep. 28, 1997 PCT Filed Oct. 10, 1995 PCT Pub. No. WO96 / 12316 PCT Pub. Date Apr. 25, 1996Fuel 
cell stacks comprising stacked separator / 
membrane electrode assembly fuel cells in which the separators comprise a series of 
thin sheet platelets, having individually configured serpentine micro-channel reactant gas humidification active areas and cooling fields therein. The individual platelets are stacked with coordinate features aligned in contact with adjacent platelets and bonded to form a monolithic separator. Post-bonding 
processing includes 
passivation, such as 
nitriding. Preferred 
platelet material is 4-25 mil Ti, in which the features, serpentine channels, tabs, lands, vias, manifolds and holes, are formed by chemical and 
laser etching, 
cutting, pressing or 
embossing, with combinations of depth and through 
etching preferred. The 
platelet manufacturing process is continuous and fast. By employing CAD based 
platelet design and 
photolithography, rapid change in 
feature design can accommodate a wide range of thermal management and humidification techniques. One hundred H2-O2 / PEM fuel 
cell stacks of this IFMT platelet design will exhibit outputs on the order of 0.75 kW / kg, some 3-6 times greater than the current 
graphite plate PEM stacks.