Abstract: An electrochemical fuel cell having an anode, an ion transfer membrane and a cathode has liquid water delivered to the fluid flow channels within the cathode so as to maintain a relative humidity of 100% throughout the fluid flow channels. A calibration method and apparatus is described for determining an optimum quantity or range of quantities of liquid water to be delivered to the cathode fluid flow channels under varying operating conditions. An operating method and apparatus is described that ensures an optimum quantity of liquid water is delivered to the cathode fluid flow channels under varying operating conditions.

Abstract: A bipolar fluid flow flied plate for a fuel cell delivers fuel to a porous anode electrode and oxidant to an adjacent porous cathode electrode. The flow field plate comprises an electrically conductive, non-porous sheet into which fluid flow conduits are formed. A first fluid flow channel is patterned into a first face of the sheet and a second fluid flow channel patterned into the opposite face of the sheet. The pattern of the first channel comprises an interdigitated comb that co-operates with a pattern of the second channel comprising a continous serpentine path, so that no portion of the first channel directly overlies the pattern of the second channel over a substantial active area of the sheet. This allows the channels to be formed with combined depths that exceed the total plate thickness, thereby increasing fluid flow volumes.

Abstract: A gasket formed of compressible material and having a first sealing surface and a second sealing surface for providing a fluid seal between a first component and a second component, a plurality of cavities provided within the gasket proximate the first and/or second sealing surfaces and extending over at least a first portion of the gasket to provide increased compressibility of the gasket in the first portion.

Abstract: A gasket formed of compressible material and having a first sealing surface and a second sealing surface for providing a fluid seal between a first component and a second component, a plurality of cavities provided within the gasket proximate the first and/or second sealing surfaces and extending over at least a first portion of the gasket to provide increased compressibility of the gasket in the first portion.