Abstract: A fuel cell system includes a first fluid flow plate including a first plurality of first channels for flow of an oxidant or a fuel. The plurality of first channel has first channel cross-sectional flow areas. A second fluid flow plate includes a second plurality of second channels for flow of an oxidant or a fuel. The plurality of second channels has second channel cross-sectional flow areas. A membrane electrode assembly is located between the first plate and the second plate. The first flow plate includes a passage for a flow of a fluid entirely on a seam side of the first flow plate as the first plurality of first channels. The passage has a cross-sectional area for flow of the fluid smaller than the first channel cross-sectional flow area.

Abstract: A method for use in manufacturing a fuel cell stack includes assembling a membrane electrode assembly to have a membrane between a first gas diffusion layer and a second gas diffusion layer. A bypass blocker is located at a space between a first gas diffusion layer of the membrane electrode assembly and a seal. The blocker is deformed on the seal and deformation is avoided of the blocker at the space such that the blocker inhibits a bypass flow of a reactant through the space between the gas diffusion layer and the seal in a direction of flow of the reactant during operation of the fuel cell. The membrane electrode assembly is located between a first fluid flow plate and a second fluid flow plate.

Abstract: A method for use in manufacturing a fuel cell stack includes assembling a membrane electrode assembly to have a membrane between a first gas diffusion layer and a second gas diffusion layer. A bypass blocker is located at a space between a first gas diffusion layer of the membrane electrode assembly and a seal. The blocker is deformed on the seal and deformation is avoided of the blocker at the space such that the blocker inhibits a bypass flow of a reactant through the space between the gas diffusion layer and the seal in a direction of flow of the reactant during operation of the fuel cell. The membrane electrode assembly is located between a first fluid flow plate and a second fluid flow plate.

Abstract: A fuel cell system includes a first fluid flow plate including a first plurality of first channels for flow of an oxidant or a fuel. The plurality of first channel has first channel cross-sectional flow areas. A second fluid flow plate includes a second plurality of second channels for flow of an oxidant or a fuel. The plurality of second channels has second channel cross-sectional flow areas. A membrane electrode assembly is located between the first plate and the second plate. The first flow plate includes a passage for a flow of a fluid entirely on a seam side of the first flow plate as the first plurality of first channels. The passage has a cross-sectional area for flow of the fluid smaller than the first channel cross-sectional flow area.

Abstract: A fuel cell system includes a first fluid flow plate including a first plurality of first channels for flow of an oxidant or a fuel. The plurality of first channel has first channel cross-sectional flow areas. A second fluid flow plate includes a second plurality of second channels for flow of an oxidant or a fuel. The plurality of second channels has second channel cross-sectional flow areas. A membrane electrode assembly is located between the first plate and the second plate. The first flow plate includes a passage for a flow of a fluid entirely on a seam side of the first flow plate as the first plurality of first channels. The passage has a cross-sectional area for flow of the fluid smaller than the first channel cross-sectional flow area.

Abstract: A fuel cell system includes a first fluid flow plate including a first plurality of first channels for flow of an oxidant or a fuel. The plurality of first channel has first channel cross-sectional flow areas. A second fluid flow plate includes a second plurality of second channels for flow of an oxidant or a fuel. The plurality of second channels has second channel cross-sectional flow areas. A membrane electrode assembly is located between the first plate and the second plate. The first flow plate includes a passage for a flow of a fluid entirely on a seam side of the first flow plate as the first plurality of first channels. The passage has a cross-sectional area for flow of the fluid smaller than the first channel cross-sectional flow area.

Abstract: Methods for increasing the durability of direct oxidation fuel cells are disclosed. In one instance, the method for increasing durability of a vapor fed direct oxidation fuel cell includes reducing fluctuations in output power, provided by the vapor fed direct oxidation fuel cell, to a load. The reduction of the fluctuations in output power can include, in one instance, utilizing a mass flow controller or an electro-osmotive pump to supply fuel to the vapor fed direct oxidation fuel cell.

Abstract: An integrated heat management assembly that is thermally coupled to a component requiring temperature control is provided. The integrated heat management assembly in one embodiment of the invention is a heat switch which includes two opposed surfaces, a first surface being a hot contact which is coupled to the component, and the second surface being a cold contact which is coupled to a heat sink. An actuator which may be a phase changing material, is mechanically coupled to one of the two surfaces such that when the component reaches a threshold temperature, the actuator is triggered to bring the two surfaces into contact. In this manner, the hot surface conducts heat to the cold surface which then delivers heat to the heat sink to thereby lower the temperature of the component. Other embodiments include heat pipes associated with the heat switch in order to further dissipate heat or to divert it to other areas of the component requiring temperature control.

Abstract: A wide-area electrostatically-actuated shutter is provided that includes a thin, flexible, diaphragm that is placed between two rigid electrode structures. In one embodiment of the invention, the diaphragm has a set of openings in it. These openings overlap with corresponding openings in one of the rigid electrodes such that when the diaphragm is contiguous to that electrode, the openings provide apertures through which vaporous fuel can flow. The opposite electrode does not have overlapping openings, thus it forms a seal that prevents gas or vapor from passing through it when the diaphragm is in contact with the opposite electrode. The shutter is actuated electrostatically by an associated driver that applies a voltage to the diaphragm such that when the high voltage is applied to the diaphragm, the diaphragm is attracted to the fixed electrode that is tied to ground.