Abstract: Embodiments of the invention relate to a device for a fluid enclosure. The device includes a sensing device that responds to a change in distance relative to a fluid enclosure. The change in distance is a function of at least one dimension of the fluid enclosure.

Abstract: Embodiments of the invention relate to a heat management system for a portable electronic device. The system includes at least one fuel cell, at least one electrical power consumer electrically connected to the at least one fuel cell, an endothermic fuel system configured to provide fuel to the at least one fuel cell and at least one thermal transmission path thermally coupling the at least one electrical power consumer and the endothermic fuel system. At least a portion of heat produced by the electrical power consumer is transferred to the endothermic fuel system.

Abstract: An adjustable flow field and flow regulation method for an electrochemical device such as field preferably includes a plurality of flow paths between an inlet and an outlet and a plurality of microvalves for regulating fluid flow through the flow paths in response to changes in the operating states of the fuel cell, such as changes in power output or temperature. For example, adjustment of the microvalves may restrict the number of flow paths through which fluid is flowing to alter the effective active area and current density of the flow field. The valves may be selectively opened or closed, either entirely or partially, to maintain a minimum pressure drop between the inlet and outlet. Alternatively or additionally, adjustment of the valves may alter the direction of fluid flow through at least some of the flow paths.

Abstract: An improved membrane electrode assembly (“MEA”) for an electrochemical fuel cell comprises coextensive ion exchange membrane and electrode layers and a rigid fluid impermeable integral seal comprising a sealant material impregnated into the porous electrode layers in sealing regions of the MEA. The integral seal envelops the peripheral region including the side edge of the MEA. The integral seal can circumscribe the electrochemically active area of the MEA and can also extend laterally beyond the edge of the MEA. An integral seal can also be provided around any openings, such as manifold openings, that are formed inside or outside the MEA. The seal has sealing features formed therein, such as raised ribs. Sealing features can be formed from the rigid sealant material or from resilient sealant material applied to the surface of the integral seal.

Abstract: Flow fields comprising a set of fluid distribution channels may be employed in fuel cells for purposes of distributing fluid reactants to an electrochemically active area of the fuel cell. Water management and reactant distribution may be improved by increasing pressure gradients between adjacent channels. Such pressure gradients may be increased by engineering the channels such that the resistance to reactant flow differs along the length of adjacent channels.

Abstract: A method and apparatus for cooling an electrochemical fuel cell which comprises coolant channels extending along the edge of the fuel cell, adjacent to the active area whereby the fuel cell is cooled by evaporating a liquid coolant in the coolant channels. The coolant may then be condensed and recirculated through the coolant channels. Efficient cooling of the fuel cell may be enhanced by reducing the boiling point of the coolant by reducing the pressure across the coolant channels.

Abstract: An improved flow field design for a flow field plate comprises fluid distribution channels having an average width W and separated by landings in which the channels are configured such that unsupported rectangular surfaces of length L and width W on an adjacent fluid diffusion layer have a ratio L/W less than about 3. Improved support may be obtained for instance by using sinusoidally shaped channels. Certain fluid diffusion layer embodiments offer desirable characteristics (for example, low cost, thickness) for use in fuel cells but may also be undesirably weak mechanically and consequently will benefit from improved mechanical support from adjacent flow field plates comprising the present flow field design.

Abstract: A flow field plate for a liquid feed fuel cell has a liquid reactant (for example, fuel) flow field comprising a plurality of horizontal parallel substantially straight channels formed on one major surface of the plate. The plate has another reactant (for example, oxidant) flow field on the other major surface of the plate. The liquid reactant channels may have an open width less than about 0.75 millimeter and/or a length to cross sectional area ratio between about 2180:1 to about 6200:1. A simple four-port configuration is employed for the inlets and outlets for the reactants. The liquid reactant can also serve as a coolant for the fuel cell.

Abstract: An improved flow field design for a flow field plate comprises fluid distribution channels having an average width W and separated by landings in which the channels are configured such that unsupported rectangular surfaces of length L and width W on an adjacent fluid diffusion layer have a ratio L/W less than about 3. Improved support may be obtained for instance by using sinusoidally shaped channels. Certain fluid diffusion layer embodiments offer desirable characteristics (for example, low cost, thickness) for use in fuel cells but may also be undesirably weak mechanically and consequently will benefit from improved mechanical support from adjacent flow field plates comprising the present flow field design.

Abstract: A rear structure of a unitized motor vehicle body with two side wall sections includes a transverse wall located below a rear window cutout. The transverse wall connects the sidewall sections with one another, and has two cross members spaced apart from one another, between which a flat part extends. The first cross member, adjacent to the rear window cutout, is fitted with zero play between the side wall sections and a bearing is provided for the second cross member on each side. The bearing ensures an adjustability of the second cross member between the side wall sections at least in the transverse direction of the vehicle. The flat part is a trim member connected exclusively with the two cross members.