Abstract: A fuel cell includes at least one electrode operatively disposed in the fuel cell, and having a catalytically active surface. The present invention further includes a mechanism for maintaining a substantially uniform maximum catalytic activity over the surface of the electrode.

Abstract: A vacuum conduit connected to a vacuum pump has a shield surface which absorbs radiation to reduce the total radiation falling on the vacuum pump. The vacuum system includes the vacuum conduit connected between a process chamber and the vacuum pump and a surface treatment along at least a portion of the shield surface adapted to absorb radiation. Since the treatment is on the interior surface of the vacuum conduit and does not extend into the center of the conduit, gaseous flow to the pump is not impeded. In this manner radiation entering the vacuum pump and falling on the cryogenic array is reduced without impeding gaseous flow to the cryogenic surface. The system therefore minimizes the radiation load on the cryogenic array in the vacuum pump without impeding the gaseous flow through the vacuum pump.

Abstract: A fuel cell in accordance with a present invention includes a plurality of reactant channels.

Abstract: A fuel cell includes one or more fuel cell assemblies. Each of the fuel cell assemblies has an electrolyte having a length, an anode having a length and disposed on one side of the electrolyte, and a cathode having a length and disposed on the same or the other side of the electrolyte. The fuel cell further includes a plurality of current collectors. Each of the current collectors is substantially embedded within, and continuously extends substantially the respective length of at least one of the electrolyte, anode and cathode.

Abstract: A fuel cell includes a fuel cell stack and a heat exchanger in fluid and thermal communication with the fuel cell stack. The heat exchanger is adjacent the fuel cell stack and both removes excess heat from the fuel cell stack and preheats a gas before entry into the fuel cell stack.

Abstract: A method for making a fuel cell has steps of forming a sacrificial layer on a substrate, forming a fuel cell on the substrate, forming a connector that connects the fuel cell to the substrate, and removing the sacrificial layer. After the sacrificial layer has been removed, the fuel cell is generally free standing over a planar surface of the substrate with a gap defined therebetween.

Abstract: A fuel cell has a MEMS fuel-cell structure including an anode, a cathode, and an electrolyte, formed on a substrate, a portion of the substrate being removed from beneath the MEMS structure to leave the MEMS structure suspended in membrane form. An opening may extend through the substrate to leave the MEMS fuel-cell structure in a cantilevered configuration, supported by only one edge. Additional openings may be formed to relieve mechanical stress near an edge or edges supporting the MEMS fuel-cell structure, and/or to limit heat-conducting paths. Specially adapted methods are disclosed for fabricating the MEMS-based fuel cell in any of its various configurations.

Abstract: A fuel cell or battery has an integral multifunction heater element operable as an integral heater, an integral temperature sensor, and/or an integral aid to current collection from the fuel cell. The integral multifunction heater element is embedded within the electrolyte, anode, or cathode, disposed in thermal contact with at least one of the electrolyte, anode, or cathode, and is formed of a thin film of material of suitable resistivity, such as a refractory metal or conductive oxide, patterned in a suitable pattern. Conductive terminals provide electrical contact to the thin film. The integral multifunction heater element may include a thermistor or thermocouple. Methods are disclosed for fabricating and using the fuel cell with an integral multifunction heater element.

Abstract: A fuel cell assembly including a substrate and an electrolyte disposed on the substrate and having a rib projecting out from the substrate. The rib has first and second side surfaces and a top surface. An anode is disposed on the first side surface and a cathode is disposed on the second side surface. The fuel cell also includes a resistive heater disposed at a location selected from the anode, the cathode, within the electrolyte, between the rib and the substrate, and any combination of these.

Abstract: The invention is a fuel cell comprising a cathode film having a side surface, an anode film having a side surface and an electrolyte film disposed between the cathode film and the anode film and having a side surface. The anode, cathode and electrolyte side surfaces are coplanar. Protons generated at the anode diffuse along the anode side surface, the electrolyte side surface or both towards the cathode side surface. Oxygen ions generated at the cathode diffuse along the cathode side surface, the electrolyte side surface, or both towards the anode side surface.

Abstract: An apparatus and method are provided for controlling a system pressure in a refrigeration system based on a variable load, which includes sensing return pressure and high side pressure in the system, and adjusting the low pressure to optimize a gas flow rate in the system by adding or removing gas from the system through an operating range of pressures in response to the sensed return pressure and the sensed high side pressure. The method further includes calculating a pressure difference between the return pressure and the high side pressure. A second pressure difference is calculated, and if the pressure difference decreases, gas is added to system and if the pressure difference increases, gas is removed from the system.

Abstract: An apparatus and method are provided for controlling a system pressure in a refrigeration system based on a variable load, which includes sensing return pressure and high side pressure in the system, and adjusting the low pressure to optimize a gas flow rate in the system by adding or removing gas from the system through an operating range of pressures in response to the sensed return pressure and the sensed high side pressure. The method further includes calculating a pressure difference between the return pressure and the high side pressure. A second pressure difference is calculated, and if the pressure difference decreases, gas is added to system and if the pressure difference increases, gas is removed from the system.

Abstract: A cryogenic refrigerator includes a shell having a reciprocative displacer and an adsorbent mounted within the shell. In one embodiment, the displacer contains both a regenerative media and the adsorbent, with the regenerative media placed between the adsorbent and a cold end of the displacer. In a method for removing contaminants from the reciprocative displacer, compressed and expanded helium gas is displaced through the displacer, with the adsorbent positioned to adsorb contaminant gases entrained in the helium gas. In another method, a filtering refrigerator containing an adsorbent is coupled to a helium circuit of a refrigeration system to remove contaminants from the circuit.

Abstract: A cryopump is regenerated by roughing the cryopump during purging. Purging and roughing is carried out in first a high temperature mode and then a lower ambient temperature mode. In the lower temperature mode, the cryogenic refrigerator is turned on. If the system fails a rough test after roughing at the lower temperature, it is repurged with the rough valve open.