Abstract: A simple, inexpensive and highly efficient fuel cell has boundary structures made of a photo-sensitive material in combination with selective patterning. Printed circuit board (PCB) fabrication techniques combine boundary structures with two and three dimensional electrical flow path. Photo-sensitive material and PCB fabrication techniques are alternately or combined utilized for making micro-channel structures or micro stitch structures for substantially reducing dead zones of the diffusion layer while keeping fluid flow resistance to a minimum. The fuel cell assembly is free of mechanical clamping elements. Adhesives that may be conductively contaminated and/or fiber-reinforced provide mechanical and eventual electrical connections, and sealing within the assembly. Mechanically supporting backing layers are pre-fabricated with a natural bend defined in combination with the backing layers' elasticity to eliminate massive support plates and assist the adhesive bonding.

Abstract: A simple, inexpensive and highly efficient fuel cell has boundary structures made of a photo-sensitive material in combination with selective patterning. Printed circuit board (PCB) fabrication techniques combine boundary structures with two and three dimensional electrical flow path. Photo-sensitive material and PCB fabrication techniques are alternately or combined utilized for making micro-channel structures or micro stitch structures for substantially reducing dead zones of the diffusion layer while keeping fluid flow resistance to a minimum. The fuel cell assembly is free of mechanical clamping elements. Adhesives that may be conductively contaminated and/or fiber-reinforced provide mechanical and eventual electrical connections, and sealing within the assembly. Mechanically supporting backing layers are pre-fabricated with a natural bend defined in combination with the backing layers' elasticity to eliminate massive support plates and assist the adhesive bonding.

Abstract: A simple, inexpensive and highly efficient fuel cell has boundary structures made of a photo-sensitive material in combination with selective patterning. Printed circuit board (PCB) fabrication techniques combine boundary structures with two and three dimensional electrical flow path. Photo-sensitive material and PCB fabrication techniques are alternately or combined utilized for making micro-channel structures or micro stitch structures for substantially reducing dead zones of the diffusion layer while keeping fluid flow resistance to a minimum. The fuel cell assembly is free of mechanical clamping elements. Adhesives that may be conductively contaminated and/or fiber-reinforced provide mechanical and eventual electrical connections, and sealing within the assembly. Mechanically supporting backing layers are pre-fabricated with a natural bend defined in combination with the backing layers' elasticity to eliminate massive support plates and assist the adhesive bonding.

Abstract: The invention relates to a method for producing a measuring transducer in order to transform at least one physical variable into at least one electric variable. According to the invention, a plurality of planar, insulating and conductive layers (21-26 and 11-17) are respectively structured according to predefineable models which are adapted to each other and which are assembled in order to form a multi-layered arrangement.

Abstract: A method and device for fuel cell heat and water management is provided. A thermally and electrically conductive hydrophilic heat and mass transport element is provided to the fuel cell spanning from inside to outside the cell. The transport element is deposited between current collector and gas diffusion layers, where heat is transported along the transport element from an interior portion of the element inside the cell to an exterior portion of the element outside the cell. Liquid water is transported along the element into or out of the cell, and heat is removed from the exterior portion by any combination of radiation, free convection and forced convection, and where the liquid water is removed from the exterior portion by any combination of convection driven evaporation and advection. The water is added to the cell from the exterior to the interior by any combination of advection and capillary wicking.

Abstract: A polymer electrolyte membrane fuel cell water management device is provided. The device includes a hydrophilic water transport element spanning from inside the fuel cell to outside the fuel cell and disposed between a gas diffusion layer and a current collector layer in the cell. The transport element includes an intermediate wick outside the fuel cell that is hydraulically coupled to the transport element, and has a transport element structure integrated with a flow field structure within the fuel cell. The device further includes an electroosmotic pump, where the pump is located outside the fuel cell and is hydraulically coupled to the intermediate wick. The hydraulically coupled pump actively removes excess water from the flow field structure and the gas diffusion layer through the transport element, where a key aspect of the invention is the decoupling of water removal from oxidant delivery and reduced parasitic loads.

Abstract: Water flooding at the cathode of a fuel cell is a common problem in fuel cells. By integrating an electroosmotic (EO) pump to remove product water from the cathode area, fuel cell power can be increased. Integration of EO pumps transforms the designs of air channel and air breathing cathodes, reducing air pumping power loads and increasing oxidant transport. Hydration of gas streams, management of liquid reactants, and oxidant delivery can also be accomplished with integrated electroosmotic pumps. Electroosmotic pumps have no moving parts, can be integrated as a layer of the fuel cell, and scale with centimeter to micron scale fuel cells.

Abstract: A bistable minivalve includes a movable component, an actuator that is electrostatically, magnetically, or mechanically coupled to the movable component for controllably switching the movable component between open and closed states, and a casing providing structural support. The movable component has an actuation surface [300] movably positioned in the valve conduit and a bistable element attached to the actuation surface providing mechanical stability to the open and closed states of the movable component. The bistable element may be realized as a pair of elastic buckling beams [302, 304] attached at their midpoints to opposite sides of the actuation surface. Optionally, there may also be elastic support beams [306, 308] attached at their endpoints to the actuation surface and attached at their midpoints to the elastic buckling beams.

Abstract: The present invention provides a miniature gas turbine engine for power generation. The engine has a highly integrated unitary rotor shaft where turbine, compressor and shaft are made in one piece in one fabrication process. The turbine and compressor are positioned back to back on the shaft in an overhung configuration, allowing the front bearings to be located in the cold zone of the engine. Preferably, the Mold SDM fabrication technique is utilized to make the unitary rotor shaft in one monolithic part out of ceramics such as silicon nitride, eliminating the need for post process assembly while strengthening the integrity, reliability, and performance of the unitary rotor shaft. Integrated with a permanent magnet in the unitary rotor shaft, the miniature gas turbine engine can generate electric power of 1 kW or less. Additionally, the axial length of the miniature gas turbine engine is about 100 mm or less.

Abstract: A simple, inexpensive and highly efficient fuel cell has boundary structures made of a photo-sensitive material in combination with selective patterning. Printed circuit board (PCB) fabrication techniques combine boundary structures with two and three dimensional electrical flow path. Photo-sensitive material and PCB fabrication techniques are alternately or combined utilized for making micro-channel structures or micro stitch structures for substantially reducing dead zones of the diffusion layer while keeping fluid flow resistance to a minimum. The fuel cell assembly is free of mechanical clamping elements. Adhesives that may be conductively contaminated and/or fiber-reinforced provide mechanical and eventual electrical connections, and sealing within the assembly. Mechanically supporting backing layers are pre-fabricated with a natural bend defined in combination with the backing layers' elasticity to eliminate massive support plates and assist the adhesive bonding.

Abstract: In a micro gas turbine engine, a capacitive sensor is used for measuring a tip clearance of a radial compressor section thereof, and an actuator is used for axially displacing a rotor shaft in response to an output from the capacitive sensor. Because the capacitive change gives an accurate measure of the size of the tip clearance, a particularly high sensitivity can be achieved in parts where the tip clearance is small, thereby providing a highly precise tip clearance control.

Abstract: The present invention provides a miniature gas turbine engine for power generation. The engine has a highly integrated unitary rotor shaft where turbine, compressor and shaft are made in one piece in one fabrication process. The turbine and compressor are positioned back to back on the shaft in an overhung configuration, allowing the front bearings to be located in the cold zone of the engine. Preferably, the Mold SDM fabrication technique is utilized to make the unitary rotor shaft in one monolithic part out of ceramics such as silicon nitride, eliminating the need for post process assembly while strengthening the integrity, reliability, and performance of the unitary rotor shaft. Integrated with a permanent magnet in the unitary rotor shaft, the miniature gas turbine engine can generate electric power of 1 kW or less. Additionally, the axial length of the miniature gas turbine engine is about 100 mm or less.

Abstract: In a micro gas turbine engine, a capacitive sensor is used for measuring a tip clearance of a radial compressor section thereof, and an actuator is used for axially displacing a rotor shaft in response to an output from the capacitive sensor. Because the capacitive change gives an accurate measure of the size of the tip clearance, a particularly high sensitivity can be achieved in parts where the tip clearance is small, thereby providing a highly precise tip clearance control.