Abstract: The invention, in various embodiments, provides planar fuel cell stack of a plurality of fuel cells, comprising an anode layer including a first anode and a second anode, an electrolyte layer, a cathode layer including a first cathode and a second cathode, and at least one interconnect at least partially disposed within the electrolyte layer, and electrically and mechanically coupling the first anode and the second cathode. In various embodiments, structural supports are provided, the fuel cells are sized to be portable, and are manufactured to produce desired power densities and/or voltages.

Abstract: A micromachined device for efficient thermal processing at least one fluid stream includes at least one fluid conducting tube having at least a region with wall thickness of less than 50 ?m. The device optionally includes one or more thermally conductive structures in thermal communication with first and second thermally insulating portions of the fluid conducting tube. The device also may include a thermally conductive region, and at least a portion of the fluid conducting tube is disposed within the region. A plurality of structures may be provided projecting from a wall of the fluid conducting tube into an inner volume of the tube. The structures enhance thermal conduction between a fluid within the tube and a wall of the tube. A method for fabricating, from a substrate, a micromachined device for processing a fluid stream allows the selective removal of portions of the substrate to provide desired structures integrated within the device.

Abstract: Fuel cells having an efficient means of thermal insulation such that all of the components requiring high temperature operation are contained within a single housing and whereby such thermal insulation is disposed exterior to such housing.

Abstract: Fuel cells having an efficient means of thermal insulation such that all of the components requiring high temperature operation are contained within a single housing and whereby such thermal insulation is disposed exterior to such housing.

Abstract: The invention relates to a fuel cell apparatus that includes a housing. The housing defines a substantially isothermal zone which integrates a fuel cell and a tail gas burner with the isothermal zone. The fuel cell and the tail gas burner are in thermal communication and share a common wall. In one embodiment, the housing further integrates a fuel reformer, where the fuel reformer is in thermal communication with the fuel cell. In one embodiment, the fuel cell and the tail gas burner can be arranged to produce a power density greater than or equal to about 2 W/cc. The fuel cell preferably is a solid oxide fuel cell.

Abstract: A structure including a support defining an opening, and a tensilely stressed thin-film membrane disposed to occlude the opening, the membrane contacting at least a portion of the support. The stressed membrane includes a material having a characteristic crack spacing greater than one-half of a minimum dimension of the membrane and less than ten times the minimum dimension. A structure including a support defining a opening having a minimum opening dimension, and a compressively stressed thin-film membrane disposed to occlude the opening, the membrane contacting at least a portion of the support. The stressed membrane includes a membrane material having a critical aspect ratio for buckling that is greater than a ratio of one-half of the minimum opening dimension to a thickness of the membrane, and the critical aspect ratio for buckling is less than a ratio of ten times the minimum opening dimension to the thickness of the membrane.