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 membrane-electrode assembly for a solid oxide fuel cell is provided. The membrane-electrode assembly has a substantially constant-thickness electrolyte layer. The electrolyte layer distinguishes first and second electrolyte layer surfaces arranged in a three-dimensional pattern with opposite first and second planar pattern surfaces. The three-dimensional pattern has a first set of features extending inward from the first planar pattern surface. It has a second set of features extending inward from the second planar pattern surface opposite to the first planar pattern surface. A first electrode layer is adjacent and conforming to the first electrolyte layer surface. At least one mechanical support structure exists within some or all of the second set of features. A second electrode layer is adjacent and conforming to the second electrolyte layer surface and to at least one mechanical support structure. The membrane-electrode assembly is deposited on a substrate with at least one through hole.

Abstract: A micromanipulator comprising a tubular structure and a structural compliance mechanism that are formed from a tube made of an elastic and/or superelastic material. The micromanipulator is useful for intravascular interventional applications and particularly ultrasonic imaging when coupled with an ultrasound transducer. Also disclosed are medical devices for crossing vascular occlusions using radio-frequency energy or rotary cutting, preferably under the guidance of real-time imaging of the occlusion, as well as accompanying methods.

Abstract: Solid oxide fuel cells selectively transport oxygen ions through an electrolyte membrane. The maximum oxygen ion transport rate limits the power density of the fuel cell. By ion irradiating the electrolyte membrane and/or the cathode, the oxygen absorption, dissociation, and incorporation rates can be improved, leading to higher ion transport rates and better fuel cell performance.

Abstract: The present invention provides nano-patterning based on flow of an ion current within an ionic conductor to bring ions in proximity to a microscope probe tip touching a surface of the conductor. These ions are then electrochemically reduced to form one or more features on the surface. Ion current flow and the electrochemical reaction are driven by an electrical potential difference between the tip and the ionic conductor. Such features can be erased by reversing the polarity of the potential difference. Indentations can be formed by mechanically removing features formed as described above. The ions in the ion current can be provided by the ionic conductor and/or by oxidation at a counter electrode.

Abstract: An improved two-step replication process for fabrication of porous metallic membranes is provided. A negative of a porous non-metallic template is made by infiltration of a liquid precursor into the template, curing the precursor to form a solid negative, and removing the template to expose the negative. Metal is deposited to surround the exposed negative. Removal of the negative provides a porous metallic membrane having pores which replicate the pores of the original template membrane. The negative is kept immersed in a liquid at all times between removing the template and depositing the metal. This immersion eliminates damage to the negative that would be incurred in drying the negative out between these processing steps. Another aspect of the invention is metallic membranes prepared according to the preceding method. For example, metallic membranes having pores smaller on one side than on the other side of the membrane are provided.

Abstract: Improved controlled therapy is provided with a polymer multi-layer structure having a predetermined micro-fabricated spatial pattern (e.g., reservoirs and channels). More specifically, all geometrical details of the spatial pattern are substantially predetermined. The increased control of pattern geometry provided by the invention allows for improved control of therapy. In preferred embodiments, the polymer multi-layer structure of the invention is biodegradable, but has an in vivo lifetime that is greater than the duration of the therapy being provided. Thus, the geometrical pattern of the polymer structure that controls delivery of the therapy persists without significant change during therapy, and the structure degrades after completion of therapy. In this manner, possible interference of degradation by-products with therapy is minimized, and delivery of therapy does not depend on details of how degradation proceeds.

Abstract: A direct methanol fuel cell is described. The DMFC uses a solid electrolyte that prevents methanol crossover. Optional chemical barriers may be employed to prevent CO2 contamination of the electrolyte.

Abstract: Sensors and systems for electrical, electrochemical, or topographical analysis, as well as methods of fabricating these sensors are provided. The sensors include a cantilever and one or more probes, each of which has an electrode at its tip. The tips of the probes are sharp, with a radius of curvature of less than about 50 nm. In addition, the probes have a high aspect ratio of more than about 19:1. The sensors are suitable for both Atomic Force Microscopy and Scanning Electrochemical Microscopy.

Abstract: This document describes fabrication method for a thin film electrolyte membrane and electrochemical devices including the membrane. As an electrolyte becomes thinner, the conductance of the electrolyte increases. Consequently, the performances of solid-state ionic devices like fuel cells, gas sensors and catalytic supporters, can be improved and operating temperature can be lowered.

Abstract: This document describes the nano-scaling effects of solid-state oxygen-ion conductors when the thickness of an ionic conductor membrane as well as size of the grains within the membrane are scaled down to less than 200 nm. By using such solid-state oxygen-ion conductor membranes as solid-state electrolytes, the performances of solid-state ionic devices like fuel cells, gas sensors and catalytic supporters, can be improved and operating temperature can be lowered.

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: A membrane electrode assembly (MEA) having a nano-tubular patterned structure and having solid (instead of porous) electrode layers is provided. Increased mechanical strength is provided by the use of solid electrode layers. The electrode layers are sufficiently thin to permit the flow of reactants to the electrolyte. The nano-tubular pattern includes multiple closed-end tubes and increase the reaction area to volume ratio of the MEA. The nano-tubular pattern also serves to increase mechanical strength, especially in a preferred honey-comb like arrangement of the closed-end tubes. A catalyst is preferably disposed on the anode and cathode surfaces of the MEA, and is preferably in the form of separated catalyst islands in order to increase reaction area. MEAs according to the invention can be fabricated by layer deposition on a patterned template. Atomic layer deposition is a preferred deposition technique.

Abstract: An improved two-step replication process for fabrication of porous metallic membranes is provided. A negative of a porous non-metallic template is made by infiltration of a liquid precursor into the template, curing the precursor to form a solid negative, and removing the template to expose the negative. Metal is deposited to surround the exposed negative. Removal of the negative provides a porous metallic membrane having pores which replicate the pores of the original template membrane. The negative is kept immersed in a liquid at all times between removing the template and depositing the metal. This immersion eliminates damage to the negative that would be incurred in drying the negative out between these processing steps. Another aspect of the invention is metallic membranes prepared according to the preceding method. For example, metallic membranes having pores smaller on one side than on the other side of the membrane are provided.

Abstract: Solvent bonding by exposure to a solvent vapor is provided. Vapor phase solvent bonding provides accurate and precise control of the amount of solvent provided to the polymer bodies or objects being bonded. Such precision control of solvent quantity enables solvent bonding to be performed in a manner that does not damage or destroy micro-patterns present in the polymer bodies being bonded. Vapor solvent bonding can be performed in two regimes: saturated and linear. In the saturated regime, the temperature of a polymer body surface is less than the condensation temperature of a polymer vapor. Thus, a liquid condensate will tend to form in this regime. In the linear regime, the temperature of a polymer body surface is greater than the condensation temperature of the polymer vapor. Although a liquid condensate will not form, bonding can still be performed.

Abstract: Methods for compression molding through holes in polymer layers are provided, as are the resulting patterned polymer layers. Two key aspects of the invention are provision of a mold and substrate having different mechanical hardness, and provision of room for local flow of material. These aspects of the invention facilitate formation of through holes by compression molding that are not blocked or partially blocked by undesirable material. These polymer layers can be formed into three dimensional patterned structures by bonding patterned layers together. Since the layers include through holes, a three-dimensional polymer pattern can be formed. These patterned polymer layers and three dimensionally patterned polymer constructs have a wide variety of applications. For example, these constructs can be used for fabrication of micro-fluidic devices, and/or can be used for various medical and biological applications including drug delivery devices and tissue engineering devices.

Abstract: A sensor embedded in a high temperature metal is incorporated into a sensing system for measuring temperature, strain, or other properties of a metal structure. An optical system transmits light to and receives output signals from the sensor for analysis. With rotating structures, an optical fiber lead transmits light between the sensor and external surface of the structure along its rotational axis, allowing the lead to remain fixed with respect to the optical system as the structure rotates at high speeds.

Abstract: A method for embedding fiber optic sensors in a high melting temperature metal structure produces embedded sensors that are uniformly and closely bonded with the metal and do not slip upon metal expansion and contraction. The structure is built in layers onto the sensor. On top of a first thin sputter-coated metallic layer, approximately 1-3 ?m thick, is electroplated a second thin layer, approximately 0.25-2 mm thick. Finally, a metal structure is built around the thin metallic layers by laser cladding, casting, welding, or other method.