Abstract: In a fuel cell for generating electrical energy at least one electrically conductive gas distributor is a reticulated three dimensional structure, comprising a ductile basic skeleton (46) of a first metal or metal alloy used under compression in its elastic domain and a conductive top layer (42) of a corrosion resistant metal or alloy.

Abstract: A device comprising an inhomogeneous solid electrolyte of doped materials which are exclusive conductors for a predetermined chemical species. The electrolyte has a first region and a second surface region, the thickness of which is usually less than 400 .ANG.. In a first alternative embodiment, the second region is formed by increasing the doping percentage of the material constituting the first region. In a second alternative embodiment, the second region is formed by depositing a thin film of doped material chosen so as to ensure that the work function to be provided by the predetermined chemical species is of lower value than in the case of the doped material constituting the first region.

Abstract: Electrochemical sensor for the concentrations of species in a fluid mixture comprising a measuring cell of the type having a partial pressure internal reference electrode incorporating a catalysis region in which the gaseous mixture is brought into thermodynamic equilibrium and functioning according to the so-called "assay" process, so that only a small quantity of the gaseous mixture to be analyzed is admitted into the sensor. It also comprises a supplementary cell functioning as an ionic pump, so as to continuously modify the composition of the gaseous mixture admitted into the sensor under the control of a regulatable electric current.

Abstract: The invention provides a process comprising a step for depositing at least one intrinsic or doped monocrystalline silicon layer on a substrate, also monocrystalline, followed by a step for forming a thin silica layer at the level of the original substrate-silicon interface. The silica layer is obtained by oxidation through the substrate, followed by a heat treatment step during which the monocrystalline silicon is oxidized by the implanted oxygen ions. The first approach may take place according to two variants: thermal or plasma oxidation of the silicon-substrate interface. Oxidation takes place during the return to ambient temperature of the stack of layers after the deposit has been made.

Abstract: The method of reduction comprises two successive steps. The first step consists in forming an electrolyte layer at the surface of the layer to be reduced which is an oxidized surface layer of a substrate. During the second step, the layer is reduced through the layer of electrolyte which is an ionic conductor for the ionizing species. The second step is carried out in a first variant by thermal reduction in a reducing atmosphere and in a second variant by exposure to a reducing plasma.

Abstract: A device for inserting a sensor into the exhaust conduits of an internal combustion engine, wherein the support of the sensor is formed by the sealing element of the assembly gaskets of these exhaust conduits. In accordance with a first variation the sensor is inserted by means of the gasket located between the manifold and the exhaust pipe, and in accordance with a second variation the sensor is inserted by means of the gasket located between the cylinder head and the exhaust manifold. This gasket may comprise several sensors, one per exhaust port. The sensor to be inserted may in particular be of the electrochemical collector type comprising a measuring cell of the concentration-stack type.

Abstract: An electrochemical sensor for measuring relative concentrations of reactive species in a fluid mixture with a first catalytic enclosure for bringing the fluid mixture into thermodynamic equilibrium, and a second enclosure having an electrochemical cell which is responsive to an excess of one of the reactive species with respect to stoichiometry of the reaction. Additional structure for selectively impeding the transfer of species of the fluid mixture to be analyzed are located upstream of or combined with the first enclosure and serve to modify the ratio of relative concentrations of the reactive species of the fluid mixture in predetermined proportions.

Abstract: The electrochemical sensor for measuring concentrations of species in a fluid mixture is of the type comprising a partial-pressure internal reference electrode constituted by a system in which a metal is combined with an oxide of said metal. One face of the reference electrode is in contact with a solid electrolyte. An inert protective coating deposited on all the other faces of the electrode is impervious to the species which are present in the fluid mixture.

Abstract: The sensor comprises an electrochemical measuring cell having a flat structure and constituted by two electrodes in contact with a solid electrolyte. One electrode which is formed of catalytic material has an extension of predetermined length in at least one direction parallel to the plane of the cell in order to be placed in contact with the fluid mixture and to bring it into thermodynamic equilibrium prior to analysis.

Abstract: In a process for producing a surface compound between a substrate and a reactive species a thin layer permeable to the species in question is deposited on the substrate. A particularly interesting case is the oxidation of a substrate of gallium arsenide, the thin layer being made from zirconia doped with lime.

Abstract: A means for producing electricity from an electrochemical reaction as well as for storing and recovering electrical energy, which utilize electrochemical reactions. The basic galvanic cell comprises a first solid non-porous body capable of storing large quantities of an ionizable species (this is the case with a metal hydride and hydrogen) the ionized species (H.sup.+ ions) migrating through a thin-film solid electrolyte (alumina) towards a second body (oxygen or atmospheric air) where the electrochemical reaction takes place (and the water produced is easily eliminated). The internal resistance of the cell is low because the electrolyte is in thin-film form. The technology of thin-film deposition is possible because the first body is a non-porous solid.

Abstract: The device is based on the use of amorphous thin layers having a thickness of the order of 1000 Angstrom units and a cellular structure on the same scale as the distances between atoms, the structure being homogeneous and isotropic inside the layer. The structure is made of substances which are physically and chemically inert towards the substances to be separated. The cellular structure is due to the incorporation in the layer of elementary particles acting as network dilators or network modifiers.

Abstract: Upon a substrate containing different zones which are to be connected with one another, there are successively deposited a layer of thickness e.sub.1, of a first metal (tantalum) oxidizable by heat treatment, and a layer of thickness e.sub.2 of a second metal (aluminium) non-oxidizable by said treatment, deposited upon the surface of the first layer in accordance with the desired connection profile. The thickness of the aluminium layer is controlled so that it is equal to the increase in thickness of the tantalum layer as a consequence of the transformation of the tantalum into tantalum oxide.

Abstract: A method of manufacturing multilayer interconnections for interconnecting veral mutually insulated groups of contact zones formed on an integrated circuit semiconductor chip is provided.The adjacent superimposed interconnection films are separated by an insulating film of a metal oxide produced by the total oxidation of a metal film deposited on the chip prior to the formation of the top layer of interconnections. The metal deposited at the locations of the contact zones is protected against oxidation so that the contact zones are all times accessible at the surface.