Abstract: The present invention concerns an integrated variable capacitance device comprising at least one membrane (12) forming at least one mobile armature and having at least one principal face facing at least one fixed armature. In accordance with the invention, the membrane has at least one rigidity rib (32) lying in a perpendicular direction to said principal face. Application in the production of resonant filters.

Abstract: The component comprises micro electromechanical systems integrated in a cavity of a substrate and a cover sealed onto the substrate and designed to make the cavity hermetic. The cover comprises at least one groove passing through the cover and defining a central zone completely covering the cavity and a peripheral zone in the cover. A sealing material is deposited at least at the bottom of the groove. Fabrication of the component can comprise a first stage of making at least one groove in the cover, a second stage of bringing the substrate and cover into contact, and a third stage of sealing by depositing a sealing material in the bottom of the groove.

Abstract: This invention relates to a secure electronic device comprising:

Abstract: The integrated electromechanical microstructure comprises a base substrate and a cavity closed by a protective cover. Means for adjusting the pressure in the cavity after the protective cover has been sealed comprise at least one element made of pyrotechnic material combustion whereof releases gas into the cavity. The pressure in the cavity can thus be adjusted independently from the sealing process. Selective ignition of the elements made of pyrotechnic material can be achieved by heating electrical resistors or by laser beams coming from outside the microstructure and directed selectively towards the elements made of pyrotechnic material through a transparent zone of the protective cover.

Abstract: The fuel cell (2) is of the kind comprising an anode (12) and a cathode (10) between which an electrolyte (18) is interposed. Solid bodies (20) storing a hydrogen mass, able to be decomposed by combustion, are associated to pyrotechnic means (24,26) to release the hydrogen and bring it into contact with the anode (12). Means (38) tap the ambient air to bring it into contact with the cathode (10). Firing of the pyrotechnic means (24,26) is placed under the control of addressing means (28) embedded in the appliance (2). The surplus water produced by the exchange between the hydrogen and the oxygen is resorbed by the temperature increase induced by combustion of the bodies (20). The solid bodies (20) are supported by an interchangeable card (22).

Abstract: The microvalve comprises a mini-piston moving due to the thrust of gases given off by firing of a pyrotechnic charge and comprising an aperture designed to enable communication to be established between ends of microchannels of a microfluidic component. When the ends between which communication is to be established open out onto a face of a first planar substrate, the mini-piston is formed in a second planar substrate, adjoined to the first, and comprises a part that is mobile in translation or in rotation in the plane of the second substrate. If a transverse slot is arranged between the ends of the microchannels between which communication is to be established, the mini-piston comprises a rod designed to slide in the slot and the aperture is formed by a transverse orifice formed in the rod of the mini-piston.

Abstract: The module is designed for supplying hydrogen to a fuel mini-cell, wherein hydrogen is gradually released by combustion of elements made of pyrotechnic material, after ignition. A device for sequential control of ignition of the pyrotechnic elements comprises a circuit (13) controlling an electrical or light energy source (11) which supplies an ignition control signal causing energy to be applied to the input of a series of connecting means (12), respectively associated with each of the pyrotechnic elements (Ei). A single pyrotechnic element (E2) is connected to the energy source at any one time, the elements (E1) preceding it having already been used. The connecting means (12) can be sensitive to temperature or to pressure.

Abstract: The present invention concerns an integrated variable capacitance device comprising at least one membrane (12) forming at least one mobile armature and having at least one principal face facing at least one fixed armature. In accordance with the invention, the membrane has at least one rigidity rib (32) lying in a perpendicular direction to said principal face.

Abstract: Device for the detection of movement of a valuable object, for example in a museum in which means of detecting at least a rotation of the object, and particularly magnetometers or inclinometers, are mechanically fixed to the object. These means are coupled to message transmission means that send a presence message as long as detection has not taken place and an alert type message when detection has taken place. A monitoring station processes these messages or the absence of these messages, to trigger an alert if necessary.

Abstract: A process for the micromechanical fabrication of nozzles for ink jets includes forming a groove on a surface of a first substrate, securing the first substrate to a second substrate to form an assembly in which the second substrate covers the groove to form a channel having walls, and then forming an internal protective coating within the channel by thermal oxidation of the walls of the channel. The first and second substrates are then cut along a plane extending perpendicular to the channel thereby to form a nozzle for dispensing a liquid jet. Scales, formed as a result of the cutting operations, are formed on the internal protective coating rather than directly on the walls of the channel. These scales then are removed from the nozzle by eliminating the internal protective coating.

Abstract: According to this process a structure is produced comprising an insulating substrate (10) carrying at least one cathode conductor (12), an insulating layer (14), a gate layer (16), holes being formed through these layers, level with the cathode conductor. In the holes are formed microtips made from a metallic material by forming a protective insulating layer (50) on the gate layer, forming a chemical deposit (60) of the metallic material at the bottom of the holes until said material overflows therefrom, by eliminating the protective layer and by electrolytically etching the metallic material. Application to the manufacture of flat screens.

Abstract: The switch is formed on a support (8) and has light guides (24, 26, 28), a rotary part (10) carrying the intermediate light guides (30, 32) and which is able to occupy, by rotations, positions in each of which an intermediate guide connects two guides to one another, and rotary means (12 to 22) for the rotary part. The switch is formed from two semiconductor substrates, in which are defined two parts which, after superimposing and fixing the substrates to one another, form the rotary part which is then released from the remainder of the substrates.

Abstract: This process consists of etching a substrate perpendicular to its surface in order to form a recess communicating therewith and in which can move laterally the flexible beam, the communication zone representing the image of the gauge to be produced, placing on the substrate surface a mask provided with an opening facing said recess and extending partly over the beam, passing through the opening a particle beam able to form a deposit of piezoresistive material constituting the gauge and electric contacts, said beam being oriented obliquely with respect to the substrate surface, eliminating the mask and producing electrical conductors on the upper and lower faces of the beam in order to supply current to the gauge.

Abstract: Process for the production of thin film Hall effect transducers of the type comprising semiconductor elements recrystallized in situ after deposition by a remelting of the semiconductor material, characterized by the following successive stages:the active elements of a transducer are cut in the form of narrow strips, the assembly is covered with a SiO.sub.2 insulating coating, this coating is covered with a conductive metal coating, the metal coating is etched so as to produce local heating resistors above the semiconductor strips, an electric current is passed into the heating resistors, the metal coating is removed from the heating resistors, followed by removal of the SiO.sub.2 coating in the non-recrystallized zones of the semiconductor.

Abstract: A directional accelerometer and a process for the microlithographic fabrication of such an accelerometer. The accelerometer includes a substrate having at least one recess to define at least one beam in the substrate. One of the ends of the beam is integrally formed with the remainder of the substrate. The beam, which is oriented in the first direction, is deformable into the recess in a second direction only, parallel to the substrate surface and perpendicular to the first direction. The second direction corresponds to the acceleration component to be measured. Electrical connections and contacts are formed in the substrate for the device measuring the deformations of the beam. These measurements make it possible to determine the acceleration components.

Abstract: The present invention relates to a capacitive hygrometer comprising a capacitor (1) having a dielectric material (3), whose dielectric constant varies as a function of the quantity of water absorbed. It has on one of its conductive faces numerous fissures bringing the dielectric material into direct contact with the atmosphere whose degree of humidity is to be measured. However, the electrical continuity of the fissured conductive face is maintained.Application to the measurement of the degree of humidity of the air.

Abstract: The present invention relates to a capacitive hygrometer comprising a capacitor (1) having a dielectric material (3), whose dielectric constant varies as a function of the quantity of water absorbed. It has on one of its conductive faces numerous fissures bringing the dielectric material into direct contact with the atmosphere whose degree of humidity is to be measured. However, the electrical continuity of the fissured conductive face is maintained. Application to the measurement of the degree of humidity of the air.

Abstract: The invention relates to a measuring device using a strain gauge.The device comprises a test body (1), whereof one face (6) is compressively stressed and to which is fixed a strain gauge (7) constituted by a resistive coating (8) deposited on a thin glass support (9), the thickness of the latter being approximately 150 .mu.m.Application to electronic weighing.

Abstract: Process for monitoring the instantaneous or momentary state of an electric circuit having to function in a range limited to two states, namely a normal state corresponding to the passage of a nominal intensity in a conductor and a critical or threshold state corresponding to a threshold intensity and in particular a zero intensity in the said conductor, using the detection of possible variations in the resistance of a magnetic layer or "magnetoresistor" of the influence of the magnetic field due to the intensity of the electric current circulating in a conductor and whereof part of the path is located in the vicinity of at least one oriented thin magnetic layer, wherein the said detection is carried out by means of a differential measurement of the magnetoresistance of at least two adjacent and separate magnetic layers, whereof one is subject to the field of the circuit to be monitored and the other is subject to the field of a reference current, the circuits and layers being arranged also in such a way as to

Abstract: Apparatus for controlling an electrolytic display cell comprising a supplementary reference electrode in the cell, means for measuring the impedance of the cell across this electrode and means for making at least one of these magnitudes dependent on the impedance.