Abstract: The invention relates to piezoelectric or pyroelectric polymer materials. It provides a process for manufacturing these materials comprising pressing polymer pellets while heating, dipping the obtained sheets in water, stretching the sheets, electrically polarizing the sheets by applying between the two faces of the sheets an electric orientation field, irradiating the sheets to obtain crosslinking and reheating the sheets.

Abstract: A process for manufacturing an electrochemical transducer, having at least one active element in the form of at least one film of a polymer material, comprises the following steps. First, clamping a polymer film between an inner set of jaws for delimitating a central area. Second, further clamping said polymer film between an outer set of jaws for delimitating a peripheral area surrounding the central area. And finally, shaping at least one of the areas by stretching.

Abstract: In a method of fabrication of piezoelectric polymer transducers by forging, a preform is subjected to flattening by compression in order to produce a radial orientation of the molecular chains constituting the polymer with respect to the center of pressure.

Abstract: The invention relates to the production of blocks of macromolecular material displaying piezoelectric and pyroelectric properties and provides a production process consisting in drawing a thin strip of a film of macromolecular material from a feed reel, electrically polarizing the said film and coating it with adhesive by means of a solution based on a polymeric binder before the forming on a mandrel of a roll of which the turns form, after drying, a monolithic structure which may be split into blocks.The invention finds particular use in the production of electromechanical transducers for applications connected with electroacoustics and underwater acoustics.

Abstract: The invention relates to an electro-acoustic transducer using a self-supporting active radiating membrane made from a polymer material. The invention provides a transducer in which a resilient shape restoring member fixed to the case capped by the radiating membrane takes on the shape of the concave parts of the membrane, so as to oppose the definitive staving-in of the membrane by an accidental thrust force acting on the dome shaped protuberance on its outer face and restore the member to its initial shape when the force is removed.

Abstract: The invention relates to piezoelectric polymer films.The invention relates to a production process consisting of stretching a polymer material blank by rolling under an electrical field between two oppositely rotating rollers.The invention is more particularly applicable to the production of electromechanical transducers, whose active elements are constituted by piezoelectric polymer films provided with electrodes.

Abstract: Electrically piezoresistor produced by means of a piezoresistive element coupled to an electromechanical transducer, whose terminals are the input terminals of the piezoresistor. The piezoresistor comprises thermal drift compensating means.

Abstract: Piezoelectric and pyroelectric transducers whose active element is formed by a polymer film. The transducer is manufactured from a flat polymer film by stretching this film over a mold so as to give it a self-supporting form and electroforming the stretched film by means of a corona discharge so as to induce in the polymer film a macromolecular chain translation between reversed and non-reversed neighboring chains.

Abstract: The invention relates to the manufacture of electromechanical transducers with at least one element made from a polymer material shaped and polarized so as to obtain an active self-supporting structure having a nondevelopable surface and to a manufacturing process which consists in shaping a structure already coated with metalizations, so that the electric polarizing field may be applied to the structure during shaping and until return thereof to ambient temperature.

Abstract: An electromechanical transducer comprising a radiating structure whose active element is formed by a polymer film placed between two electrodes.The invention provides a transducer in which a closure element having the exact shape of a spherical surface portion is connected to at least one active peripheral suspension which simulates the movements of a pulsating sphere portion completing the closure element.

Abstract: The invention relates to bimorph electromechanical transducers made from polymer material.It specifically relates to a transducer comprising a plurality of superimposed dielectric sheets for forming a bimorph structure, whose deformations are controlled in linear manner by a voltage. None of the sheets is piezoelectric. The linearity of operation is obtained because at least one of the dielectric sheets carries a permanent electric charge.The invention is applicable to the construction of microphones, telephone receivers, loudspeakers, as well as to the construction of optical components, whose precise, small displacements it is desired to control.

Abstract: The invention relates to devices using transducer elements comprising a film of piezoelectric polymer arranged between electrodes. The transducer element in accordance with the present invention is in the form of a thermoformed protuberance. These devices are used for detecting and generating elastic compression waves, for infrared radiation, and for storing electrical energy.

Abstract: A pressure-sensing piezoelectric transducer device having an active element fabricated from polymeric material which has previously been polarized and comprising electrodes, at least one of which is embedded in the polymeric material. The device has the configuration of a multiwire cable or of a molded object.

Abstract: The invention provides an image converter device which utilizes a liquid crystal cell in which a layer of a nematic material or a nematic-cholesteric mixture is enclosed between a first plate of a photoconductive material, provided with an external electrode, and a second transparent plate, provided with an internal electrode. The photoconductive material may be bismuth oxide, or a mixture of the latter with germanium or silicon oxide. A direct or alternative voltage is applied between the electrodes. An X-rays image, or an image displayed on the screen of a C.R. tube is projected onto the photoconductive plate whose conductivity, thus spatially modulated, causes a spatially variable voltage to be applied in the liquid crystal layer.

Abstract: Piezoelectric acceleration pickup incorporating a transducer film made from a polymer material which, after treatment, has piezoelectric properties, two electrodes and a seismic mass provided by an excrescence on the polymer film, the assembly being obtained in one operation by moulding. According to a second variant, the pickup is in the form of an elongated object obtained by moulding a polymer material and in which are embedded two facing planar electrodes, the polymer material between these two electrodes constituting the transducer member and the material above these electrodes constituting the seismic mass.

Abstract: A piezoelectric transducer having at least one active element consisting of a film of polymer material is disclosed. Electrodes are formed on the two principal faces of the film after polarization of the film. The film is endowed with piezoelectric properties under the sole action of an electric field oriented along the normal to its principal faces and without any need for preliminary stretching. The anisotropy induced as a result of this orientation is solely electrical.

Abstract: The invention relates to piezoelectric and pyroelectric transducers whose active element is formed by a polymer film. The invention provides a process for manufacturing a transducer from a flat polymer film which consists in stretching this film over a mold so as to give it a self-supporting form and to electroform this film by means of a corona discharge.

Abstract: The composite material is obtained by coating a fabric with a polymer. Coating is performed either in the cold state by dipping the fabric in a solution of polymer dissolved in a solvent or in the hot state by dipping in a molten polymer. The film of composite material thus obtained is then endowed with piezoelectric properties by subjecting it to an intense electric field.

Abstract: The invention relates to devices using transducer elements comprising a film of piezoelectric polymer arranged between electrodes. The transducer element in accordance with the present invention is in the form of a thermoformed protuberance. These devices are used for detecting and generating elastic compression waves, for infrared radiation, and for storing electrical energy.

Abstract: The detector comprises at least one plate of an electrooptical material having good photoconduction properties and high absorption of X- or .gamma.-rays, preferably materials comprising bismuth oxide. The plate is placed between two electrodes connected to an electric generator through a resistor. A polarized luminous beam passes through the plate. Under the action of the radiation, the conductivity of the plate varies and produces a modification of the polarization state of the luminous beam. This modification is analysed and then detected. In this way there is obtained an indication of the radiation dose received for a given period.