Molecular Aligning Or Molecular Orientating (e.g., Poling, Etc.) Patents (Class 264/435)
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Patent number: 6887923Abstract: The present invention disclose a method for the orientation of a high density polyethylene (“HDPE”) film. The process of the invention comprises forming a HDPE-wax mixture by adding to a HDPE batch a normally solid hydrocarbon wax. The HDPE-wax mixture is subsequently stretched into a film at an orientation temperature below the film's melt temperature. The hydrocarbon wax is characterized by having a drop point equal to or lower than the melting point of the HDPE film. The present invention also provides a film made by the process of the invention and a master batch thereof.Type: GrantFiled: December 11, 2002Date of Patent: May 3, 2005Assignee: Equistar Chemicals, L.P.Inventors: Robert J. Bowling, D. Ryan Breese
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Patent number: 6843941Abstract: A film made of a vinylidene-trifluoroethylene or tetrafluoroethylene copolymer is uniaxially drawn to fabricate a uniaxially drawn film. Then, the uniaxially drawn film is thermally treated at a temperature within a temperature range of the Curie temperature through the melting point of the vinylidene-trifluoroethylene or tetrafluoroethylene copolymer for five hours or over, to diffuse the molecular chains of the uniaxially drawn film along the orientation direction and thus, to remove the intertwining between the molecular chains.Type: GrantFiled: April 29, 2002Date of Patent: January 18, 2005Inventor: Hiroji Ohigashi
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Patent number: 6821474Abstract: The invention allows the fabrication of small, dense beads of dielectric materials with selected compositions, which are incorporated into a polymeric matrix for use in capacitors, filters, and the like. A porous, generally spherical bead of hydrous metal oxide containing titanium or zirconium is made by a sol-gel process to form a substantially rigid bead having a generally fine crystallite size and correspondingly finely distributed internal porosity. The resulting gel bead may be washed and hydrothermally reacted with a soluble alkaline earth salt (typically Ba or Sr) at elevated temperature and pressure to convert the bead into a mixed hydrous titanium- or zirconium-alkaline earth oxide while retaining the generally spherical shape. Alternatively, the gel bead may be made by coprecipitation. This mixed oxide bead is then washed, dried and calcined to produce the desired (BaTiO3, PbTiO3, SrZrO3) structure. The sintered beads are incorporated into a selected polymer matrix.Type: GrantFiled: March 18, 2003Date of Patent: November 23, 2004Assignee: UT-Battelle, LLCInventors: Robert J. Lauf, Kimberly K. Anderson, Frederick C. Montgomery, Jack L. Collins, John J. Felten
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Patent number: 6800238Abstract: A method for domain patterning of nonlinear ferroelectric materials. The method seeks to reduce the formation of random and spontaneous micro-domains that typically result during thermal cycling of ferroelectric materials and which leads to patterning defects and degraded performance. In accordance with the invention, a ferroelectric wafer is provided with a conductive layer on the top and bottom surfaces of the wafer. A sufficient bias voltage is applied across the conductive layers to polarize the wafer into a single direction. At least one of the conductive layers is selectively patterned to form a conductive domain template. A sufficient revise bias voltage is then applied to the conductive domain template and a remaining conductive layer to produce the domain patterned structure. According to a preferred embodiment of the invention, the ferroelectric wafer is formed of LiNbO3 or LiTaO3.Type: GrantFiled: January 15, 2002Date of Patent: October 5, 2004Assignee: Silicon Light Machines, Inc.Inventor: Gregory D. Miller
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Patent number: 6759792Abstract: In a polarization method of the multi-layered piezoelectric body in which a plurality of piezoelectric layers and a plurality of internal electrodes are alternately laminated and adjacent piezoelectric layers are polarized in the thickness direction such that the polarized directions thereof are in opposite directions, a first polarization process in which an electric field in one direction is applied in the thickness direction to the multi-layered piezoelectric body and a polarization is uniformly performed in the thickness direction, and a secondary polarization process in which an electric field in the opposite direction is applied to the piezoelectric layers on both sides of one of the internal electrodes and the direction of polarization of only one of the piezoelectric layers on one side of the internal electrode is reversed are provided.Type: GrantFiled: November 30, 2001Date of Patent: July 6, 2004Assignee: Murata Manufacturing Co., LTDInventor: Mikio Nakajima
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Patent number: 6750592Abstract: The present invention relates to a surface acoustic wave filter in which a plurality of pairs of comb electrode patterns are formed on an upper surface of a chip substrate made of a piezoelectric material. The surface acoustic wave filter includes a high-resistance pattern formed to surround a peripheral portion of the chip substrate on an upper surface side thereof, and a plurality of patterns formed to connect the high-resistance pattern to the respective comb electrode patterns.Type: GrantFiled: November 6, 2001Date of Patent: June 15, 2004Assignee: NRS Technologies, Inc.Inventors: Yoshihiro Takahashi, Tadaaki Tsuda, Yasushi Yamamoto, Hiroshi Kawahara
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Patent number: 6706234Abstract: A direct-write method for depositing a polarized material of a predetermined computer-aided pattern onto a target surface, the method including the following steps: (1) forming a solution of a material capable of being polarized using a polarization solvent which can be removed by evaporation to provide a polarized material; (2) operating dispensing devices to dispense and deposit the solution onto the target surface substantially point by point and at least partially removing the solvent from the deposited solution to form a thin layer of substantially solidified material of the predetermined pattern; and (3) during the solvent-removing step, operating a high DC voltage for poling the deposited solution to achieve polarization in the material. The invention also provides a freeform fabrication method for building a multi-layer device, such as a micro-electro-mechanical system (MEMS), that exhibits piezoelectric or pyroelectric properties.Type: GrantFiled: August 8, 2001Date of Patent: March 16, 2004Assignee: Nanotek Instruments, Inc.Inventor: Wen-Chiang Huang
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Publication number: 20040048054Abstract: A thermal conductive polymer molded article is formed by molding a thermotropic liquid crystalline composition comprised mainly of a thermotropic liquid crystalline polymer, wherein the thermal conductive polymer molded article is formed by applying a magnetic field or an electric field to the thermotropic liquid crystalline composition melted by heating so that the thermal conductive polymer molded article has a first thermal conductivity (&lgr;1) higher than a second thermal conductivity (&lgr;2) of a molded article formed by molding the thermotropic liquid crystalline polymer without the application of the field. The thermal conductive polymer molded article preferably has a first thermal conductivity (&lgr;1) of between 0.7 and 20 W/(m·K). Preferably, the thermotropic liquid crystalline polymer comprises at least one polymer selected from (A) a wholly aromatic polyester and (B) a wholly aromatic polyester amide.Type: ApplicationFiled: July 11, 2003Publication date: March 11, 2004Inventors: Masayuki Tobita, Toru Kimura, Naoyuki Shimoyama, Tsukasa Ishigaki
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Patent number: 6649115Abstract: A method of forming an interconnection component with integral conductive elastomeric sheet material, comprising providing a connector frame defining an opening, casting uncured elastomeric conductive polymer interface (ECPI) material onto the connector frame spanning the opening, and curing the ECPI in the presence of a magnetic field, to integrally couple the ECPI to the connector frame, and create a series of spaced conductive columns through the ECPI thickness.Type: GrantFiled: November 4, 2002Date of Patent: November 18, 2003Assignee: Paricon Technologies CorporationInventors: Roger E. Weiss, Everett F. Simons
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Patent number: 6642341Abstract: Molded polyurethane articles having improved flex modulus and impact strength are produced by subjecting a polyurethane-forming reaction mixture which has been introduced into a mold to a static electric field. The static electric field must have a field strength which is less than the dielectric strength of the polyurethane being produced but sufficiently strong to align the hard segment dipoles of the polyurethane.Type: GrantFiled: May 21, 2002Date of Patent: November 4, 2003Assignee: Bayer CorporationInventors: Kieth G. Spitler, Allison E. Yeske
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Patent number: 6628042Abstract: In order to polarize a piezoelectric material in high-temperature gas, a temperature-raising portion raises the temperature of the piezoelectric material to a temperature required to polarize the piezoelectric material. A constant-temperature bath has an atmosphere of the temperature of which is kept at the required temperature, and incorporates a polarizing portion that polarizes the piezoelectric material whose temperature is kept at the required temperature. When the temperature of the piezoelectric material is raised quickly to the temperature required to polarize the piezoelectric material by the temperature raising portion and is placed into the constant-temperature bath, the temperature of the piezoelectric material is at a temperature near a set temperature of the inside of the constant-temperature bath, so that the piezoelectric material can be polarized in a short period of time with high precision.Type: GrantFiled: December 4, 2001Date of Patent: September 30, 2003Assignee: Murata Manufacturing Co., Ltd.Inventor: Hiroshi Tomohiro
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Publication number: 20030153665Abstract: A method of manufacturing a heat conductive molded part having determined heat conductivity properties is provided. The method includes providing a polymer composition containing boron nitride powder. A magnetic field is impressed to the polymer composition containing boron nitride powder, field orienting the boron nitride powder in the polymer composition to a fixed direction. The polymer composition is set containing boron nitride powder with the boron nitride powder oriented in the polymer composition to the fixed direction. The polymer composition may also be provided containing a solvent. The solvent is removed after field orienting the boron nitride powder in the polymer composition to the fixed direction The composition is then set with the field oriented boron nitride powder after having removed the solvent.Type: ApplicationFiled: February 18, 2003Publication date: August 14, 2003Applicant: Polymatech Co., Ltd.Inventors: Masayuki Tobita, Shinya Tateda, Tsunehisa Kimura, Masahumi Yamato
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Patent number: 6593442Abstract: A semicrystalline propylene polymer composition with good suitability for producing biaxially oriented films and prepared by polymerizing propylene, ethylene and/or C4-C18-1-alkenes, where at least 50 mol % of the monomer units present arise from the polymerization of propylene. Also described is the use of the semicrystalline propylene polymer composition for producing films, fibers or moldings, the films, fibers and moldings made from these compositions, biaxially stretched films made from the semicrystalline propylene polymer compositions, and also a method for characterizing the semicrystalline propylene polymer compositions.Type: GrantFiled: December 18, 2000Date of Patent: July 15, 2003Assignee: Basell Polypropylen GmbHInventors: Wolfgang Bidell, Roland Hingmann, Franz Langhauser, Dieter Lilge, Volker Rauschenberger, Günther Schweier, Florian Stricker, Jürgen Suhm
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Patent number: 6558585Abstract: Method for manufacturing an electro-optic polymer waveguide device including the step of electrode poling an electro-optic polymer material of the device in an oxygen-free environment. In a preferred embodiment, the electrode poling is performed at a temperature close to a glass transition temperature of the electro-optic polymer material.Type: GrantFiled: November 2, 2000Date of Patent: May 6, 2003Assignee: Pacific Wave Industries, Inc.Inventors: Hua Zhang, Min-Cheol Oh, William Steier, Harold R. Fetterman, Joseph Michael
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Patent number: 6555293Abstract: A method for fabricating periodically poled structures. The method produces an electric field within a ferroelectric substrate by applying a voltage waveform to an electrode structure disposed on a surface of the substrate. The waveform raises the electric field magnitude to a level substantially greater than that required to reverse domains within the substrate. The waveform then lowers the voltage such that the electric field has a value at which a domain wall velocity is most sensitive to changes in the field. The waveform maintains the electric field value until a current through the substrate drops substantially. The electric field is then lowered to a value below a level required to sustain domain wall motion, but greater than a level below which backswitching occurs. The electric field is then lowered to zero in such a way as to prevent backswitching.Type: GrantFiled: December 14, 1999Date of Patent: April 29, 2003Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Martin M. Fejer, Gregory D. Miller, Robert G. Batchko, Robert L. Byer
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Patent number: 6464925Abstract: A method of polarization-treating a piezoelectric body, which is constructed such that current flows through the piezoelectric body in response to application of a DC voltage to the piezoelectric body, includes the steps of measuring current flowing through the piezoelectric body, and stopping the application of the DC voltage at the time when the measured current value reaches a set level. The polarization degree is controlled based on the current value by utilization of a correlation between the current and the polarization degree during polarization. With this method, a desired polarization degree is obtained, and dispersion of the polarization is reduced.Type: GrantFiled: August 12, 2000Date of Patent: October 15, 2002Assignee: Murata Manufacturing Co., Ltd.Inventors: Hiroshi Tomohiro, Naoki Fujii
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Patent number: 6451410Abstract: The present invention provides a sheet of crystallizable material, having opposed first and second surfaces, the sheet comprising: (a) a plurality of crystalline regions located in the first surface; and (b) an amorphous matrix surrounding and separating the crystalline regions from one another. The present invention also provides a method of making a flexible, cut resistant, and abrasion resistant sheet material, the method comprising the steps of: (a) providing a sheet of crystallizable amorphous material having opposed first and second surfaces; (b) crystallizing discrete regions of the first surface of the sheet of material, the discrete regions being separated from one another by a continuous amorphous matrix.Type: GrantFiled: July 20, 1999Date of Patent: September 17, 2002Assignee: The Procter & Gamble CompanyInventors: Kenneth Stephen McGuire, Peter Worthington Hamilton, Richard Tweddell, III, Richard Emil Hildebrand, IV, Geneva Gail Otten
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Patent number: 6427360Abstract: A method for preheating a permeable, thermoformable material having first and second sides includes supplying heated fluid to a fluid distribution system; regulating flow of the fluid such that fluid having a first temperature flows at a first velocity, and fluid having a second temperature less than the first temperature flows at a second velocity greater than the first velocity; introducing the fluid onto the first side of the material; and developing a suction on the second side of the material sufficient to draw the fluid through the material thereby convectively heating the material; wherein the flow of the fluid is regulated so as to transfer substantially uniform energy flux to the material.Type: GrantFiled: January 25, 2001Date of Patent: August 6, 2002Assignee: Lear CorporationInventor: Sunil K. Gupté
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Patent number: 6423260Abstract: A method and apparatus for producing ordered parts by from non-ordered liquid crystal monomers. Liquid crystal monomers contain stiff, rod-like mesogenic segments which can be aligned by an external force such as shear, electric field or magnetic field, causing an anisotropy in properties. When cured in the aligned stated by photopolymerizing the aligned monomers the anisotropic structure is “locked in” resulting in materials with anisotropic physical and mechanical properties. The rigid structure of the mesogenic segments can result in cured networks with high glass transition temperatures if the spacer groups which connect the mesogenic core with the reactive end groups are kept short. Glass transition temperatures of postcured parts ranged from 75 to 148° C. depending on resin and processing conditions. A mechanical anisotropy on the order of two was measured for aligned samples.Type: GrantFiled: March 21, 2000Date of Patent: July 23, 2002Assignee: University of DaytonInventors: Richard P. Chartoff, John W. Schultz, Jill S. Ullett
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Patent number: 6414089Abstract: A method of manufacturing a polymer film having second order non-linear optical properties which has excellent stability of orientated molecules and does not become disorientated, and a polymer film and a non-linear optical element are provided. A polymer solution is placed between two substrates, which are disposed substantially perpendicular with respect to a rotating stand and substantially symmetrical with respect to a rotation axis of the rotating stand, and the rotating stand is rotated. A polymer film having second order non-linear optical properties is formed by the centrifugal force generated at the polymer solution.Type: GrantFiled: August 29, 2000Date of Patent: July 2, 2002Assignees: Riken, Japan Science and Technology CorporationInventors: Hiromi Kimura-Suda, Hiroyuki Sasabe, Tatsuo Wada
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Patent number: 6403012Abstract: In a method of polarization-treating a piezoelectric material, the maximum polarization degree &Dgr;f180max achieved by 180° rotation is determined. A residual polarization degree &Dgr;f as a target value and the maximum polarization degree &Dgr;f180max are compared. In the case of &Dgr;f≦&Dgr;f180max, a determination is made as to the temperature TA for obtaining the polarization degree &Dgr;f made up solely of the polarization degree achieved by 180° rotation. Half-polarization is carried out at the temperature TA, and aging is conducted at the temperature TA, whereby a piezoelectric material of which the ratio of the polarization achieved by 180° rotation is 100%, which is stable thermally with passage of time, and has a polarization degree &Dgr;f correctly coincident with a target value, can be obtained.Type: GrantFiled: December 7, 1999Date of Patent: June 11, 2002Assignee: Murata Manufacturing Co., Ltd.Inventors: Hiroshi Tomohiro, Naoki Fujii
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Patent number: 6399011Abstract: A method of inducing biaxial particle alignment in a body of crystalline particles of a material such as a high temperature superconducting material, having anisotropic magnetic susceptibility so that at least a major portion of the crystalline particles have at least two crystalline axes generally parallel, comprises subjecting the particles to a magnetic field which varies cyclically relative to the body of crystalline particles with time, and which has an average magnitude which is a maximum in a first direction, a lower average magnitude in a second direction generally orthogonal to said first direction and a minimum or zero average magnitude in a third direction generally orthogonal to said first and second directions. Alignment of the axis of maximum magnetic susceptibility of the particles generally with the direction of maximum average magnitude and the axis of minimum magnetic susceptibility of the particles generally with the minimum or zero average magnitude direction is induced.Type: GrantFiled: September 21, 1998Date of Patent: June 4, 2002Assignee: Industrial Research LimitedInventor: Michael Staines
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Publication number: 20020045531Abstract: A method of manufacturing oriented sintered ceramic product which enables to manufacture an oriented sintered product with an average crystal grain size of 20 &mgr;m or less and a grain width 0.4 times or less of the grain size, or an oriented sintered product with an average crystal grain size of 20 &mgr;m or more and a grain width 0.5 times or more of the grain size with no grain growth of plate-like seed crystals, the method comprising dispersing a non-ferromagnetic powder having a not-cubic crystal structure into a slurry, consolidating the slurry under a magnetic field and sintering the molding product.Type: ApplicationFiled: May 15, 2001Publication date: April 18, 2002Inventors: Toru Suzuki, Yoshio Sakka
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Patent number: 6287505Abstract: Self-tuning materials which can efficiently emit or receive radio waves in spite of being simple in their construction and small in their dimension, and are applied to patch antenna, wave directors or the like. Metallic chips containing two or more kinds of ingredients which are distributed in a layered, net-like or needle-shaped configuration, and an organic or inorganic bonding material which is small in dissipation of electric power under radio waves of high frequencies are mixed with each other, and are pressurized under a high pressure while being highly electrified in the direction perpendicular to the pressurizing direction to mold the metallic chips and the bonding material in a plate-shaped configuration while being heated.Type: GrantFiled: July 6, 1999Date of Patent: September 11, 2001Assignee: Suisaku LimitedInventor: Etsuko Kaitani
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Patent number: 6287486Abstract: The structure of the barium titanate changes from cubic to tetragonal when the cooling temperature passes through the Curie temperature. This cooling process induces 90° and 180° domains in the crystal. The 90° domains, especially, are difficult to eliminate. In the present invention of this technique, the crystal is vibrated to release and dissipate the stress in the crystal, and pressed in the a-axis direction of the crystal. The vibrating contact cumulates the strength and differs from a continual press such as in the uniaxial pressure method. Consequently, only a slight force is needed to re-orient the domains, and thus eliminate the 90° domains.Type: GrantFiled: May 28, 1999Date of Patent: September 11, 2001Assignee: National Science CouncilInventors: Jyh-Chen Chen, Yeou-Chang Lee
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Patent number: 6207240Abstract: The invention relates to a process for generating a marking on an effect coating or molding compound comprising cholesteric liquid-crystalline main-chain or side-group polymers or comprising a combination of main-chain and side-group polymers, which comprises inducing a color change at the irradiated sites of the effect coating or molding compound by laser irradiation.Type: GrantFiled: August 13, 1999Date of Patent: March 27, 2001Assignee: Clariant GmbHInventors: Axel Schoenfeld, Andreas Stohr, Hans Joachim Metz
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Patent number: 6168746Abstract: A method for injection molding fine particulate ceramic ferroelectric materials to form an article such as ink jet printhead includes the steps of spray drying fine particulate ceramic ferroelectric material to form agglomerate material; mixing the spray dried fine particulate ceramic ferroelectric agglomerate material with a binder system including materials selected from the group consisting of wax having wax components of different molecular weight, magnesium-X silicate, agaroid gel forming material, and agaroid gel forming material mixed with magnesium-X silicate to form a compounded material; injecting the compounded material at a selected pressure into a mold to form a green article; debinding or drying the green article; sintering the debinded or dried green article to form the final molded article; poling the final molded article to align the electrical dipoles within the piezoelectric material; forming a coating of conductive material over the top and bottom surfaces of the final molded article and tType: GrantFiled: February 22, 1999Date of Patent: January 2, 2001Assignee: Eastman Kodak CompanyInventors: Dilip K. Chatterjee, Syamal K. Ghosh, James K. Lee
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Patent number: 6156255Abstract: A method of patterning domains within a body of a ferroelectric material includes the application of an electric field thereto via spaced conductors. Prior to applying the electric field to the material effects on the patterning of the existence of fringe electric field components which will be created in said body by said application of an electric field, surface treatments, and relative geometries of the body and the conductors are examined.Type: GrantFiled: July 7, 1998Date of Patent: December 5, 2000Assignee: The Board of Trustees of the Leland Stanford, Jr. UniversityInventors: Robert L. Byer, Martin M. Fejer, Gregory D. Miller, Lawrence E. Myers
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Patent number: 6117385Abstract: A method and apparatus for producing ordered parts by stereolithography from non-ordered liquid crystal monomers. Liquid crystal monomers contain stiff, rod-like mesogenic segments which can be aligned by an external force such as shear, electric field or magnetic field, causing an anisotropy in properties. When cured in the aligned stated by photopolymerizing the aligned monomers the anisotropic structure is "locked in" resulting in materials with anisotropic physical and mechanical properties. The rigid structure of the mesogenic segments can result in cured networks with high glass transition temperatures if the spacer groups which connect the mesogenic core with the reactive end groups are kept short. Glass transition temperatures of postcured parts ranged from 75 to 148.degree. C. depending on resin and processing conditions. A mechanical anisotropy on the order of two was measured for aligned samples.Type: GrantFiled: August 3, 1998Date of Patent: September 12, 2000Assignee: The University of DaytonInventors: Richard P. Chartoff, John W. Schultz, Jill S. Ullett
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Patent number: 6090332Abstract: Fused ring bridge, ring locked dyes that form thermally stable photorfractive compositions. The fused ring bridge structures are .pi.-conjugated bonds in benzene-, naphthalene- or anthracene-derived fused ring systems that connect donor and acceptor groups. The donor and acceptor groups contribute to a high molecular dipole moment and linear polarizability anisotropy. The polarization characteristics of the dye molecules are stabilized since the bonds in the fused ring bridge are not susceptible to rotation, reducing the opportunity for photoisomerization. The dyes are compatible with polymeric compositions, including thermoplastics. The dyes are electrically neutral but have charge transport, electronic and orientational properties such that upon illumination of a composition containing the dye, the dye facilitates refractive index modulation and a photorefractive effect that can be utilized advantageously in numerous applications such as in optical quality devices and biological imaging.Type: GrantFiled: May 13, 1998Date of Patent: July 18, 2000Assignee: California Institute of TechnologyInventors: Seth R. Marder, Nasser Peyghambarian, Bernard Kippelen, Boris Volodin, Eric Hendrickx
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Patent number: 6013221Abstract: A method of domain patterning a body of ferroelectric material is disclosed. This method includes patterning the surface of the material with conducting strips for applying an electric field of desired configuration to said body and covering the conductive strips and surface of the body with insulating material to control the fringe electric field components in the body of ferromagnetic material.Type: GrantFiled: May 13, 1998Date of Patent: January 11, 2000Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Robert L. Byer, Martin M. Fejer, Gregory D. Miller, Lawrence E. Myers
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Patent number: 5993985Abstract: A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost.Type: GrantFiled: April 9, 1998Date of Patent: November 30, 1999Assignee: Siemens Westinghouse Power CorporationInventor: Brian P. Borglum
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Patent number: 5886070Abstract: The present invention offers a production method for anisotropic resin-bonded magnets with precise dimensions in high productivity. It comprises the aligning step in which the preform is preliminary compression-molded in the preforming molding die 22 in the preforming press 20 with an applied magnetic field to align the magnetization direction of the magnet powder at a temperature in which the thermosetting resin in the compound becomes liquid state, the transferring step in which said preform is transferred from preforming press 20 to densifying molding die 32 in a densifying press 30, and densifying step in which said partly cured preform is compression-molded by applying pressure in a densifying press 30 to obtain desired shape of magnet.Type: GrantFiled: July 1, 1997Date of Patent: March 23, 1999Assignee: Aichi Steel Works, Ltd.Inventors: Yoshinobu Honkura, Hironari Mitarai, Koichi Maekawa, Yoshinobu Sugiura
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Patent number: 5800767Abstract: A method of domain patterning a body of ferroelectric material. The method includes the steps of adhering spaced conducting strips to a surface of said body; covering portions of said surface of said body between said strips with material which is insulative relative to electric current produced when an electric field configuration is created in said body and which controls the formation of fringe electric field components in said material; and applying potentials simultaneously to said conducting strips and to a surface of said insulative material to create an electric field configuration in said body whereby said strips define said electric field configuration within said body and wherein said insulating material between said strips defines a potential within said body which is generally the same as the potential applied to said conducting strips.Type: GrantFiled: September 16, 1994Date of Patent: September 1, 1998Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Robert L. Byer, Martin M. Fejer, Gregory D. Miller, Lawrence E. Myers
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Patent number: 5725825Abstract: A method of producing a cylindrical piezoelectric element includes:(a) injecting the molding fluid containing calcined powder of piezoelectric material in a mold having cylindrical cavity and wire-shaped core inserted therein;(b) heating to dry the molding fluid injected in the mold so as to obtain cylindrical member;(d) removing cylindrical member from the mold; and(e) sintering the cylindrical member to obtain a piezoelectric element.Type: GrantFiled: July 9, 1996Date of Patent: March 10, 1998Assignee: Minolta Co., Ltd.Inventors: Hideo Hotomi, Kenji Masaki, Kusunoki Higashino
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Patent number: 5605659Abstract: In the embodiments described in the specification, a ceramic piezoelectric plate is polarized by compressing the plate between electrode plates with intervening slightly conductive rubber sheets or by applying electric charge from a corona discharge device to one surface of the plate while the opposite surface is grounded until the applied charge is sufficient to create a breakdown.Type: GrantFiled: June 2, 1995Date of Patent: February 25, 1997Assignee: Spectra, Inc.Inventors: Edward R. Moynihan, David W. Gailus, Robert G. Palifka, Paul A. Hoisington, Nathan P. Hine, David Adams-Brady, Melvin L. Biggs, Marlene M. McDonald, Steven H. Barss, Diane Mackay, Bruce A. Paulson, Stephen C. Mackay
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Patent number: 5599412Abstract: In color printing, and in the fine arts, cholesteric liquid crystal (CLC) color inks are known to possess much higher color saturation and brightness than conventional pigment and dyed based inks. However, prior art CLC ink formulations are inconvenient because in the liquid phase they have to be confined in cells, and in the solid phase, they have to be applied at high temperature, and have to be aligned by some means to produce the optimum color. This invention solves the problem encountered in the CLC prior art, by making pre-aligned CLC platelets or flakes of appropriate thickness and size and mixing them in appropriate host fluids producing a novel CLC ink which can be applied at room temperature and without the need for alignment. The new pre-aligned room temperature CLC ink can be used as a substitute for conventional inks in almost all printing and plotting, and manual drawing and painting. Using the notch filter CLC platelets, the brightness is further enhanced.Type: GrantFiled: June 27, 1994Date of Patent: February 4, 1997Inventor: Sadeg M. Faris
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Patent number: 5529741Abstract: The present invention provides methods of preparing thermotropic and lyotropic liquid crystalline polymer film-based and tubular components having a controlled CTE and components produced by such methods. The methods of the present invention include treating a melt or dope of liquid crystalline polymer with simultaneous biaxial shearing forces and with an electric or magnetic field normal to each of the biaxial shearing forces.Type: GrantFiled: September 7, 1993Date of Patent: June 25, 1996Assignee: Foster-Miller, Inc.Inventors: Leslie S. Rubin, Kent G. Blizard
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Patent number: 5512218Abstract: A biopolymer film and other materials that exhibit nonlinear optical (NLO) properties and a method for making this film. Alignment of biopolymer molecules, which is required for NLO phenomena, is achieved by application of an electric field parallel to the surface of a biopolymer solution as the film is formed. In one embodiment, a solution of poly(.gamma.-benzyl-L-glutamate), PBLG, in methylene chloride is employed. Upon application of an electric field, laminar structures perpendicular to both the field direction and to the film surface are formed. These ordered structures are captured in the film upon evaporation of the biopolymer solvent.Type: GrantFiled: March 24, 1994Date of Patent: April 30, 1996Assignee: Cambridge Scientific, Inc.Inventors: Joseph D. Gresser, Debra J. Trantolo, Donald L. Wise, Gary E. Wnek
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Patent number: 5494617Abstract: An improved method of inducing piezoelectric properties in polymer films, ch as polyvinylidene fluoride (PVDF) films and co-polymers thereof. This improved method involves applying uniaxial tensile forces to pre-aligned polymer films while simultaneously applying an electric poling field to the pre-aligned polymer films at room temperature to provide enhanced piezoelectric properties. This improved method does not require the use of heating equipment or temperature cycling equipment during the electric field poling of the polymer and thus represents a simpler and more cost efficient process of inducing piezoelectric properties in polymers.Type: GrantFiled: May 16, 1994Date of Patent: February 27, 1996Assignee: The United States of America as represented by the Secretary of the NavyInventor: Nancy E. Iwamoto