Patents by Inventor Takaaki Otagawa

Takaaki Otagawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5403680
    Abstract: The present invention relates to a method to produce a thin film three dimensional microelectrode of an electrically conductive polymer having an organized array of identical microprotrusions, which method comprises:(a) depositing at least one conductive metal thin film on an essentially smooth substrate,(b) depositing a thin film of a micropositive photoresist on the surface of the at least one conductive metal thin film,(c) subjecting the combination of step (b) to photolithographic or electron beam lithographic conditions with a mask capable of producing a metallic microwell,(d) electrochemically polymerizing an electrically conductive polymer onto the conducting metal,(e) removing the photoresist to produce the three dimensional microelectrode array of the electrically conductive polymer. Preferred electrically conductive polymers of step (d) are selected from polypyrrole or polyaniline.
    Type: Grant
    Filed: January 31, 1992
    Date of Patent: April 4, 1995
    Assignee: Osaka Gas Company, Ltd.
    Inventors: Takaaki Otagawa, Marc J. Madou, Leonor A. Wachsman
  • Patent number: 5294504
    Abstract: The present invention concerns a three dimensional conductive organic polymer covered micro structure having improved current carrying capacity as compared to a substantially smooth surface. More specifically, it relates to a three-dimensional poly(aniline) or poly(pyrrole)-substrate micro structure for use as a battery electrode, having improved properties as compared to a substantially smooth surface, which structure comprises: a thin surface layer of poly(aniline) or poly(pyrrole) film on a substrate surface, wherein the polyaniline or poly(pyrrole) film has a thickness of between about 0.1 and 10 microns and the substrate surface is irregular or patterned having a protruding surface, wherein representative protrusions amount to between about 40 to 90 percent of the surface of the electrode. The processes to produce the three-dimensional microstructure are also disclosed.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: March 15, 1994
    Assignee: Osaka Gas Company, Ltd.
    Inventors: Takaaki Otagawa, Arvind N. Jina, Marc J. Madou
  • Patent number: 5187034
    Abstract: The present invention relates to an electrically conducting polymer, the water-insoluble polymer having essentially permanent self-doping properties, and the polynmer comprises:(a) electrically polymerized polyaniline in covalent combination with(b) an organic dopant having at least one sulfonic acid functional group. The electrically conducting polymer-dopant is preferred wherein the organic dopant is selected from benzenesulfonic acid, toluenesulfonic acid, benzenesulfonyl chloride, dodecylbenzenesulfonic acid, poly(vinylsulfonic) acid, trifluoromethanesulfonic acid, 1-butanesulfonic acid, modified NAFION, 2,3,5-trichlorobenzenesulfonic acid, vinylphenylsulfonic acid, or the alkali metal salts thereof. In another aspect, the present invention discloses a method to produce a water-insoluble polyaniline in which an aromatic organic dopant is covalently bonded to the polyaniline, which method comprises (a) electropolymerizing aniline in an aqueous solvent which contains the organic dopant.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: February 16, 1993
    Assignee: Osaka Gas Company Limited
    Inventors: Takaaki Otagawa, Marc J. Madou
  • Patent number: 5151224
    Abstract: The present invention relates to a process of manufacture of an essentially smooth texture-free conductive polymer comprising poly(dithiophene) which is subsequently doped with a dopant comprising an organometallic compound, preferably an optionally substituted metal phthalocyanine. Specifically, the process relates to a process to produce a smooth, texture-free conductive polymer comprising poly(dithiophene) and an organometallic compound which process comprises:A. contacting a solution itself comprising:(a) dithiophene is present in between about 0.01 and 0.001 M concentration;(b) a water-soluble salt of an optionally substituted organometallic wherein the metal is selected from iron, copper, cobalt or nickel, at a concentration of between about 0.01 and 10 mM;(c) in a solution of acetonitrile/water in a ratio of between about 30:70 and 10:90 percent by volume with a cycling potential of between about 0.1 volts and 10 volts at between about 0.degree. and 95.degree. C. for between about (0.
    Type: Grant
    Filed: May 5, 1988
    Date of Patent: September 29, 1992
    Assignee: Osaka Gas Company, Ltd.
    Inventors: Marc J. Madou, Subhash C. Narang, Takaaki Otagawa, Sharon Wing
  • Patent number: 5134042
    Abstract: The present invention relates to solid materials for use as electrolyte for a fuel cell, or for a sensor, or as a catalyst. Representative structures include lanthanum fluoride, lead potassium fluoride, lead bismuth fluoride, lanthanum strontium fluoride, lanthan strontium lithium fluoride, calcium uranium, cesium fluoride, PbSnFy, KSn.sub.2 F.sub.4, SrCl.sub.2.KCl, LaOF.sub.2, PbSnF.sub.8.PbSnO, lanthanum oxyfluoride, oxide, calcium fluoride, SmNdFO, and the like. In another aspect, the present invention relates to a composite and a process to obtain it of the formula:A.sub.1-y ByQO.sub.3having a perovskite or a perovskite-type structure as an electrode catalyst in combination with:A.sub.y B.sub.1-y F.sub.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: July 28, 1992
    Assignee: SRI International
    Inventors: Marc J. Madou, Takaaki Otagawa, Arden Sher
  • Patent number: 5047352
    Abstract: A portable instrument for use in the field in detecting, identifying, and quantifying a component of a sampled fluid includes a sensor which chemically reacts with the component of interest or a derivative thereof, an electrical heating filament for heating the sample before it is applied to the sensor, and modulator for continuously varying the temperature of the filament (and hence the reaction rate) between two values sufficient to produce the chemical reaction. In response to this thermal modulation, the sensor produces a modulated output signal, the modulation of which is a function of the activation energy of the chemical reaction, which activation energy is specific to the particular component of interest and its concentration. Microprocessor which compares the modulated output signal with standard responses for a plurality of components to identify and quantify the particular component of interest.
    Type: Grant
    Filed: January 23, 1989
    Date of Patent: September 10, 1991
    Assignee: Arch Development Corporation
    Inventors: Joseph R. Stetter, Takaaki Otagawa
  • Patent number: 5002700
    Abstract: The present invention relates to an electrically conducting polymer, the water-insoluble polymer having essentially permanent self-doping properties, and the polymer comprises:(a) electrically polymerized polyaniline in covalent combination with(b) an organic dopant having at least one sulfonic acid functional group. The electrically conducting polymer-dopant is preferred wherein the organic dopant is selected from benzenesulfonic acid, toluenesulfonic acid, benzenesulfonyl chloride, dodecylbenzenesulfonic acid, poly(vinylsulfonic) acid, trifluoromethanesulfonic acid, 1-butanesulfonic acid, modified NAFION, 2,3,5-trichlorobenzenesulfonic acid, vinylphenylsulfonic acid, or the alkali metal salts thereof. In another aspect, the present invention discloses a method to produce a water-insoluble polyaniline in which an aromatic organic dopant is covalently bonded to the polyaniline, which method comprises (a) electropolymerizing aniline in an aqueous solvent which contains the organic dopant.
    Type: Grant
    Filed: April 6, 1989
    Date of Patent: March 26, 1991
    Assignee: Osaka Gas Company Limited
    Inventors: Takaaki Otagawa, Marc J. Madou
  • Patent number: 4973391
    Abstract: The present invention relates to a process for the production of an electrochromic electrically conductive composite membrane, which process comprises:(a) combining aniline and metal phthalocyanine in dilute hydrochloric acid; and(b) applying to the solution of step (a) a constant current density of between about 0.05 and 0.2 milliamperes/cm.sup.2 for between about 1 to 10 minutes on an electrode selected from a transparent platinum electrode or an ITO electrode to produce the improved electrically conductive electrochromic membrane. The present invention also relates to a process for the production of an electrically conductive composite membrane which comprises:(a) combining aniline, organic sulfonic acid and NAFION.RTM. all in the acid form and electropolymerizing the aqueous solution to obtain the polyaniline thin film. The electrochromic electrically conductive composite membrane produced by the process is described which is colorless when subjected to between about -0.
    Type: Grant
    Filed: August 30, 1988
    Date of Patent: November 27, 1990
    Assignee: Osaka Gas Company, Ltd.
    Inventors: Marc J. Madou, Takaaki Otagawa
  • Patent number: 4948680
    Abstract: The present invention relates to solid materials for use as solid electrolytes for a fuel cell. Specifically, the invention relates to a solid O.sup.2- conducting material for use as an electrolyte for a fuel cell, comprising:a monocrystal or polycrystal structure of the formula: A.sub.1-x B.sub.x Z, whereinA is independently selected from lanthanum, cerium, neodymium, praseodymium, scandium or mixtures thereof;B is independently selected from strontium, calcium, barium or magnesium, andx is between about 0 and 0.9999,Z is selected from the group consisting of F.sub.3-x and O.sub.c F.sub.d where F is fluorine, O is oxygen, x is between about 0 and 0.9999 and 2c+d=3-x,wherein c is between 0.0001 and 1.5 and d is between 0.0001 and less than or equal to 3, with the proviso when A is lanthanum, Z is F.sub.3-x and x is 0, the solid material is only a monocrystal.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: August 14, 1990
    Assignee: SRI International
    Inventors: Marc J. Madou, Takaaki Otagawa, Arden Sher
  • Patent number: 4900405
    Abstract: The present invention is concerned with electrode structures and microsensors having fast response times and high sensitivity and to methods using such structures and/or microsensors. This is accomplished in any one of several ways. In one, the sensing and counter electrodes are positioned close enough together on an active area so that ion migration therebetween is fast. The thickness of the electrolytic medium on the active area is restricted to be no more than about 10 microns so that diffusion therethrough between the electrodes is at least as fast as the ion migration. In another, the sensing electrode may have outwardly extending portions extending beyond the electrolytic medium and not being covered thereby. Or, conductive particles can be distributed in the electrolytic medium. Or the medium can be very thin. Or, the electrodes can be interdigited. Combinations of the above structural features are also set forth.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: February 13, 1990
    Assignee: SRI International
    Inventors: Takaaki Otagawa, Marc J. Madou
  • Patent number: 4874500
    Abstract: The invention relates to a microelectrochemical electrode structure comprising a monolithic substrate having a front surface and a back surface facing generally away from one another, a first well extending into the substrate from the surface towards the back surface and ending in a first well bottom, and a first passage extending into the substrate from the back surface to the first well bottom. A first electrode is located wholly within the first well. A first conductor in the first passage serves for electrically communicating the first electrode to adjacent the back surface. A plurality of such electrode structures can be provided on a single substrate. The use of semiconductor processing technology allows the entire sensor to be extremely small. If desired, an integrated circuit can be provided on the back surface of the substrate for amplifying or otherwise processing signals from the first electrode. Analysis can be carried out for vapors or dissolved species (ionic or non-ionic).
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: October 17, 1989
    Assignee: SRI International
    Inventors: Marc J. Madou, Takaaki Otagawa
  • Patent number: 4851303
    Abstract: The present invention relates to solid materials for use as electrolyte for a fuel cell, or for a sensor, or as a catalyst. Representative structures include lanthanum fluoride, lead potassium fluoride, lead bismuth fluoride, lanthanum strontium fluoride, lanthan strontium lithium fluoride, calcium uranium, cesium fluoride, PbSnFy, KSn.sub.2 F.sub.4, SrCl.sub.2.KCl, LaOF.sub.2, PbSnF.sub.8.PbSnO, lanthanum oxyfluoride, oxide, calcium fluoride, SmNdFO, and the like. In another aspect, the present invention relates to a composite and a process to obtain it of the formula:A.sub.1-y ByQO.sub.3having a perovskite or a perovskite-type structure as an electrode catalyst in combination with:A.sub.y B.sub.1-y F.sub.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: July 25, 1989
    Assignee: SRI-International
    Inventors: Marc J. Madou, Takaaki Otagawa, Arden Sher
  • Patent number: 4812221
    Abstract: The present invention relates to a sensor for gaseous and vaporous species. The sensor comprises a substrate having a surface having an opening therein. A gas and vapor permeable sensing electrode having front and back sides is located across the opening with the front side facing generally the same direction as does the surface. A gas flow path leads to the back side of the sensing electrode. An electrolytic medium is in contact with the front side of the electrode. An additional electrode is in contact with the electrolytic medium and is electronically isolated from the sensing electrode other than via the electrolytic medium. A gas sensor as described has a very fast response time and an extended lifetime and can be made selective for any of a number of different gaseous species.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: March 14, 1989
    Assignee: SRI International
    Inventors: Marc J. Madou, Takaaki Otagawa
  • Patent number: 4765864
    Abstract: A method is set forth of constructing an electrochemical cell from a crystalline slab having front and back sides facing generally away from one another. Masking layers are provided covering the front and back sides of the slab and a back resist layer is provided covering the front masking layer, the front and resist layer having at least one opening therethrough exposing a portion of the masking layer therebehind. A passage is etched through the exposed part of the back masking layer and extending into the slab to terminate at the front masking layer. A conductor is deposited in the passage. A second front masking layer is formed covering the front side other than where the passage terminates. The masking layers are etched away opposite the passage sufficiently to expose the conductor. The technology provides electrochemical cells either on or completely below the surface of a slab, for example a silicon slab. Integrated circuitry can be provided on the side of the slab removed from the electrochemistry.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: August 23, 1988
    Assignee: SRI International
    Inventors: Christopher E. Holland, Eugene R. Westerberg, Marc J. Madou, Takaaki Otagawa
  • Patent number: 4591414
    Abstract: A method and instrument including an electrochemical cell for the detection and measurement of methane in a gas by the oxidation of methane electrochemically at a working electrode in a nonaqueous electrolyte at a voltage about about 1.4 volts versus R.H.E. (the reversible hydrogen electrode potential in the same electrolyte), and the measurement of the electrical signal resulting from the electrochemical oxidation.
    Type: Grant
    Filed: August 27, 1984
    Date of Patent: May 27, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Solomon Zaromb, Takaaki Otagawa, Joseph R. Stetter