Abstract:
PROBLEM TO BE SOLVED: To provide a fuel container for a biofuel cell and a biofuel cell system, whereby fuel solution in a battery can be exchanged simply and conveniently without a need for a fuel supply mechanism such as a pump in a fuel cell body.SOLUTION: The fuel container including: a fuel solution storage part in which the fuel solution is stored; a waste liquid storage part in which waste liquid is stored; and a liquid feed mechanism by which the fuel solution is discharged and the solution after use is sucked is used to exchange fuel of the biofuel cell equipped with an electrode having oxygen existing on the surface. Concretely, the fuel solution stored in the fuel solution storage part of the fuel container is poured into the biofuel cell by the fuel feed mechanism, and the solution (waste liquid) after use in the biofuel cell is recovered in the waste liquid storage part.
Abstract:
PROBLEM TO BE SOLVED: To provide a fuel cell which can generate electric energy by confining one or more kinds of enzymes and optionally a coenzyme in a small space and carrying out an enzymatic reaction utilizing the space as a reaction zone to thereby remove electrons from glucose or the like efficiently, and which enables the immobilization of the enzyme and optionally the coenzyme onto an electrode readily; and a process for manufacturing the fuel cell.SOLUTION: An enzyme-immobilized electrode is produced by encapsulating an enzyme 13, 14 and a coenzyme 15, which are required for an enzymatic reaction, into a liposome 12 and immobilizing the liposome 12 onto the surface of an electrode comprising a porous carbon material or the like. An antibiotic 16 is bound to a lipid bilayer membrane that composes the liposome 12, thereby forming one or more holes 17 through which glucose can pass. The enzyme-immobilized electrode can be used, for example, as a negative electrode for a biofuel cell.
Abstract:
PROBLEM TO BE SOLVED: To provide a fuel supply body for a biofuel cell and a biofuel cell system which have high usability and large energy capacity.SOLUTION: A fuel supply body is formed of a material containing a biopolymer in part or all thereof as a main component and a biocatalyst for decomposing this biopolymer by metabolism is housed or bonded/fixed therein. Moreover, a biofuel cell system is constituted of this fuel supply body and a biofuel cell equipped with an electrode having redox enzyme existing on the surface, fuel and/or the biocatalyst is supplied from the fuel supply body to the biofuel cell, and the fuel supply body itself is used as the fuel.
Abstract:
PROBLEM TO BE SOLVED: To provide a simple method for obtaining a recombinant bilirubin oxidase derived from an incomplete filamentous bacterium Myrothecium verrucaria having high expression and high activity.SOLUTION: The method for producing a recombinant bilirubin oxidase includes a step of transferring a bilirubin oxidase gene derived from an incomplete filamentous bacterium Myrothecium verrucaria to Escherichia coli and expressing the gene. The recombinant bilirubin oxidase is obtained by the production method. The recombinant bilirubin oxidase has higher enzyme activity than a natural type bilirubin oxidase derived from an incomplete filamentous bacterium Myrothecium verrucaria.
Abstract:
PROBLEM TO BE SOLVED: To provide a biofuel cell having a mechanism for automatically recovering from the fuel concentration gradient or the pH gradient in a fuel solution which occurs as the oxidation reduction reaction of fuel progresses, and from decrease in battery output due to temperature variation in the vicinity of an electrode.SOLUTION: The biofuel cell A has a polymer gel 2 which swells or contracts reversibly in response to characteristic change of a fuel solution 3 touching the surface and/or the interior of an electrode 1. Since the polymer gel 2 swells or contracts in response to characteristic change of the touching fuel solution 3, diffusibility of the fuel solution 3 or the substance in the solution can be enhanced or the fuel solution 3 can be agitated in the biofuel cell A.
Abstract:
PROBLEM TO BE SOLVED: To provide a biofuel cell capable of continuously obtaining high output by enhancing fuel concentration in a fuel solution.SOLUTION: A biofuel cell A is provided which includes; a negative electrode 3 as a reacting field of redox reaction of fuel containing oxidoreductase as a catalyst; a fuel holding part 32 which contactably supplies fuel held inside to the negative electrode 3; a waste liquid storage part 33 in which fuel after coming into contact with the negative electrode 3 is recovered and stored; and a heating part 5 which heats the inside of the fuel holding part 32 and/or the waste liquid storage part 33. In the biofuel cell A, the inside temperature of the fuel holding part 32 is heated by the heating part 5, and a fuel solution is condensed and the fuel concentration is enhanced by promoting evaporation of a solvent of the fuel solution.
Abstract:
PROBLEM TO BE SOLVED: To provide a biofuel cell capable of controlling the temperature of its electrode and an area in the vicinity thereof at a temperature optimum to a catalytic reaction.SOLUTION: To provide a biofuel cell A comprising: an electrode 2 which becomes a reaction field of an oxidation reduction reaction of fuel using an oxidoreductase as a catalyst; and an insulating heat conductive material 3 arranged in such a manner that at least a part of which contacts with the electrode 2, and at the same time at least a part of which is exposed to the outside of a battery case 1. In the biofuel cell A, the temperature of the electrode 2 and an area in the vicinity thereof can be controlled by bringing a hot-heat source or a cold-heat source in contact with the part of the insulating heat conductive material 3, the part being exposed to the outside of the battery case 1, thus transmitting hot-heat or cold-heat to the electrode 2.
Abstract:
PROBLEM TO BE SOLVED: To provide a fuel cell capable of preventing elution of nicotine amide adenine dinucleotide immobilized on an electrode and/or its derivative and capable of preventing performance degradation due to the elution, and to provide a method for manufacturing the fuel cell.SOLUTION: In a biofuel cell having such structure that a positive electrode and a negative electrode are opposed to each other through a proton conductor and is configured so as to extract electrons from fuel by using an enzyme, the negative electrode is composed of an electrode including carbon and/or an inorganic compound having holes whose sizes are 2 nm or more and 100 nm or less on the surface and nicotine amide adenine dinucleotide and/or its derivative is immobilized on the carbon and/or the inorganic compound. A carbon particle, a carbon sheet or a carbon fiber is used as carbon. Biocarbon, Ketjenblack, active carbon, or the like is used as the carbon particle. An enzyme necessary for enzyme reaction may be immobilized on the carbon through a pyrene derivative as necessary.
Abstract:
PROBLEM TO BE SOLVED: To provide a fuel cell and its manufacturing method which can confine one or more kinds of enzymes or further coenzymes in a minute space and, by carrying out enzymatic reaction using this space as a reaction field, can extract electrons efficiently from glucose, etc. to generate electric energy, and also can easily get these kinds of enzymes or further coenzymes stuck to an electrode.SOLUTION: Enzymes 13, 14 and coenzymes 15 which are needed for enzymatic reaction are sealed in a liposome 12, and an antibiotic 16 is bound to a lipid bilayer membrane constituting the liposome 12 to form one or more holes 17 through which glucose can pass, and further a sterol 18 is bound to the lipid bilayer membrane. The liposome 12 is gotten stuck to the surface of an electrode consisting of porous carbon, etc. to form an enzyme immobilized electrode. The enzyme immobilized electrode is used, for example, as an anode of a biofuel cell.
Abstract:
PROBLEM TO BE SOLVED: To prevent a fuel solution from leaking.SOLUTION: A valve control portion 20 of a fuel leak prevention structure includes first and second electrodes 3a, 3b. The first electrode 3a is fitted to a movable first member 2a, and when the first member 2a is moved by applying pressing force, the first and second electrodes 3a, 3b come into contact to feed electricity. The first and second electrodes 3a, 3b are connected to a controller 4, which opens a control valve 7 when the first and second electrodes 3a, 3b enter the electricity feed state. Thus, the control valve 7 is opened and closed with the pressing force, thereby easily supplying the fuel solution.