JP2013008562A - Biofuel cell, bioreactor, and biosensor - Google Patents

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.

Description

  The present technology relates to a biofuel cell, a bioreactor, and a biosensor. More specifically, the present invention relates to a biofuel cell that can control the temperature of an electrode and the vicinity thereof to an optimum temperature for an enzyme catalytic reaction.

  In recent years, biofuel cells in which an oxidoreductase is immobilized as a catalyst on at least one of an anode and a cathode have been developed. In a biofuel cell, a high capacity can be obtained by efficiently extracting electrons from a fuel that is difficult to react with normal industrial catalysts such as glucose and ethanol. For this reason, in the biofuel cell, it is also possible to use a liquid such as a beverage containing glucose, ethanol or the like as the fuel solution. For example, Patent Literature 1 discloses a power supply device including a fuel cell unit that uses beverage as fuel.

JP 2009-048858 A

  In order to bring out sufficient performance in a biofuel cell, it is necessary to maintain the temperature of the electrode or the vicinity thereof at the optimum temperature for the activity of the enzyme and to promote the catalytic reaction efficiently. The optimum temperature for the activity of the enzyme is about 37 ° C. and is usually higher than the temperature at which the biofuel cell is used (usually room temperature).

  Therefore, the main object of the present technology is to provide a biofuel cell that can control the temperature of the electrode and the vicinity thereof to an optimum temperature for the catalytic reaction of the enzyme.

In order to solve the above problems, the present technology provides an electrode serving as a reaction field for a redox reaction of a fuel using an oxidoreductase as a catalyst, and at least a part of the electrode is in contact with the electrode and at least a part of the electrode is exposed outside the battery case. And a biofuel cell having an insulating heat conductive material disposed in a row. In this biofuel cell, it is possible to control the temperature of the electrode and the vicinity thereof by conducting the heat or cold to the electrode by contacting the heat source or the cold source with the exposed portion of the insulating heat conductive material outside the battery case. .
The biofuel cell according to the present technology is further arranged so as to face the electrode with a storage space for fuel supplied to be in contact with the electrode, and at least a part of the heat is exposed to the outside of the battery casing. It is preferable to have a conductive material. By conducting the outside air temperature to the fuel storage space through this heat conducting material, the fuel can be convected and stirred by the temperature difference between the heated or cooled electrode and its vicinity.
The biofuel cell according to the present technology includes a heat insulating material capable of covering a portion of the insulating heat conductive material exposed to the outside of the battery housing and / or a portion of the heat conductive material exposed to the outside of the battery housing. The material can be repositioned between a position where the insulating heat conductive material is exposed to the outside of the battery case and / or a position where the heat conductive material is exposed to the outside of the battery case and a position where the material is not covered. It is preferable. Further, the biofuel cell according to the present technology is such that the heat insulating material does not cover a portion of the insulating heat conductive material exposed outside the battery housing and / or a portion of the heat conductive material exposed outside the battery housing. In some cases, it is preferable to have a coolant disposed in contact with a portion of the insulating heat conductive material exposed to the outside of the battery housing and / or a portion of the heat conductive material exposed to the outside of the battery housing. By having these heat insulating material and cooling material, the heat conduction through the insulating heat conducting material and the heat conducting material is controlled, and the temperature inside the electrode and the battery housing is set to a desired value according to the use state of the battery. Can be set to temperature.
The biofuel cell according to the present technology preferably includes a member for attaching the battery casing to the body in a state where a portion of the insulating heat conductive material exposed to the outside of the battery casing is positioned on the human body surface side. . This member is used when body temperature is used as a heat source that comes into contact with a portion of the insulating heat conductive material exposed to the outside of the battery casing.
In addition, the present technology provides an electrode serving as a reaction field for a redox reaction of a substance using an oxidoreductase as a catalyst, and at least a part of the electrode is in contact with the electrode, and at least a part is exposed outside the housing. And a bioreactor having a heat conductive material. Furthermore, the present technology provides an electrode that serves as a reaction field for the oxidation-reduction reaction of a substance that uses an oxidoreductase as a catalyst, and an insulation that is disposed so that at least a portion thereof is in contact with the electrode and at least a portion is exposed outside the housing. There is also provided a biosensor having a heat conductive material. Also in these bioreactors and biosensors, by contacting a heat source or a cold source with a portion exposed to the outside of the casing of the insulating heat conductive material, the hot or cold heat is conducted to the electrode as the reaction element, and the electrode and The temperature in the vicinity can be controlled.

  The present technology provides a biofuel cell that can control the temperature of the electrode and the vicinity thereof to an optimum temperature for the catalytic reaction.

It is a mimetic diagram for explaining composition of a biofuel cell concerning a first embodiment of this art. It is a schematic diagram for demonstrating the structure of the modification of the biofuel cell which concerns on 1st embodiment. It is a schematic diagram for demonstrating the structure of the biofuel cell which concerns on 2nd embodiment of this technique. It is a schematic diagram for demonstrating the structure of the biofuel cell which concerns on 3rd embodiment of this technique. It is a schematic diagram for demonstrating the structure of the biofuel cell which concerns on 4th embodiment of this technique. It is a schematic diagram for demonstrating the structure of the biofuel cell which concerns on 5th embodiment of this technique. It is a schematic diagram for demonstrating the structure for mounting | wearing the body with the biofuel cell which concerns on this technique.

Hereinafter, preferred embodiments for carrying out the present technology will be described. In addition, embodiment described below shows an example of typical embodiment of this technique, and, thereby, the scope of this technique is not interpreted narrowly. The description will be made in the following order.

1. 1. Biofuel cell according to the first embodiment (1) Battery structure (2) Electrode material (3) Insulating heat conductor material (4) Fuel (5) Enzyme (6) Current collector / proton conductor / separator 2. Biofuel cell according to modification of first embodiment (1) Cell structure (2) Heat insulating material 3. Biofuel cell according to the second embodiment (1) Cell structure (2) Thermal conductor material 4. Biofuel cell according to the third embodiment 5. Biofuel cell according to the fourth embodiment 6. Biofuel cell according to fifth embodiment Bioreactor and biosensor

1. Biofuel Cell According to First Embodiment FIG. 1 shows a configuration of a biofuel cell according to the first embodiment of the present technology.

(1) Battery structure In the figure, a biofuel cell indicated by symbol A includes a battery housing 1, an electrode 2 disposed in the battery housing 1, and at least a part of which is in contact with the electrode 2, and at least one And an insulating heat conductor 3 that is disposed so as to be exposed outside the battery housing 1.

  Here, only one electrode is shown as the electrode 2, but the biofuel cell A has a negative electrode (fuel electrode) that extracts electrons by a fuel oxidation reaction and a positive electrode (reduction reaction of oxygen supplied from the outside) (fuel electrode). Air electrode). Hereinafter, the term “electrode 2” may be a negative electrode or a positive electrode.

  In addition to the above-described configuration, the biofuel cell A has a configuration included in a normal biofuel cell such as a fuel, a current collector, a separator, and a proton conductor. The fuel is filled in the storage space 11 of the battery housing 1 in a state of being in contact with the negative electrode. The battery housing 1 may be provided with a supply port for supplying fuel therein. The battery housing 1 may also be provided with an introduction port for introducing air that is in contact with the positive electrode. Each of the negative electrode and the positive electrode is electrically connected to a current collector, and each current collector can be connected to an external circuit that sends electrons extracted by the negative electrode to the positive electrode. The separator is disposed between the negative electrode and the positive electrode to prevent a short circuit. In addition, a proton conductor (electrolytic solution) is filled between the negative electrode and the positive electrode in contact with the electrode.

  An enzyme that catalyzes the oxidation reaction of fuel or the reduction reaction of oxygen exists on or in the electrode 2. The enzyme is not limited to or on the electrode 2 as long as electrons can be exchanged, and may exist in the vicinity of the electrode 2.

  The insulative heat conductor 3 conducts heat or cold from a portion exposed to the outside of the battery housing 1 to the contacted electrode 2 and functions to change the temperature of the electrode 2 and the vicinity thereof. Therefore, the temperature of the electrode 2 and the vicinity thereof can be controlled to a desired temperature by bringing the heat source or the cold source into contact with the portion of the insulating heat conductor 3 exposed to the outside of the battery casing 1.

  When using a heat source, the electrode 2 can be heated to a temperature at which the enzyme can exhibit high catalytic activity via the insulating heat conductor 3. Thereby, sufficient battery performance can be obtained even in a low temperature environment. Although a general-purpose heating means such as a heater may be used as the heat source, the electrode 2 can be maintained at about 37 ° C., which is the optimum temperature for activity, by using the human body temperature. By using a body temperature that can be used ubiquitously at all times, battery performance can be improved without using internal or external energy of the biofuel cell A or preparing a separate heat source even at room temperature.

  In addition, when the beverage is to be used as fuel, if the beverage is cooled, immediately after the beverage is supplied into the battery case from the supply port, the efficiency of the oxidation reaction of the fuel is low due to the low temperature. In order to obtain output, it is necessary to wait for the beverage filled inside to warm to room temperature. In such a case, in the biofuel cell A, since the insulating heat conductor 3 quickly conducts the outside air temperature to the electrode 2, the temperature of the electrode 2 and the beverage in contact therewith can be quickly raised to room temperature. Power generation can be started in a short time. Furthermore, if a heat source such as a heater or body temperature is used, power generation can be started in a shorter time or instantaneously.

  On the other hand, when a cold heat source is used, the electrode 2 can be cooled to a low temperature through which the enzyme has no catalytic activity or becomes extremely low through the insulating heat conductor 3. As a result, during the period when the biofuel cell A is not used, the natural degradation of the enzyme over time can be suppressed, and the cell can be stored while maintaining the performance. As the cold heat source, general-purpose cooling means such as a heat exchanger and a coolant can be used.

(2) Electrode material The material of the electrode 2 is a carbon-based material such as porous carbon, carbon pellets, carbon paper, carbon felt, carbon fiber, or a laminate of carbon fine particles. Of these, porous carbon-based materials are particularly preferable.

(3) Insulating thermal conductor material Examples of the material of the insulating thermal conductor material 3 include polymer compounds containing sintered ceramics such as aluminum nitride, boron nitride, and alumina as fillers. As the polymer compound, polyphenylene sulfide, epoxy resin, polycarbonate resin, silicone, or the like is used. In addition, various ceramics such as silicon nitride and silicon carbide can be used as the material of the insulating heat conductor material 3. The insulating heat conductor material 3 and the electrode 2 can be bonded by a paste-like insulating high heat conductive material.

(4) Fuel The fuel is a substance that can be used as a fuel for a biofuel cell, and is preferably a liquid containing at least one substance that can be a substrate for an oxidase on the negative electrode. Examples of substances that can be used as fuel include sugars, alcohols, aldehydes, lipids, and proteins. Specific examples include sugars such as glucose, fructose, and sorbose, alcohols such as ethanol and glycerin, and organic acids such as acetic acid and pyruvic acid. In addition, fats and proteins, organic acids that are intermediate products of these sugar metabolisms, and the like can be mentioned. In addition, a commercially available drink can be used for the fuel solution.

(5) Enzyme On the negative electrode or in the negative electrode is an enzyme that catalyzes the redox reaction of the fuel and extracts electrons. Examples of such enzymes include glucose dehydrogenase, alcohol dehydrogenase, aldehyde reductase, aldehyde dehydrogenase, lactate dehydrogenase, and hydroxy parbet reductase. An oxidized coenzyme, a coenzyme oxidase, and an electron transfer mediator may be fixed to the negative electrode.

  An enzyme that catalyzes the reduction reaction of oxygen supplied from the outside exists on or in the positive electrode. Examples of such an enzyme include an enzyme having an oxidase activity using oxygen as a reaction substrate, such as laccase, bilirubin oxidase, and ascorbate oxidase. An electron transfer mediator may be fixed to the positive electrode.

  The mode in which the enzyme is present on the electrode 2 is not limited to the mode in which the enzyme is immobilized on the electrode surface by the immobilized membrane. For example, a microorganism that catalyzes a redox reaction and acts as a reaction catalyst is attached to the electrode surface. It is also possible to adopt the mode. Immobilization of an enzyme, a coenzyme and an electron transfer mediator using an immobilization membrane can be performed by a conventionally known method. The immobilization is particularly preferably performed by forming an immobilization film using a bio-derived polymer such as a polypeptide. Here, the “surface of the electrode” includes both the outer surface of the electrode and the surface of the void inside the electrode when the electrode is formed of a porous material.

(6) Current collector / proton conductor / separator The current collector is preferably a metal member from the viewpoint of battery performance. As the proton conductor, an electrolyte that has no electron conductivity and can transport H ⁺ is used. As the proton conductor, for example, an electrolytic solution containing a buffer substance is used. As the electrolytic solution, a neutral buffer solution around pH 7 is particularly preferably used. The separator is formed of a material that can permeate the electrolytic solution or its constituent components, and is formed of, for example, a cellulose-based nonwoven fabric or cellophane.

  The configuration of the present embodiment is applicable to both the “immersion system” in which the fuel solution is in contact with both the negative electrode and the positive electrode, and the “atmosphere exposure system” in which only the negative electrode is in contact with the fuel solution. . In addition, the configuration of the present embodiment is applicable not only to a “single cell” structure in which one battery part is provided in the battery body, but also to a structure in which a plurality of battery parts are connected in series or in parallel. Is possible.

2. FIG. 2 shows a configuration of a biofuel cell according to a modification of the first embodiment of the present technology.

(1) Battery structure In the figure, a biofuel cell indicated by symbol B includes a battery casing 1, an electrode 2 disposed in the battery casing 1, and at least a part of which is in contact with the electrode 2 and at least one of them. And an insulating heat conductor 3 that is disposed so as to be exposed outside the battery housing 1. A part of the insulating heat conductor 3 is covered with a heat insulating material 31.

  In the biofuel cell B, the insulating heat conductor 3 is formed so that a thin column is formed between the contact portion to the electrode 2 and the exposed portion to the outside of the battery housing 1. Heat or cold from the portion exposed to the outside of the battery housing 1 is conducted through the column portion and changes the temperature of the electrode 2. The insulating heat conductor 3 is covered with a heat insulating material 31 including the columnar portion except for the contact surface to the electrode 2 and the exposed surface to the outside of the battery housing 1. Thereby, the heat conduction from the part exposed outside the battery housing 1 to the contact part to the electrode 2 can be made efficient.

  Since the configuration of the biofuel cell B other than the point having the heat insulating material 31 and the shape of the insulating heat conductor 3 is the same as that of the biofuel cell A, the description thereof is omitted.

(2) Heat insulating material As the material of the heat insulating material 31, fiber materials such as glass wool, rock wool, wool and carbonized cork, and foam materials such as urethane, phenol foam, foamed polystyrene, foamed polypropylene and the like can be used. Moreover, you may ensure heat insulation by a hollow structure.

3. Biofuel Cell According to Second Embodiment FIG. 3 shows a configuration of a biofuel cell according to the second embodiment of the present technology.

(1) Battery structure In the figure, the biofuel cell indicated by symbol C includes a battery housing 1, an electrode 2 disposed in the battery housing 1, and at least a part of which is in contact with the electrode 2, and at least one And an insulating heat conductor 3 that is disposed so as to be exposed outside the battery housing 1. Furthermore, the biofuel cell C is disposed so as to face the electrode 2 with a fuel storage space 11 supplied so as to come into contact with the electrode 2, and at least part of the heat is exposed to the outside of the battery housing 1. Conductive material 4 is provided.

  The heat conductor 4 conducts the outside air temperature from the portion exposed to the outside of the battery housing 1 to the fuel storage space 11 in the battery housing 1. Therefore, for example, when a heat source is brought into contact with the portion of the insulating heat conductor 3 exposed to the outside of the battery housing 1 and the temperature of the electrode 2 and its vicinity is higher than the outside air temperature, the heat conductor 4 The fuel solution in the storage space 11 can be subjected to thermal convection (see the arrow in the figure) due to the temperature difference with the vicinity.

  In the biofuel cell, as the oxidation-reduction reaction proceeds, gradients of pH, fuel concentration, and product concentration are formed in the fuel solution near the electrode, and the reaction may be inhibited by these. In the biofuel cell C, as described above, the fuel solution in the storage space 11 is convected by heat to prevent the gradient from being formed or to eliminate the formed gradient. Recovery is possible.

  The configuration of the biofuel cell C other than the point having the heat conducting material 4 is the same as that of the biofuel cell A, and thus the description thereof is omitted.

(2) Thermal conductor material The material of the thermal conductor material 4 includes sintered ceramics such as aluminum nitride, boron nitride, and alumina, and various ceramics such as silicon nitride and silicon carbide, or includes them alone as a filler. Polymer compounds such as polyphenylene sulfide, epoxy resin, polycarbonate resin and silicone are used. Also, various metals such as aluminum and copper, and those obtained by subjecting them to a coating treatment such as anodizing can be used as the heat conductor. You may mix and use these ceramics, a high molecular compound, and a metal.

4). Biofuel Cell According to Third Embodiment FIG. 4 shows a configuration of a biofuel cell according to the third embodiment of the present technology.

  In the figure, a biofuel cell indicated by a symbol D includes a battery casing 1, an electrode 2 disposed in the battery casing 1, and at least a part of which is in contact with the electrode 2, and at least a part of the battery casing. 1 and an insulating heat conductor 3a disposed so as to be exposed to the outside. Further, the biofuel cell D has a heat insulating material 31 that can cover a portion of the insulating heat conductive material 3a exposed to the outside of the battery housing 1.

  4A shows a state where the insulating heat conductive material 3a is exposed to the outside of the battery housing 1, and FIG. 4B shows a portion where the insulating heat conductive material 3a is exposed to the outside of the battery housing 1 as a heat insulating material. The state covered with 31 is shown. The position of the heat insulating material 31 can be changed between a position (see (B)) that covers a portion of the insulating heat conductive material 3a exposed to the outside of the battery casing 1 (see (B)) and a position that does not cover (see (A)). It is configured. Here, the insulating heat conductive material 3b is provided integrally with the heat insulating material 31, and in a state where the insulating heat conductive material 3a is exposed, warm or cold heat is conducted to the electrode 2 through the insulating heat conductive material 3b. showed that. The insulating heat conductive material 3b slides together with the heat insulating material 31, whereby the insulating heat conductive material 3a is covered with the heat insulating material 31, and the conduction of warm or cold heat to the electrode 2 is cut off.

  In the state shown in FIG. 4A, in the biofuel cell D, the temperature of the electrode 2 and the vicinity thereof can be controlled to a desired temperature by bringing the heat source or the cold source into contact with the insulating heat conductive material 3b. On the other hand, in the state shown in (B), heat conduction from the heat source or the cold source is blocked by the heat insulating material 31, and heating or cooling of the electrode 2 and its vicinity is stopped, or the electrode 2 at a predetermined temperature is used. And the temperature in the vicinity thereof can be maintained.

  For example, when the human body temperature is used as a heat source, the surface of the human body is brought into contact with the insulating heat conductive material 3b in the state shown in FIG. Thereby, the temperature of the electrode 2 and its vicinity and the fuel solution (beverage) can be heated and maintained at about 37 ° C. which is the optimum temperature of the enzyme activity. When the battery is not used, heat conduction from the body surface is blocked by the heat insulating material 31 as shown in (B), and heating of the electrode 2 and the vicinity thereof is stopped.

  The material of the heat insulating material 31 can be the same as that of the biofuel cell B described above. Moreover, since the structure of the biofuel cell D other than the point which has the heat insulating material 31 is the same as that of the biofuel cell A, description is abbreviate | omitted.

5). Biofuel Cell According to Fourth Embodiment FIG. 5 shows a configuration of a biofuel cell according to the fourth embodiment of the present technology.

  In the figure, a biofuel cell indicated by symbol E includes a battery housing 1, an electrode 2 disposed in the battery housing 1, and at least a part of which is in contact with the electrode 2, and at least a part of the battery housing. 1 includes an insulating heat conductor 3a disposed so as to be exposed outside, and a heat insulating material 31 capable of covering a portion of the insulating heat conductive material 3a exposed to the outside of the battery housing 1. Furthermore, the biofuel cell E is disposed opposite to the electrode 2 with a fuel storage space 11 supplied so as to come into contact with the electrode 2, and at least part of the heat is exposed to the outside of the battery housing 1. The conductive material 4a and the heat insulating material 41 which can coat | cover the part exposed outside the battery housing | casing 1 of the heat conductive material 4a are included.

  FIG. 5A shows a state in which the insulating heat conductive material 3a is exposed to the outside of the battery housing 1 and a portion of the heat conducting material 4a exposed to the outside of the battery housing 1 is covered with the heat insulating material 41. (B) shows a state in which the insulating heat conductive material 3a is exposed to the outside of the battery housing 1 and the heat conductive material 4a is also exposed. Furthermore, (C) shows that the portion of the insulating heat conductive material 3a exposed to the outside of the battery housing 1 is covered with the heat insulating material 31, and the portion of the heat conductive material 4a exposed to the outside of the battery housing 1 is also the heat insulating material 41. The state covered by is shown. Here, when the heat conductive material 4b is provided integrally with the heat insulating material 41 and the heat conductive material 4a is exposed, the outside air temperature is conducted to the fuel storage space 11 in the battery housing 1 through the heat conductive material 4b. The configuration is shown. The heat conductive material 4b slides together with the heat insulating material 41, whereby the heat conductive material 4a is covered with the heat insulating material 41, and the conduction of the outside air temperature to the storage space 11 is cut off. The configuration of the insulating heat conductive material 3b integrally with the heat insulating material 31 is the same as that of the biofuel cell D described above.

  In the state shown in FIG. 5A, in the biofuel cell E, the temperature of the electrode 2 and the vicinity thereof can be controlled to a desired temperature by bringing the heat source or the cold source into contact with the insulating heat conductive material 3b. At this time, since the heat conductive material 4a is covered with the heat insulating material 41, the heat or cold from the heat source is efficiently stored in the electrode 2 and the vicinity thereof.

  Subsequently, when the biofuel cell E is in the state shown in FIG. 5B, the outside air temperature is conducted to the fuel storage space 11 in the battery housing 1 via the heat conducting material 4b, and the electrode 2 and the vicinity thereof are connected. Due to the temperature difference, the fuel solution in the storage space 11 can be subjected to thermal convection (see arrows in the figure).

  In the state shown in (C), heat conduction from the heat source or the cold source is cut off by the heat insulating material 31, and heating or cooling of the electrode 2 and its vicinity is stopped, or the electrode 2 and its temperature set at a predetermined temperature The temperature in the vicinity can be maintained. At this time, by covering the heat conductive material 4a with the heat insulating material 41, the temperature of the electrode 2 and the vicinity thereof can be effectively maintained.

  For example, when the human body temperature is used as a heat source, the surface of the human body is brought into contact with the insulating heat conductive material 3b in the state shown in FIG. Thereby, the temperature of the electrode 2 and its vicinity and the fuel solution (beverage) can be heated and maintained at about 37 ° C. which is the optimum temperature of the enzyme activity. As the oxidation-reduction reaction proceeds, a gradient of pH, fuel concentration, and product concentration is formed in the fuel solution in the vicinity of the electrode, and when the output decreases, as shown in FIG. The covering of the conductive material 4a is released, the outside air temperature is introduced into the storage space 11, and the fuel solution is convected. Thereby, the formed gradient can be eliminated and the battery performance can be recovered. When the battery is not used, heat conduction from the body surface to the insulating heat conductive material 3a is blocked by the heat insulating material 31, and the heat of the electrode 2 and its vicinity and the fuel solution is radiated to the outside air through the heat conductive material 4a. Then, as shown in (C), the heat conductive material 4a is also covered with the heat insulating material 41, and the battery is stored.

  The material of the heat insulating materials 31 and 41 can be the same as that of the heat insulating material 31 of the biofuel cell B described above. Moreover, since the structure of the biofuel cell E other than the point which has the heat insulating material 41, the heat conductor 4a, and the heat conductor 4b is the same as that of the biofuel cell D, description is abbreviate | omitted.

6). Biofuel Cell According to Fifth Embodiment FIG. 6 shows a configuration of a biofuel cell according to the fifth embodiment of the present technology.

  In the figure, a biofuel cell indicated by a symbol F includes a battery housing 1, an electrode 2 disposed in the battery housing 1, at least a part of which is in contact with the electrode 2, and at least a part of the battery housing. 1 and an insulating heat conductor 3a disposed so as to be exposed to the outside. Furthermore, the biofuel cell F has a coolant 5 disposed in contact with a portion of the insulating heat conductive material 3a exposed to the outside of the battery casing 1.

  FIG. 6A shows a state in which the insulating heat conductive material 3a is exposed outside the battery housing 1, and FIG. 6B shows a coolant on the portion of the insulating heat conductive material 3a exposed outside the battery housing 1. 5 shows a contact state. It is preferable that the coolant 5 is detachably attached in the accommodation space formed by the heat insulating material 31. The position of the coolant 5 can be changed between a position (see (B)) where the insulating heat conductive material 3a is exposed to the portion exposed to the outside of the battery casing 1 (see (B)) and a position where it is not covered (see (A)). It is configured. Here, the insulating heat conductive material 3b is provided integrally with the heat insulating material 31, and in a state where the insulating heat conductive material 3a is exposed, warm or cold heat is conducted to the electrode 2 through the insulating heat conductive material 3b. showed that. The insulating heat conductive material 3b slides together with the heat insulating material 31 and the coolant 5, whereby the coolant 5 comes into contact with the insulating heat conductive material 3a, and the cold heat to the electrode 2 is conducted.

  In the state shown in FIG. 6A, in the biofuel cell F, the temperature of the electrode 2 and the vicinity thereof can be controlled to a desired temperature by bringing the heat source into contact with the insulating heat conductive material 3b. On the other hand, in the state shown in (B), the electrode 2 and its vicinity can be cooled by conduction of cold heat from the coolant 5.

  For example, when a human body temperature is used as a heat source, the surface of the human body is brought into contact with the insulating heat conductive material 3b in the state shown in FIG. Thereby, the temperature of the electrode 2 and its vicinity and the fuel solution (beverage) can be heated and maintained at about 37 ° C. which is the optimum temperature of the enzyme activity. When the battery is not used, the coolant 5 is brought into contact with the insulating heat conductive material 3a as shown in (B), the temperature of the electrode 2 and its vicinity is lowered, and the catalytic reaction of the enzyme is reduced or stopped.

  When the coolant 5 is configured to be detachable, the temperature of the electrode 2 and its vicinity can be reduced or denatured by bringing the coolant 5 that has been cooled in a refrigerator or the like into contact with the insulating heat conductive material 3a. The temperature can be quickly lowered to a preventable temperature. Thereby, when the use of the biofuel cell F is stopped, it becomes possible to store the battery while maintaining the performance.

  The material of the heat insulating material 31 can be the same as that of the biofuel cell B described above. Moreover, since the structure of the biofuel cell F other than the point which has the coolant 5 is the same as that of the biofuel cell D, description is abbreviate | omitted.

  FIG. 7 shows a configuration for attaching the biofuel cell according to the present technology to the body.

  As described above, in the biofuel cell according to the present technology, the portion exposed to the outside of the battery housing 1 of the insulating heat conductor 3 is brought into contact with the body surface, so that the electrode 2 is optimally activated using body temperature. It can be warmed and maintained at a temperature of about 37 ° C.

  In the figure, the biofuel cell indicated by symbol G is a band 6a (A) as a member for mounting the battery in a state where the portion of the insulating heat conductor 3 exposed to the outside of the battery housing 1 is in contact with the body surface. And a clip 6b (B).

  The band 6a is used to hold the battery by bringing the exposed portion of the insulating heat conductor 3 into contact with the surface of the arm or finger, for example, like a wristwatch or a ring. The clip 6b is used for attaching the biofuel cell G to, for example, a collar or sleeve of clothing, a waist portion or a chest portion. At this time, it is preferable that the exposed portion of the insulating heat conductor 3 is attached in direct contact with the skin surface. However, as long as the exposed portion side of the insulating heat conductor 3 of the battery housing 1 is located on the human body surface side, the body temperature can be used even when the battery housing 1 is worn in contact with the skin surface through clothing. .

7). Bioreactor and biosensor In the above-described biofuel cell, the electrode through the insulating heat conductive material and the temperature control in the vicinity thereof are provided with an electrode serving as a reaction field for the oxidation-reduction reaction of a substance using an oxidoreductase as a catalyst. The present invention can also be applied to a bioreactor that performs a biochemical reaction using a catalyst and a biosensor that detects the substance by a change in a substrate-specific substance caused by the biochemical reaction. Such a bioreactor or biosensor uses an electrode on which an oxidoreductase is immobilized as a reaction element.

  The temperature of the biochemical reaction can be increased by heating the electrode (reaction element) and the temperature in the vicinity thereof to an optimum temperature for the biochemical reaction via the insulating heat conductive material. Therefore, in the bioreactor or biosensor described above, a desired substance can be reacted at a higher reaction rate than in the past, or a desired substance can be detected with high sensitivity. Conversely, if the electrode (reaction element) and its vicinity are cooled via an insulating heat conducting material, natural degradation of the enzyme over time can be suppressed during periods when the bioreactor or biosensor is not used. It is possible to store it while maintaining

In addition, this technique can also take the following structures.
(1) Insulating heat disposed at least partly in contact with the electrode and at least partly exposed to the outside of the battery case, and an electrode serving as a reaction field for fuel redox reaction using oxidoreductase as a catalyst And a biofuel cell having a conductive material.
(2) The above (1), comprising a heat conductive material disposed opposite to the electrode with a fuel storage space supplied so as to come into contact with the electrode, and at least a part of which is exposed outside the battery casing. The biofuel cell as described.
(3) It has a heat insulating material which can coat | cover the part exposed outside the battery housing | casing of the said insulating heat conductive material and / or the part exposed outside the battery housing | casing of the said heat conductive material, and this heat insulating material is the said insulating property. (2) The position of the heat conducting material exposed to the outside of the battery case and / or the position of the heat conducting material exposed to the outside of the battery case is changeable between a position covering and a position not covering the part. The biofuel cell as described.
(4) When the heat insulating material is in a position not covering the portion of the insulating heat conductive material exposed to the outside of the battery case and / or the portion of the heat conductive material exposed to the outside of the battery case, the insulating heat The biofuel cell according to (3), further comprising a coolant disposed in contact with a portion of the conductive material exposed to the outside of the battery housing and / or a portion of the heat conductive material exposed to the outside of the battery housing.
(5) The above (1) to (4) having a member for mounting the battery case on the body in a state where the portion of the insulating heat conductive material exposed outside the battery case is positioned on the human body surface side The biofuel cell according to any one of the above.
(6) Insulating heat conduction in which an electrode serving as a reaction field for the oxidation-reduction reaction of a substance using oxidoreductase as a catalyst, and at least part of which is in contact with the electrode and at least part of which is exposed outside the housing And a bioreactor.
(7) Insulating heat conduction in which an electrode serving as a reaction field for the oxidation-reduction reaction of a substance using oxidoreductase as a catalyst, and at least a part of which is in contact with the electrode and at least a part of which is exposed outside the housing And a biosensor.

  The biofuel cell according to the present technology can control the temperature of the electrode and the vicinity thereof to an optimum temperature for the catalytic reaction of the enzyme, so that it has sufficient performance even in a use environment at a temperature lower or higher than the optimum temperature of the enzyme activity. Obtainable.

A, B, C, D, E, F, G: biofuel cell, 1: battery housing, 11: storage space, 2: electrode, 3, 3a, 3b: insulating heat conductor, 31, 41: heat insulation Material, 4, 4a, 4b: Thermal conductor, 5: Coolant, 6a: Band, 6b: Clip

Claims (7)

An electrode serving as a reaction field for the oxidation-reduction reaction of the fuel catalyzed by oxidoreductase,
A biofuel cell comprising: an insulative heat conductive material disposed at least partially in contact with the electrode and at least partially exposed outside the battery housing.   2. The biofuel according to claim 1, further comprising a heat conducting material that is disposed to face the electrode across a storage space for fuel that is supplied so as to come into contact with the electrode, and at least a part of which is exposed outside the battery casing. battery. A heat insulating material capable of covering a portion of the insulating heat conductive material exposed outside the battery case and / or a portion of the heat conductive material exposed outside the battery case;
The heat insulating material can be repositioned between a position where the insulating heat conductive material is exposed to the outside of the battery case and / or a position where the heat conductive material is exposed to the outside of the battery case and a position where the heat insulating material is not covered. The biofuel cell according to claim 2, which is configured. When the heat insulating material is in a position that does not cover a portion of the insulating heat conductive material exposed outside the battery housing and / or a portion of the heat conductive material exposed outside the battery housing,
The biofuel cell according to claim 3, further comprising a coolant disposed in contact with a portion of the insulating heat conductive material exposed to the outside of the battery housing and / or a portion of the heat conductive material exposed to the outside of the battery housing.   5. The biofuel cell according to claim 4, further comprising a member for attaching the battery case to a body in a state where a portion of the insulating heat conductive material exposed to the outside of the battery case is positioned on a human body surface side. An electrode serving as a reaction field for the oxidation-reduction reaction of a substance catalyzed by oxidoreductase,
A bioreactor comprising: an insulative heat conductive material disposed at least partially in contact with the electrode and at least partially exposed outside the housing. An electrode serving as a reaction field for the oxidation-reduction reaction of a substance catalyzed by oxidoreductase,
A biosensor comprising: an insulative heat conductive material disposed at least partially in contact with the electrode and at least partially exposed outside the housing.

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