JP7380810B2 - Diapers and systems equipped with enzyme batteries - Google Patents

Description

The present invention relates to diapers and systems equipped with enzyme batteries.

Increasing medical costs and labor shortages due to the declining birthrate and aging society have become problems. Particularly in nursing care settings, chronic labor shortages are an issue, and there is an urgent need to improve the working environment.
Among nursing care tasks, incontinence care for bedridden patients and the elderly places an excessive physical and mental burden on caregivers.
Normally, in nursing homes and hospitals, diapers are checked regularly and diapers are checked to prevent diapers from being left unattended for long periods of time, and to prevent diaper leaks from contaminating sheets and beds. being done. However, this confirmation work often includes cases where the diaper has not been excreted or when there is no need to change the diaper, resulting in unnecessary diaper opening/closing work and diaper changing work that does not need to be done. This places a heavy burden on people.
If the presence or absence of urination could be detected by a sensor or the like and the presence or absence of urination could be known without checking the diaper, it would be possible to reduce unnecessary diaper opening/closing and changing operations.

As an improvement measure, a method has been reported in which a moisture sensor is installed on the inner surface of the diaper to detect urination (Patent Documents 1 and 2). However, conventional moisture sensors require a separate power source to operate, which causes issues such as the hassle of battery replacement and wiring, and if the sensor uses metal electrodes, the hassle of separating them when disposing of them. Become.

Japanese Patent Application Publication No. 2011-19726 JP-A-6-300723

An object of the present invention is to provide a power source and a sensor for detecting urination that can be easily disposed of without the hassle of battery replacement using a diaper equipped with an enzyme battery.

The present inventors have conducted repeated studies to solve the above problems, and as a result, they have arrived at the present invention.
That is, the present invention provides a diaper including at least a top sheet, a water absorbent material, and a back sheet as constituent members, wherein an enzyme cell is located between the top sheet and the back sheet,
The enzyme battery includes a positive electrode and a negative electrode,
The present invention relates to a diaper equipped with an enzyme battery, characterized in that at least one of the positive electrode and the negative electrode contains an enzyme.

Further, the present invention relates to the diaper in which the enzyme cell is located between a top sheet and a water absorbent material.

Further, the present invention relates to the diaper in which the enzyme battery is located inside the water-absorbing material.

The present invention also relates to the diaper in which the enzyme battery is located between the water absorbent material and the backsheet.

Further, the present invention relates to the diaper described above, in which the enzyme battery contains an enzyme capable of generating electricity from components in urine supplied from outside the diaper.

Moreover, the present invention further relates to the above-mentioned diaper containing fuel inside or near the enzyme cell.

The present invention also relates to the above diaper containing an enzyme capable of generating electricity from one or more types of organic substances contained in urine.

The present invention also relates to a system that uses the diaper described above and includes means for calculating the amount of urine from the remaining amount of fuel and the amount of electricity generated.

The present invention also relates to a system that uses the diaper described above and includes means for calculating the concentration of one or more types of organic substances contained in urine from the amount of power generated by the enzyme battery.

The present invention also relates to a system that uses the diaper described above and includes means for calculating the number of times of urination from changes in the amount of electricity generated by the enzyme cell due to urination.

Moreover, the present invention further relates to the above system including an external transmission means linked to power generation of the enzyme battery.

By using a diaper equipped with the enzyme battery of the present invention, it becomes possible to realize a sensor and a power source for a sensor that detects urination that can be easily disposed of without the hassle of battery replacement.

FIG. 1 is a configuration diagram schematically showing the position where the enzyme battery is mounted in a diaper equipped with the enzyme battery according to the present invention (Examples 1, 4, and 7). FIG. 2 is a configuration diagram schematically showing the position where the enzyme battery is mounted in a diaper equipped with the enzyme battery according to the present invention (Examples 2 and 5). FIG. 3 is a configuration diagram schematically showing the position where the enzyme battery is mounted in a diaper equipped with the enzyme battery according to the present invention (Examples 3 and 6). FIG. 4 is a diagram showing the amount of change in power generation amount with respect to glucose concentration in a diaper (4) equipped with an enzyme battery. FIG. 5 is a diagram showing the amount of change in power generation amount with respect to the amount of ultrapure water input in the diaper (1) equipped with an enzyme battery.

The present invention will be explained in detail below.

<Diapers equipped with enzyme batteries (top sheet, water absorbing material, back sheet)>
The diaper according to the present invention includes at least a top sheet, a water absorbent material, and a back sheet. The top sheet is the part that comes into direct contact with the skin and constitutes the innermost (skin side) of the diaper.It is made of nonwoven fabric (polypropylene, polyester, rayon, etc.) or cotton, and it quickly diffuses and penetrates excreted urine. It plays the role of sending water to the water-absorbing material.
The water-absorbing material is made of cotton-like pulp, polymeric water-absorbing agents, water-supplying paper, etc., and plays the role of absorbing and retaining urine that flows in from the top sheet. The back sheet is made of polyethylene film or the like, has a waterproof function, and plays the role of preventing urine leakage.

When an enzyme battery is mounted on a diaper, it has a top sheet, a water absorbent material, and a back sheet in this order, and the enzyme battery is located between the top sheet and the back sheet. That is, it is mounted at any position between the top sheet and the water-absorbing material, inside the water-absorbing material, or between the water-absorbing material and the back sheet. The fact that the enzyme battery is mounted inside the top sheet has an important meaning in ensuring sufficient penetration of urine into the interior of the enzyme battery, which is necessary for stable operation. When the enzyme cell is inside the top sheet, urine diffuses and permeates into the enzyme cell from the top sheet made of hydrophilic material or the water absorbing material, so the enzyme cell is It becomes possible to effectively supply urine into the body. In addition, since the top sheet is not exposed to the outside, the enzyme battery is prevented from coming into direct contact with the skin, thereby preventing rashes and damage to the enzyme battery.

<Enzyme battery>
Enzyme batteries generate electricity by using enzymes to oxidize various organic substances such as sugars, alcohols, and organic acids, generate electrons and ions at the anode (negative electrode), and perform an oxygen reduction reaction at the cathode (positive electrode). It is a device.
In addition to being used as a power source, by detecting the presence or absence of power generation and the amount of power generation, it can also be used as a sensor for detecting organic substances that can be used as fuel.
Furthermore, by driving the sensor using the power generated by the enzyme reaction, it can be used as a power-free sensor that does not require an external power supply.
There are two ways to generate electricity using components such as organic matter and water contained in urine. One is when organic matter is used as fuel to generate electricity, and the other is when fuel is placed inside or near the enzyme cell in advance, and the fuel is moved by the water in the urine and reacts with the enzyme to generate electricity. This is the case.
That is, organic matter in urine, urine sugar, uric acid, etc. is used as a fuel and/or a sensing target. In addition, even if biological samples supplied from the outside such as urine do not contain organic substances that can be used as fuel, by incorporating organic substances that can be used as fuel into the diaper in advance, liquid components such as moisture supplied from the outside can be used as fuel. The fuel can also be transported and reacted with enzymes to generate electricity. Thus, in the present invention, the enzyme battery can be used as a power source, as a sensor, or both.
The structure of an enzyme cell includes an anode that oxidizes fuel, a cathode where oxygen reduction occurs, and a separator that separates the anode and cathode. However, the separator does not necessarily have to be provided as long as the anode and cathode can be electrically separated. Further, it may include an ion conductor for transmitting ions from the anode to the cathode side. In consideration of size, weight reduction, storage stability, etc., an enzyme cell using an electrolyte contained in the fuel and/or urine, which is the object to be sensed, may be preferable in some cases.
In enzyme cells where the anode and cathode are not completely separated, and which use a non-separator system or a separator made of paper, etc., impurities contained in the fuel may poison the oxygen reduction catalyst for the cathode reaction. , caution is required as this tends to cause a decrease in activity and destabilization of the output. In particular, noble metal catalysts such as platinum are easily poisoned, so their use in the same system may be undesirable. On the other hand, carbon catalysts for enzyme batteries that do not contain noble metals are more resistant to poisoning than these noble metal catalysts, and therefore can be suitably used even in systems where impurities are present.
In addition, when the carbon catalyst for enzyme batteries used in the present invention is used as a cathode for devices that are manufactured by directly coating an anode and cathode on easily disposable separators such as nonwoven fabric, felt, or paper, expensive precious metals and oxygen are used. It becomes possible to realize a disposable device (easy disposal, no need for recycling, etc.) at low cost without using reductase.

<Circuit wiring>
Circuit wiring is a conductive member for electrically connecting a positive electrode and a negative electrode to external devices in an enzyme battery to form a circuit. For circuit wiring, the positive or negative electrode may be connected to a separately prepared conductive member and then connected to an external device, or the conductive support of the positive or negative electrode may be extended as it is and connected to the external device as circuit wiring. Good too. There are no particular limitations on the method of connecting circuit wiring and external devices, and in addition to connections using adhesives or adhesives, connections using snap buttons, magnets, clips, fasteners, Velcro (registered trademark), etc. I can give an example.
The material for the circuit wiring is not particularly limited as long as it is a non-metallic material that has conductivity. For example, in addition to conductive carbon materials such as carbon paper, carbon cloth, and carbon felt, conductive carbon compositions for enzyme battery circuit wiring, polyaniline, polyacetylene, polypyrrole, polythiophene, etc. can be used on nonconductive supports such as paper and cloth. A conductive polymer coated and dried or a combination thereof may be used. From the viewpoint of ease of disposal and cost, it is preferable to use a non-conductive support coated with a conductive carbon composition for enzyme cell circuit wiring and dried. In particular, the non-conductive support is preferably a bendable support. Furthermore, it is preferable to use a non-conductive paper support coated with a conductive carbon composition for enzyme cell circuit wiring and dried.

<Conductive carbon composition for enzyme battery circuit wiring>
The conductive carbon composition for enzyme battery circuit wiring contains at least conductive carbon such as graphite, carbon black, or graphene-based material, a solvent, and a binder. Further, the conductive carbon composition for enzyme cell circuit wiring may contain a dispersant, a thickener, a film-forming aid, an antifoaming agent, a leveling agent, a preservative, a pH adjuster, and the like, as necessary. The ratios of the conductive carbon, the solvent, the binder, and the dispersant are not particularly limited, and can be appropriately selected within a wide range. From the viewpoint of VOC emission, it is preferable to use water or an aqueous solvent, and accordingly, it is preferable that the binder, dispersant, etc. are also aqueous.

<Conductive support>
In the enzyme battery, conductive supports may be used for the positive and negative electrodes. The conductive support used in the enzyme battery is not particularly limited as long as it is a conductive material. Examples include a conductive layer made of conductive carbon material such as carbon paper and carbon cloth, metal foil, and metal mesh. In addition, similar to circuit wiring, conductive carbon compositions for enzyme battery circuit wiring or conductive polymers such as polyaniline, polyacetylene, polypyrrole, polythiophene, etc. are applied to a non-conductive support such as paper or cloth and dried. or a combination thereof may be used. The method for applying the composition is not particularly limited, and general methods such as those used in producing circuit wiring for enzyme batteries can be applied.
From the viewpoint of ease of disposal and cost, it is preferable to use a non-conductive support coated with a conductive carbon composition for enzyme cell circuit wiring and dried. In particular, the non-conductive support is preferably a bendable support. Furthermore, it is preferable to use a paper non-conductive support coated with a conductive carbon composition for enzyme cell circuit wiring and dried.

<Negative electrode for enzyme batteries>
In the negative electrode for enzyme cells, electrons generated by the oxidation reaction of fuel are supplied to the cathode. The negative electrode for enzyme batteries is a coating film obtained by directly coating a conductive carbon composition for enzyme battery circuit wiring, a paste of a conductive carbon material, a carbon catalyst for enzyme batteries, etc. on a base material such as a conductive support or a separator, and then drying the paste. Alternatively, the coating film formed by applying the conductive carbon composition for enzyme battery circuit wiring onto a transfer substrate, etc. and drying it is transferred to a support, separator, etc., and the enzyme or mediator is supported on the coating film prepared. Alternatively, it can be produced by directly supporting an enzyme or mediator on a conductive support, or by applying a conductive carbon composition for enzyme battery circuit wiring containing an enzyme to a support and drying it.
The method for applying the composition is not particularly limited, and general methods such as those used in producing circuit wiring for enzyme batteries can be applied.
The enzyme or mediator may be supported by including it in the above composition, or it may be carried out afterwards on a coated film dried after application or on a conductive support. If it is carried out later, a method can be used in which the coating film or conductive support is immersed in a solution in which the enzyme or mediator is dissolved, and then dried and supported.

<Enzyme for enzyme battery negative electrode>
The enzyme used in the present invention is not particularly limited as long as it can give and receive electrons through reaction, and is appropriately selected depending on the fuel to be supplied, cost, type of device, etc. Preferred enzymes include oxidoreductases that catalyze many redox reactions in living bodies, such as substance metabolism.
The enzyme used for the negative electrode of the enzyme battery may be any enzyme as long as it can release electrons, and oxidases and dehydrogenases of sugars and organic acids can be used. Among these, glucose oxidase and glucose dehydrogenase are preferable because they are cheaper and more stable than other enzymes, and can use glucose contained in biological samples such as human blood and urine as fuel.

<Mediator>
Depending on the type of enzyme, there are direct electron transfer (DET) enzymes that can directly transfer electrons to the electrode and enzymes that cannot directly transfer electrons. Enzymes other than the DET type can be used in combination with a mediator that plays the role of transferring electrons generated by oxidation of fuel from the enzyme to the electrode (anode) or transferring electrons received from the anode from the electrode (cathode) to the enzyme. preferable. The mediator is not particularly limited as long as it is a redox substance that can transfer electrons to and from the electrode, and conventionally known mediators can be used.
Methods for using the mediator include a method in which it is supported on an electrode, a method in which it is dissolved in an electrolytic solution, and the like. Examples of the mediator include tetrathiafulvalene, quinones such as hydroquinone and 1,4-naphthoquinone, ferrocene, ferricyanide, osmium complexes, and polymers modified with these compounds. Non-metallic compounds are preferred from the viewpoint of separation and disposal.

<Positive electrode for enzyme batteries>
The positive electrode for an enzyme battery receives electrons generated at the anode and consumes them through a reduction reaction within the electrode. For example, in the case of an oxygen reduction reaction that uses oxygen as an electron acceptor, the structure of the positive electrode for an enzyme battery is such that an electron and proton conduction path and an oxygen supply path are secured to the active site of the positive electrode catalyst, which is the reaction site. It is preferable for efficient power generation to be as follows. Positive electrodes for enzyme batteries include those that use inorganic compounds as catalysts and those that use enzymes. A method in which a composition containing a positive electrode catalyst is directly applied to a base material such as a conductive support (carbon paper or a conductive carbon layer) or a separator and dried, or a method in which the composition is applied to a transfer substrate, etc. It is produced by a method of transferring a coating film formed by drying and drying to the above-mentioned conductive support, separator, etc. Further, when an enzyme is used as a positive electrode catalyst, the composition may be prepared and applied in the same manner as for the negative electrode for enzyme batteries.
The method for applying the composition is not particularly limited, and examples include general methods such as knife coater, bar coater, blade coater, spray, dip coater, spin coater, roll coater, die coater, curtain coater, and screen printing. methods can be applied.

<Catalyst for enzyme battery positive electrode>
When an inorganic compound is used as a catalyst in the positive electrode of an enzyme battery, examples of the oxygen reduction catalyst include a noble metal catalyst, a base metal oxide catalyst, and a carbon catalyst for enzyme batteries. Carbon catalysts are preferred from the viewpoint of cost.
A noble metal catalyst is a catalyst containing one or more elements selected from ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold among transition metal elements. These noble metal catalysts may be used alone or supported on other elements or compounds.
The base metal oxide catalyst is an oxidation catalyst containing at least one base metal element selected from the group consisting of zirconium, tantalum, titanium, niobium, vanadium, iron, manganese, cobalt, nickel, copper, zinc, chromium, tungsten, and molybdenum. More preferably, carbonitrides of these base metal elements and carbonitrides of these transition metal elements can be used.
A carbon catalyst for enzyme batteries (hereinafter also simply referred to as a carbon catalyst) is made of a carbon material with a basic skeleton of carbon elements, and has physical and chemical interactions (bonds) between its constituent units. It is a catalytic material that contains different elements, such as heteroatoms such as N, B, and P, and further contains a base metal element in some cases, and has oxygen reduction activity. The base metal elements here refer to transition metal elements other than noble metal elements (ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold), and base metal elements include cobalt, iron, nickel, It is preferable to contain one or more selected from the group consisting of manganese, copper, titanium, vanadium, chromium, zinc, and tin.
Containing a hetero element and a base metal element has an important meaning in terms of having oxygen reduction activity. Carbon catalysts for enzyme batteries use, as catalytic active sites, nitrogen atoms introduced into the edges of the hexagonal network of carbon that constitutes the basic skeleton of the carbon material, carbon atoms in the vicinity, and base metals on the catalyst surface. Examples include nitrogen atoms and base metal atoms in a base metal-N4 structure in which four nitrogen atoms are arranged in a plane around an element.
The carbon catalyst for enzyme cells is a carbon catalyst prepared by mixing one or more carbon materials and a compound containing a nitrogen element and/or the base metal element and heat-treating the mixture, and is a carbon catalyst prepared by heat-treating the mixture and using a conventionally known carbon catalyst. You can use the following. The carbon material used in the carbon catalyst is not particularly limited as long as it is carbon particles derived from an inorganic material and/or carbon particles obtained by heat treating an organic material.
In addition, when an enzyme is used as a catalyst, any enzyme that can consume electrons may be used at the positive electrode of the enzyme battery. Enzymes can be used. A positive electrode for an enzyme battery that uses oxygen reductase may have lower durability in use than an inorganic compound catalyst due to potential load and deterioration of the enzyme during side reactions.

<Separator>
The separator is not particularly limited as long as it can electrically separate the negative electrode and the positive electrode (preventing short circuits), and conventionally known materials can be used. Specifically, polyethylene fibers, polypropylene fibers, glass fibers, resin nonwoven fabrics, glass nonwoven fabrics, felt, filter paper, Japanese paper, etc. can be used. Further, if a structure is adopted in which the positive electrode and the negative electrode are kept at a sufficient distance and there is no short circuit due to contact, it is not necessary to use a separator.

<Ionic conductor>
The ion conductor in the present invention conducts ions between an anode and a cathode. The form of the ion conductor is not particularly limited as long as it has ion conductivity. As the ion conductor, an electrolytic solution in which an electrolyte such as a phosphate or a sodium salt is dissolved, or a solid polymer electrolyte may be used.
Electrolytes may be stored in the diaper in advance, or electrolytes contained in urine may be used, or both may be used.

<Fuel>
The fuel required to operate the enzyme cell of the present application is not particularly limited as long as it can be decomposed by enzymes, and may be organic substances such as monosaccharides such as D-glucose, polysaccharides such as starch, or organic acids. It is widely available.
When operating an enzyme battery mounted on a diaper, one or more types of organic substances that serve as fuel are built into the enzyme battery or diaper in advance, and the enzyme battery is operated when the organic substances are eluted and diffused into the urine water. One or more organic substances contained in urine, such as glucose, can be used to operate an enzyme battery, or one or more organic substances used as fuel can be built into the enzyme battery or diaper in advance, and the organic substances can be eluted into the urine water. It is also possible to operate an enzyme battery using one or more organic substances contained in urine.
In the case where fuel is stored in advance, solid fuel such as sugar is preferable. In addition, it is preferable to use glucose from the viewpoint of cost and versatility.

As described above, the diaper equipped with the enzyme battery according to the present invention can function as a power source and a sensor (moisture, organic matter) using the power generated by the enzyme battery by supplying urine. As for how to use it, the enzyme battery of the present invention can be used as a power source for a conventional resistance detection type sensor, or one or more types of the enzyme battery of the present invention can be used as a power source and a sensor.

<System equipped with external communication means>
The diaper equipped with the enzyme battery of the present invention can be combined with a wireless transmitter and used as a system for wirelessly transmitting sensing information to the outside.
For example, in the case of a urination sensor, it is possible to use a built-in fuel to sense the water in urine, and at the same time use the water to generate electricity to operate a wireless transmitter. The generated electricity can be used to operate a wireless transmitter and another type of urination sensor, and in the case of a urine sugar sensor, the sugar in the urine is used as fuel and sensing object, and the electricity obtained can be used to operate a wireless transmitter and another type of urine sensor. It can operate a wireless transmitter, use sugar in urine as a sensing target, store fuel in advance, use water in urine to generate electricity, and operate a wireless transmitter with the electricity generated. <System comprising a means for calculating the amount of urine, a means for calculating the concentration of organic matter, and a means for calculating the number of times of urination>
In the diaper equipped with the enzyme battery of the present invention, the amount of electricity generated and the change in the amount of electricity generated are correlated with the amount of urine, the concentration of organic matter in the urine, the number of times of urination, etc. From this information, the amount of urine and the organic matter in the urine can be determined. It can be used as a system to calculate the concentration of urination and the number of times of urination. The calculated information can be transmitted to the outside by the external transmission means.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the following Examples do not limit the scope of the present invention in any way. In addition, "part" in Examples and Comparative Examples represents "part by mass", and % represents mass %.

<Preparation of conductive carbon composition for enzyme battery circuit wiring>
18 parts of scaly graphite CB-150 (manufactured by Nippon Graphite Co., Ltd.), 4.5 parts of furnace black VULCAN (registered trademark) ) (solid content 50%), 50 parts of a carboxymethyl cellulose aqueous solution (solid content 2%) as a dispersant, and 49.5 parts of water as a solvent were mixed in a mixer, and further put in a sand mill for dispersion. A conductive carbon composition (1) for enzyme battery circuit wiring was obtained.

<Preparation of circuit wiring for enzyme battery>
The conductive carbon composition (1) for enzyme battery circuit wiring was applied to qualitative filter paper No. 1 as a base material. 1 (manufactured by Advantech) using a doctor blade, the conductive layer was dried by heating, and the thickness of the conductive layer was adjusted to 80 μm to obtain circuit wiring for an enzyme battery (1).

<Preparation of conductive support for enzyme battery>
Similarly to the enzyme battery circuit wiring, the conductive carbon composition for enzyme battery circuit wiring was applied to qualitative filter paper No. 1 as a base material. 1 (manufactured by Advantech) using a doctor blade, and then heated and dried to adjust the thickness of the conductive layer to 80 μm. A rectangular piece with a length of 9 cm and a width of 8 cm was cut out as a conductive support for an enzyme battery (1).

<Preparation of negative electrode for enzyme battery>
As a conductive carbon material, a composition of Furnace Black VULCAN (registered trademark) /cm ² , a methanol solution of tetrathiafulvalene as a mediator and a glucose oxidase aqueous solution as a negative electrode catalyst were added dropwise, and air-dried to obtain a negative electrode (1) for an enzyme battery.

<Manufacture of carbon catalyst for enzyme batteries>
[Manufacture example 1]
Graphene nanoplatelets xGnP-C-750 (manufactured by XGscience) and iron phthalocyanine P-26 (manufactured by Sanyo Shiki Co., Ltd.) were each weighed so that the mass ratio was 1/0.5 (graphene nanoplatelets/iron phthalocyanine). Then, dry mixing was performed to obtain a mixture. The above mixture was filled into an alumina crucible and heat-treated in an electric furnace at 800° C. for 2 hours in a nitrogen atmosphere to obtain a carbon catalyst for enzyme cells (1).

<Preparation of positive electrode for enzyme battery>
4.8 parts of carbon catalyst for enzyme cells (1), 49.2 parts of water as an aqueous liquid medium, and 40 parts of a carboxymethyl cellulose aqueous solution (solid content 2%) as a dispersant were mixed in a mixer, and then put in a sand mill. and dispersed. Thereafter, 6 parts (solid content: 50%) of an emulsion-type acrylic resin dispersion solution (manufactured by Toyochem Co., Ltd.: W-168) was added as a binder and mixed with a mixer to obtain an electrode composition (1) for an enzyme battery positive electrode.
Thereafter, the enzyme battery positive electrode composition (1) was applied to one end of the conductive support (1) using a doctor blade so that the dry carbon catalyst weight was 2 mg/ ^cm2 . It was coated and dried at 95° C. for 60 minutes in a standby atmosphere to obtain a positive electrode (1) for an enzyme battery.

<Preparation of enzyme battery>
In addition to the enzyme cell circuit wiring, positive electrode, and negative electrode prepared above, a filter paper on which glucose as a fuel and sodium chloride as an ion conductor was supported was attached to a separator to prepare an enzyme cell (1). An enzyme battery (2) was produced in the same manner except that glucose and sodium chloride were not supported on the separator.

[Examples 1 to 6] [Comparative example 1]
<Production of diaper equipped with enzyme battery>
A nursing care diaper (Lifree 4-dose absorption manufactured by Unicharm Co., Ltd.) consisting of a top sheet, a water absorbent material, and a back sheet was disassembled, and the enzyme battery prepared above (1 ) were installed in each, and then returned to their original positions to produce diapers (1) to (3) equipped with enzyme batteries (Examples 1 to 3)
In addition, diapers (4) to (4) equipped with enzyme batteries were prepared in the same manner as diapers (1) to (3) equipped with enzyme batteries, except that enzyme battery (1) was replaced with enzyme battery (2). 6) were produced (Examples 4 to 6).
In addition, the enzyme battery (1) was attached to the outside of the top sheet of a nursing care diaper (Lifree 4-dose absorbent manufactured by Unicharm Co., Ltd.) with double-sided tape, and a diaper (7) was prepared in which the enzyme battery was mounted. (Comparative example 1)

<Construction of wireless communication circuit>
For the enzyme battery produced above, a boost converter (LTC3108 manufactured by Strawberry Linux (registered trademark)) and a wireless module (transmission module IM315TX, reception module IM315RX manufactured by Interplan) were connected from the enzyme battery in the diaper to the boost converter, We constructed a wireless communication circuit that connects the boost converter to the transmitter module, and also uses the receiver module to receive the wireless signal sent from the transmitter module. The enzyme battery positive electrode (1) and negative electrode (1) were connected to the boost converter by bonding circuit wiring (1) together.

<Evaluation of wireless transmission of diapers equipped with enzyme batteries>
When ultrapure water was poured into the top sheets of the diapers of Examples 1 to 3 to simulate moisture in urine, signal reception was confirmed by the receiving module in all cases. This shows that the glucose and sodium chloride in the filter paper are dissolved and diffused into the water that reached the enzyme cell when water was added, and function as a fuel and an ion conductor, respectively, and the enzyme cell generates electricity. In the case of the diapers of Examples 1 and 2, reception of wireless signals was confirmed when 150 mL of water was poured at once. On the other hand, in the case of the diaper of Example 3, reception of a wireless signal was confirmed only after 600 mL or more was put into the diaper. This is considered to be because, in the case of Example 3, the injected water reached the enzyme cell for the first time when the amount exceeded the allowable amount of the water-absorbing material, and power generation occurred.
Regarding Examples 4 to 6, the operation of the wireless module was verified in the same manner as Examples 1 to 3, except that the ultrapure water was changed to a 0.1M phosphate buffer solution with pH 7 in which 0.01M glucose was dissolved. Similar behavior was observed. This shows that the enzyme cell is functioning and generating electricity using glucose in the urine as fuel.

From Examples 1 to 6, it was revealed that the enzyme battery mounted inside the diaper could be driven by components in urine (moisture and organic matter). At the same time, it is possible to create a diaper equipped with a urine sensor that does not require a power source, is easy to dispose of, and is made of biologically safe materials.Also, by operating the transmitter using the generated electricity, sensing information can be transmitted wirelessly. For example, it becomes possible to transmit to a receiver, a mobile terminal, etc.

<Evaluation of stable drive of diapers equipped with enzyme batteries>
Using diapers equipped with the enzyme batteries of Examples 4 to 6 and Comparative Example 1, stable operation of the enzyme batteries was evaluated. A 0.1M phosphate buffer solution with pH 7 in which 0.01M glucose was dissolved was used as a simulated urine. Four diapers each of Examples 4 to 6 and Comparative Example 1 were produced (lots 1 to 4), and simulated urine was put inside the diapers to verify whether the wireless module operated. The results are shown in Table 1.

The evaluation criteria for stable drive are shown below.

(Stable drive evaluation)
〇: Wireless module works ×: Wireless module does not work

From Table 1, it can be seen that the diapers of Examples 4 to 6 can drive the enzyme battery more stably than Comparative Example 1. This is different from Comparative Example 1 in which the enzyme cell is exposed outside the top sheet when simulated urine penetrates into the inside of the enzyme cell necessary for power generation, but in Examples 4 to 6, the enzyme cell is inside the top sheet. It is believed that urine is sufficiently diffused and permeated into the enzyme cell from the top sheet and water-absorbing material made of hydrophilic materials, leading to stable operation.

[Example 7]
<Evaluation of sensing ability for urine sugar>
The positive electrode for the enzyme battery of the diaper (4) equipped with the enzyme battery was used as the working electrode, and the negative electrode for the enzyme battery was used as the counter electrode, and connected to a potentio-galvanostat (VersaSTAT3, manufactured by Princeton Applied Research) to simulate the urine of a diabetic patient. Then, a 0.1M phosphate buffer solution with a pH of 7 in which a glucose concentration of 0.001 to 0.01M was dissolved was poured into the inside of the diaper, and in the LSV measurement at room temperature, the amount of electricity generated relative to the glucose (sensing target) concentration was measured. We investigated the changes. The results are shown in FIG.
As is clear from FIG. 4, it was found that the amount of power generation changes proportionally with changes in glucose concentration, so in the diaper (4) equipped with the enzyme battery produced according to the present invention, By examining the history of power generation, it was found that the device could be used as a sensor to detect glucose concentration in urine.

[Example 8]
<Urine volume sensing>
After 30 minutes have passed after pouring 150, 300, and 600 mL of ultrapure water into the diaper (1) equipped with the enzyme battery, the positive electrode for the enzyme battery is used as the working electrode, and the negative electrode for the enzyme battery is used as the counter electrode. It was connected to a STAT (VersaSTAT3, manufactured by Princeton Applied Research), and the amount of power generation was investigated by LSV measurement at room temperature. The results are shown in FIG.
As is clear from FIG. 5, it was found that the amount of power generation attenuated proportionally depending on the amount of ultrapure water input. This indicates that the glucose stored as fuel is eluted according to the amount of liquid added, and the amount of power generated is proportional to the amount of remaining glucose. This suggests that the diaper (1) equipped with an enzyme cell may be able to sense the amount of urine urinated by checking the amount of power generated according to the amount of remaining fuel.

[Example 9]
<Urine frequency sensing>
Using the diaper equipped with the enzyme battery of Example 4, after adding 150 mL of ultrapure water as simulated urine, after 90 minutes and 180 minutes, 150 mL of ultrapure water was added, and the wireless module was activated. We verified that The results are shown in Table 2.
As is clear from Table 2, the operation of the wireless module was confirmed only immediately after adding ultrapure water.
This shows that immediately after adding ultrapure water, the inside of the enzyme cell is sufficiently wet, and the ions necessary for the reaction are sufficiently diffused, compared to the state 90 minutes have passed after adding ultrapure water. This is thought to be because the amount of power generation could be obtained. With this, it was found that it was possible to detect changes in the amount of electricity generated due to the injection of liquid and to sense the number of urination cycles.

(Wireless operation)
〇: Wireless module works ×: Wireless module does not work

1... Enzyme battery, 2... Top sheet, 3... Water absorbing material, 4... Back sheet

Claims (9)

A system that uses a diaper equipped with an enzyme battery and includes means for calculating the amount of urine from the remaining amount of fuel and the amount of electricity generated,
The diaper includes at least a top sheet, a water-absorbing material, and a back sheet as structural members, and an enzyme battery is located between the top sheet and the back sheet, and the enzyme battery has a positive electrode and a negative electrode. A system characterized in that at least one of the positive electrode or the negative electrode contains an enzyme, and further contains a fuel inside or near the enzyme cell . The system of claim 1, wherein the enzyme cell is located between a topsheet and a water absorbent material. 2. The system of claim 1, wherein the enzyme cell is located inside a water-absorbing material. The system of claim 1, wherein the enzyme cell is located between a water absorbing material and a backsheet. The system according to any one of claims 1 to 4, wherein the enzyme battery contains an enzyme capable of generating electricity from components in urine supplied from outside the diaper. The system according to any one of claims 1 to 5 , which contains an enzyme capable of generating electricity from one or more types of organic substances contained in urine. 7. The system according to claim 6, further comprising means for calculating the concentration of one or more organic substances contained in urine from the amount of power generated by the enzyme battery. 8. The system according to claim 1, further comprising means for calculating the number of times of urination from changes in the amount of electricity generated by the enzyme battery due to urination . The system according to any one of claims 1 to 8, further comprising an external transmission means linked to the power generation of the enzyme battery.