JP2018194486A - Moisture detection paper and moisture detection sensor - Google Patents

Abstract

To provide moisture detection paper and a moisture detection sensor which are easy to attach to a detection place, and whose low cost allows disposal.SOLUTION: Moisture detection paper 1 includes: paper 30 which moisture containing ions permeates; and a pair of detection electrodes 10, 20 in which oxidation-reduction potentials formed on a surface of the paper 30 differ from each other. A moisture detection sensor 2 includes: the paper 30 which moisture containing ions permeates; the pair of detection electrodes 10, 20 in which the oxidation-reduction potentials formed on the surface of the paper 30 differ from each other; and a voltage detection part 50 for detecting an electromotive voltage generated between the detection electrodes 10, 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a moisture detection paper and a moisture detection sensor for detecting moisture and moisture-containing materials.

  The moisture detection sensor is used to detect water leakage in a water-circulating part such as a kitchen of a general house or a drain pipe facility such as a factory.

  In addition, the moisture detection sensor is also used in nursing care. For example, it is desirable that the moisture detection sensor that notifies the replacement of the diaper does not require a power source such as a battery and can be discarded together with excrement.

  As a moisture detection sensor that does not use a battery, for example, one disclosed in Patent Document 1 is known.

JP 2006-53057 A

  The moisture detection sensor disclosed in Patent Document 1 includes a sensor using a chemical battery in a housing, and it is not easy to attach to a detection location. It is difficult to attach the housing to a diaper or the like without a sense of incongruity. Moreover, a special mounting tool is required for mounting on a drain pipe or the like.

  Another problem is that it is expensive to dispose of the moisture sensor together with the diaper.

  The present invention has been made in view of these problems, and it is an object of the present invention to provide a moisture detection paper and a moisture detection sensor that can be easily attached to a detection location and can be discarded at low cost.

  The gist of the moisture detection paper according to one aspect of the present embodiment is that it includes paper that permeates moisture containing ions, and a pair of detection electrodes that have different oxidation-reduction potentials applied to the surface of the paper.

  In addition, the moisture detection sensor according to an aspect of the present embodiment is generated between paper that allows moisture including ions to permeate, a pair of detection electrodes with different oxidation-reduction potentials applied to the surface of the paper, and the detection electrode. The gist of the present invention is to include a voltage detection unit that detects an electromotive voltage.

  According to the present invention, it is possible to provide a moisture detection paper and a moisture detection sensor that are easy to attach to a detection location and that can be discarded at low cost.

It is a figure which shows typically an example of the external appearance of the moisture detection paper which concerns on embodiment of this invention, (a) is a top view, (b) is AA sectional drawing of (a). It is a figure which shows typically the other example of the external appearance of the moisture detection paper which concerns on embodiment of this invention, (a) is a top view, (b) is BB sectional drawing of (a). It is a figure which shows typically an example of the external appearance of the moisture detection paper of a comparative example, (a) is a top view, (b) is CC sectional drawing of (a). It is a figure which shows the result of having measured the voltage change of the open circuit voltage at the time of dripping pseudo urine on the moisture detection paper which concerns on embodiment of this invention. It is a figure which shows the discharge characteristic from the open circuit voltage shown in FIG. It is a figure which shows the relationship between the moisture content at the time of exposing the moisture detection paper which concerns on embodiment of this invention to pseudo urine, a voltage change, and an output density. It is a figure which shows typically the example which made the electrode shape of the moisture detection paper which concerns on embodiment of this invention the comb-tooth shape. It is a figure which shows typically the example which arranged several pairs of detection electrodes of the moisture detection paper which concerns on embodiment of this invention. It is a figure which shows typically the structure of the moisture detection sensor which concerns on embodiment of this invention. It is a block diagram which shows the function structural example of the moisture detection sensor which added the power supply part, the vibration detection part, and the radio | wireless part to the moisture detection sensor shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Composition of moisture detection paper]
In FIG. 1, an example of the external appearance of the moisture detection paper of this embodiment is typically shown. Fig.1 (a) is a top view of the moisture detection paper 1, FIG.1 (b) is the AA sectional drawing. The dimensions shown in FIG. 1 are an example. The moisture detection paper 1 detects moisture using the battery reaction of a zinc-air battery.

  The moisture detection paper 1 includes a paper 30 that permeates moisture containing ions, and a pair of detection electrodes 10 and 20 that are formed on the surface of the paper 30 and have different oxidation-reduction potentials. In this example, the detection electrode 10 is formed in a shape in which a part of the surface of the circular paper 30 is cut out in a U shape. Then, the detection electrode 20 is formed in the notched recess with a certain distance from the detection electrode 10. An alphabet letter U is formed between the adjacent detection electrodes 10 and 20.

  The detection electrode 10 is made of, for example, carbon and functions as a positive electrode (air electrode). The detection electrode 20 is made of, for example, zinc and functions as a negative electrode. The paper 30 has water absorption, and is composed of, for example, Japanese paper, a water-absorbing polymer, a superabsorbent resin, and a polymer absorber.

  For example, Japanese paper (paper 30) has much longer fibers than western paper, and therefore exhibits excellent water absorption and is not easily torn. Therefore, Japanese paper is suitable as the paper 30 of this embodiment.

  The moisture detection response varies depending on the thickness of the paper 30. The paper 30 needs to have a certain thickness so that, for example, sweat is not erroneously determined as urine. For example, if it has a thickness of 150 μm or more, it is possible to suppress a reaction to a small amount of sweat.

  The reaction formula in the detection electrode 10 (positive electrode (air electrode)) is expressed by the following formula, and oxygen in the air is used as an active material.

_{O 2 + 2H 2 O + 4e} - → 4OH - (1)
The detection electrode 10 (positive electrode) according to the present embodiment includes at least a conductive material, and includes a binder or the like as necessary. Carbon is suitable as the conductive material. Moreover, since the positive electrode is formed of only carbon, it is convenient for disposable use. As the conductive material of the positive electrode, for example, carbon blacks such as ketjen black and acetylene black, activated carbon, graphites, carbon fibers, carbon sheets, carbon cloth and the like can be used.

  As the binder, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polybutadiene rubber, or the like can be used. These binders are used as powders or dispersions.

The detection electrode 20 (negative electrode) according to the present embodiment contains zinc. The reaction formula in the negative electrode is represented by the following formula.
Zn → Zn ²⁺ 2e ⁻ (2)

[Production method of moisture detection paper]
In the moisture detection paper 1 according to the present embodiment, detection electrodes 10 and 20 having an arbitrary shape are formed on a paper 30 using a mask.

  The detection electrode 10 is formed by applying a slurry containing carbon and a binder onto the paper 30 and drying it. Alternatively, pencil carbon may be applied to the paper 30.

  The detection electrode 20, a slurry containing zinc powder and a binder is applied to the paper 30 and dried. Alternatively, galvanizing spray may be produced by spraying on the paper 30.

(Experimental example 1)
In the moisture detection paper 1 of Experimental Example 1, the detection electrodes 10 and 20 having the shape shown in FIG. 1 were formed on the surface of a paper 30 (Japanese paper (Inbe, manufactured by Awagami Factory) with a thickness of 150 μm).

  The detection electrode 20 which is a negative electrode was formed by masking the surface of the paper 30 with a plastic mask and spraying a zinc plating spray. The thickness of the detection electrode 20 was 1 μm, and after natural spraying was performed overnight after spraying.

  The detection electrode 10 which is a positive electrode (air electrode) was formed by applying a slurry containing carbon and a binder to a paper 30 after masking with a plastic mask. The thickness of the detection electrode 10 was set to 1 μm, which is the same as that of the detection electrode 20, for example.

(Experimental example 2)
In the moisture detection paper 1 of Experimental Example 2, the detection electrodes 10 and 20 having the shape shown in FIG. 2 were formed on the surface of the paper 30. The formation method of the detection electrodes 10 and 20 is the same as in Experimental Example 1.

(Comparative Example 1)
In FIG. 3, the moisture detection paper of the comparative example 1 is shown. In Comparative Example 1, the detection electrodes 10 and 20 are formed on the front and back sides of the paper 30. Conditions such as the thickness of the paper 30 and the thicknesses of the detection electrodes 10 and 20 are the same as those in Experimental Examples 1 and 2. The formation method is also the same.

(Response to moisture)
For the purpose of evaluating the responsiveness to moisture of the moisture detection paper 1 according to the present embodiment, an experiment was conducted in which 1 ml of pseudo urine (0.9 wt% saline) penetrates the paper 30.

  FIG. 4 shows the 0 CV change. The horizontal axis of FIG. 4 is the time (min) after urine input, and the vertical axis is the open circuit voltage (mV).

  0 CV is an open circuit voltage (open voltage) in a state where no voltage or current is applied to the detection electrodes 10 and 20. For the measurement of 0 CV, a charge / discharge measuring device (BioLogic VMP-3) was used.

  Immediately after the urine drops, the voltage begins to increase. In Experimental Example 1, a voltage of 700 mV or more was shown after 3 (min). In Experimental Example 2, it took about 6 minutes to reach 700 mV. The difference between the experimental examples 1 and 2 is influenced by the electrode lengths of the adjacent detection electrodes 10 and 20. That is, it is considered that the longer the length of the adjacent detection electrodes 10 and 20 of the moisture detection paper 1 of this embodiment, the higher the voltage.

  On the other hand, the comparative example 1 in which the detection electrodes 10 and 20 are formed on the front and back sides of the paper 30 shows a characteristic that the rise of the voltage is further slower than in the experimental example 2. In Comparative Example 1, it took about 9 (min) to reach 700 mV.

  As described above, in the moisture detection paper 1 according to the present embodiment, the detection electrodes 10 and 20 are formed on the same surface of the paper 30, so that the detection electrode 10, 20 is formed on the front and back of the paper 30. Excellent response to moisture.

  Table 1 shows the difference in characteristics between Experimental Example 1 and Comparative Example 1.

比較例１は、実験例１の電圧変化及び出力密度の約60%程度の特性を示す。この結果から、紙３０の同一面に検知電極１０，２０を形成した方が、その表裏に検知電極１０，２０を形成するよりも良い特性を示すことが分かる。

Comparative Example 1 shows characteristics of about 60% of the voltage change and output density of Experimental Example 1. From this result, it can be seen that the detection electrodes 10 and 20 formed on the same surface of the paper 30 exhibit better characteristics than the detection electrodes 10 and 20 formed on the front and back sides.

FIG. 5 shows the discharge characteristics. The horizontal axis in FIG. 5 is the discharge time (min), and the vertical axis is the discharge voltage (mV). Discharge was performed at a current density of 1 μA / cm ² and the change in voltage between the detection electrodes 10 and 20 was measured.

Experimental Example 1 showed a discharge voltage of 550 mV and an output density of 0.55 μW / cm ² . Experimental Example 2 showed a discharge voltage of 370 mV and an output density of 0.37 μW / cm ² . Comparative Example 1 showed a discharge voltage of 300 mV. Each discharge voltage is a value of 5 (min) after the start of discharge.

  As described above, the moisture detection paper 1 according to the present embodiment is more responsive to simulated urine than the comparative example 1, and can perform a constant discharge. Therefore, the moisture detection paper 1 can be used for the purpose of detecting moisture containing ions.

  Since the moisture detection paper 1 according to the present embodiment has a simple configuration in which the pair of detection electrodes 10 and 20 are formed on the surface of the paper 30 that permeates moisture including ions, the cost is low. Moreover, since it is a simple structure as described above, it can be easily mounted by winding it around a drain pipe or the like. That is, no special mounting tool is required for mounting at the detection location. It is also easy to integrate into a diaper or the like.

(Response to simulated stool)
Using the moisture detection paper 1 of Experimental Example 1 that showed a quick response to simulated urine, the responsiveness to simulated stool was evaluated. A variety of simulated stools were prepared by changing the amount of water contained in the mashed potato.

  Evaluation was made by measuring the discharge characteristics after measuring the open circuit voltage 3 minutes after the introduction of the artificial stool.

In FIG. 6, the responsiveness with respect to the artificial stool which changed the moisture content is shown. The horizontal axis of FIG. 6 is the moisture content of the artificial stool, the vertical axis is the voltage change (V) and the output density (μW / cm ² ), the characteristic indicated by the solid line is the voltage change, and the characteristic indicated by the alternate long and short dash line is the output density. . A 100% water content is simulated urine.

  As shown in FIG. 6, there is a large difference in characteristics between 60 to 70%, which is the amount of water in healthy stool, and more than that. The voltage change in the range of moisture content 60 to 75% is 0.1 V or less, and the voltage change in the range of moisture content 80% or more is 0.4 V or more.

Further, power density, 450nW / cm ² in water content of 100%, showed a 50 nW / cm ² in water content of 60%. The tendency of the change in the output density with respect to the amount of water is the same as the change in voltage.

From this change, it is possible to distinguish between feces and urine. Further, since electric power of 50 to 450 nW / cm ² is obtained, moisture detection using an electronic circuit operable at the nW level is possible. A moisture detection sensor using an electronic circuit will be described later.

(Other electrode shapes)
As described above, the longer the adjacent detection electrodes 10 and 20 are, the larger the open circuit voltage and the output density are. Therefore, for example, in order to increase the open circuit voltage and the output density, an example in which each pair of the detection electrodes 10 and 20 has a comb shape is considered.

  FIG. 7 shows a moisture detection paper 1 (Experimental Example 3) according to this embodiment in which each of the detection electrodes 10 and 20 has a comb shape. Each of the pair of detection electrodes 10 and 20 is formed in a comb-like shape, and the tip of the other comb-teeth is inserted between the one comb-teeth, and the two are arranged with a space therebetween.

  By forming the detection electrodes 10 and 20 in this way, even when the shape of the paper 30 is 18 mm in diameter and the same as in Experimental Example 2, the length of the adjacent electrode can be increased by about 3.7 times.

  Table 2 shows the difference in characteristics between Experimental Example 3 and Experimental Example 1.

電極形状を櫛歯状にした実験例３は、実験例１よりも電圧変化と出力密度共に大きな値を示した。この結果から、隣接する正極と負極の長さが長いほど、良い特性を示すことが分かる。

In Experimental Example 3 in which the electrode shape was comb-like, both the voltage change and the output density were larger than those in Experimental Example 1. From this result, it can be seen that the longer the length of the adjacent positive and negative electrodes, the better the characteristics.

  Further, an even number of two or more pairs of detection electrodes 10 and 20 may be provided, and the detection electrodes may be connected in series. The open circuit voltage can be increased by connecting a plurality of pairs in series with the pair of detection electrodes 10 and 20 as a unit.

  FIG. 8 shows an example of the moisture detection paper 1 in which three pairs of detection electrodes are connected in series. In addition, the description of the paper 30 is omitted.

  In FIG. 8A, the detection electrode 10a that makes a pair with the detection electrode 20a and the detection electrode 20b are connected by a conductive wire 40, and the detection electrode 10b that makes a pair with the detection electrode 20b and the detection electrode 20c have a conductive wire. 41 is connected. FIG. 8B is an example in which the arrangement of the detection electrodes is opposite to that in FIG.

  The moisture detection paper 1 shown in FIG. 8 includes a plurality of pairs of detection electrodes 10 and 20, and the detection electrodes 10 a, 20 a, 10 b, 20 b, 10 c, and 20 c are arranged in parallel, and the detection electrodes on both outer sides. Two detection electrodes 20a and 10b and 20b and 10c are connected to each other by conductive lines 40 and 41 from one side excluding 10a and 20c. The conductive wires 40 and 41 may be made of, for example, an inexpensive carbon tape.

  With this configuration, the open circuit voltage of the moisture detection paper 1 can be three times that of the pair of detection electrodes 10 and 20.

  A plurality of detection electrodes 10 and 20 may be connected in parallel. By connecting the plurality of detection electrodes 10 and 20 in parallel, the output density of the moisture detection paper 1 can be mainly increased. The shape of the electrodes in which the plurality of detection electrodes 10 and 20 are connected in parallel is the comb shape shown in FIG.

(Effect of electrolyte salt)
The moisture detection sensor disclosed in Patent Document 1 uses a chemical battery containing an electrolyte salt. The moisture detection paper 1 according to this embodiment differs from the moisture detection sensor in that an electrolyte salt is not used as an electrolyte.

  By not using an electrolyte salt, the stability of moisture detection can be improved. For the purpose of confirming the stability of moisture detection, a moisture detection paper added with NaCl was prepared, and the characteristics were compared with those of a moisture detection paper not added with NaCl.

  As for the addition of NaCl, the moisture detection paper 1 of Experimental Example 1 was completely settled in physiological saline and then dried to precipitate NaCl crystals on the surface of the moisture detection paper 1. The characteristics of the moisture detection paper 1 on which NaCl crystals were deposited on the surface were compared with those of the moisture detection paper 1 to which no NaCl was added.

  For comparison of characteristics, the two were left in a constant temperature and humidity chamber at a temperature of 25 ° C. and a humidity of 60%, and the open circuit voltages were measured after 5 days, 7 days, and 10 days. The results are shown in Table 3.

ＮａＣｌを添加しない水分検知紙１は、0Vを維持し続けるのに対し、ＮａＣｌを添加した水分検知紙１は、5日後に電圧が発生し、その後、徐々に開回路電圧が高くなることが確認できた。

It is confirmed that the moisture detection paper 1 without adding NaCl continues to maintain 0 V, whereas the moisture detection paper 1 with addition of NaCl generates a voltage after 5 days and then gradually increases the open circuit voltage. did it.

  This result shows that the moisture detection paper 1 malfunctions due to the deliquescence (water absorption) of the electrolyte salt. In other words, the moisture detection paper 1 according to the present embodiment does not use an electrolyte salt and thus is less likely to malfunction with respect to the moisture detection sensor disclosed in Patent Document 1 using a chemical battery containing an electrolyte salt.

[Moisture detection sensor using electronic circuit]
As described above, the moisture detection paper 1 according to the present embodiment generates electric power of 50 to 450 nW / cm ² . Next, a moisture detection sensor that operates an electronic circuit using this electric power and outputs a detection signal will be described.

  FIG. 9 shows a configuration example of the moisture detection sensor 2 according to the present embodiment. The moisture detection sensor 2 generates an electromotive voltage generated between the detection electrodes 10 and 20 and the paper 30 that permeates moisture including ions, the pair of detection electrodes 10 and 20 that are formed on the surface of the paper 30 and have different oxidation-reduction potentials. And a voltage detection unit 50 for detection.

  The configuration of the paper 30 and the detection electrodes 10 and 20 is the same as that of the moisture detection paper 1 except that the shape of the paper 30 is a square and the size is different. The detection electrodes 10 and 20 and the voltage detection unit 50 are connected by conductive wires 40 and 41.

  The voltage detection unit 50 uses, for example, a weak signal detection IC (manufactured by SII Semiconductor Corporation, S-5470 series). Since this weak signal detection IC can detect a signal at about 0.7 nW, it can operate with the power generated by the moisture detection paper 1.

  The voltage detection unit 50 operates with an electromotive voltage generated between the detection electrodes 10 and 20 when moisture is detected, and outputs, for example, 700 mV (signal level “1”). When moisture is not detected, 0 mV (signal level “0”) is output.

  If the electromotive force of the moisture detection paper 1 is large (for example, mW order), a light emitting element such as an LED may emit light in accordance with the signal level. Alternatively, an alarm sound may be generated.

  The voltage detection unit 50 can be mounted on a film substrate, for example. The film substrate can be easily integrated with the paper 30. Therefore, the moisture detection sensor 2 including the voltage detection unit 50 can be discarded after use.

  A moisture detection sensor that combines the moisture detection sensor 2 and energy harvesting is also conceivable. Environmental power generation refers to power generation that converts environmental energy such as solar cells, temperature difference power generation (Seebeck element), and vibration power generation into electric power.

  By using energy harvesting, a moisture detection sensor can be configured without using a battery. Next, a moisture detection sensor using energy harvesting will be described.

  FIG. 10 shows a functional configuration example of the moisture detection sensor 3 using energy harvesting. The moisture detection sensor 3 includes a voltage detection unit 50, a power supply unit 60, a vibration detection unit 80, and a radio unit 100. Note that the capacitor 70 connected between the power supply unit 60 and the vibration detection unit 80 and between the common electrode may be included in the power supply unit 60. The capacitor 70 stores electric power generated by, for example, a solar battery.

  Further, the Zener diode 90 connected between the vibration detection unit 80 and the radio unit 100 and between the common electrode may be included in the vibration detection unit 80. The Zener diode 90 functions to stabilize the power supply voltage of the radio unit 100. Further, the antenna 110 may be included in the radio unit 100.

  The voltage detection unit 50 is a voltage detection unit that constitutes the moisture detection sensor 2 described above. In FIG. 10, the paper 30 and the detection electrodes 10 and 20 are not shown. The voltage detection unit 50 outputs, for example, a signal level “1” when moisture is detected, and outputs a signal level “0” when moisture is not detected.

  The vibration detection unit 80 includes, for example, a ball-type sensor, and transmits the electric power stored in the capacitor 70 to the radio unit 100 when the vibration detection unit 80 tilts. That is, the vibration detection unit 80 intermittently supplies power to the radio unit 100 each time the vibration detection unit 80 tilts.

  The radio unit 100 includes a ring transmitter that starts and oscillates at high speed with intermittently applied power. The wireless unit 100 performs wireless transmission when power is supplied from the vibration detection unit 80 and the voltage detection unit 50 outputs, for example, a signal level “1”.

  By receiving the presence / absence of this wireless transmission with a receiver (not shown), it is possible to detect the presence / absence of moisture at a remote location.

  The power supply unit 60 may use energy harvesting other than solar cells. By using energy harvesting for the power supply unit 60, the moisture detection sensor 3 can be configured without a battery.

  In short, the moisture detection sensor 3 includes the power supply unit 60 that converts environmental energy into electric power, the vibration detection unit 80 that intermittently transmits the electric power converted by the power supply unit 60, and the detection electrode that uses the electric power transmitted by the vibration detection unit 80. And a wireless unit 100 that wirelessly transmits the presence or absence of an electromotive voltage between 10 and 20.

  The power supply unit 60, the capacitor 70, the vibration detection unit 80, the Zener diode 90, the radio unit 100, the antenna 110, and the voltage detection unit 50 may be configured separately. That is, the moisture detection sensor 3 may be configured by combining the moisture detection sensor 2 having the configuration shown in FIG. 9 with the power supply unit 60, the capacitor 70, the vibration detection unit 80, the Zener diode 90, the wireless unit 100, and the antenna 110. Good.

  By separately configuring in this way, the moisture detection sensor 2 can be easily discarded.

  As described above, according to the moisture detection paper 1 according to the present invention, since the pair of detection electrodes 10 and 20 are formed on the surface of the paper 30 that permeates moisture including ions, the cost can be reduced. Can do. In addition, the moisture detection paper 1 can be easily wound around a drain pipe or the like. It is also easy to integrate into a diaper or the like. Moreover, since the moisture detection paper 1 does not use an electrolyte salt, the possibility of malfunctioning is low.

  Further, according to the moisture detection sensor 2 of the present invention, the presence or absence of moisture can be notified by the binary value of the electrical signal. Further, if the electromotive force of the moisture detection paper 1 constituting the moisture detection sensor 2 is increased, the presence or absence of moisture can be notified, for example, by light emission, alarm sound or the like.

  Moreover, according to the water | moisture-content detection sensor 3 which concerns on this invention, the presence or absence of a water | moisture content can be notified with a radio signal.

  As described above, according to the present invention, moisture can be detected with high accuracy without external power supply. In addition, since the moisture detection paper 1 is formed by forming a positive electrode and a negative electrode made of a material having a low environmental load on the surface of the paper 30, it can be easily and hygienically discarded without collecting the battery after use. It is.

1: Moisture detection paper 2, 3: Moisture detection sensor 10: Detection electrode (positive electrode)
20: Detection electrode (negative electrode)
30: Paper 40, 41: Conductive wire 50: Voltage detection unit 60: Power supply unit 70: Capacitor 80: Vibration detection unit 90: Zener diode 100: Radio unit 110: Antenna

Claims (7)

Paper that impregnates moisture containing ions,
A moisture detection paper comprising: a pair of detection electrodes having different oxidation-reduction potentials formed on the surface of the paper.   2. The moisture detection paper according to claim 1, wherein one of the pair of detection electrodes is made of carbon as a material of one of the detection electrodes and zinc of a material of the other detection electrode.   The moisture detection paper according to claim 1, wherein the pair of detection electrodes are formed on one surface of the paper. A plurality of the pair of detection electrodes;
4. Each of the pair of detection electrodes is arranged in parallel, and two detection electrodes are connected to each other from one side excluding both outer detection electrodes by a conductive wire. The moisture detection paper according to any one of the above.   Each of the pair of detection electrodes is formed in a comb-tooth shape, the tip of the other comb-tooth is inserted between one comb-tooth, and the one and the other comb-tooth are arranged at an interval. The moisture detection paper according to any one of claims 1 to 3, wherein Paper that impregnates moisture containing ions,
A pair of sensing electrodes with different redox potentials formed on the surface of the paper;
A moisture detection sensor comprising: a voltage detection unit that detects an electromotive voltage generated between the pair of detection electrodes. A power supply unit that converts environmental energy into electric power;
A vibration detector that intermittently transmits the power;
The moisture detection sensor according to claim 6, further comprising: a wireless unit that wirelessly transmits the presence / absence of the electromotive voltage with the electric power transmitted from the vibration detection unit.

Images