CN111067716A

CN111067716A - Double-sided directional weighting quantification moisture state detection sensor

Info

Publication number: CN111067716A
Application number: CN201911312946.0A
Authority: CN
Inventors: 黄新凯; 徐菲; 陈阵
Original assignee: Shenzhen Generation Technology Co ltd
Current assignee: Shenzhen Generation Technology Co ltd
Priority date: 2019-04-03
Filing date: 2019-12-18
Publication date: 2020-04-28
Also published as: CN211633919U

Abstract

The invention provides a double-sided directional weighting quantification moisture state detection sensor, which comprises a film type capacitance sensor, wherein the capacitance sensor comprises an induction strip, the induction strip is in a flexible strip structure and comprises an upper induction surface and a lower induction surface, quantification moisture state detection of the upper surface and the lower surface can be respectively realized, and the moisture states of the upper surface and the lower surface can be weighted and output according to specific proportion, so that comprehensive moisture state information related to a specific layer and a specific direction of a specific detection object can be provided.

Description

Double-sided directional weighting quantification moisture state detection sensor

Technical Field

The invention relates to a sensor, in particular to a double-sided directional weighting quantification moisture state detection sensor related to moisture state detection of disposable absorbent articles.

Background

The disposable absorbent articles include sanitary products such as paper diapers, pull-ups, training pants, sanitary napkins and urine pads, for convenience of description, the following description will use paper diapers as an example, and the related contents also apply to other disposable absorbent articles. The paper diaper usually comprises a surface layer, an absorption layer and a leakage-proof layer, and the water absorption performance of the paper diaper is mainly embodied on the absorption layer. When urine wet occurs, urine can enter the absorption layer through the surface layer, and the high polymer material in the absorption layer can absorb moisture in the urine and lock the moisture, so that the surface layer is restored to a dry and comfortable state.

However, the water absorbing and locking capacity of the absorbent layer of the diaper is limited, when the amount of urine is large, the water cannot be completely absorbed and locked, and if the diaper is squeezed, the water flows back from the absorbent layer of the diaper, which is called liquid reverse osmosis, the surface layer of the diaper becomes wet and seeps, which is uncomfortable for users and also easily causes skin diseases (such as diaper rash), and the diaper is replaced as soon as possible, and if the diaper is not replaced, the urine is easy to leak, and bed pads are polluted.

Therefore, scientific paper diaper urine wet detection needs to know whether the surface layer or the bottom layer of the paper diaper is wet by urine or not, and also needs to know whether the absorption layer of the paper diaper is saturated or not, whether reverse osmosis occurs or not and whether the paper diaper needs to be replaced or not. Specifically, is it known whether the diaper topsheet is wet from above or back-impregnated from the absorbent layer? Although the topsheet of the diaper is wet, it represents two different conditions, the former being considered as the onset of wetting, and the latter being considered as the absorbent layer being saturated, a condition which requires urgent replacement.

If a sensor can be arranged between the surface layer and the absorption layer of the paper diaper and the sensor can respectively detect the moisture states of the surface layer and the absorption layer, a great help is brought. To do this, a film sensor with a double-sided directional moisture detection function is needed, which can be disposed at a specific position/layer of the diaper to realize moisture detection in a specific direction. It would be most desirable if the sensor could further quantify the wetness state of the upper and lower surfaces at a specific location and output them in a superimposed manner with a specified weight (e.g., a weight that increases the saturated reverse osmosis state of the absorbent layer), so that the output value represents the integrated wetness or urgency of diaper replacement, which is of great reference value for scientific and rational diaper usage and replacement.

For example, chinese patent application publication No. CN107174408A discloses an electronic moisture-sensing absorbent article and a related method, which uses a flexible electrode printed on the outer surface of a leakage-proof layer of the absorbent article as a sensor to achieve quantitative moisture state detection of the absorbent article, but the moisture state is the existence state of liquid between the leakage-proof layer and the absorbent layer, not the surface layer moisture state and the absorbent layer saturation/reverse osmosis state, and even the moisture state detection function of double-sided orientation and weighting cannot be achieved.

Chinese patent application publication No. CN107854220A discloses an electronic moisture-sensitive absorbent article and a method for detecting moisture level thereof, which uses flexible electrodes printed on the inner and outer surfaces of a leakage-proof layer of the absorbent article as sensors to detect the moisture state of the absorbent article, and similarly, the moisture state only represents the existence state of liquid between the absorption layer and the leakage-proof layer of the absorbent article, but not the moisture state of the surface layer of the absorbent article and the saturation/reverse osmosis state of the absorption layer, and the dual-sided orientation and weighted moisture state detection function cannot be realized.

Chinese patent application publication No. CN102650608A discloses a liquid detection device and method based on an electrochemical capacitor, and a diaper, which uses a conductive ink induction line directly contacting with urine in the diaper as a sensor, and realizes a quantitative urine wetness detection function by means of the electrochemical capacitor. Although these lines can be placed on different layers of the diaper, they cannot distinguish the liquid from different directions, and they cannot perform directional urine detection and weighting treatment, and the electrochemical capacitance generated by them is large, so the reaction speed of the system is very slow, and it is difficult to meet the requirement of real-time status monitoring.

Chinese patent application publication No. CN106691699A discloses a sensor for detecting urine wetness by setting conductive tape on a hydrophilic substrate, which can be set on the surface layer of a paper diaper and also can be set between the surface layer and an absorbing layer, but the sensor can not distinguish urine from different directions, because urine in any direction can be infiltrated with the hydrophilic substrate to generate a urine wetness alarm signal, and meanwhile, the sensor adopts a resistance mode of urine wetness short circuit to detect the presence of urine, which can only detect whether urine wetness occurs and can not detect the degree of urine wetness in principle, i.e. quantitative urine wetness detection function can not be realized, and more, double-sided directional and weighted wetness state detection function can not be realized.

U.S. patent publication No. US2013/0018340a1 discloses a wetness detecting system for an absorbent article that has an array of sensors disposed on the outer surface of the absorbent article to detect changes in capacitance of the absorbent article to determine the degree of wetness. Since the sensor is non-invasive, the detected value is a comprehensive value seen from the outside, and the urine wetting conditions on different layers cannot be distinguished. In addition, the dielectric constant detection device is an open dielectric capacitor, and the dielectric constant detection device detects the dielectric constant change of peripheral substances, so that whether the urine reverse osmosis condition occurs in the absorbing article or not is unknown. In addition, the capacitance of the open type dielectric capacitor is usually very small, and the open type dielectric capacitor is easily interfered by the capacitance of a human body and peripheral substances, and the moisture state detection function of double-sided orientation and weighting cannot be realized.

The above prior art solutions have various disadvantages, and new solutions are needed to solve the problems.

Disclosure of Invention

The invention aims to solve the technical problem of providing a double-sided directional weighting quantification moisture state detection sensor capable of realizing rapid detection, which comprises a film type capacitance sensor/induction strip, wherein the film type capacitance sensor/induction strip is provided with an upper induction surface and a lower induction surface, is suitable for being arranged on different layers of a paper diaper for use, can realize moisture state detection of the upper surface and the lower surface, can carry out quantification treatment, can adjust state weights of the upper surface and the lower surface as required and can carry out weighting output so as to meet different application requirements of users. When the sensor is arranged between the surface layer and the absorption layer of the paper diaper, the moisture state detection of the surface layer and the reverse osmosis state detection of the absorption layer can be realized, the output weight of the reverse osmosis state of the absorption layer can be increased, and the signal for replacing the paper diaper can be more quickly presented in the reverse osmosis state of the absorption layer.

In order to solve the above technical problems, the present invention provides a double-sided directional weighting and quantification moisture state detection sensor, which comprises a thin film type capacitance sensor, wherein the capacitance sensor comprises a sensing strip, the sensing strip is in a flexible strip structure, and comprises an upper sensing surface and a lower sensing surface, the moisture state detection of the upper surface and the lower surface can be respectively realized, and the moisture states of the upper surface and the lower surface can be weighted and output according to a specific proportion, so that comprehensive moisture state information related to a specific layer and a specific direction of a specific detection object is provided.

The sensor comprises an upper waterproof film corresponding to the upper sensing surface and a lower waterproof film corresponding to the lower sensing surface, wherein a sealed sensing layer is arranged between the upper waterproof film and the lower waterproof film, and the sensing layer is formed by covering and insulating the upper waterproof film and the lower waterproof film.

The sensing strip comprises a first detection electrode and a second detection electrode, the first detection electrode and the second detection electrode are arranged in the sensing layer, are completely covered by the upper waterproof film and the lower waterproof film, and are not in contact with the liquid to be detected in work; or

The first detection electrode and the second detection electrode are arranged in the induction layer, wherein the first detection electrode is completely covered by the upper waterproof film and the lower waterproof film and is not contacted with the liquid to be detected in work, at least one part of the second detection electrode is exposed outwards through the interlayer edges of the upper waterproof film and the lower waterproof film or any other gaps or gaps arranged on the waterproof films, and is contacted with the liquid to be detected containing electrolyte through the exposed part in work to enable the liquid to be equipotential with the liquid to be detected and form a liquid electrode.

The sensing strip comprises a first detection electrode and a second detection electrode, the first detection electrode is arranged in the sensing layer and protected, and is not in contact with the liquid to be detected in work, the second detection electrode is positioned on the outer surface of either side of the upper waterproof film and the lower waterproof film, and is directly in contact with the liquid to be detected containing electrolyte in work, so that the liquid is equipotential with the liquid and forms a liquid electrode; and

the orthographic projection of the first and second detection electrodes comprises an overlapping part, and the electrodes of the overlapping part form a capacitor with an initial capacitance value of C₀The dielectric capacitance of (1); and

when the liquid electrode is covered on the outer surface of the waterproof film corresponding to the first detection electrode, an electrolytic capacitor is generated between the liquid electrode and the first detection electrode, and the first detection electrode and the second detection electrode form the medium capacitor C₀Adding the electrolytic capacitor to C and outputting, wherein the wet state can be represented by formula (C-C)₀)/C₀The larger the numerical value, the more serious the comprehensive moisture degree of a specific layer of the specific detection object; and

the induction strip has the length self-adaption capability, and the comprehensive moisture state ((C-C) of a specific layer of the specific detection object₀)/C₀) Regardless of the length of the sensor strip.

When the liquid to be detected containing electrolyte is accumulated on the upper sensing surface and the lower sensing surface, the first detection electrode, the second detection electrode, the upper waterproof film, the lower waterproof film and the liquid to be detected jointly form a non-polar electrolytic capacitor, wherein the first detection electrode and the second detection electrode form the electrodes of the electrolytic capacitor, the liquid to be detected forms the electrolyte of the electrolytic capacitor, the waterproof film forms the dielectric medium of the electrolytic capacitor, the capacitance of the electrolytic capacitor is in direct proportion to the area of the liquid to be detected on the sensing surface corresponding to the first detection electrode, the detection sensitivity of the upper sensing surface and the lower sensing surface is in direct proportion to the dielectric constants of the upper waterproof film and the lower waterproof film and in inverse proportion to the thicknesses of the upper waterproof film and the lower waterproof film, and the weights of the wet states of the upper sensing surface and the lower sensing surface are in inverse proportion to the weights of the upper waterproof film and the lower waterproof film, The detection sensitivity of the lower sensing surface is proportional.

The disposable excrement absorption device comprises an excrement bearing and absorption device, a surface layer, an absorption layer and a leakage-proof layer, wherein the excrement bearing and absorption device is provided with the appearance design of the disposable absorption article and comprises the surface layer, the absorption layer and the leakage-proof layer, and the induction strip is arranged on the surface layer, or between the surface layer and the absorption layer, or between the absorption layer and the leakage-proof layer.

The device comprises a detection device, wherein the detection device comprises a capacitance detection device which is electrically connected with a first detection electrode and a second detection electrode of the induction strip when in use and realizes the comprehensive moisture state detection function of the excrement bearing and absorbing device on a specific layer and in a specific direction in a capacitance detection mode.

The capacitance detection device comprises a contact electrode, the contact electrode comprises a metal needle point, and the metal needle point can penetrate through the waterproof film of the induction strip and is electrically connected with the detection electrode when in use.

The device comprises a wireless transmitting unit and a wireless receiving and displaying device, and can transmit and receive the moisture state information of the absorbing articles and perform related state display or state alarm prompt.

Wherein, the width of the induction strip comprises 5 to 50 millimeters, the thickness of the induction strip comprises 0.01 to 1 millimeter, the thickness of the waterproof film comprises 5 to 500 micrometers, the detection electrode comprises a conductive ink printing line or a metal foil line, the upper waterproof film or the lower waterproof film comprises a plastic film, the plastic film comprises a high tensile strength film, the high tensile strength film comprises a BOPP film or a PET film, the thickness of the lower waterproof film is less than that of the upper waterproof film, the excrement bearing and absorbing device comprises a paper diaper, a pull-up diaper, a training pant, a sanitary towel or a urine pad, the liquid to be detected containing electrolyte comprises urine, the wireless receiving and displaying device comprises a mobile phone or a computer, the induction strip comprises more than two groups of detection electrodes, each group of detection electrodes comprises at least one first detection electrode and one second detection electrode, each set of detection electrodes is capable of directionally detecting a wetness state on a particular sensing surface, and the first detection electrode or the second detection electrode of one set is multiplexed with the first detection electrode or the second detection electrode of the other set.

The disposable film sensor with the two sensing surfaces has the advantages that the disposable film sensor is suitable for being arranged on a specific layer of a paper diaper for use, can detect the quantized moisture states of the upper sensing surface and the lower sensing surface respectively, can set different detection sensitivities for the upper sensing surface and the lower sensing surface so as to perform signal superposition output with different weights, meets different requirements of a user on the use of the paper diaper, and provides an objective and scientific basis for reasonable use and timely replacement of the paper diaper.

Meanwhile, the sensing strips are arranged in the paper diaper in a coiled manner before being arranged in the paper diaper, the detection electrodes are arranged in parallel, and the cross sections of the detection electrodes at any position in the length direction are equal, so that the sensing strips can be suitable for manufacturing the paper diapers with different specifications and lengths.

Meanwhile, the electrolytic capacitor urine wetness detection mode adopted by the invention has higher detection sensitivity and reliability and higher reaction speed, the time constant of a detection loop is usually millisecond grade, real-time state monitoring can be carried out, and the invention is an intelligent paper diaper urine wetness detection technical scheme which has the advantages of high speed, high precision, low cost and standardization.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a moisture status detection sensor according to an embodiment of the present invention.

Fig. 2 is a schematic view of a layered structure of a sensor for detecting moisture status with double-sided directional weighting and quantification according to an embodiment of the present invention, which includes a sensor strip and a disposable excreta-bearing and absorbing device.

Fig. 3 is a schematic diagram of a layered structure of a sensor strip of a double-sided directional weighted moisture status detection sensor according to an embodiment of the present invention.

Fig. 4 is a side sectional view (longitudinal section) of a sensor strip of a double-sided directional-weighting moisture status detection sensor according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of a cross-sectional structure of a sensor strip a-a' of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting and an equivalent circuit according to an embodiment of the present invention.

FIG. 6 is a graph of capacitance versus liquid coverage/length for a sensor strip of a dual-sided directionally weighted quantitative wetness detection sensor in accordance with an embodiment of the present invention.

Fig. 7 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the invention.

Fig. 8 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention.

Fig. 9 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention.

Fig. 10 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting according to an embodiment of the present invention.

Fig. 11 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting according to an embodiment of the present invention.

Fig. 12 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the invention.

Fig. 13 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting according to an embodiment of the present invention.

Fig. 14 is a schematic cross-sectional view and an equivalent circuit diagram of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting according to an embodiment of the present invention.

Fig. 15 is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighting quantification moisture state detection sensor according to an embodiment of the present invention, which includes a plurality of groups of detection electrodes.

Fig. 16 is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention, which includes a plurality of sets of detection electrodes.

Fig. 17 is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a double-sided directional weighting quantification moisture state detection sensor according to an embodiment of the present invention, where the sensor strip includes multiple sets of detection electrodes and there is an electrode multiplexing situation.

Fig. 18 is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention, wherein the sensor strip includes multiple sets of sensing electrodes and has an electrode multiplexing condition.

Fig. 19 is a schematic diagram of an embodiment of the present invention, in which a sensor strip of a double-sided directional weighting quantification moisture status detection sensor and a capacitance detection device are electrically connected through a needle tip.

Fig. 20 is a block diagram of a double-sided directional weighted moisture status detection sensor according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments refers to the accompanying drawings, which are included to illustrate specific embodiments in which the invention may be practiced. The terms of direction and position of the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "top", "bottom", "side", etc., refer to the direction and position of the attached drawings. Accordingly, the use of directional and positional terms is intended to illustrate and understand the present invention and is not intended to limit the scope of the present invention.

The invention is further described below with reference to the accompanying drawings. Fig. 1 is a schematic structural diagram of a moisture status detecting sensor according to an embodiment of the invention. In the figure 10 is shown a disposable excreta bearing and absorbing device which has the appearance design and basic function of the conventional disposable absorbent article (including diapers, nappies, toddlers, pull-up pants, diaper, sanitary napkins, etc.), so that the embodiment of the present invention 10 can also be regarded as/referred to as a disposable absorbent article. These absorbent articles include a topsheet (inner layer, dry layer, facing the user's skin when in use), a leakproof layer (outer layer, bottom layer, facing away from the user's skin when in use), and an absorbent layer (interlayer, hygroscopic layer, between the topsheet and leakproof layer).

In fig. 20, a disposable film-type capacitive sensor (which may be referred to simply as a film sensor, a capacitive sensor) is disposed on a particular layer of the disposable absorbent article 10 (e.g., a topsheet-absorbent layer, an absorbent layer-backsheet, etc.), and the film sensor includes a strip-like flexible sensor strip, which in the present embodiment is generally in the form of a sensor strip, and thus can be represented by a sensor strip, and in the present embodiment 20 can represent both a film sensor and a sensor strip. The sensor strip includes a first sensing electrode 21 and a second sensing electrode 22, the combination of the

sensing electrodes

21 and 22 can be marked with 23, which is usually printed by conductive ink (e.g. carbon paste) on a waterproof film (e.g. BOPP biaxially oriented polypropylene film, PET polyester film or other plastic film) by means of gravure printing, flexography, etc., and is a conductive ink line, so the sensing electrode of the embodiment of the present invention can also be referred to as a conductive ink line. In addition, the detection electrode may be formed on the waterproof film by vacuum metal evaporation (e.g., aluminum plating) or other processes, and may be a metal film/metal foil (e.g., aluminum film/aluminum foil) electrode.

The detection electrode printed by conductive ink or evaporated by metal is generally very thin and is attached to the flexible waterproof film, so that the whole induction strip has flexibility, and the detection electrode in the embodiment of the invention can also be called as a flexible electrode. The detection electrode in the figure is composed of two parallel electrodes, and in practical application, the detection electrode can have various designs, and can also comprise a plurality of electrodes or a plurality of groups of electrodes (each group of electrodes can comprise one or more electrodes). Also included is an external (with respect to the absorbent article 10) sensing device 30 comprising a capacitive sensing device used in combination with the sensing electrode 23 via electrical connection 24 to capacitively sense (digitize) the wetness state of the disposable absorbent article 10. In practical applications, the length of the sensor strip may be the same as or shorter than the length of the absorbent article, and in order to facilitate the electrical connection with the capacitive sensing device 30, one end of the sensor strip 20 is usually flush (or nearly flush) with the edge of one end of the absorbent article (e.g., at the front abdomen/waistband position), so that the capacitive sensing device can be conveniently clipped onto the absorbent article and electrically connected to the sensor strip.

The sensor strip is the most basic unit of the double-sided directional weighting quantification moisture state detection sensor in the embodiment of the invention, the disposable absorbent article is a matched excrement carrying and absorbing device, and the integration of the sensor strip and the absorbent article enables the sensor strip to have a specific detection object, which is one of the specific expression forms of the embodiment of the invention. Similarly, the sensor of the present invention can be provided with a digital output form by adding a detection device to digitize the state information of the sensor strip. The present invention may also integrate the sensor strip with more functional devices (e.g., wireless devices) to provide more functional features, all of which are within the scope of the present invention.

Referring to fig. 2 again, it is a schematic diagram of a layered structure of a double-sided directional weighted moisture status detection sensor including a sensor strip and a disposable excreta carrier and absorbent device according to an embodiment of the present invention. The following description will be given by taking a diaper as an example, and the description is also applicable to other disposable absorbent articles such as diapers, toddlery pants, pull-up pants, diaper, sanitary napkins and the like. The diaper in the figure comprises a surface layer 11, an absorption layer 12 and a leakage-proof layer 15. When the absorbent article is used, the surface layer 11 directly contacts the skin of a human body (for example, covers the crotch of the human body), when the human body urinates, urine can enter the absorbent layer 12 through the hydrophilic and porous breathable surface layer 11, and is absorbed by wood pulp and polymer absorbent materials (SAP) in the absorbent layer to lock water in the absorbent layer, so that the surface layer 11 is restored to a dry state. As for the leakage-preventing layer 15, mainly for preventing urine leakage, it is generally formed of a polyethylene film (PE) which is permeable or non-permeable.

The figure includes a sensor strip 20, and a detection electrode 23, which is composed of a first detection electrode and a second detection electrode, is included on the sensor strip 20. In order to realize the moisture state detection of the diaper surface layer and the reverse osmosis state detection of the absorption layer, the sensing strip 20 is preferably arranged between the diaper surface layer 11 and the absorption layer 12 in the embodiment. The sensing strip has an upper surface and a lower surface, and has the humidity detection/humidity sensing capacity in the corresponding directions of the upper surface and the lower surface, the upper surface and the lower surface of the sensing strip are respectively called as an upper sensing surface and a lower sensing surface, the sensing strip in the figure can detect urine (passing through the upper sensing surface) from a human body on the upper paper diaper surface layer and can also detect liquid (passing through the lower sensing surface) reversely seeped from the paper diaper absorption layer on the lower surface, and therefore, the humidity detection with double-sided orientation (in the upper direction and the lower direction) is realized. For convenience of expression, the components (including the surface layer 11, the absorption layer 12, the leakage-proof layer 15, and the sensing strip 20) of the diaper of this embodiment are drawn in a layered manner, and in practical application, the components are bonded together by structural adhesive/hot melt adhesive, etc. The surface layer and the leakage-proof layer of the paper diaper are usually longer than the absorption layer, and the absorption layer can be wrapped in the absorption layer to prevent liquid in the absorption layer from leaking.

In practical applications, the sensor strip 20 may also be disposed on different layers of the absorbent article 10 to achieve moisture detection on a specific layer and a specific direction, for example, the sensor strip 20 may be attached to the surface layer 11 of the diaper, the upper sensor surface faces the skin of the user to achieve moisture detection on the skin of the human body, and the lower sensor surface contacts the surface layer of the diaper to achieve moisture detection on the surface layer; for another example, the sensor strip 20 may be disposed between the absorbent article leakage layer 15 and the absorbent layer 12 with the upper sensing surface facing the absorbent layer such that the upper sensing surface can detect wetness in the absorbent article absorbent layer 12.

Referring to fig. 3, a schematic diagram of a layered structure of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting according to an embodiment of the present invention is shown. In the figure, 20 is a sensor strip comprising a lower waterproof membrane 25, an upper waterproof membrane 26, and a detection electrode 23 printed/arranged on the inner surface of the lower waterproof membrane. For convenience of expression, the components of the induction bars in the drawing are drawn in a layered manner. In practical application, the components are bonded together by structural adhesive/hot melt adhesive or pressed together by hot pressing. The upper and lower waterproof films can seal the main body part (circuit) of the detection electrode, and prevent liquid (including urine) containing electrolyte in the absorption layer from contacting the electrode to influence the normal work of the sensor.

In practical applications, the width of the sensor strip is moderate. If too wide, it will not only increase the cost, but also affect the air and water permeability of the diaper topsheet, since the sensor strip itself is impermeable to air and water. Simultaneously the response strip also can not be too narrow, if too narrow, the measuring electrode setting will have the difficulty to also be difficult to implement the electricity with the measuring electrode and be connected, and can reduce the tensile strength of response strip, the condition that the response strip was pulled apart appears easily in making the production process. Before the paper diaper is formed, the induction strip is usually in the form of a coiled material, the length of each coil of the induction strip is different from hundreds of meters to thousands of meters, and the induction strip can be used for producing hundreds of to thousands of different paper diaper products. When the paper diaper is produced, the sensing strip coil can be unreeled, straightened, bonded and cut off together with other materials/coils (such as a surface layer material and a bottom film material) of the paper diaper on a production line, if the tensile strength is not enough, the sensing strip coil can be broken in the unreeling or bonding process, so that a waterproof film with the width of 5-50 mm, preferably a high tensile strength plastic film with the width of 10-30 mm can be selected in practical application, and all indexes can meet the requirements more easily and have better cost benefit.

In the figure, it can be seen that the detection electrode patterns of the sensor strip 20 are the same from top to bottom (i.e. they are arranged in parallel), which means that the roll of sensor strip is suitable for making paper diapers of any specification and length, and when it is produced, it is only necessary to cut the paper diapers according to the length, and the cutting of the sensor strip at any position will not affect the performance and destroy the integrity of the detection electrode (i.e. its cross section is the same). This is an important property of diaper manufacturing material, and webs with this property can be used without the need for cut-to-size cutting, as long as they are cut transversely as required. Certainly, it is also feasible to add a blank area without the detection electrode pattern at the head and tail positions of the sensor strip, and because there is no detection electrode in the blank area, it can effectively avoid the liquid from short-circuiting the detection electrode at the cut-off position of the sensor strip to affect the normal operation of the sensor strip.

As for the thickness of the sensor strip, from 0.01 mm to 1 mm is useful, as long as it is not too thick, it does not affect the comfort of the absorbent article. For waterproof films, the thickness of films of different materials usually varies, and theoretically films with thickness of 5 to 500 micrometers are all usable, and preferably a biaxially oriented polypropylene film (BOPP) and a polyester film (PET) with thickness of 10 to 50 micrometers are used, because the strength of the two films is relatively high (belonging to a high tensile strength film, or called a rigid plastic film), and the two films can be relatively thin (for example, 12 micrometers) on the premise of meeting the requirement of tensile strength, and the two films can present good flexibility under the condition of the thickness.

The upper waterproof film and the lower waterproof film can be made of the same material, or different materials can be selected, for example, one of the materials can be a high tensile resistant film (such as BOPP or PET), and the other material can be a soft comfortable film (such as polyethylene PE or EVA), so that the waterproof fabric has good performance in strength and comfort. Alternatively, a waterproof coating may be formed by directly coating a waterproof paint on the detection electrode instead of one of the waterproof films, in which case the waterproof coating may be considered as one of the waterproof films.

Referring to fig. 4, a cross-sectional side view (vertical cross-section) of a sensor strip of a sensor for detecting a moisture state according to an embodiment of the present invention is shown. In the figure, 20 is a sensor/sensor strip comprising an upper waterproof membrane 26, a lower waterproof membrane 25, and a sensing layer 17 between the upper and lower waterproof membranes, the sensing layer 17 comprising a detection electrode 23. When a liquid 16 containing an electrolyte (referred to as a liquid to be detected) accumulates on the outer surface of upper water repellent film 26, a detectable electrolytic capacitance is created between the detection electrodes in sensing layer 17. Similarly, when a liquid containing an electrolyte, such as urine 18, seeps back up from the absorbent layer, accumulates on the outer surface of lower waterproof membrane 25, another detectable electrolytic capacitance is created between the detection electrodes in sensing layer 17. If the thicknesses (or dielectric constants) of the upper waterproof film and the lower waterproof film are different, capacitance values generated by the liquid to be detected in the same coverage range are different, and the capacitance values are specifically represented as different detection sensitivities of the upper sensing surface and the lower sensing surface. The thinner the waterproof film (or the larger the dielectric constant) the larger the capacitance value produced, i.e., the higher the detection sensitivity. Where L is the total effective length/detection area of the sensor strip 20, L is the actual coverage/length of the

liquids

16 and 18 on the sensor strip, and the ratio of L to L is referred to herein as the liquid saturation or wetness of the sensor.

For convenience of description, the side of the

waterproof films

25 and 26 in contact with the sensing layer 17 is referred to as an inner surface, the side of the

waterproof films

25 and 26 not in contact with the sensing layer 17 is referred to as an outer surface, the side of the outer surface of the upper waterproof film 26 is referred to as an upper sensing surface, and the upper sensing surface faces a user in use and can detect liquid (e.g., urine) from a human body. And this side of the outer surface of the lower waterproof membrane 25 is referred to as the lower sensing surface, which faces away from the user when in use, and which can detect reverse osmosis liquid from below to above. In practical application, the sensing strips can be arranged on different layers of the paper diaper according to requirements, and the thicknesses of the upper waterproof film and the lower waterproof film can be selected according to requirements. For example, when the sensing strip is arranged between the surface layer and the absorption layer of the paper diaper, the thickness of the upper waterproof film can be selected to be a little thicker than that of the lower waterproof film, so that not only can the humidity conditions of the upper sensing surface and the lower sensing surface be detected, but also the weighted output of the humidity state of the lower sensing surface can be realized. In the present embodiment, the thickness of the upper waterproof film 26 is 3 times the thickness of the lower waterproof film 25, so that when the upper and lower waterproof films are the same (same dielectric constant), the detection sensitivity of the lower sensing surface is 3 times higher than that of the upper sensing surface, that is, the lower sensing surface realizes a 3-times weighted output (with respect to the upper sensing surface).

When the upper and lower sensing surfaces simultaneously have liquid, the generated signals (capacitance values) are added together and output. When the upper sensitivity and the lower sensitivity are different, the proportion of signal superposition output is different, and the superposition proportion of the sensing surface of the embodiment of the invention is in direct proportion to the detection sensitivity. In the above case, when the sensor strip is disposed between the surface layer and the absorbent layer of the diaper, the stacking specific gravity of the lower sensor surface (corresponding to the reverse osmosis state of the absorbent layer) is 3 times that of the upper sensor surface (corresponding to the wet state of the surface layer of the diaper), that is, the reverse osmosis state of the absorbent layer is more rapid to present the information for changing the diaper than the wet state of the surface layer.

Regarding the manufacturing problem of the sensor strip 20, in the embodiment of the present invention, the detecting electrode 23 is preferably printed on either one of the upper and lower waterproof films by using a carbon conductive ink, and then the one printed with the electrode is combined with the other waterproof film, so that the upper and lower waterproof films can cover the detecting electrode 23. The compounding can be carried out by adopting an adhesive (comprising a structural adhesive, a hot melt adhesive and the like), or hot-pressing compounding by adopting a pre-coating film, or compounding by adopting the processes of hot-coating film, chemical coating film and the like.

In order to achieve electrical connection with the detection electrode in the waterproof film interlayer, the embodiment of the present invention preferably achieves electrical connection with the detection electrode 23 by providing the contact electrode 27 with a metal tip (needle point) on the capacitive detection device and piercing the waterproof film through the needle point. Generally, the connection is performed at the head and tail positions of the sensor strip, so as to avoid that liquid containing electrolyte infiltrates the contact electrodes at the head and tail positions of the sensor strip to affect the detection operation, in practical application, the effective detection range L of the sensor is narrowed to a certain extent, that is, L is shorter than the length of the sensor strip 20, so that a safe area is provided, and the electric connection is implemented between the safe area and an external capacitance detection device.

Referring to fig. 5, a schematic diagram of a cross-sectional structure of a-a' of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting and quantization and an equivalent circuit diagram according to an embodiment of the present invention are further described with reference to the foregoing embodiment of fig. 4. The figure includes an upper waterproof film 26, a lower waterproof film 25, and detection electrodes 21 and 22 (collectively referred to as detection electrodes 23) between the upper and lower waterproof films, in addition to a liquid 16 to be detected containing an electrolyte accumulated on the outer surface of the upper waterproof film 26 and a liquid 18 to be detected containing an electrolyte accumulated on the outer surface of the lower waterproof film 25. The embodiment of the present invention will be referred to as 21 as a first detection electrode (or a first conductive ink line) and 22 as a second detection electrode (or a second conductive ink line). The upper waterproof film 26, the first detecting electrode 21, the second detecting electrode 22, and the liquid 16 containing electrolyte together form a nonpolar electrolytic capacitor C1 (called a first electrolytic capacitor), wherein 21, 22 are electrodes of the electrolytic capacitor C1, 26 is a dielectric of the electrolytic capacitor C1, 16 is an electrolyte of the electrolytic capacitor C1, and the electrolytic capacitance of C1 is inversely proportional to the thickness of 26, proportional to the dielectric constant of 26, and proportional to the coverage/length l of the liquid 16.

Meanwhile, the lower waterproof film 25, the first detection electrode 21, the second detection electrode 22, and the liquid 18 containing the electrolyte together constitute another nonpolar electrolytic capacitor C2 (referred to as a second electrolytic capacitor), wherein 21 and 22 are electrodes of the electrolytic capacitor C2, 25 is a dielectric of the electrolytic capacitor C2, 18 is an electrolyte of the electrolytic capacitor C2, and the electrolytic capacitance of C2 is inversely proportional to the thickness of 25, proportional to the dielectric constant of 25, and proportional to the coverage/length l of the liquid 18.

The capacitors C1 and C2 are connected in parallel, and the capacitance value C detected from both ends of the

detection electrodes

21 and 22 is the sum of the two capacitors, i.e., C1+ C2. The value of C2 is greater than C1 for the same liquid coverage/length, because the thickness of the lower waterproofing membrane 25 forming C2 is thinner than the upper waterproofing membrane 26 forming C1 in this embodiment, making the detection sensitivity of the lower sensing surface higher than that of the upper sensing surface, i.e. making the reverse osmosis state of the absorbent layer of the diaper more likely to cause the diaper change information to appear faster than the wet state of the topsheet (when the sensor strip is disposed between the diaper topsheet and the absorbent layer). In the figure, the thickness of the lower waterproof film 25 is only one third of that of the upper waterproof film 26, so that the capacitance of the C2 is 3 times that of the C1 (assuming that the upper and lower waterproof films are made of the same material and have the same liquid coverage).

In practical application, the sensing strip is preferably arranged between the surface layer and the absorption layer of the paper diaper, the upper waterproof film/upper sensing surface faces the surface layer of the paper diaper, and the lower waterproof film/lower sensing surface faces the absorption layer of the paper diaper in use. When a human body urinates, urine can be firstly absorbed by the surface layer of the paper diaper and then enters the absorption layer through the surface layer, and the water in the urine can be locked by the macromolecular absorption material (SAP) in the absorption layer, so that the urine cannot reversely permeate the surface layer of the paper diaper, and the paper diaper can be dried/recovered to be dry.

When the human body urinates, the upper sensing surface firstly detects and outputs a capacitance value C1 representing the wet state of the surface layer of the paper diaper. Then under the action of gravity, the urine flows into the absorption layer further, and is gradually absorbed by the wood pulp and the high molecular materials in the absorption layer and locks the water, and the whole process is about ten seconds to several minutes. Because the sensing strip is formed by the waterproof film and is waterproof, urine can only enter the absorption layer from two sides of the sensing strip, therefore, the lower surface of the sensing strip can still keep dry under the condition of small urine volume, and the capacitance value output by the sensing strip is mainly C1. When the urine volume is increased, especially when the absorption layer of the diaper is saturated and liquid reverse osmosis occurs, a large amount of urine is accumulated on the lower sensing surface of the sensing strip, so that C2 is rapidly increased. Due to the higher sensitivity of the lower sensing surface, the output of the sensing strip is mainly represented as C2 at this time, thereby realizing the weighted output of the reverse osmosis state of the lower sensing surface.

Referring to fig. 6, a graph of capacitance versus liquid coverage/length of a sensor strip of a sensor for dual-sided directional weighted quantification according to an embodiment of the present invention is shown. The abscissa L in the figure is the liquid coverage/length of the upper and lower sensing surfaces, and L is the effective detection range/length of the sensor strip 20. The ordinate C in the figure is the capacitance value appearing between the

detection electrodes

21 and 22, where C1 is the capacitance value generated by the upper sensing surface due to the liquid 16, C2 is the capacitance value generated by the lower sensing surface due to the liquid 18, the total capacitance value of the upper and lower sensing surfaces is C1+ C2, and when the liquid to be detected covers the entire effective range L of the sensor, C1-C1, C2-C2, and the capacitance C between the detection electrodes 21 and 22-C1 + C2 are maximum values.

It can be seen that the capacitance C2 is greater than C1 for the same liquid coverage/length, i.e. the specific gravity (weighting coefficient) of the lower sensing surface is higher than that of the upper sensing surface for the capacitance C between the

electrodes

21, 22, and the reverse osmosis state of the absorption layer corresponding to the lower sensing surface is more early to indicate the change of the diaper than the wet state of the upper sensing surface for the same liquid coverage/length when the sensor strip is disposed between the surface layer and the absorption layer of the diaper.

The capacitance range of the electrolytic capacitance value C in the embodiment of the invention is usually between 0-10 nF, and the capacitance values can be influenced by different widths, thicknesses, lengths and liquid immersion ranges of the detection electrodes. The loop resistance of the detection electrode of the embodiment of the invention is within 500 kilo-ohms, so that the maximum time constant τ -R-C-500-10 of the corresponding detection loop³*10*10^-9≈5*10^-3Seconds, i.e., 5 milliseconds. That is, the detection system formed by the thin film capacitive sensor of the embodiment of the invention has a relatively fast response speed, and can meet the requirement of real-time urine wet state detection.

Referring to fig. 7, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention. The main difference from the embodiment shown in fig. 5 is that the second detection electrode 22 of this embodiment is located at the edge of the sensing layer/interlayer, and its outer edge is located at the seam line 22c of the upper and lower waterproof films and exposed outwards, when the liquid containing electrolyte (liquid to be detected) 16/18 is soaked to the position of 22c, it can contact with the second detection electrode 22, and since the liquid containing electrolyte is conductive, it is equipotential with 22 after contacting with the electrode 22 and becomes a part of the electrode 22 on the circuit, and the liquid equipotential with the detection electrode is called liquid electrode or electrolyte electrode in this embodiment.

In the figure, 14 is a boundary line between the upper and lower sensing surfaces, when the liquid 16 containing the electrolyte infiltrates the upper sensing surface and contacts with 22C, the upper waterproof film 26, the first detection electrode 21, the second detection electrode 22 and the liquid 16 together form a nonpolar electrolytic capacitor C1 (referred to as a first electrolytic capacitor), wherein the

detection electrodes

21 and 22 are electrodes of an electrolytic capacitor C1, 16 is the electrolyte of the electrolytic capacitor C1, 26 is the dielectric of the electrolytic capacitor C1, the capacitance of the electrolytic capacitor C1 is inversely proportional to the thickness of 26, is proportional to the dielectric constant of 26, and is proportional to the coverage/length l of the liquid 16 above the first detection electrode 21.

Meanwhile, when the liquid 18 containing the electrolyte wets the lower sensing surface and contacts with the liquid 22C, the liquid becomes a liquid electrode which is equal to the potential of the liquid 22, and at this time, the lower waterproof film 25, the first detection electrode 21, the second detection electrode 22 and the liquid 18 together form a nonpolar electrolytic capacitor C2 (referred to as a second electrolytic capacitor), wherein 21 and 22 are electrodes of the electrolytic capacitor C2, 18 is the electrolyte of the electrolytic capacitor C2, 25 is the dielectric of the electrolytic capacitor C2, the capacitance of C2 is inversely proportional to the thickness of the electrolytic capacitor C2, is proportional to the dielectric constant of the electrolytic capacitor C25 and is proportional to the coverage area/length l of the liquid 18 under the first detection electrode 21.

In this embodiment, the thickness of the lower waterproof film 25 is about one third of that of the upper waterproof film 26, and if the material is the same (i.e., the dielectric constant is the same), the capacitance of C2 is about three times that of C1 when the sensor is completely wetted, thereby achieving a weighted output of the absorbent article absorbent layer reverse osmosis state associated with the lower waterproof film (when the sensor strip is disposed between the topsheet and the absorbent layer of the diaper).

Referring to fig. 8, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention. In the figure, 25 is a lower waterproof film26 is an upper waterproof film, 21 is a first detection electrode having upper and lower waterproof films covered with an insulator, and 22 is a second detection electrode provided on the outer surface of the lower waterproof film 25. Unlike the first and second detection electrodes of the previous embodiment, which are disposed on the same layer and have a symmetrical structure, the first and

second detection electrodes

21 and 22 of the present embodiment are disposed on different layers, and both electrodes include a portion overlapping each other (i.e., the orthographic projection of any one electrode on the other electrode includes an overlapping portion, which may be referred to as shadow overlap), at this time, the

detection electrodes

21 and 22 and the waterproof film 25 together form a parallel plate capacitor (dielectric capacitor), and the capacitance of the capacitor is proportional to the overlapping area of the

electrodes

21 and 22, proportional to the dielectric constant of the waterproof film 25 and inversely proportional to the thickness of the waterproof film 25, according to the formula C ∈ S/d (epsilon is the dielectric constant of the medium between the plates, S is the plate area, and d is the plate distance). In the dry state, the capacitance between the first and second detection electrodes is referred to as initial capacitance C₀When C is equal to C₀。

In the figure, 14 is a boundary line between the upper and lower sensing surfaces, 16 is a liquid for wetting the upper sensing surface, and 18 is a liquid for wetting the lower sensing surface. When the diaper is wetted, the liquid 16 first soaks the upper sensing surface, the detection electrode 21 corresponds to the liquid 16, the electrode 22 is electrically isolated by the electrode 21, the liquid 16 cannot act on the electrode 22, and the capacitance C between the

electrodes

21 and 22 is maintained substantially unchanged from the initial capacitance C0.

As the urine wetting increases, the urine flows to the lower sensing surface and becomes part of the liquid 18, which changes as the liquid 18 soaks the lower sensing surface. The electrolyte liquid 18 contacts the electrode 22 and becomes a liquid electrode having an equipotential with the electrode 22, and since the liquid 18 is connected to the liquid 16, which makes the liquid 16 also have an equipotential with the electrode 22, it is equivalent to the electrode 22 being extended to the upper sensing surface by the

liquid electrodes

18, 16, and a capacitance is generated between the liquid 16 and the electrode 21 on the upper sensing surface, and since one of the electrodes is the electrolyte liquid, it constitutes an electrolytic capacitor. When the upper and lower sensing surfaces are fully immersed in the liquid 16, 18, the newly generated electricityDielectric capacitance value approximately equal to C₀At this time, the total capacitance C between the

electrodes

21 and 22 is 2xC₀The wet state (degree of liquid infiltration) of the sensor can be represented by the formula (C-C)₀)/C₀When the sensor is dry, the value is 0 (0%, minimum value, where C ═ C₀) The value of the sensor at full immersion is 1 (100%, maximum value, where C is 2xC₀) The numerical range of the above formula is 0-100%, representing the degree of wetting of the sensor. The present embodiment may express the wetness state of the sensor by a well-defined number, thereby enabling quantitative wetness detection, which benefits primarily from the shadow overlap of the first and second electrodes, which provides a basis/reference for the calculation of quantitative wetness state detection.

Referring to fig. 9, this is another schematic cross-sectional structure diagram and equivalent circuit diagram of the sensor strip of the double-sided directional weighting quantification moisture state detection sensor according to the embodiment of the present invention, which is similar to the embodiment of fig. 8, except that the second detection electrode 22 in fig. 9 is disposed on the outer surface of the upper waterproof film 26 instead of the outer surface of the lower waterproof film 25, however, the moisture detection function is not affected, and the liquid infiltration degree can also be expressed by the formula (C-C)₀)/C₀To represent.

Referring to fig. 10, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention. When urine 16, which contains electrolyte on the upper sensing surface, contacts the second detection electrode 22 at 14, it becomes equipotential with the detection electrode 22 and becomes a liquid electrode, which extends the detection electrode 22 to the area covered by the liquid 16 and forms a non-polar electrolytic capacitor with the first detection electrode 21 and the upper waterproof membrane 26. Since the width of the electrode 21 is half of that of the electrode 22, when the liquid 16 completely covers the sensing surface, the newly added electrolytic capacitance value is approximately equal to the initial dielectric capacitance value C generated by the

electrodes

21 and 22 due to the shadow overlapping₀When the total capacitance C is 2x C₀. The wet state (degree of liquid immersion) of the upper sensing surface of this embodiment can be represented by the formula (C-C)₀)/C₀To indicate that the user is not in a normal position,when the degree of impregnation is 0 (0%, i.e. C ═ C)₀) Representing dry and comfortable; the degree of wetting is 1 (100%, i.e., C ═ 2 xC)₀) Representing the upper sensing surface fully covered by liquid.

When the lower sensing surface is wetted by the liquid 18, the width of the detection electrode 22 is the same as the width of the lower sensing surface and shields the detection electrode 21, so that the liquid 18 on the lower sensing surface does not act on the electrode 21, and thus the present embodiment can realize the directional moisture state detection function only for the upper sensing surface, which is a specific example of the double-sided directional moisture detection of the embodiment of the present invention, that is, the weight of the moisture state of the upper sensing surface of the present embodiment is 1, and the weight of the moisture state of the lower sensing surface is 0, so that the full-weight output of the moisture state of the upper sensing surface, which is not affected by the liquid on the lower sensing surface, is realized.

Referring to fig. 11, it is another schematic cross-sectional structure diagram and equivalent circuit diagram of the sensor strip of the sensor for detecting moisture status with double-sided directional weighting according to the embodiment of the present invention, in which the electrode position relationship is exactly opposite to that of the aforementioned fig. 10, and it can be found through analysis that the detection sensitivity of the upper sensing surface is 0, the detection sensitivity of the lower sensing surface is 1, and the moisture status (liquid infiltration degree) of the lower sensing surface can be expressed by the formula (C-C)₀)/C₀(the numerical range is 0-100%), which is another special example of the double-sided directional moisture detection in the embodiment of the invention, when the sensing strip is arranged between the surface layer and the absorption layer of the diaper, the directional detection function focusing on the reverse osmosis state of the absorption layer of the diaper can be realized.

Referring to fig. 12, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to an embodiment of the present invention. In the figure, the first detection electrode 21 is disposed in the sensing layer without contacting the liquid, and the second detection electrode 22 is disposed on the outer surface of the upper waterproof film 26 and has a width half of that of the first detection electrode 21. In the dry state, an initial dielectric capacitance C exists between the

detection electrodes

21 and 22₀The magnitude of the capacitance is proportional to the width of the second detection electrode 22. When the upper sensing surface is wetted with the liquid 16, the electrolyte liquid 16 contacts the electrodes 22 andequipotential with 22, thereby becoming a liquid electrode and extending the electrode 22 into the coverage of the liquid 16. In this case, the upper waterproof film 26, the first detecting electrode 21, the second detecting electrode 22, and the electrolyte liquid 16 together constitute an electrolytic capacitor having a value of about 1xC when the upper sensing surface is fully wetted with the liquid 16₀Plus an initial dielectric capacitance C₀When the total capacitance C is 2x C₀. The presence of the liquid on the upper sensing surface increased C by 1 time compared to the dry state, and the detection sensitivity of the upper sensing surface in this example was considered to be 1.

When the liquid penetrates further into the absorption layer and when the absorption layer is saturated and reverse osmosis occurs, the lower sensing surface is also wetted by the liquid, at which point the liquid 18 is conducted to 16 and becomes part of the electrode 22 and another electrolytic capacitance is created between the liquid 18 and the first detection electrode 21. Assuming that the upper and lower waterproof films are of the same thickness and material and the width of the electrode 21 is twice that of the electrode 22, the electrolytic capacitance value generated between the electrode 21 and the liquid 18 under the condition of full immersion is about 2xC₀Plus an initial dielectric capacitance C₀And electrolytic capacitor 1xC of upper induction surface₀The total capacitance C of the sensor of this embodiment under full immersion is 4xC₀。

A 2xC is generated due to the lower sensing surface liquid 18₀The capacitance value of the size at this time is considered to be 2. As is clear from the above analysis, the detection sensitivity of the upper sensitive surface in this example was 1, and thus it was found that the total sensitivity (upper sensitivity + lower sensitivity) was 3, and if (C-C) was used₀)/C₀When representing the overall wet state of the absorbent article, the value ranges from 0 to 3, with 0 representing a fully dry state and 3 representing a fully wet state. It is to be noted that in the present embodiment, C is always greater than or equal to C₀Of (1) thus C-C₀)/C₀No negative number condition occurs. It is to be noted that the formula (C-C) of the wet state (degree of wetting) of the embodiment of the present invention₀)/C₀Depending only on the liquid-wetting ratio (degree) of the sensor strip and not on the length of the sensor strip, although diapers of different sizes may not be configuredThe capacitance values generated by the induction bars with the same length in the use process are different (the longer the induction bar is, the larger the capacitance value is), but (C-C)₀)/C₀The proportion of (2) is invariable all the time, the user does not need to set different urine wet alarm triggering threshold values for the paper diapers adopting the induction strips with different lengths, namely, the wet state of the embodiment has self-adaptive capacity, and the premise is that the length of the paper diapers is consistent with the length of the induction strips, so that the infiltration degree of the induction strips is consistent with the wet degree of the paper diapers.

Referring to fig. 13, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a sensor for detecting a moisture state with double-sided directional weighting and quantization according to an embodiment of the present invention, which have a structure different from that of fig. 12, but the initial capacitance and the sensitivities of the upper and lower sensing surfaces are the same, and this is a variation of the embodiment shown in fig. 12.

Referring to fig. 14, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighting quantification moisture state detection sensor according to another embodiment of the present invention, which is a variation of the embodiment shown in fig. 12, that the second detection electrode 22 is moved from the outer surface of the upper waterproof film 26 to the outer surface of the lower waterproof film 25, and other parameters, including the widths of the first and second detection electrodes and the overlapping width of the two electrodes in the orthographic projection direction, are not changed. In this case, the parameters and performance of the upper and lower sensing surfaces are reversed, the sensitivity of the upper sensing surface is increased, and the detection sensitivity of the lower sensing surface is relatively decreased.

Referring to fig. 15, a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighting quantification moisture state detection sensor according to an embodiment of the invention include multiple sets of detection electrodes, which is a variation of the embodiment shown in fig. 5. The present embodiment includes two sets of detection electrodes, a first detection electrode 21A and a second detection electrode 22A in the first set of detection electrodes, and a first detection electrode 21B and a second detection electrode 22B in the second set of detection electrodes. An intermediate water-proof membrane 28 is included between the first and second sets of detection electrodes, and is positioned between and separates the upper and lower water-

proof membranes

26, 25.

The first group of detection electrodes of the embodiment are arranged between the upper waterproof film 26 and the middle waterproof film 28, and the

detection electrodes

21A and 22A, the liquid 16 to be detected and the upper waterproof film 26 form a first electrolytic capacitor C1 during operation, and the first electrolytic capacitor C1 is mainly used for directionally detecting the moisture state of the upper sensing surface; and the second group of detection electrodes are arranged between the lower waterproof film 25 and the middle waterproof film 28, and the

detection electrodes

21B and 22B, the liquid 18 to be detected and the lower waterproof film 25 form a second electrolytic capacitor C2 during working, and the second electrolytic capacitor C2 is mainly used for directionally detecting the moisture state of the lower sensing surface.

The intermediate waterproof membrane 28 of this embodiment is usually made of a relatively thick plastic film, so as to provide a barrier function, and prevent the liquid 16 on the outer surface of the upper waterproof membrane from affecting the

electrodes

21B, 22B on the lower waterproof membrane. The intermediate waterproofing membrane likewise prevents the liquid 18 on the outer surface of the lower waterproofing membrane from acting on the

electrodes

21A, 22A on the upper waterproofing membrane. That is, in the embodiment of the present invention, due to the existence of the middle waterproof film 28, the first electrolytic capacitance value C1 can reflect the wet state of the upper sensing surface more independently, and the second electrolytic capacitance value C2 can reflect the wet state of the lower sensing surface more independently, thereby realizing a more independent double-sided directional and quantitative wet state detection function. Whether or not the C1, C2 are weighted, and how the weights are weighted, can be left to the capacitive sensing device 30 electrically connected to the sensor bars 20, which adds flexibility to later signal processing. Of course, it is also possible to perform weighting processing at the ends of the sensor strip, and the weighting output can be realized by connecting the first detection electrodes of each group of detection electrodes and the second detection electrodes of each group of detection electrodes in parallel.

Referring to fig. 16, it is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a sensor strip of a double-sided directional weighted moisture status sensor according to another embodiment of the present invention, which includes multiple sets of sensing electrodes, and is a variation and combination of the embodiments shown in fig. 12 and fig. 14. In the figure, 26 is an upper waterproof film, 25 is a lower waterproof film, 28 is a middle waterproof film, 21A/22A is a first group of detection electrodes positioned on the upper and lower surfaces of the upper

waterproof film

26, 21B/22B is a second group of detection electrodes positioned on the upper and lower surfaces of the lower waterproof film 25, wherein the first detection electrode 21A, the second detection electrode 22A, the upper waterproof film 26 and the liquid 16 containing electrolyte on the outer surfaces of the first group of detection electrodes form a first electrolytic capacitor C1 together; at the same time, the first detection electrode 21B, the second detection electrode 22B, the lower water-repellent film 25, and the liquid 18 containing the electrolyte on the outer surface of the 25 of the second group of detection electrodes constitute a second electrolytic capacitor C2. A dielectric capacitance C3 is also created between the

sensing electrodes

21A and 21B, but since C3 is fixed, its value is independent of whether the liquid 16, 18 is present.

The electrolytic capacitance values C1 and C2 of the present embodiment correspond to the liquid existing states of the upper and lower sensing surfaces, respectively, and hardly affect each other, that is, the liquid 16 on the upper sensing surface has no effect on C2, and the liquid 18 on the lower sensing surface has no effect on C1, so that the present embodiment realizes a relatively stable and independent double-sided directional quantized moisture state detection function, and the capacitances C1 and C2 are respectively proportional to the coverage areas of the

liquids

16 and 18 on the upper and lower sensing surfaces. Whether the C1, C2 is weighted or not can be left to the capacitive sensing device 30 connected to the sensor bars to determine, thereby adding flexibility to the post signal processing. Of course, it is also possible to perform weighting processing at the ends of the sensor strip, and the weighting output can be realized by connecting the first detection electrodes of each group of detection electrodes and the second detection electrodes of each group of detection electrodes in parallel.

Referring to fig. 17, which is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a double-sided directional weighted moisture state detection sensor according to an embodiment of the present invention, which includes multiple sets of detection electrodes and has an electrode multiplexing situation, it is a variation of the embodiment shown in fig. 16 that the middle waterproof film 28 in fig. 16 is removed and the

electrodes

21A and 21B are combined into a common first detection electrode 21, so that the first detection electrode 21 can form a first set of detection electrodes with the second detection electrode 22A on the upper waterproof film and a first electrolytic capacitor C1 with the upper waterproof film 26 and the liquid 16, can form a second set of detection electrodes with the second detection electrode 22B on the lower waterproof film and a second electrolytic capacitor C2 with the lower waterproof film 25 and the liquid 18, thus, C1 and C2 can represent the quantized moisture levels of the upper and lower sensing surfaces, respectively, and perform similar functions as described above with respect to the embodiment of fig. 16.

Fig. 18 is a schematic cross-sectional structure diagram and an equivalent circuit diagram of a double-sided directional weighting quantification moisture state detection sensor according to an embodiment of the present invention, in which the sensor strip includes multiple sets of detection electrodes and has an electrode multiplexing situation, which is a case of performing the stitching/electrode multiplexing on the embodiments shown in fig. 10 and 11. In the figure, 22 is a multiplexed second detection electrode, when the sensor strip is fully soaked by the liquid containing the electrolyte (including the

liquids

16 and 18 to be detected), the detection electrode 22 can form a first group of detection electrodes with the first detection electrode 21A on the upper waterproof film and a first electrolytic capacitor C1 with the upper waterproof film 26 and the liquid 16, and can form a second group of detection electrodes with the first detection electrode 21B on the lower waterproof film and a second electrolytic capacitor C2 with the lower waterproof film 25 and the liquid 18, so that C1 and C2 can respectively represent the quantized moisture states of the upper and lower sensing surfaces and realize the moisture detection function added to the embodiments shown in the foregoing fig. 10 and fig. 11.

In practical application, there may be more sets of detection electrodes, as long as each set of detection electrodes includes at least one first detection electrode (covered by the waterproof film and not in contact with the liquid to be detected in operation) and at least one second detection electrode (in contact with or not in contact with the liquid to be detected in operation), and an electrolytic capacitor related to the moisture state of a specific sensing surface can be generated between the first and second detection electrodes in each set of detection electrodes, so that the moisture state detection function of multi-direction and multi-sensing surface quantization can be realized.

The structure of the induction strip of the above embodiment of the invention is consistent in the length direction, and the cross section of the induction strip cut off in any length is the same. The induction strip provided by the embodiment of the invention can be rolled into a film coiled material before being integrated with the paper diaper, the length of each roll can reach hundreds of meters to thousands of meters, and the induction strip can be used for producing hundreds of to thousands of unequal paper diapers. After the induction strip is added in the paper diaper, the paper diaper can be changed into an intelligent paper diaper with a quantitative urine wet state detection function, so that the intelligent upgrading of the traditional paper diaper industry is very facilitated, a brand new product can be produced without any technical transformation on the existing production equipment, the main material of the existing paper diaper is not required to be changed, the appearance and the performance of the existing paper diaper are not influenced, and the intelligent paper diaper urine wet detection solution is low in cost, high in performance and capable of being standardized.

Referring to fig. 19, it is a schematic diagram (cross-sectional view) illustrating an embodiment of a double-sided directional weighted moisture status detection sensor according to the present invention, in which a sensor strip and a capacitive detection device are electrically connected through a tip. In the figure, 30 is a capacitance detecting device electrically connected to the sensor strip 20, the capacitance detecting device 30 includes

contact electrodes

31, 32, and the ends of the contact electrodes include metal tips (needle points), and the needle points can pierce through the upper and lower

waterproof films

26, 25 to electrically connect to the detecting

electrodes

21, 22 covered by the upper and lower waterproof films in the sensor layer. The detecting

electrodes

21, 22 on the connecting

points

37, 38 will be attached to the upper and lower waterproof films, and after the waterproof films are pierced, the waterproof films will generate a centripetal contraction force to hold the needle tips tightly, and the centripetal contraction force will make the detecting electrodes and the needle tips realize reliable electrical connection.

Referring to fig. 20, a block diagram of a double-sided directional weighted moisture status detection sensor according to an embodiment of the present invention is shown. In the figure, 10 is a disposable excrement loading and absorbing device (disposable absorbing article, such as a diaper), 20 is a sensing strip arranged on the diaper, and 30 is a detection device which comprises a capacitance detection device 33 which can be connected with a detection electrode on the sensing strip through an electric connection 24, monitors the moisture state of the diaper 10 in real time through a capacitance mode, and then sends out relevant state information (including alarm information) in a wireless mode (48) through a wireless transmission unit 36. The wireless receiving and displaying device 50 receives signals through the receiving unit 51, and then displays/indicates the status through the status display unit 52, or gives an alarm through the status alarm unit 53. In practical applications, a mobile phone or a computer (e.g., a tablet computer) may also be used to take the role of the wireless receiving and displaying device 50, obtain relevant status information through its Wi-Fi or bluetooth and its running App, and perform relevant status display or alarm prompt through its display screen. With this structure, the double-sided directional weighting and quantification moisture state detection sensor according to the embodiment of the present invention has the function of a wireless sensor, and is an advanced expression.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. A double-sided directional weighting quantification moisture state detection sensor is characterized by comprising a film type capacitance sensor, wherein the capacitance sensor comprises a sensing strip, the sensing strip is of a flexible strip-shaped structure and comprises an upper sensing surface and a lower sensing surface, quantification moisture state detection of the upper surface and the lower surface can be realized respectively, and the moisture states of the upper surface and the lower surface can be weighted and output according to a specific proportion, so that comprehensive moisture state information related to a specific layer and a specific direction of a specific detection object is provided.

2. The sensor of claim 1, including an upper waterproof membrane corresponding to said upper sensing surface and a lower waterproof membrane corresponding to said lower sensing surface, a sealed sensing layer being included between said upper and lower waterproof membranes, said sensing layer being insulated from said upper and lower waterproof membranes.

3. The sensor of claim 2, wherein the sensor strip comprises a first detection electrode and a second detection electrode, and the first and second detection electrodes are disposed in the sensing layer, completely covered by the upper and lower waterproof films, and are in no contact with the liquid to be detected during operation; or

4. The sensor of claim 2, wherein said sensor strip comprises a first sensing electrode disposed within said sensing layer and protected from contact with said fluid to be sensed during operation, and a second sensing electrode disposed on an outer surface of either of said upper and lower water-resistant membranes and in operation in direct contact with said fluid to be sensed comprising an electrolyte and rendering said fluid equipotential therewith and forming a fluid electrode; and

when the liquid electrode is covered on the outer surface of the waterproof film corresponding to the first detection electrode, an electrolytic capacitor is generated between the liquid electrode and the first detection electrode, and the first detection electrode and the second detection electrode form the medium capacitor C₀Adding the electrolytic capacitor to C and outputting the result when the product is in a wet stateAvailable formula (C-C)₀)/C₀The larger the numerical value, the more serious the comprehensive moisture degree of a specific layer of the specific detection object; and

5. The sensor according to claim 3 or 4, wherein when the liquid to be detected containing electrolyte accumulates on the upper and lower sensing surfaces, the first detecting electrode, the second detecting electrode, the upper waterproof film, the lower waterproof film and the liquid to be detected together constitute a non-polar electrolytic capacitor, wherein the first and second detecting electrodes constitute electrodes of the electrolytic capacitor, the liquid to be detected constitutes the electrolyte of the electrolytic capacitor, the waterproof film constitutes a dielectric of the electrolytic capacitor, the capacitance of the electrolytic capacitor is proportional to the area of the liquid to be detected on the sensing surface corresponding to the first detecting electrode, and the detection sensitivity of the upper and lower sensing surfaces is proportional to the dielectric constants of the upper and lower waterproof films and inversely proportional to the thicknesses of the upper and lower waterproof films, the weight of the wet state of the upper and lower sensing surfaces is in direct proportion to the detection sensitivity of the upper and lower sensing surfaces.

6. The sensor of claim 5, comprising an excreta bearing and absorption device having the design of a disposable absorbent article and comprising a facing layer, an absorption layer and a leakage-proof layer, wherein the sensor strip is disposed on the facing layer, or between the facing layer and the absorption layer, or between the absorption layer and the leakage-proof layer.

7. A sensor according to claim 6, comprising a sensing means, said sensing means comprising capacitive sensing means, electrically connected in use to said first and second sensing electrodes of said sensor strip, for performing a combined wetness state sensing function at a particular level and in a particular direction of said excreta carrying and absorption means by capacitive sensing.

8. The sensor of claim 7, wherein the capacitive sensing means comprises a contact electrode comprising a metal needle tip which, in use, can pierce the water-resistant membrane of the sensor strip and be electrically connected to the sensing electrode.

9. The sensor of claim 8, comprising a wireless transmitting unit and a wireless receiving and displaying device, which can transmit and receive the moisture status information of the absorbent article and perform related status display or status alarm prompt.

10. The sensor of claim 9, wherein the sensor strip width comprises 5 to 50 millimeters, the sensor strip thickness comprises 0.01 to 1 millimeter, the waterproofing membrane thickness comprises 5 to 500 micrometers, the detection electrodes comprise conductive ink printed wires or metal foil wires, the upper waterproofing membrane or the lower waterproofing membrane comprises a plastic membrane, the plastic membrane comprises a high tensile strength membrane, the high tensile strength membrane comprises a BOPP membrane or a PET membrane, the lower waterproofing membrane thickness is less than the upper waterproofing membrane, the fecal load bearing and absorbing device comprises a diaper, a training pant, a sanitary napkin, or a diaper, the liquid to be detected containing electrolytes comprises urine, the wireless receiving and display device comprises a cell phone or a computer, the sensor strip comprises more than two sets of detection electrodes, each set of detection electrodes comprises at least one first detection electrode and one second detection electrode, each set of detection electrodes is capable of directionally detecting a wetness state on a particular sensing surface, and the first detection electrode or the second detection electrode of one set is multiplexed with the first detection electrode or the second detection electrode of the other set.