TW202141032A - Solution sensor - Google Patents

Abstract

A solution sensor is disclosed, which comprises: a substrate; a pH value sensing module disposed on the substrate, and the pH value sensing module including a work electrode and a reference electrode; and a thin-film transistor disposed on the substrate, the thin transistor including a control end and a first end, and the control end connected to the work electrode; wherein a first voltage is provided to the reference electrode, and a second voltage is provided to the first end, the first voltage and the second voltage are conformed to the following equation: V2 ≥ V1+1, wherein V1 is the first voltage, and V2 is the second voltage.

Description

Solution sensor

This disclosure relates to a solution sensor, especially a solution sensor containing thin film transistors.

Since in the solution sensor, each parameter has its corresponding sensing electrode, and each sensing electrode corresponds to an independent sensing circuit, therefore, a variety of Electronic components make the size of the circuit board difficult to shrink, and its application is limited.

Therefore, it is necessary to develop a solution sensor to improve the applicability of the previous solution sensor to meet industrial use.

In view of this, the present disclosure provides a solution sensor in which a thin film transistor structure and a special circuit design are provided in the solution sensor to improve the applicability of the solution sensor on the market.

To achieve the above objective, the present disclosure provides a solution sensor including: a substrate; a pH sensing group disposed on the substrate, and the pH sensing group includes a working electrode and a reference electrode; and A thin film transistor is disposed on the substrate. The thin film transistor includes a control terminal and a first terminal, and the control terminal is connected to the working electrode; wherein, a first voltage is provided to the reference electrode, and a second A voltage is provided to the first terminal, and the first voltage and the second voltage conform to the relationship: V2 ≥ V1+1, where V1 is the first voltage, and V2 is the second voltage.

The following specific examples illustrate the implementation of the present disclosure. Those familiar with this technology can easily understand the other advantages and effects of the present disclosure from the content disclosed in this specification. The present disclosure can also be implemented or applied by other different specific embodiments, and various details in this specification can also be modified and changed according to different viewpoints and applications without departing from the spirit of the creation.

It should be noted that, in this text, unless otherwise specified, the provision of "a" element is not limited to the provision of a single element, but one or more of the elements may be provided.

Furthermore, the ordinal numbers used in the description and claims, such as the terms "first", "second", "third", etc., are only used to modify the requested element, and do not in itself mean or represent the requested element Any previous ordinal numbers do not represent the order of a certain request element and another request element, or the order of the manufacturing method. The use of these ordinal numbers is only used to enable a request element with a certain name to be compatible with another. Request elements with the same name can be clearly distinguished.

In this disclosure, the term "about" usually means within 20%, or within 10%, or within 5%, or within 3%, or within 2% of a given value or range, or Within 1%, or within 0.5%. The quantity given here is an approximate quantity, that is, the meaning of "covenant" can still be implied in the absence of a specific description of "covenant".

In addition, the positions mentioned in the specification and claims, such as "above", "above" or "above", may mean that the two elements are in direct contact, or may mean that the two elements are not in direct contact. Similarly, the positions mentioned in the specification and claims, such as "below", "below" or "below", can mean that the two elements are in direct contact, or can mean that the two elements are in direct contact.

In addition, the terms described in the specification and claims, for example, “connected” not only means direct connection with other elements, but also indirect connection and electrical connection with other elements.

In addition, the terms described in the specification and claims, such as "contact" not only mean direct contact with other components, but also mean indirect contact with other components.

In addition, if a value is between a first value and a second value, the value may be the first value, the second value, or another value between the first value and the second value.

The following are exemplary embodiments of the disclosure, but the disclosure is not limited thereto. A feature of an embodiment can be applied to other embodiments through appropriate modification, substitution, combination, and separation. In addition, the present disclosure can be combined with other known structures to form another embodiment.

FIG. 1 is a schematic top view of a solution sensor according to an embodiment of the disclosure. As shown in FIG. 1, the solution sensor of the present disclosure includes: a substrate 1; a pH sensing group 11 disposed on the substrate 1, and the pH sensing group 11 includes a working electrode 111 and a reference Electrode 112; and a thin film transistor TFT disposed on the substrate 1. The thin film transistor TFT includes a control terminal 21 and a first terminal 51, and the control terminal 21 is connected to the working electrode 111.

When a first voltage V1 is provided to the reference electrode 112 and a second voltage V2 is provided to the first terminal 51, the first voltage V1 and the second voltage V2 conform to the relationship: V2 ≥ V1+1. In an embodiment of the disclosure, the first voltage V1 may be greater than or equal to 1V and less than 5V. When the first voltage V1 is too small, the corresponding output current is small, resulting in poor sensitivity; when the first voltage V1 is too large, Then the corresponding output current is large, the electrode will exceed the load, and the electrode film will be discolored and broken.

As shown in FIG. 1, in an embodiment of the present disclosure, the solution sensor may further include a temperature sensing group 12 disposed on the substrate, and the temperature sensing group 12 includes a temperature sensing electrode 121 for interacting with The solution to be tested is contacted to detect the temperature of the solution to be tested. In some embodiments, it further includes an insulating layer disposed on the temperature sensing electrode 121 to prevent the temperature sensing electrode 121 from adsorbing ions in the solution to be measured, so as to improve the accuracy of temperature measurement. The temperature sensing electrode 121 may be, for example, a resistor, and the resistance may be greater than or equal to 100Ω and less than or equal to 100kΩ, for example. In one embodiment of the present disclosure, the resistance of the temperature sensing electrode 121 is greater than or equal to 1 kΩ and less than or equal to 10 kΩ. In addition, as shown in FIG. 1, the solution sensor may further include at least one passive element 122 electrically connected to the temperature sensing electrode 121. The passive element 122 may be, for example, a resistor, but the disclosure is not limited to this.

As shown in FIG. 1, in another embodiment of the present disclosure, the solution sensor may further include a conductivity sensing group, and the conductivity sensing group includes at least two conductivity sensing electrodes 13 disposed on the substrate 1 Above, the distance between two of the at least two conductivity sensing electrodes 13 is greater than or equal to 2 mm and less than or equal to 10 mm. For example, two of the at least two conductivity sensing electrodes 13 may be respectively It is closest to the edge of the substrate, but the disclosure is not limited to this. In an implementation aspect of the present disclosure, the conductivity sensing group includes two conductivity sensing electrodes 13 disposed on the substrate 1, and the distance between the two conductivity sensing electrodes 13 is greater than or equal to 2 mm and less than or Equal to 10mm. In another embodiment of the present disclosure, as shown in FIG. 1, the conductivity sensing group includes three conductivity sensing electrodes 13 disposed on the substrate. More specifically, the three conductivity sensing electrodes 13 are respectively The first conductivity sensing electrode 131, the second conductivity sensing electrode 132, and the third conductivity sensing electrode 133. There is a first conductivity sensing electrode between the first conductivity sensing electrode 131 and the second conductivity sensing electrode 132. Distance d1, there is a second distance d2 between the second conductivity sensing electrode 132 and the third conductivity sensing electrode 133, and there is a distance between the first conductivity sensing electrode 131 and the third conductivity sensing electrode 133 The third distance d3, where the first distance d1 is not equal to the second distance d2, and the third distance d3 is greater than or equal to 2 mm and less than or equal to 10 mm. When the distance between the two conductivity sensing electrodes 13 is relatively short, the solution to be tested with high conductivity can be detected; when the distance between the two conductivity sensing electrodes 13 is relatively long, the solution with low conductivity can be detected The solution to be tested, therefore, the design position of the conductivity sensing electrode 13 can be adjusted as needed. Taking the first conductivity sensing electrode 131 and the second conductivity sensing electrode 132 as examples, the first distance d1 is measured, for example, from the center of the first conductivity sensing electrode 131 to the second conductivity sensing electrode 132 The distance from the center, or the distance from the far right of the first conductivity sensing electrode 131 to the far right of the second conductivity sensing electrode 132, or the far left of the first conductivity sensing electrode 131 to the farthest of the second conductivity sensing electrode 132 For the distance on the left, the measurement method of the second distance d2 and the third distance d3 is the same or similar to the measurement method of the first distance d1, so it will not be repeated here.

As shown in FIG. 1, in another embodiment of the present disclosure, the solution sensor may further include an antenna circuit 14 disposed on the substrate to transmit or receive wireless signals.

In the solution sensor of the present disclosure, a plurality of wires 22 and a plurality of contact pads 23 are disposed on the substrate 1, wherein the plurality of wires 22 are electrically connected to the plurality of contact pads 23, and the plurality of wires 22 are respectively connected to the working electrode 111 , The reference electrode 112, the temperature sensing electrode 121 and the conductivity sensing electrode 13 are electrically connected. The external electronic components can be electrically connected to the solution sensor through the contact pad 23 to drive the solution sensor.

In addition, the position of the wire 22 shown in FIG. 1 is only one embodiment. In other embodiments of the present disclosure, the wire 22 can surround the working electrode 111 or the reference electrode 112, or other arrangements can be made as needed. Similarly, the setting positions of the working electrode 111, the reference electrode 112, the temperature sensing electrode 121 and the conductivity sensing electrode 13 shown in FIG. 1 are also an implementation aspect, and the setting positions can be changed as needed. For example, in the pH sensing group 11 of FIG. 1, the working electrode 111 and the reference electrode 112 are arranged parallel to a first direction X. However, in other embodiments of the present disclosure, the working electrode 111 and the reference electrode 112 It can be arranged parallel to a second direction Y, wherein the second direction Y is different from the first direction X.

When the solution sensor of the present disclosure is used for detection, the working electrode 111, the reference electrode 112, the temperature sensing electrode 121, and the conductivity sensing electrode 13 are in contact with the solution to be tested. It should be known that the temperature sensing electrode 121 An insulating layer can also be included between the solution and the solution to be tested, but the disclosure is not limited to this. The working electrode 111 is affected by different pH values in the solution to be tested, which means that when the solution has different hydrogen ion concentrations, the working electrode 111 can have different induced voltage changes. For example, when the first voltage V1 is provided to the reference electrode 112, When the second voltage V2 is applied to the first terminal 51 of the thin film transistor TFT, and the induced voltage of the working electrode 111 has a different value from the second voltage V2, the control terminal 21 of the thin film transistor TFT is the induced voltage of the working electrode 111, The first voltage V1 and the second voltage V2 conform to the relationship: V2 ≥ V1+1, so the first terminal 51 of the thin film transistor TFT can generate currents of different magnitudes according to the induced voltage of the control terminal 21, so the second terminal 52 can Different voltages are generated, and the pH value of different solutions to be tested can be detected by the change of the voltage of the second terminal 52; the temperature sensing electrode 121 senses the temperature of the solution to be tested, and the resistance of the temperature sensing electrode 121 is based on the test solution. The temperature of the solution changes, and the linear correlation between resistance and temperature can detect the temperature of the solution to be tested; the conductivity sensing electrode 13 is used to detect the conductivity of the solution to be tested; the antenna circuit 14 can be used to The signals detected by the value sensing group 11, the temperature sensing group 12, and the conductivity sensing group are emitted and placed with external electronic components.

Fig. 2 is a schematic cross-sectional view taken along the section line A-A' of Fig. 1. Fig. 3 is a schematic cross-sectional view taken along the line B-B' of Fig. 1. Fig. 4 is a schematic cross-sectional view taken along the line C-C' of Fig. 1. Fig. 5 is a schematic cross-sectional view taken along the line D-D' of Fig. 1. Fig. 6 is a schematic cross-sectional view taken along the section line E-E' of Fig. 1. Fig. 7 is a schematic cross-sectional view taken along the section line F-F' of Fig. 1.

Please refer to FIG. 2. First, a substrate 1 is provided. The substrate 1 can be an inflexible substrate, a flexible substrate or a film or a combination of the above, and the material of the substrate 1 can include, for example, glass, quartz, silicon wafer, sapphire, polycarbonate (PC), polyimide (polyimide, PI), polypropylene (PP), polyethylene terephthalate (PET), other plastics or polymers, other inorganic materials or other organic materials, or a combination of the foregoing, but this Disclosure is not limited to this.

A first metal layer 2 is formed on the substrate 1, and the first metal layer 2 includes a control terminal 21 and a plurality of wires 22. The material of the first metal layer 2 may include, for example, gold, silver, copper, aluminum, titanium, chromium, nickel, molybdenum, tungsten, copper alloy, aluminum alloy, molybdenum alloy, tungsten alloy, gold alloy, chromium alloy, nickel alloy, platinum Alloys, titanium alloys, other suitable metals, or combinations of the above, or other conductive materials with good conductivity or low resistance. In addition, the first metal layer 2 may have a single-layer or multi-layer structure. But this disclosure is not limited to this.

Next, a gate insulating layer 3 is formed on the first metal layer 2. The material of the gate insulating layer 3 may include silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, photoresist, polymer, resin or a combination thereof, but the disclosure is not limited thereto.

After that, an active layer 4 is formed on the gate insulating layer 3, wherein the active layer 4 is disposed corresponding to the control terminal 21. The material of the active layer 4 includes amorphous silicon, low-temperature polysilicon, or metal oxide. The metal oxide may include indium gallium zinc oxide (IGZO), aluminum indium zinc oxide (AIZO), hafnium indium zinc oxide (HIZO), and indium oxide. Tin zinc (ITZO), indium gallium zinc tin oxide (IGZTO) or indium gallium tin oxide (IGTO), but the present disclosure is not limited thereto. In an embodiment of the disclosure, the active layer 4 includes amorphous silicon.

Next, a second metal layer 5 is formed on the active layer 4. The second metal layer 5 includes a first end 51, a second end 52 and an antenna 53, wherein the first end 51 and the second end 52 are connected to the active Layer 4 is electrically connected. In addition, referring to FIG. 7, the gate insulating layer 3 may include a first contact hole 3 a, and the antenna 53 may be electrically connected to the wire 22 through the first contact hole 3 a. Here, the material of the second metal layer 5 is similar to that of the first metal layer 2, which will not be repeated here, and the first metal layer 2 and the second metal layer 5 may use the same or different materials, respectively.

Thus, the thin film transistor TFT and the antenna circuit 14 of the solution sensor of the present disclosure can be formed. Wherein, as shown in FIG. 2, the thin film transistor TFT includes a control terminal 21 as a gate; a gate insulating layer 3 is arranged on the gate; an active layer 4 is arranged on the gate insulating layer 3, and The gate is correspondingly arranged; a first terminal 51 can be used as a source and a second terminal 52 can be used as a drain on the active layer 4 and electrically connected to the active layer 4. Here, the thin film transistor TFT has a bottom gate structure, but the present disclosure is not limited to this. In other embodiments of the present disclosure, the thin film transistor TFT may have a top gate structure. Wherein, as shown in FIG. 7, the antenna circuit 14 includes an antenna 53, and the antenna 53 is not particularly limited. For example, it can be a monopole antenna, an inverted-F antenna (IFA) or a planar inverted-F antenna (PIFA), but the present disclosure Not limited to this. In an embodiment of the disclosure, the antenna 53 is an inverted F antenna.

After that, a first insulating layer 6 is formed on the thin film transistor TFT and the antenna 53. Here, the material of the first insulating layer 6 includes silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, photoresist, polymer, resin or a combination thereof, but the disclosure is not limited thereto.

Next, referring to FIGS. 3 to 6, a working electrode 111, a temperature sensing electrode 121, a passive element 122, and at least two conductivity sensing electrodes 13 are formed on the first insulating layer 6. In addition, the gate insulating layer 3 may include a first contact hole 3a, the first insulating layer 6 may include a second contact hole 6a, and the working electrode 111, the temperature sensing electrode 121, the passive element 122, and the conductivity sensing electrode 13 can be electrically connected to the wire 22 through the first contact hole 3a and the second contact hole 6a.

Here, the materials of the working electrode 111, the temperature sensing electrode 121, the passive element 122, and the conductivity sensing electrode 13 include metals, conductive metal oxides or a combination thereof, and the same or different materials may be used to prepare the working electrodes. 111. Temperature sensing electrode 121, passive element 122, and conductivity sensing electrode 13. Wherein, the metal includes gold, silver, copper, aluminum, titanium, chromium, nickel, molybdenum or a combination thereof, but the present disclosure is not limited thereto. Among them, the conductive metal oxide includes indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), indium gallium zinc oxide (IGZO), but the present disclosure is not limited thereto. In an embodiment of the disclosure, the material of the working electrode 111, the temperature sensing electrode 121, and the conductivity sensing electrode 13 is indium tin oxide. In another embodiment of the present disclosure, the material of the passive element 122 is indium tin oxide.

In addition, as shown in FIG. 3, a reference electrode 112 is also formed on the first insulating layer 6. Although not shown in the figure, similar to the working electrode 111 in FIG. 4, the reference electrode 112 can be electrically connected to the wire 22 through the first contact hole 3 a and the second contact hole 6 a. Here, the reference electrode 112 includes an inner layer electrode 1121 and an outer layer electrode 1122. The material of the inner electrode 1121 includes a single-layer structure formed by silver, or may also include a multilayer structure composed of titanium/silver, chromium/silver, and nickel/silver, but the present disclosure is not limited to this; and the outer electrode 1122 The material contains silver chloride. In an embodiment of the disclosure, the inner electrode 1121 includes nickel/silver or chromium/silver, and the outer electrode 1122 includes silver chloride.

Here, silver is first deposited as the inner electrode 1121, and then by electrolysis or solution method, for example, the inner electrode 1121 is reacted with ferric chloride to form silver chloride as the outer electrode 1122 to prepare the one described in this disclosure. Reference electrode 112. The thickness of the inner electrode 1121 may be approximately between 5000 Å and 10000 Å; and the thickness of the outer electrode 1122 is approximately 10-90% of that of the inner electrode, for example, may be 30-70%.

In the present disclosure, the order of forming the working electrode 111, the reference electrode 112, the temperature sensing electrode 121, and the conductivity sensing electrode 13 is not particularly limited. For example, in an embodiment of the present disclosure, the working electrode 111, the temperature sensing electrode 121, and the conductivity sensing electrode 13 may be formed first, and then the reference electrode 112 may be formed. However, in another embodiment of the present disclosure, the reference electrode 112 can also be formed first, and then the working electrode 111, the temperature sensing electrode 121, and the conductivity sensing electrode 13 are formed. Alternatively, when the material of the working electrode 111, the temperature sensing electrode 121, or the conductivity sensing electrode 13 is the same as the material of the reference electrode 112, they can be prepared through the same step.

Thus, the pH sensor group 11, the temperature sensor group 12, and the conductivity sensor group of the solution sensor of the present disclosure can be formed. Among them, the pH sensing group 11, the temperature sensing group 12, and the electrical conductivity sensing group are electrically insulated from each other.

Here, the pH sensing group 11 includes a working electrode 111 and a reference electrode 112. The working electrode 111 is disposed adjacent to the reference electrode 112 and is electrically insulated from the reference electrode 112. In addition, the temperature sensing electrical assembly 12 includes a temperature sensing electrode 121 and a passive element 122, wherein the temperature sensing electrode 121 is electrically connected to the passive element 122. The conductivity sensing group includes at least two conductivity sensing electrodes 13, and the at least two conductivity sensing electrodes 13 are electrically insulated from each other.

Next, after forming the working electrode 111, the reference electrode 112, the temperature sensing electrode 121, and the conductivity sensing electrode 13, a second insulating layer 7 is formed. Wherein, the second insulating layer 7 covers the thin film transistor TFT, the passive element 122, the antenna 53 and the wire 22. Here, the material of the second insulating layer 7 is similar to that of the first insulating layer 6, which will not be repeated here, and the first insulating layer 6 and the second insulating layer 7 can be made of the same or different materials, respectively.

After that, the second insulating layer 7 on the working electrode 111, the reference electrode 112 and the conductivity sensing electrode 13 is removed to expose at least part of the surface of the working electrode 111, the reference electrode 112 and the conductivity sensing electrode 13. If the exposed area of the working electrode 111 is too small, the sensitivity will be poor, and if the exposed area of the working electrode 111 is too large, the volume of the solution sensor will be larger. Therefore, the width of the working electrode 111 may be between 1 mm and 6 mm, for example, between 2 mm and 4 mm, and the length of the working electrode 111 may be between 1 mm and 30 mm, for example, between 2 mm and 25 mm. Here, the length and width of the working electrode 111 refer to the length and width of the working electrode 111 exposed from the second insulating layer 7. In addition, when the length of the working electrode 111 is fixed, the width of the temperature sensing electrode 121 will affect the change of the temperature on the resistance value. For example, when the length of the temperature sensing electrode 121 is fixed to 15 mm, the width of the temperature sensing electrode 121 is about When it is 19.8μm, there will be a resistance change of about 3.15Ω per °C; when the width of the temperature sensing electrode 121 is about 55.9μm, there will be a resistance change of about 1.17Ω per °C; when the width of the temperature sensing electrode 121 is about When it is 167μm, there will be a resistance change of about 0.24Ω per °C. Therefore, the temperature of the solution to be tested can be detected by the change in resistance value. In an embodiment of the disclosure, when the length of the temperature sensing electrode 121 is fixed at 4 mm, when the width of the temperature sensing electrode 121 is about 14.0 µm, there will be a resistance change of about 1.17Ω per °C; The width and length of the electrode 121 can be adjusted according to design requirements, as long as it can meet the resistance change requirement of about 0.5-5Ω per °C. When the resistance change of the temperature sensing electrode 121 is less than 0.5Ω per °C, the design value of the width of the temperature sensing electrode 121 is larger, which is disadvantageous to the shrinkage of the solution sensor; when the resistance change of the temperature sensing electrode 121 is greater than 5Ω per °C, Therefore, the design value of the width of the temperature sensing electrode 121 is small, and the manufacturing process is not easy to control the variation range of the design value. .

As mentioned above, in an embodiment of the present disclosure, the working electrode 111, the reference electrode 112, the temperature sensing electrode 121, and the conductivity sensing electrode 13 are formed on the first insulating layer 6, and then the second Insulation layer 7. However, in another embodiment of the present disclosure, the second insulating layer 7 can also be formed on the first insulating layer 6, and then after the second insulating layer 7 is patterned, the working electrode 111, the reference electrode 112, and the temperature The sensing electrode 121 and the conductivity sensing electrode 13.

In addition, in this embodiment, the wire 22 is formed by the first metal layer 2, and the working electrode 111, the reference electrode 112, the temperature sensing electrode 121, the conductivity sensing electrode 13, and the antenna 14 respectively pass through the first contact hole 3a and/or the second contact hole 6a are electrically connected to the wire 22. However, in another embodiment of the present disclosure, the wire 22 can also be formed by the second metal layer 5, and the working electrode 111, the reference electrode 112, the temperature sensing electrode 121, and the conductivity sensing electrode 13 can respectively pass through the second contact The hole 6a is electrically connected to the wire 22. Alternatively, in another embodiment of the present disclosure, the wire 22 may also be formed of a third metal layer, where the third metal layer is disposed on the first insulating layer 6, then the working electrode 111, the reference electrode 112, and the temperature sensor The electrode 121 and the conductivity sensing electrode 13 can be directly electrically connected to the wire 22 through the third metal layer, and the antenna 53 can be electrically connected to the wire 22 through the second contact hole 6a.

In summary, the pH sensing group of the solution detector of the present disclosure includes thin film transistors, and the pH of the solution is detected by the working electrode electrically connected to the gate, which can improve the sensitivity and use Due to the circuit design, the size of the circuit board is reduced, so that the solution detector of the present disclosure can be applied to a portable detection system. In addition, the solution detector of the present disclosure can also perform temperature and conductivity detection, and can be applied to water quality detection systems on the market.

The above specific embodiments should be construed as merely illustrative, and not restricting the rest of the present disclosure in any way, and the features between different embodiments can be mixed and used as long as they do not conflict with each other.

1: substrate 11: pH sensor group 111: working electrode 112: Reference electrode 1121: inner electrode 1122: Outer electrode 12: Temperature sensing group 121: temperature sensing electrode 122: passive components 13: Conductivity sensing electrode 131: The first conductivity sensing electrode 132: Second conductivity sensing electrode 133: The third conductivity sensing electrode 14: Antenna circuit 2: The first metal layer 21: Control terminal 22: Wire 23: Contact pad 3: Gate insulation layer 3a: The first contact hole 4: active layer 5: The second metal layer 51: first end 52: second end 53: Antenna 6: The first insulating layer 6a: second contact hole 7: The second insulating layer TFT: Thin Film Transistor d1: first distance d2: second distance d3: third distance X: first direction Y: second direction

FIG. 1 is a schematic top view of a solution sensor according to an embodiment of the disclosure. Fig. 2 is a schematic cross-sectional view taken along the section line A-A' of Fig. 1. Fig. 3 is a schematic cross-sectional view taken along the line B-B' of Fig. 1. Fig. 4 is a schematic cross-sectional view taken along the line C-C' of Fig. 1. Fig. 5 is a schematic cross-sectional view taken along the line D-D' of Fig. 1. Fig. 6 is a schematic cross-sectional view taken along the section line E-E' of Fig. 1. Fig. 7 is a schematic cross-sectional view taken along the section line F-F' of Fig. 1.

1: substrate

11: pH sensor group

111: working electrode

112: Reference electrode

12: Temperature sensing group

121: temperature sensing electrode

122: passive components

13: Conductivity sensing electrode

131: The first conductivity sensing electrode

132: Second conductivity sensing electrode

133: The third conductivity sensing electrode

14: Antenna circuit

21: Control terminal

22: Wire

23: Contact pad

51: first end

52: second end

53: Antenna

TFT: Thin Film Transistor

d1: first distance

d2: second distance

d3: third distance

X: first direction

Y: second direction

Claims (10)

A solution sensor including: A substrate; A pH sensing group is arranged on the substrate, and the pH sensing group includes a working electrode and a reference electrode; and A thin film transistor arranged on the substrate, the thin film transistor including a control terminal and a first terminal, and the control terminal is connected to the working electrode; Wherein, a first voltage is provided to the reference electrode, and a second voltage is provided to the first terminal. The first voltage and the second voltage conform to the relationship: V2 ≥ V1+1, where V1 is the first voltage , And V2 is the second voltage. The solution sensor according to claim 1, wherein the width of the working electrode is between 1 mm and 6 mm, and the length of the working electrode is between 1 mm and 30 mm. The solution sensor according to claim 1, wherein the material of the reference electrode includes silver chloride, Ti/Ag/AgCl, Cr/Ag/AgCl, Ni/Ag/AgCl, or a combination of the foregoing. The solution sensor according to claim 1, wherein the first voltage is greater than or equal to 1V and less than 5V. The solution sensor according to claim 1, further comprising a temperature sensing group disposed on the substrate, and the temperature sensing group includes a temperature sensing electrode, wherein the temperature sensing electrode has a resistance, the The resistance is greater than or equal to 100Ω and less than or equal to 100kΩ. The solution sensor according to claim 5, wherein the resistance is greater than or equal to 1 kΩ and less than or equal to 10 kΩ. The solution sensor according to claim 5, wherein the material of the temperature sensing electrode includes conductive metal oxide. The solution sensor according to claim 5 further includes at least one passive element electrically connected to the temperature sensing electrode. The solution sensor according to claim 1, further comprising a conductivity sensing group, and the conductivity sensing group includes at least two conductivity sensing electrodes disposed on the substrate, wherein the at least two conductivity The distance between two of the sensing electrodes is greater than or equal to 2 mm and less than or equal to 10 mm. The solution sensor according to claim 1, further comprising an antenna circuit arranged on the substrate.

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