CN112268946A - Structure and manufacturing method of miniature electrochemical sensor based on miniature three-dimensional electrode - Google Patents
Structure and manufacturing method of miniature electrochemical sensor based on miniature three-dimensional electrode Download PDFInfo
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Abstract
The invention discloses a structure and a manufacturing method of a miniature electrochemical sensor based on a miniature three-dimensional electrode, and the structure comprises a flexible circuit board and an electrode group, wherein the flexible circuit board is curled into a column to form a sensor shell, the electrode group is arranged on the flexible circuit board, the top end of the sensor shell and the bottom end of the sensor shell are respectively provided with a sealing element, a welding disc is arranged on the sensor shell, and electrolyte is filled in the sensor shell.
Description
Technical Field
The invention relates to the field of sensors, in particular to a structure of a miniature electrochemical sensor based on a miniature three-dimensional electrode, and further relates to a manufacturing method of the miniature electrochemical sensor based on the miniature three-dimensional electrode.
Background
The electrochemical sensor is a sensor for sensing and detecting based on the electrochemical property of an object to be detected and converting the chemical quantity of the object to be detected into electric quantity, and the electrochemical property of the object to be detected is characterized by measuring the change of electric signals such as electric potential, current and the like generated in the target electrochemical reaction when in use.
Among many sensor types, the electrochemical sensor has the advantages of relatively small size, low power consumption, simple structure, low cost, etc., and has gradually become the key point of the research field and wide application range. But it also has the problems of measurement drift, measurement accuracy degradation, need of regular calibration and maintenance, etc. With further miniaturization, miniaturization and intellectualization of the electrochemical sensor, the electrochemical sensor can be more widely applied to the fields of scientific research, medical treatment, industry, national defense, environment and the like.
Electrochemical sensors are typically composed of an electrode assembly, an electrolyte and a permeable membrane. The electrode assembly may employ 2 electrodes (2 electrode system) or 3 electrodes (3 electrode system), including a reference electrode (reference electrode), a working electrode (working electrode), and sometimes an auxiliary electrode (counter electrode). The reference electrode is typically used to provide a known solution potential, and is typically of the type used such as a standard hydrogen electrode, calomel electrode, and most typically a silver/silver chloride electrode. The working electrode is typically made of an inert metal, such as platinum, gold, etc.; the auxiliary electrode is also typically made of an inert metal, but the electrode area needs to be much larger than the working electrode. The electrolyte provides an ion-exchangeable environment that allows the targeted electrochemical reaction (redox reaction) to take place and efficiently transfer ionic charges to the electrodes. The electrolyte environment needs to remain stable and compatible with the electrode material to form a stable reference potential with the reference electrode. The change in the electrolyte ion concentration directly affects the stability of the reference potential and thus the actual measurement result. In addition, in order to control the interference caused by other substances or reactions, some electrochemical sensors incorporate a filtering membrane (permeable membrane) to selectively pass the substance to be detected and generate the target electrochemical reaction.
Electrochemical sensors generally employ chronoamperometry, in which an electrode set is in the same electrolyte solution, and when a specific voltage is applied between the electrode sets (working electrode and reference electrode), a target electrochemical reaction occurs in the electrode set, thereby generating a certain current between the electrodes. This reaction current is directly related to the reaction rate in the solution, and specifically to the rate of diffusion of molecules in the solution to the surface of the working electrode, as determined by its diffusion model, and is generally linear. The diffusion model is related to the concentration of ions to be measured and the shape and size of the electrode. Therefore, a specific target concentration value can be obtained after calibration calculation by applying a specific voltage to the sensor electrode and measuring the reaction current.
In addition, there are also electrochemical sensors that characterize physical quantities by measuring the potential difference between electrodes. Such sensors typically have a selective electrode for a particular ion as a working electrode, and a reference electrode in combination to form an electrode assembly. The electrode potential is the potential difference between the plate and the solution in the electrode, and different types of electrodes will have different potentials. The reference electrode can be generally considered to have stable potential and does not change along with the change of the measurement environment, but the working electrode can generate different potentials in solutions with different ion concentrations, so that the potential difference between the working electrode and the reference electrode is measured by comparing with the reference electrode, and the concentration value of the ions to be measured in the solution can be obtained after calibration calculation.
There are several electrochemical sensors that have been described so far:
1. the Chinese patent application: the micro electrochemical sensor based on the direct forming mesoporous carbon technology and the manufacturing method apply the publication number: CN 104502428A;
2. the Chinese patent application: a preparation method of a miniature electrochemical sensor for detecting dopamine is disclosed in the application publication number: CN 110940712A;
3. the Chinese patent application: an electrochemical sensor for blood enzyme detection, application publication No.: CN 111638256A;
4. the Chinese patent application: a dissolved oxygen electrochemical sensor, application publication No.: CN 101042365A;
5. the Chinese patent application: dissolved oxygen electrochemical sensor, application publication No.: CN 104698045A;
6. polarography dissolved oxygen sensor.
In summary, electrochemical sensors all face the following problems:
firstly, because the volume and the area of the miniaturized sensor are limited, and the area of the reference electrode is small, the stability of the reference potential is not high, potential drift exists, the service life is limited, and the like.
Secondly, because the volume of the miniature electrochemical sensor is limited, the miniature electrochemical sensor has a simple structure, and has no relatively stable chloride ion concentration environment, and the reference electrode generates potential fluctuation along with the change of the surrounding chloride ion concentration to influence the measurement accuracy, so the stability is not high.
And thirdly, the area of some working electrodes is packaged in the glass cylinder by metal wires, and only the cross section of the bottom end is exposed, so that the effective area of the working electrodes is small and the sensitivity is low.
Fourthly, the volume is larger. The sensor based on traditional glass electrode, ventilated membrane, reference electrode and electrolyte, its volume has pen size, is difficult further miniaturized.
Fifthly, the traditional glass or silicon-based structure has insufficient toughness and is fragile and easy to break; some miniaturized flat-plate electrochemical sensors have small electrode size, limited sensor response, limited internal solution capacity and low stability. Some working electrodes of the sensor are far away from the oxygen permeable membrane, so that the response speed is low.
Sixth, the processing technique is relatively complex and the cost is high. Such as electrodes made based on photolithography, require expensive precision instruments and clean room environments, complex manufacturing processes, and expensive production and material costs.
Due to the above several problems, electrochemical sensors all have the following requirements:
the first, reference electrode needs to be as stable as possible. For example, a silver/silver chloride reference electrode needs to work in an electrolyte with a certain chloride ion concentration, and the electrolyte needs to be isolated from a solution to be measured or connected through a salt bridge. Different environments of chloride ion concentration will produce different reference electrode potentials, and thus changes in chloride ion concentration in the environment will cause fluctuations in the reference electrode potential. In addition, the specification and quality of the reference electrode itself also determine its stability, such as the proportion of silver chloride in the silver/silver chloride reference electrode. However, the current passing through the reference electrode will change the silver chloride content to some extent, and a reference electrode of generally larger area will contribute to its stability.
Secondly, the core size of the working electrode needs to be in the size of tens of microns, so that a microelectrode is formed, and a better dissolving and diffusing effect is obtained. Meanwhile, the sensitivity of the sensor can be effectively improved by the larger area of the working electrode. The larger working electrode area can promote more target reactions to occur, generate larger reaction current, obtain larger response range in measurement and improve the measurement sensitivity. Meanwhile, in order to meet the requirement of core parameters of the working electrode, the core size is controlled to be a smaller scale, and the strip electrode or the multi-microelectrode array is produced.
And thirdly, the shortest distance between different electrodes is required to be ensured, so that the internal resistance of the sensor can be effectively reduced, and the sensitivity and the measurement precision of the sensor are improved.
Fourth, the surface of the working electrode should be as close to the solution to be measured as possible to reduce the sensor response time.
Fifthly, if a microelectrode array is adopted, certain space intervals among array units are ensured so as to ensure better dissolving and diffusing effects and improve the measurement quality.
To address the above problems and needs, the present invention provides a structure and method of mounting a miniature electrochemical sensor based on a miniature three-dimensional electrode.
Disclosure of Invention
To this end, the present invention provides a structure and a manufacturing method of a micro electrochemical sensor based on a micro three-dimensional electrode to solve the above problems.
In order to achieve the above purpose, the invention provides the following technical scheme:
in a first aspect of the present invention, a structure of a micro electrochemical sensor based on a micro three-dimensional electrode includes a flexible circuit board and an electrode set, the flexible circuit board is curled into a column to form a sensor housing, the electrode set is disposed on the flexible circuit board, a sealing member is respectively mounted on a top end of the sensor housing and a bottom end of the sensor housing, a bonding pad is disposed on the sensor housing, and an electrolyte is filled in the sensor housing, wherein the sealing member may be a sealing cover or a gas permeable membrane, etc.
Further, the electrode group comprises a working electrode, an auxiliary electrode and a reference electrode, the working electrode is arranged on the upper surface of the flexible circuit board, the auxiliary electrode is arranged on the upper surface of the flexible circuit board, the reference electrode is arranged on the lower surface of the flexible circuit board, the upper surface of the flexible circuit board is the outer surface of the sensor shell, and the lower surface of the flexible circuit board is the inner surface of the sensor shell.
Furthermore, an opening is formed in the gap between the auxiliary electrode and the working electrode, the opening penetrates through the flexible circuit board, and the opening is used for communicating the upper surface of the flexible circuit board with the lower surface of the flexible circuit board to form a channel for ions between the working electrode and the reference electrode.
Furthermore, the working electrode is of a multilayer structure, the first layer of the working electrode is of a strip-shaped structure, the first layer of the working electrode is a metal electrode, the second layer of the working electrode is an insulating layer, and the insulating layer covers the strip-shaped structure.
Further, a circular hole is formed in the insulating layer and used for exposing a part of the metal electrode to form a working electrode.
Furthermore, the reference electrode is in a reciprocating wave shape or a straight line shape perpendicular to the direction of the bus of the sensor shell, and the auxiliary electrode is in a reciprocating wave shape or a straight line shape perpendicular to the direction of the bus of the sensor shell.
Further, the seal and the sensor shell are connected through an adhesive, and the welding disc is arranged on the side face of the sensor shell.
Furthermore, the sensor shell is internally filled with a mesh-shaped porous structure, the mesh-shaped porous structure is any one of electrolyte colloid, sponge or filter paper, and the mesh-shaped porous structure is used for stabilizing the ion concentration in the electrolyte.
Further, the sensor further comprises a flexible breathable film ferrule, and the flexible breathable film ferrule covers the outer surface of the sensor shell.
Further, the electrode structure also comprises a breathable film, wherein the breathable film is covered on the working electrode and the auxiliary electrode, and the breathable film is connected with the flexible breathable film ferrule.
According to a second aspect of the present invention, a method for manufacturing a micro electrochemical sensor based on a micro three-dimensional electrode, using the structure of the micro electrochemical sensor based on a micro three-dimensional electrode according to any one of the first aspect of the present invention, comprises the following steps:
and 7, covering a flexible breathable film ferrule or a breathable film on the outer surface.
The invention has the following advantages:
1. the structure of the miniature electrochemical sensor based on the miniature three-dimensional electrode can greatly reduce the whole size, realize the area maximization of the electrode group at a fixed size, simplify the structure, simplify the assembly and production steps, improve the sensitivity, enhance the stability, accelerate the reaction speed and reduce the cost, and provide possibility for further popularization and application of the electrochemical sensor in a wider application scene.
2. The invention upgrades the traditional 2-dimensional electrode into three-dimensional design, fully utilizes the inner and outer three-dimensional surfaces of the miniaturized sensor, designs and realizes the electrode group, and effectively increases the area of the electrode group on the premise of not increasing the volume of the sensor. The increase of the working electrode area can effectively enhance the response of the sensor and increase the sensitivity. The increase of the area of the reference electrode can effectively improve the stability, control the potential drift and increase the limit of the service life.
3. The working electrode group of the miniature electrochemical sensor is designed on an arc surface (the outer surface of the cylindrical shell), so that the working electrode or the working electrode array units face to an environment to be measured in a fan shape, a better diffusion effect can be obtained, and the performance of the sensor is improved.
4. The miniature electrochemical sensor introduced by the invention designs the electrode group on the inner surface and the outer surface of the sensor shell, and fully uses the internal space to store electrolyte. Due to the increase of the space, the electrolyte capacity can be remarkably increased; due to the protection of the shell, the contact area between the internal electrolyte and the external environment is obviously reduced, so that the ion diffusion with the external environment can be effectively reduced, a more stable internal ion concentration environment is realized, the potential fluctuation of the reference electrode along with the change of the peripheral ion concentration is reduced, and the stability is improved.
5. The arrangement of the reticular porous structure can stabilize ions in the electrolyte and weaken the ion diffusion with the external environment.
6. The invention designs the electrode group by fully utilizing the inner area and the outer area of the sensor shell, and the breathable film is directly attached to the outer surface, so that the design can effectively realize the miniaturization of the volume and can easily realize the overall dimension of a few millimeters.
7. The flexible material is used as the substrate of the electrode group and is also used as the shell of the sensor, the flexible material has certain softness and toughness, and can generate certain deformation without fracture when being subjected to external pressure, certain damage caused by the fracture of the sensor can not occur, and the performance of the sensor can not be influenced.
8. The working electrode or the working electrode array and the auxiliary electrode are designed on the outer surface of the sensor shell, and the breathable film is directly attached to the outer surface, so that the distance between the working electrode and the environment to be measured is shortened to the maximum extent, and the reaction time of the sensor is shortened. Meanwhile, the reference electrode is designed on the inner surface of the sensor shell and is in an internal stable electrolyte environment, so that the contact with the external environment is reduced as much as possible. Meanwhile, the electrodes on the inner side and the outer side are communicated through a plurality of small holes in the shell, so that ion communication between the working electrode and the reference electrode is realized, the function of a salt bridge is similar, but the distance is very short, and the impedance between the electrodes is effectively reduced.
9. The invention is processed and manufactured based on the production process of the flexible circuit board, the produced flexible circuit board is rolled up to form the core shell of the sensor when being assembled, and the electrode groups on the upper surface and the lower surface of the flexible circuit board form the final electrode groups on the inner surface and the outer surface of the sensor. The whole manufacturing process is relatively simple and the cost is low.
10. The auxiliary electrode and the reference electrode are designed into a reciprocating wave shape, so that the pressure applied to the electrode in the curling process is effectively reduced when the flexible circuit board is curled into a column shape, and the electrode is prevented from deforming, cracking and separating.
11. The working electrode is designed into a strip shape, the length direction of the working electrode is vertical to the bus direction of the sensor shell, the curling direction is along the width direction of the electrode, the width is small, and therefore stress is small, and pressure on the electrode in the curling process can be effectively reduced through the design.
12. The sensor shell converts the electrode on the plane into the electrode on the curved surface, and the area of the inner surface and the outer surface of the sensor shell is fully utilized to realize a larger electrode.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.
The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions that the present invention can be implemented, so that the present invention has no technical significance, and any modifications of the structures, changes of the ratio relationships, or adjustments of the sizes, the number of the through holes, and the adjustments of the sizes, should still fall within the scope of the technical contents disclosed in the present invention without affecting the efficacy and the achievable purpose of the present invention.
Fig. 1 is a front view of a planar structure of a micro electrochemical sensor based on a micro three-dimensional electrode according to some embodiments of the present invention.
Fig. 2 is a back view of a micro electrochemical sensor based on the micro three-dimensional electrode shown in fig. 1.
Fig. 3 is a perspective view of the structure of a micro electrochemical sensor based on a micro three-dimensional electrode according to some embodiments of the present invention.
Fig. 4 is a cross-sectional view of a micro electrochemical sensor based on micro three-dimensional electrodes shown in fig. 3.
Fig. 5 is a diagram illustrating the structural assembly steps of a micro electrochemical sensor based on a micro three-dimensional electrode according to some embodiments of the present invention.
In the figure: 1. the flexible circuit board comprises a flexible circuit board upper surface, 2 working electrodes, 3 insulating layers, 4 auxiliary electrodes, 5 flexible circuit board lower surfaces, 6 reference electrodes, 7 openings, 8 bonding pads, 9 sealing elements, 10 adhesives, 11 electrolytes, 12 and a breathable film.
Detailed Description
The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
As shown in fig. 1 to 4, the structure of a miniature electrochemical sensor based on miniature three-dimensional electrodes in this embodiment includes a flexible circuit board and an electrode group, the flexible circuit board is rolled into a cylindrical shape to form a sensor housing, the electrode group is disposed on the flexible circuit board, a sealing member 9 is disposed at each of a top end of the sensor housing and a bottom end of the sensor housing, a bonding pad 8 is disposed on the sensor housing, and an electrolyte 11 is filled in the sensor housing.
The sealing member in this embodiment may be a sealing cover or a gas permeable membrane, etc.
The technical effect that this embodiment reaches does:
1. the utility model provides a miniature electrochemical sensor's structure based on miniature three-dimensional electrode can be very big reduce overall dimension, realizes the area maximize of electrode group at size one time, simplifies the structure simultaneously, simplifies the equipment, and the production step promotes its sensitivity, strengthens stability for reaction rate, reduce cost provides the possibility for further promoting and use electrochemical sensor in wider application scene.
2. The flexible material is used as the substrate of the electrode group and the shell of the sensor, has certain flexibility and toughness, can deform to a certain extent without breaking when being subjected to external pressure, does not bring certain damage due to the breakage of the sensor, and even does not influence the performance of the sensor.
3. The invention is processed and manufactured based on the production process of the flexible circuit board, the produced flexible circuit board is rolled up to form the core shell of the sensor when being assembled, and the electrode groups on the upper surface and the lower surface of the flexible circuit board form the final electrode groups on the inner surface and the outer surface of the sensor. The whole manufacturing process is relatively simple and the cost is low.
4. The sensor shell converts the electrode on the plane into the electrode on the curved surface, and the area of the inner surface and the outer surface of the sensor shell is fully utilized to realize a larger electrode.
Example 2
As shown in fig. 1 to 4, the structure of a micro electrochemical sensor based on a micro three-dimensional electrode in this embodiment includes all the technical features of embodiment 1, in addition to that, the electrode set includes a working electrode 2, an auxiliary electrode 4 and a reference electrode 6, the working electrode 2 is disposed on the upper surface 1 of the flexible circuit board, the auxiliary electrode 4 is disposed on the upper surface 1 of the flexible circuit board, the reference electrode 6 is disposed on the lower surface 5 of the flexible circuit board, the upper surface 1 of the flexible circuit board is an outer surface of the sensor housing, and the lower surface 5 of the flexible circuit board is an inner surface of the sensor housing.
In one particular embodiment: the working electrode 2, the auxiliary electrode 4 and the reference electrode 6 can also be arranged on the same side of the circuit board and are arranged on the inner surface of the sensor shell after being assembled. The working electrode 2 and the auxiliary electrode 4 can be silver/silver chloride electrodes, and other inert metals can be adopted for the working electrode 2.
The beneficial effects in this embodiment are:
1. according to the invention, the working electrode 2 and the auxiliary electrode 4 of the miniature electrochemical sensor are designed on an arc surface (the outer surface of the cylindrical shell), so that the working electrode 2 (or the units of the working electrode 2 array) faces towards the environment to be measured in a fan shape, a better diffusion effect can be obtained, and the performance of the sensor is improved.
2. Based on the existing mature flexible circuit board manufacturing process, a double-sided structure or a single-sided structure, the PCB directly produced can be used as an electrode substrate and forms various electrodes, for example, a gold leaching process can be used for designing a working electrode and an auxiliary electrode, metal silver is plated on the gold leaching process by electroplating or evaporation, and then the silver/silver chloride electrode is chloridized. The whole production process is simple and the cost is low.
3. The design of the circuit board can optimize the layout of a multi-electrode system, so that the working electrode meets the requirement of small key size and realizes larger integral area.
Example 3
As shown in fig. 1 to 4, the structure of a micro electrochemical sensor based on a micro three-dimensional electrode in this embodiment includes all the technical features of embodiment 2, in addition, an opening 7 is formed in a gap between the auxiliary electrode 4 and the working electrode 2, the opening 7 penetrates through the flexible circuit board, and the opening 7 is used for communicating ions between the working electrode 2 and the reference electrode 6 formed by the upper surface 1 of the flexible circuit board and the lower surface 5 of the flexible circuit board.
Preferably, the working electrode 2 is a multilayer structure, the first layer of the working electrode 2 is in a strip-shaped structure, the length direction of the first layer of the working electrode 2 is perpendicular to the bus direction of the sensor shell, the second layer of the working electrode 2 is an insulating layer 3, the first layer of the working electrode 2 is a metal electrode, and the insulating layer 3 covers the strip-shaped structure.
Preferably, the insulating layer 3 is provided with a circular hole for exposing a portion of the metal electrode to form the working electrode 2.
Optionally, the reference electrode 6 is in a complex wave shape or a linear shape perpendicular to the direction of the bus of the sensor housing, and the auxiliary electrode 4 is in a reciprocating wave shape or a linear shape perpendicular to the direction of the bus of the sensor housing.
The beneficial effects in this embodiment are:
1. electrodes on the inner side and the outer side of the sensor shell are communicated through small holes in the shell, ion communication between the working electrode and the reference electrode is achieved, the function similar to that of a salt bridge is achieved, the distance is short, and impedance between the electrodes is effectively reduced.
2. The auxiliary electrode and the reference electrode are designed into a reciprocating wave shape, so that the pressure applied to the electrode in the curling process is effectively reduced when the flexible circuit board is curled into a column shape, and the electrode is prevented from deforming, cracking and separating.
3. The working electrode is designed into a strip shape, the length direction of the working electrode is vertical to the bus direction of the sensor shell, the curling direction is along the width direction of the electrode, the width is small, and therefore stress is small, and pressure on the electrode in the curling process can be effectively reduced through the design.
Example 4
As shown in fig. 1 to 4, the structure of a micro electrochemical sensor based on a micro three-dimensional electrode in this embodiment includes all the technical features of embodiment 3, in addition, a sealing member 9 is connected with a sensor housing through an adhesive 10, the adhesive 10 is used for sealing and fixing the upper and lower ports of the sensor housing, and a bonding pad 8 is disposed on the side surface of the sensor housing.
The sensor shell is filled with a mesh-shaped porous structure, the mesh-shaped porous structure is any one of electrolyte colloid, sponge or filter paper, and the mesh-shaped porous structure is used for stabilizing the ion concentration in the electrolyte 11.
And one of a flexible breathable film ferrule or a breathable film 12 is further included, and one of the flexible breathable film ferrule or the breathable film 12 covers the outer surface of the sensor shell.
In one embodiment, the working electrode is provided in a multi-layer structure, a layer of insulating material is covered on the strip electrodes of the flexible circuit board, and the layer of insulating material is provided with a plurality of circular holes, so that a part of the metal electrodes below is exposed, specifically, metal parts of a plurality of prototypes are exposed, thereby forming the working electrode array, each prototype area is an array unit, and all units are integrated in the inner part.
The beneficial effects in this embodiment are:
1. the arrangement of the reticular porous structure can stabilize ions in the electrolyte and weaken the ion diffusion with the external environment.
2. The invention designs the electrode group by fully utilizing the inner area and the outer area of the sensor shell, and the breathable film is directly attached to the outer surface, so that the design can effectively realize the miniaturization of the volume and can easily realize the overall dimension of a few millimeters.
3. The working electrode and the auxiliary electrode are designed on the outer surface of the sensor shell, and the breathable film is directly attached to the outer surface, so that the distance between the working electrode and the environment to be measured is shortened to the maximum extent, and the reaction time of the sensor is shortened. Meanwhile, the reference electrode is designed on the inner surface of the shell and is in an internal stable electrolyte environment, so that the contact with the external environment is reduced as much as possible.
4. The invention can simplify the production and assembly steps and realize the electrochemical sensor with the micro size of a few millimeters. The flexible circuit board is rolled up in a column shape, and sealing caps are mounted at upper and lower ends, and both end openings are sealed using an adhesive (e.g., epoxy, glue, etc.). The sensor is internally added with a colloidal electrolyte, such as a hydrogel electrolyte, or an electrolyte with a stable mesh-shaped porous structure (containing a chloride ion electrolyte with a specific known concentration) such as sponge, filter paper and the like. This allows as much electrolyte as possible to be filled in a limited volume to ensure stability of the reference electrode.
Example 5
As shown in fig. 5, the method for manufacturing a micro electrochemical sensor based on a micro three-dimensional electrode in this embodiment uses a structure of a micro electrochemical sensor based on a micro three-dimensional electrode as in any one of embodiments 1 to 4, and includes the following steps:
and 7, covering a flexible breathable film ferrule or a breathable film 12 on the outer surface.
Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
In the present specification, the terms such as upper, lower, left, right, middle, and the like are used for clarity of description only, and are not used to limit the scope of the present invention, and changes or modifications of the relative relationship thereof may be made without substantial changes in the technical content.
Claims (10)
1. The structure of the miniature electrochemical sensor based on the miniature three-dimensional electrode is characterized by comprising a flexible circuit board and an electrode group, wherein the flexible circuit board is curled into a columnar sensor shell, the electrode group is arranged on the flexible circuit board, the open ends of the top end of the sensor shell and the bottom end of the sensor shell are respectively provided with a sealing element (9), the sensor shell is provided with a welding disc (8), and the sensor shell is filled with electrolyte (11).
2. The structure of the miniature electrochemical sensor based on miniature three-dimensional electrode as claimed in claim 1, wherein the electrode set comprises a working electrode (2), an auxiliary electrode (4) and a reference electrode (6), the working electrode (2) is disposed on the upper surface (1) of the flexible circuit board, the auxiliary electrode (4) is disposed on the upper surface (1) of the flexible circuit board, the reference electrode (6) is disposed on the lower surface (5) of the flexible circuit board, the upper surface (1) of the flexible circuit board is the outer surface of the sensor housing, and the lower surface (5) of the flexible circuit board is the inner surface of the sensor housing.
3. The structure of the miniature electrochemical sensor based on the miniature three-dimensional electrode as claimed in claim 2, wherein an opening (7) is formed in the gap between the auxiliary electrode (4) and the working electrode (2), the opening (7) penetrates through the flexible circuit board, and the opening (7) is used for communicating the upper surface (1) of the flexible circuit board and the lower surface (5) of the flexible circuit board to form a channel for ions between the working electrode (2) and the reference electrode (6).
4. The structure of the miniature electrochemical sensor based on the miniature three-dimensional electrode as claimed in claim 2, wherein the working electrode (2) is a multi-layer structure, the shape of the first layer of the working electrode (2) is a strip-shaped structure and the length extension line is perpendicular to the length extension line of the flexible circuit board when the flexible circuit board is unfolded, the first layer of the working electrode (2) is a metal electrode, the second layer of the working electrode (2) is an insulating layer (3), and the insulating layer (3) covers the strip-shaped structure.
5. The structure of a miniature electrochemical sensor based on miniature three-dimensional electrodes as claimed in claim 4, wherein said insulating layer (3) is provided with a circular hole for exposing a portion of said metal electrode to form a working electrode (2), and said working electrode (2) is composed of one of a micro-electrode or a plurality of micro-electrode arrays.
6. The structure of the miniature electrochemical sensor based on the miniature three-dimensional electrode as claimed in claim 2, wherein the shape of the reference electrode (6) is a reciprocating wave shape or a straight line shape perpendicular to the direction of the bus bar of the sensor housing, and the shape of the auxiliary electrode (4) is a reciprocating wave shape or a straight line shape perpendicular to the direction of the bus bar of the sensor housing.
7. The structure of the miniature electrochemical sensor based on miniature three-dimensional electrode as claimed in claim 1, wherein the seal (9) and the sensor housing are connected by an adhesive (10), the adhesive (10) is used for sealing and fixing the seal (9) of the upper and lower ports of the sensor housing, and the bonding pad (8) is arranged on the side surface of the sensor housing.
8. The structure of a miniature electrochemical sensor based on miniature three-dimensional electrodes as claimed in claim 1, wherein the sensor housing is filled with a mesh-like porous structure, the mesh-like porous structure is any one of electrolyte colloid, sponge or filter paper, and the mesh-like porous structure is used for stabilizing the ion concentration in the electrolyte (11).
9. The structure of a miniature three-dimensional electrode-based miniature electrochemical sensor according to claim 1, further comprising one of a flexible gas permeable membrane collar or a gas permeable membrane (12), said one of a flexible gas permeable membrane collar or a gas permeable membrane (12) covering said sensor housing outer surface.
10. The method for manufacturing the miniature electrochemical sensor based on the miniature three-dimensional electrode is characterized in that the structure of the miniature electrochemical sensor based on the miniature three-dimensional electrode as claimed in any one of claims 1 to 9 is used, and comprises the following steps:
step 1, producing a flexible circuit board, wherein a bare electrode substrate is arranged on the flexible circuit board and various electrodes are formed, a working electrode (2) and an auxiliary electrode (4) are arranged on the upper surface (1) of the flexible circuit board, a reference electrode (6) is arranged on the lower surface (5) of the flexible circuit board, the auxiliary electrode (4) and the reference electrode (6) are made by adopting a surface gold-plating process, and the surface material of the working electrode is changed by adopting the surface gold-plating process or surface treatment on the working electrode (2);
step 2, adding a metal silver layer on the substrate of the reference electrode (6) on the lower surface (5) of the produced flexible circuit board by adopting an electroplating or evaporation method, and then chloridizing a silver/silver chloride electrode on the silver layer of the reference electrode (6) on the lower surface (5) of the flexible circuit board;
step 3, rolling the flexible circuit board into a column shape to form a sensor shell, wherein the upper surface (1) of the flexible circuit board faces outwards, the lower surface (5) of the flexible circuit board faces inwards, a part of overlapped part is reserved at a seam, and the overlapped part is fixed by an adhesive (10) to ensure that the upper edge and the lower edge are aligned;
step 4, placing a sealing element (9) into the lower end of the sensor shell, enabling the lower surface of the sealing element (9) to be flush with the lower edge of the lower end opening of the sensor shell, placing the sealing element upside down, and injecting an adhesive (10) into the sealing element (9) for fixing to enable the lower end opening of the flexible circuit board to be closed;
step 5, filling electrolyte (11) into the sensor shell;
step 6, placing a sealing element (9) at the upper end of the sensor shell, wherein the upper surface of the sealing element (9) is flush with the upper edge of the opening at the upper end of the sensor shell, and injecting an adhesive (10) on the sealing element (9) for fixing to seal the opening at the upper end of the flexible circuit board;
and 7, covering one of a flexible breathable film ferrule or a breathable film on the outer surface.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113504276A (en) * | 2021-08-10 | 2021-10-15 | 盛密科技(上海)有限公司 | Electrochemical sensor and method of assembling the same |
| CN113640362A (en) * | 2021-07-15 | 2021-11-12 | 清华大学 | Reference electrode implantation method and three-electrode battery |
| CN115015343A (en) * | 2022-06-07 | 2022-09-06 | 中国科学院天津工业生物技术研究所 | Method for manufacturing all-solid-state micro dissolved oxygen electrode |
| CN116337971A (en) * | 2023-03-21 | 2023-06-27 | 深圳市雷诺华科技实业有限公司 | Reference electrode-free micro-matrix biosensor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113640362A (en) * | 2021-07-15 | 2021-11-12 | 清华大学 | Reference electrode implantation method and three-electrode battery |
| CN113640362B (en) * | 2021-07-15 | 2022-05-06 | 清华大学 | Reference electrode implantation method and three-electrode battery |
| CN113504276A (en) * | 2021-08-10 | 2021-10-15 | 盛密科技(上海)有限公司 | Electrochemical sensor and method of assembling the same |
| CN115015343A (en) * | 2022-06-07 | 2022-09-06 | 中国科学院天津工业生物技术研究所 | Method for manufacturing all-solid-state micro dissolved oxygen electrode |
| CN115015343B (en) * | 2022-06-07 | 2024-04-26 | 中国科学院天津工业生物技术研究所 | Manufacturing method of all-solid-state miniature dissolved oxygen electrode |
| CN116337971A (en) * | 2023-03-21 | 2023-06-27 | 深圳市雷诺华科技实业有限公司 | Reference electrode-free micro-matrix biosensor |
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