Multi-structure integrated electrochemical sensing yarn and preparation method thereof
By designing a multi-structure integrated electrochemical sensing yarn, the problem of incompatibility between thin-film sensors and textile structures was solved, resulting in a highly integrated, soft, and breathable sweat sensor that can actively guide and efficiently detect biomarkers in sweat.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-03-10
AI Technical Summary
Existing thin-film sweat sensors are incompatible with the structure of textiles, have low integration, affect wearing comfort, and have limited sweat management capabilities, making it difficult to achieve active guidance and targeted enrichment of trace amounts of sweat.
Design a multi-structure integrated electrochemical sensing yarn, including a hydrophilic detection region and a hydrophobic barrier region, and integrate three electrode leads along the axial direction. It is integrally formed by coaxial spinning technology to form a Janus asymmetric structure, with the electrode fibers embedded inside the fiber, and the hydrophilic region modified with biosensitive materials.
It achieves a high degree of integration between the sensing yarn and the fabric, maintaining softness and breathability. The independent detection units do not interfere with each other, enabling active guidance of sweat and efficient biochemical detection.
Smart Images
Figure CN121629591A_ABST
Abstract
Description
Technical Field
[0001] This invention pertains to the field of smart fibers, specifically to a multi-structure integrated electrochemical sensing yarn and its preparation method. Background Technology
[0002] Sweat contains various biomarkers such as glucose, lactic acid, cortisol, electrolytes, and pH, making it an ideal biofluid for continuous, non-invasive health monitoring. Currently, most mainstream wearable sweat sensors are fabricated using planar flexible printed circuit board technology. Existing technologies all employ a "planar thin film" structure. This type of technology typically involves fabricating sensing electrodes and functional layers on a two-dimensional flexible substrate through processes such as photolithography, printing, or spraying, forming a layered, stacked film-like device.
[0003] Such thin-film devices have the following inherent defects: Incompatibility with textiles: The two-dimensional planar structure is mechanically incompatible with the one-dimensional yarn and three-dimensional fabric structure. Integration can lead to localized stiffness and poor breathability in the fabric, severely affecting wearing comfort, and is prone to delamination, open circuits, or damage during repeated washing and bending. Passive and limited integration methods: Thin-film sensors can usually only be attached to the fabric surface through "post-processing" methods such as bonding, pasting, or encapsulation, resulting in low integration, a stiff feel, and affecting the original appearance and texture of the fabric. Limited sweat management capabilities: Their hydrophilic and hydrophobic structures are usually used as the substrate or encapsulation layer of the entire device, focusing on unidirectional sweat wicking or protection, making it difficult to achieve the complex functions required for biochemical sensing, such as actively guiding, directionally enriching, and physically confining trace amounts of sweat. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to break through the existing thin film paradigm in terms of structural form, solve the problem of integration with textiles, and provide a multifunctional electrochemical sensing yarn with high structural integration, active sweat guidance, prevention of cross-interference, and direct weaving into clothing.
[0005] An electrochemical sensing yarn of the present invention includes a hydrophilic detection region and a hydrophobic barrier region; three electrode leads are integrated along the axial direction in the sensing yarn, which serve as the working electrode, counter electrode and reference electrode of the electrochemical detection system, respectively; the counter electrode is located in the hydrophobic barrier region, and the working electrode and reference electrode are located in the hydrophilic detection region.
[0006] Furthermore, the sensing yarn is integrally formed during the drawing process.
[0007] Furthermore, the hydrophilic detection area is composed of a porous hydrophilic polymer matrix, wherein the porous hydrophilic polymer is polyvinyl alcohol, sodium alginate, or gelatin.
[0008] The hydrophobic barrier region is composed of a hydrophobic polymer, which is polydimethylsiloxane, polyurethane, or a fluorinated polymer.
[0009] Furthermore, the working electrode is an Ag electrode fiber or a carbon-based electrode fiber, the counter electrode is an Ag conductive fiber or a platinum conductive fiber, and the reference electrode is an Ag / AgCl electrode fiber.
[0010] Furthermore, the surface of the working electrode is modified with a biosensitive material, which is one of glucose oxidase, lactate oxidase, and uricase.
[0011] Based on the electrochemical sensing yarn of the present invention, the present invention also provides a method for preparing the sensing yarn, comprising the following steps:
[0012] Step 1: Prepare spinning solution and precursor, wherein the spinning solution includes hydrophilic spinning solution and hydrophobic spinning solution;
[0013] Preparation of hydrophilic spinning solution: Dissolve the hydrophilic polymer in deionized water to prepare a homogeneous and transparent solution with a mass fraction of 8%-15%, and then perform degassing treatment;
[0014] Preparation of hydrophobic spinning solution: Dissolve the hydrophobic polymer in tetrahydrofuran to prepare a homogeneous solution with a mass fraction of 15%-25%;
[0015] Prepare electrode precursors: Prepare three conductive fibers, which will serve as leads for the working electrode, counter electrode, and reference electrode, respectively.
[0016] Step 2, coaxial spinning and integrated molding
[0017] Spinning is performed using a coaxial wet spinning device. The hydrophobic spinning solution is used to form a hydrophobic barrier region, and the hydrophilic spinning solution is used to form a hydrophilic detection region. The two components are extruded together through a coaxial spinneret.
[0018] During the spinning process, three conductive fibers are introduced and positioned from the rear of the spinneret to ensure that two electrodes are guided into the hydrophilic detection area as working electrodes and reference electrodes, and the other is guided into the hydrophobic barrier area as the counter electrode.
[0019] The nascent fibers extruded by coaxial spinnerets are introduced into a coagulation bath. The hydrophilic spinning solution and the hydrophobic spinning solution undergo phase separation and solidification in the coagulation bath to form a sensing yarn with electrode fibers, a hydrophobic barrier region, and a hydrophobic barrier region.
[0020] Furthermore, the preparation method of the present invention further includes modifying the working electrode and the reference electrode; the process of modifying the working electrode is as follows:
[0021] The hydrophilic detection section of the sensing yarn is immersed in a phosphate buffer containing glucose oxidase and a cross-linking agent and reacted at 4°C for 2-6 hours to fix the enzyme on the surface of the working electrode fiber. After removal, it is rinsed with buffer to remove unfixed enzyme.
[0022] Furthermore, the process of modifying the reference electrode is as follows: the reference electrode is a silver fiber, and an electrochemical chlorination method is used to use the reference electrode as the working electrode. In a solution containing chloride ions, a constant anodic potential is applied to partially oxidize the surface of the reference electrode to form an Ag / AgCl layer.
[0023] Furthermore, the hydrophilic polymer is polyvinyl alcohol, and the hydrophobic polymer is, for example, polydimethylsiloxane.
[0024] Beneficial effects: Compared with the prior art, the present invention has the following significant features:
[0025] 1. Integrated and process-shaped manufacturing: The three major functions of sample collection (sweat), signal conversion (electrochemical detection), and signal transmission (electrodes) are integrated into a single yarn, miniaturizing and fiberizing the complex biochemical detection function, realizing the miniaturization, fiberization and functional integration of the device.
[0026] 2. The sensing yarn can be blended and interwoven with ordinary yarn to make gloves, socks, clothing pieces and other shapes without changing the inherent properties of the fabric such as softness, breathability and stretchability, thus realizing the goal of "electronics as fiber, fabric as circuit".
[0027] 3. Multiple sensing yarns can be woven in the fabric at intervals, with each yarn being an independent and complete detection unit. The hydrophobic area on the outside of the yarn naturally and physically isolates the lateral crosstalk of sweat between different yarns, providing an architecture for achieving highly reliable simultaneous detection of multiple indicators. Attached Figure Description
[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0029] Figure 1 This is a schematic diagram of the cross-sectional structure of the electrochemical sensing yarn;
[0030] Figure 2 This is a schematic diagram of the overall structure of the electrochemical sensing yarn;
[0031] Figure 3 This is a schematic diagram of electrochemical sensing yarn woven into a fabric substrate;
[0032] Figure 4 This is a performance test diagram of electrochemical sensing yarn used for glucose detection;
[0033] The components include: 1. Hydrophilic detection area; 2. Hydrophobic barrier area; 3. Working electrode; 4. Counter electrode; and 5. Reference electrode. Detailed Implementation
[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0035] Example 1
[0036] This invention proposes a multi-structure integrated electrochemical sensing yarn and its preparation method for the detection of sweat biomarkers. The sensing yarn is a one-dimensional fiber, such as... Figure 1 As shown, the cross-section of the sensing yarn includes a hydrophilic detection region 1 and a hydrophobic barrier region 2, which are tightly bonded together to form a Janus asymmetric structure; as Figure 2 As shown, three micro-electrode leads are integrated axially inside the fiber, which respectively constitute the working electrode 3, counter electrode 4, and reference electrode 5 of the electrochemical detection system; the counter electrode 4 is located in the hydrophobic barrier region 2, and the working electrode 3 and reference electrode 5 are located in the hydrophilic detection region 1.
[0037] The sensor yarn itself is a yarn with textile processing properties. It can be used as warp or weft yarn to directly participate in weaving and knitting, achieving three-dimensional, seamless, and invisible integration.
[0038] The Janus structure, in which the hydrophilic detection region 1 and the hydrophobic barrier region 2 are tightly integrated, is formed inside the one-dimensional fiber body. It is not a simple laminated film, but an integrally formed structure with radial asymmetry during the fiber drawing process.
[0039] Three microelectrodes, namely the working electrode 3, the counter electrode 4, and the reference electrode 5, each with different functions, are embedded in the polymer matrix in parallel along the fiber axis, like "bones and ligaments." This constitutes an independent electrochemical detection system embedded inside the fiber, rather than a planar circuit pattern fabricated on the substrate surface.
[0040] The hydrophilic detection area 1 is composed of a porous hydrophilic polymer matrix and is modified with a biosensitive element. The porous hydrophilic polymer includes polyvinyl alcohol, sodium alginate, or gelatin.
[0041] The biosensitive element includes glucose oxidase, lactate oxidase, and uricase.
[0042] The hydrophobic barrier region 2 is composed of a hydrophobic polymer, including polydimethylsiloxane, polyurethane, or fluorinated polymer.
[0043] The working electrode 3 is made of Ag electrode fiber or carbon-based electrode fiber; the counter electrode 4 is made of Ag conductive fiber or platinum conductive fiber; and the reference electrode 5 is made of Ag / AgCl electrode fiber.
[0044] The active ends of the working electrode 3 and the reference electrode 5 are located within the hydrophilic detection area 1, allowing them to directly contact and guide sweat. The counter electrode 4 is embedded within the hydrophobic barrier area 2, forming an ion-conducting circuit with the working electrode 3 and the reference electrode 5 through the sweat within the hydrophilic detection area 1.
[0045] The surface of the working electrode 3 is modified with a biosensitive material, which includes one of glucose oxidase, lactate oxidase, and uricase.
[0046] Example 2
[0047] Based on the multi-structure integrated electrochemical sensing yarn in Example 1, this example provides a method for preparing a multi-structure integrated electrochemical sensing yarn, including the following sequential steps:
[0048] Step 1: Preparation of spinning solution and precursor, wherein the spinning solution includes hydrophilic spinning solution and hydrophobic spinning solution.
[0049] Preparation of hydrophilic spinning solution: Dissolve hydrophilic polymers, such as polyvinyl alcohol, in deionized water to prepare a homogeneous and transparent solution with a mass fraction of 8%-15%, and then perform degassing treatment.
[0050] Preparation of hydrophobic spinning solution: Dissolve the hydrophobic polymer, such as polydimethylsiloxane, in tetrahydrofuran to prepare a homogeneous solution with a mass fraction of 15%-25%.
[0051] Prepare electrode precursors: Prepare three independent micro-conductive fibers, which will serve as leads for the working electrode 3, counter electrode 4, and reference electrode 5, respectively. The working electrode 3 and counter electrode 4 are made of silver fibers with a diameter of 20-50 micrometers, and the reference electrode 5 is also made of silver fiber electrodes of the same specifications.
[0052] Step 2: Coaxial spinning and integrated molding.
[0053] Spinning is performed using a coaxial wet spinning machine. The hydrophobic spinning solution forms the upper half of the fiber cross-section, and the hydrophilic spinning solution forms the lower half. Both are extruded together through a coaxial spinneret. During spinning, three electrode precursor fibers are introduced from the rear of the spinneret and precisely positioned to ensure that two (working electrode 3 and reference electrode 5) are guided into the hydrophilic layer region, and the other (counter electrode 4) is guided into the hydrophobic layer region. The co-extruded nascent fibers are then introduced into a coagulation bath. The hydrophilic and hydrophobic spinning solutions undergo phase separation and solidification in the coagulation bath, forming a preliminary Janus structure fiber with a hydrophobic polymer as the upper half and a hydrophilic polymer as the lower half. Simultaneously, the three electrode precursors are firmly embedded in the designated spatial positions.
[0054] Step 3: Electrode functionalization and biomodification.
[0055] Modification of working electrode 3: Immerse the Janus hydrophilic detection region 1 of the fiber in a solution containing a biosensitive element. Taking glucose sensing as an example, immerse the fiber in a phosphate buffer containing glucose oxidase and a cross-linking agent (glutaraldehyde) and react at 4°C for 2-6 hours to firmly immobilize the enzyme on the surface of the working electrode 3 fiber. After removal, rinse with buffer to remove unimmobilized enzyme.
[0056] Reference electrode 5: Using electrochemical chlorination, the silver fiber used as reference electrode 5 is used as the working electrode. In a solution containing chloride ions (0.1 M KCl solution), a constant anodic potential is applied to partially oxidize its surface, forming a dense and stable Ag / AgCl layer.
[0057] Step 4: Post-processing and packaging. The functionalized fibers are cleaned and dried. Finally, the fibers are wound up to obtain the final multifunctional electrochemical sensing yarn that can be directly used in textiles.
[0058] Example 3
[0059] The steps for preparing the sensing yarn for glucose detection are as follows:
[0060] Step 1: Preparation of spinning solution and precursor.
[0061] Preparation of hydrophilic spinning solution: Dissolve polyvinyl alcohol in deionized water to prepare a homogeneous and transparent solution with a mass fraction of 10%, and then perform degassing treatment.
[0062] Preparation of hydrophobic spinning solution: Dissolve polydimethylsiloxane in tetrahydrofuran to prepare a homogeneous solution with a mass fraction of 20%.
[0063] Preparation of electrode precursors: Three independent micro-conductive fibers are prepared to serve as leads for the working electrode 3, counter electrode 4, and reference electrode 5, respectively. The working electrode 3 and counter electrode 4 are made of silver fibers with a diameter of 30 micrometers, and the reference electrode 5 is made of silver fiber electrode of the same specification.
[0064] Step 2: Coaxial spinning and integrated molding.
[0065] Spinning is performed using a coaxial wet spinning machine. The hydrophobic spinning solution forms the upper half of the fiber cross-section, and the hydrophilic spinning solution forms the lower half. Both are extruded together through a coaxial spinneret. During spinning, three electrode precursor fibers are introduced from the rear of the spinneret and precisely positioned to ensure that two (working electrode 3 and reference electrode 5) are guided into the hydrophilic layer region, and the other (counter electrode 4) is guided into the hydrophobic layer region. The co-extruded nascent fibers are then introduced into a coagulation bath. The hydrophilic and hydrophobic spinning solutions undergo phase separation and solidification in the coagulation bath, forming a preliminary Janus structure fiber with a hydrophobic polymer as the upper half and a hydrophilic polymer as the lower half. Simultaneously, the three electrode precursors are firmly embedded in the designated spatial positions.
[0066] Step 3: Electrode functionalization and biomodification.
[0067] Modification of working electrode 3: The hydrophilic detection region 1 of the fiber was immersed in glucose oxidase phosphate buffer containing 2.5% glutaraldehyde and cross-linked at 4°C for 4 hours to firmly fix glucose oxidase onto the surface of working electrode 3. After removal, it was rinsed with buffer to remove unfixed enzyme.
[0068] Reference electrode preparation: The silver fiber used as reference electrode 5 was used as the working electrode by electrochemical chlorination. A constant anodic potential was applied in a chloride ion-containing solution (0.1 M KCl solution) to partially oxidize its surface and form a dense and stable Ag / AgCl layer.
[0069] Step 4: Post-processing and packaging. The functionalized fibers are cleaned and dried. Finally, the fibers are wound up to obtain the final glucose-sensing yarn that can be directly used in textiles.
[0070] like Figure 3 As shown, the prepared glucose-sensing yarn was woven in parallel into the forehead contact area of a sports headband. Subjects wore the headband for a 30-minute running exercise. Detection was performed using a portable multi-channel electrochemical workstation. A working potential of +0.4 V was applied to the glucose-sensing yarn, and its current response was recorded. The results are as follows: Figure 4As shown, the sensing yarn exhibits a good dose-response relationship to sweat glucose concentration. Throughout the exercise process, the signal baseline remains stable and the response is rapid, successfully achieving real-time and continuous monitoring of sweat glucose levels during exercise.
Claims
1. An electrochemical sensing yarn, characterized in that, The sensing yarn comprises a hydrophilic detection zone and a hydrophobic barrier zone; Three electrode leads are integrated in the sensing yarn along the axial direction, serving as the working electrode, the counter electrode and the reference electrode of the electrochemical detection system, respectively; The counter electrode is located in the hydrophobic barrier zone, and the working electrode and the reference electrode are located in the hydrophilic detection zone.
2. The electrochemical sensing yarn of claim 1, wherein, The sensing yarn is integrally formed during the drawing process.
3. The electrochemical sensing yarn of claim 1, wherein, The hydrophilic detection zone is composed of a porous hydrophilic polymer matrix, and the porous hydrophilic polymer is polyvinyl alcohol, sodium alginate or gelatin. The hydrophobic barrier zone is composed of a hydrophobic polymer, and the hydrophobic polymer is polydimethylsiloxane, polyurethane or fluorinated polymer.
4. The electrochemical sensing yarn of claim 1, wherein, The working electrode is an Ag electrode fiber or a carbon-based electrode fiber, the counter electrode is an Ag conductive fiber or a platinum-gold conductive fiber, and the reference electrode is an Ag / AgCl electrode fiber.
5. The electrochemical sensing yarn of claim 1, wherein, The surface of the working electrode is modified with a biological sensitive material, and the biological sensitive material is one of glucose oxidase, lactic acid oxidase and uricase.
6. A method of making a sensing yarn as claimed in claim 1, characterized in that, The method comprises the following steps: Step 1, preparation of spinning solution and precursor, the spinning solution comprises hydrophilic spinning solution and hydrophobic spinning solution; Preparation of hydrophilic spinning solution: dissolve the hydrophilic polymer in deionized water to prepare a uniform transparent solution with a mass fraction of 8%-15%, and perform defoaming treatment; Preparation of hydrophobic spinning solution: dissolve the hydrophobic polymer in tetrahydrofuran to prepare a uniform solution with a mass fraction of 15%-25%; Preparation of electrode precursor: prepare three conductive fibers as the leads of the working electrode, the counter electrode and the reference electrode, respectively; Step 2, coaxial spinning and integrated forming Use coaxial wet spinning equipment for spinning, the hydrophobic spinning solution is used to form the hydrophobic barrier zone, and the hydrophilic spinning solution is used to form the hydrophilic detection zone, and the two are extruded through the coaxial spinneret; In the spinning process, introduce and position the three conductive fibers from the rear part of the spinneret, ensure that two electrodes serve as the working electrode and the reference electrode and are guided into the hydrophilic detection zone, and the other serves as the counter electrode and is guided into the hydrophobic barrier zone; Guide the nascent fiber extruded by the coaxial spinneret into the coagulation bath, and the hydrophilic spinning solution and the hydrophobic spinning solution undergo phase separation and solidification in the coagulation bath to form the sensing yarn with the electrode fiber, the hydrophobic barrier zone and the hydrophobic barrier zone.
7. The preparation method according to claim 6, characterized in that, Also include modification of the working electrode and the reference electrode; The modification process of the working electrode is as follows: Immerse the hydrophilic detection zone segment of the sensing yarn in a phosphate buffer solution containing glucose oxidase and a crosslinking agent, react at 4°C for 2-6 hours, so that the enzyme is fixed on the surface of the working electrode fiber, and then take out and rinse with buffer solution to remove the unfixed enzyme.
8. The production method according to claim 7, characterized by, The modification process of the reference electrode is as follows: the reference electrode is a silver fiber, and an electrochemical chlorination method is used, the reference electrode is used as the working electrode, in a solution containing chloride ions, a constant anode potential is applied, part of the surface of the reference electrode is oxidized to form an Ag / AgCl layer.
9. The preparation method according to claim 7, characterized in that, The hydrophilic polymer is polyvinyl alcohol, and the hydrophobic polymer is polydimethylsiloxane.
10. The preparation method according to claim 7, characterized in that, The working electrode, the counter electrode and the reference electrode all use silver fibers with a diameter of 20-50 microns.