An all-fiber fabric sensor structure and method of making

Abstract

The application discloses a full-fiber fabric sensor structure and a preparation method thereof. The structure comprises a front-end angle linkage structure, a rear-end angle linkage structure and a middle part. The middle part is sequentially and spacedly provided with a lower electrode layer, a lower spacing layer, a functional layer, an upper spacing layer and an upper electrode layer from bottom to top. The two sides of each layer of the middle part are connected with the front-end angle linkage structure and the rear-end angle linkage structure. The upper spacing layer and the lower spacing layer are matrixly provided with spacing layer cavities. The front-end angle linkage structure and the rear-end angle linkage structure, the electrode layer and the spacing layer are prepared from nylon fibers and are warp and weft yarns. The functional layer is prepared from warp yarns of nylon fibers and weft yarns of ion functional fibers. The application can realize accurate detection of physiological signals such as limb movement and finger pressure distribution while maintaining excellent wearing comfort, and is suitable for long-term and continuous health state monitoring scenes.

Description

Technical Field

[0001] This invention relates to the field of wearable fabric sensor technology, and in particular to a capacitive sensing array with an all-fiber fabric sensor structure integrated on a flexible fabric, its large-scale fabrication method, and its application in health monitoring and human-computer interaction textiles. Background Technology

[0002] Current flexible sensors have a limited structure, limiting their placement to specific locations, such as attaching to the surface of a particular object or a single area of ​​the human body for detection. Compared to traditional thin-film materials and paper-based sensors, flexible fabric sensors possess a unique fabric structure and the excellent flexibility of textile materials, allowing them to be tightly integrated with textiles to create smart textiles. These sensors can measure physical quantities such as tension, pressure, temperature, and humidity, providing real-time feedback to users or systems, offering greater comfort and adaptability. Due to their flexible structure, they can be attached to various objects and human surfaces for wide-ranging measurements. Flexible fabric sensors in smart electronic textiles serve as close-fitting mobile devices for daily life and health monitoring. They collect data on human behavior and vital signs through skin contact, transmitting the signals wirelessly to a terminal for further calculation and analysis. By monitoring body surface pressure in real time, they provide more accurate data analysis and feedback, helping users better understand their physical condition, prevent sports injuries, and promote rehabilitation and training effectiveness.

[0003] Among numerous sensing mechanisms, flexible capacitive sensors stand out due to their simple structure, low power consumption, and sensitivity to both static and dynamic pressure. Fabric capacitive sensors, in particular, using textiles as a substrate and conductive yarns or coatings as electrodes, are considered a key pathway to realizing next-generation invisible wearable devices because of their softness, breathability, and washability, similar to traditional textiles. Currently, most fabric capacitive sensors employ a sandwich structure, with a layer of flexible dielectric material (such as polyurethane film, silicone rubber, or the fabric itself) sandwiched between two layers of conductive fabric electrodes. However, this sandwich structure has inherent technical limitations. First, to detect the initial capacitance signal, the electrodes and dielectric layer typically need to be pre-bonded. This results in limited changes in the effective contact area and electrode spacing under slight pressure, leading to low sensitivity. Furthermore, as pressure increases, the dielectric layer is rapidly compacted, causing the sensing response to saturate quickly and resulting in a narrow dynamic range. Second, this structure faces severe mechanical instability challenges. Under repeated bending, stretching, or shear stress, the bonding interfaces between layers are prone to slippage or even peeling, leading to baseline drift and poor response repeatability of the sensing signal. More importantly, when such unit sensors are expanded into arrays for spatial pressure distribution detection, the aforementioned instabilities are amplified, and crosstalk interference becomes significant. The literature "Eco-Friendly Conformal and Self-Adhesive Electrochemical Sensors for Sweat Monitoring" (ACS Applied Materials & Interfaces, 2025, Vol. 17, pp. 54411-54422) reports a sandwich-structure wearable sweat capacitive sensor made with screen-printed sandwich electrodes on a thin-film substrate. While achieving signal detection, it suffers from poor breathability, non-fiber-level electrode integration, poor comfort and biocompatibility, lack of a three-dimensional woven structure, and poor stability. Furthermore, existing fabric sensors lack systematic structural design; for example, row and column wiring, warp and weft distribution, flexible interconnection, and back-end signal acquisition algorithms have not yet formed standardized solutions, hindering their large-scale application in clinical medicine, rehabilitation engineering, and wearable smart clothing.

[0004] Therefore, there is an urgent need in this field for a more optimized structure, more integrated functions, and more stable performance of all-fiber fabric sensor array to meet the future needs of smart textiles for multimodal and high-precision health monitoring. Summary of the Invention

[0005] The purpose of this invention is to address the limitations of current technologies by providing an all-fiber fabric sensor structure and its fabrication method. This array employs a three-dimensional interlocking structure weaving process to integrate the upper / lower electrode layers, spacer layers, and functional layers. The upper and lower spacer layers are fabricated using a "continuous warp, discontinuous weft" weaving process, which significantly improves the multi-level contact sensitivity and detection range between the electrode and functional layer, achieving a capacitive sensing mechanism with multi-level contact between fibers, yarns, and fabric. The electrode layer is constructed from interwoven silver-plated nylon fibers, the spacer layer from interwoven nylon fibers, and the functional layer from interwoven ion-functional fibers. No post-processing or bonding steps are required. This invention solves industry challenges related to breathability, washability, elasticity recovery, and high spatial resolution, while also addressing technical difficulties in long-term wearability comfort, high sensitivity, and signal stability in existing wearable sensing devices. While maintaining excellent wearability comfort, it enables accurate detection of physiological signals such as limb movements and finger pressure distribution, making it suitable for long-term, continuous health monitoring scenarios.

[0006] The technical solution of this invention is as follows:

[0007] A sensor structure and fabrication method made of all-fiber fabric includes a front corner interlocking structure, a rear corner interlocking structure and a middle part. The middle part has a lower electrode layer, a lower spacer layer, a functional layer, an upper spacer layer and an upper electrode layer distributed from bottom to top. The two sides of each layer of the middle part are respectively connected to the front corner interlocking structure and the rear corner interlocking structure.

[0008] The upper electrode layer is located 0.5mm-1mm above the upper spacer layer, and the lower electrode layer is located 0.5mm-1mm below the lower spacer layer. The functional layer is located between the upper and lower spacers, with a distance of 0.5mm-1.5mm from both spacers.

[0009] The electrode layer, functional layer, and spacer layer have the same dimensions, which are 1.5-2.5 cm in length and 1.5-2.5 cm in width.

[0010] The upper and lower spacer layers are matrix-distributed with spacer layer voids, the size of which is 1-4mm × 1-4mm, preferably 2mm; the row spacing between adjacent spacer layer voids is 2-4mm; the column spacing is 2-4mm; the total area of ​​the voids accounts for 30%-70% of the spacer layer area, preferably 40%.

[0011] The front and rear corner interlocking structures are made of nylon fibers, with warp and weft yarns as the main components; the horizontal width of the corner interlocking structure is 2-5mm.

[0012] The electrode layer consists of nylon fiber warp yarns and silver-plated nylon fiber weft yarns.

[0013] The spacer layer is made of nylon fibers as warp and weft yarns;

[0014] The functional layer is made of nylon fiber as warp and ion-functional fiber as weft;

[0015] The warp direction of the electrode layer, spacer layer, functional layer, front corner interlocking structure, and rear corner interlocking structure is longitudinal (along the length of the fabric) and parallel to the selvage; the weft direction is transverse (perpendicular to the warp) and spans the width of the fabric.

[0016] The array electrodes of the electrode layer are made of silver-plated nylon fibers and nylon fibers; the silver plating layer in the silver-plated nylon fibers is 1.0 ± 0.2 μm thick; the warp direction is nylon yarn; the weft direction is only silver-plated nylon yarn located directly below the projection of the spacer layer holes; the rest are nylon yarn. The array electrodes are prepared by the warp-weft-break method.

[0017] The nylon fibers in the upper and lower electrode layers, upper and lower spacer layers, functional layers, front corner interlocking structure, and rear corner interlocking structure may have the same or different dimensions, ranging from 150D to 250D. 200D is preferred.

[0018] The diameter of the ion-functionalized fiber is 150D-250D.

[0019] The thickness of the upper electrode layer, lower electrode layer, upper spacer layer, lower spacer layer, and functional layer is 0.5mm-1mm.

[0020] The method for fabricating the all-fiber fabric sensor structure includes the following steps:

[0021] First, the interlaced electrode layer is formed by the warp and weft yarns; the interlaced functional layer is formed by the warp and weft yarns.

[0022] Secondly, a perforated structure is formed in the spacer layer by using the "warp-through weft-discontinuity" method according to the preset aperture size;

[0023] Finally, by weft insertion, the upper and lower electrode layers, functional layers, and upper and lower spacer layers are connected into an overall structure with a three-dimensional interlocking structure, spacer layers, and electrode layers.

[0024] The aforementioned all-fiber fabric sensor structure is used for one or more applications, including gesture recognition, pressure distribution detection, electromyography signal acquisition, or heart rate variability monitoring.

[0025] The essential features of this invention are:

[0026] Currently, the main structure used in the field of three-dimensional fabric capacitive sensors is the sandwich structure, which is a three-layer stacked structure of electrode-dielectric layer-electrode. The advantages of the sandwich structure are its simple structure, convenient fabrication and stable performance. The clear layer separation design allows each functional layer to be optimized independently. It can be mass-produced through mature processes, with a stable initial baseline and easy reliable packaging. However, since the layers are usually tightly bonded, there is a lack of effective deformation space, which leads to insignificant capacitance changes under small pressures. Under larger pressures, the dielectric layer is easily compacted and quickly reaches response saturation. There is a lack of a reliable integrated spacer layer process that can precisely control the compressive modulus of the layer under different pressure ranges through microstructure design, thereby achieving high sensitivity and high stability. In addition, the planar tightly contacted structure is prone to interlayer delamination when repeatedly bent, affecting the mechanical durability and signal stability of the device. There is still a lack of an all-fiber fabric sensor that combines high spatial resolution, excellent mechanical durability, washability and array spatial resolution.

[0027] This invention utilizes a three-dimensional angular interlocking structure within a three-dimensional woven structure to integrally mold the upper / lower electrode layers, upper and lower spacer layers, and functional layers, achieving a high spatial resolution, excellent mechanical durability, washability, and array-based spatial resolution capability in an all-fiber fabric sensor. Square holes in the spacer layers enable multi-level contact at the electrode-functional layer interface, achieving high-resolution and highly stable detection of gestures and plantar pressure. The provided all-fiber fabric sensor can effectively detect physiological signals such as human gestures and plantar pressure, enabling monitoring of human health.

[0028] The beneficial effects of this invention are as follows:

[0029] The fabric structure of this invention's all-fiber fabric sensor significantly improves air permeability compared to traditional silicone and hydrogel-based sensors; within a pressure range of 1-10000 kPa, the linearity of the relative capacitance change rate reaches R0. 2 =0.998, repeatability error less than 3%; electrical performance degradation less than 5% after 10,000 cycles; by adjusting the reed number, threading count, and heald frame number, electrode size, spacer layer thickness, and hole shape can be flexibly adjusted, making it suitable for multiple physiological signal sensitive areas such as finger joints, wrists, and soles of the feet. It is applicable to various health monitoring scenarios such as gesture recognition, gait analysis, electromyography signal acquisition, and heart rate variability detection. Its all-fabric structure exhibits excellent skin affinity, breathability, and mechanical durability, supporting repeated machine washing and long-term use, demonstrating significant practical value and promising prospects for widespread adoption. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the sensor array of the present invention;

[0031] Figure 2 This is a schematic diagram of the electrode layer structure;

[0032] Figure 3 This is a schematic diagram of the spacer layer structure;

[0033] Figure 4 This is a schematic diagram of the functional layer structure;

[0034] Figure 5 This is a schematic diagram of the principle of an all-fiber fabric sensor;

[0035] Figure 6 The relative capacitance change curves of the all-fiber fabric sensor under pressures of 1-10000 kPa were obtained during the implementation.

[0036] Figure 7 The relative change curve of capacitance was measured five times under different pressures during the implementation process.

[0037] Figure 8 The curves show the relative change of capacitance under different loading rates during implementation.

[0038] Figure 9 To ensure stability during implementation, 10,000 cycles were performed.

[0039] Among them, 1-front end corner connection structure, 2-rear end corner connection structure, 3-upper electrode layer, 4-lower electrode layer, 5-functional layer, 6-upper spacer layer, 7-lower spacer layer, 8-electrode. Detailed Implementation

[0040] The nylon yarn of the 200D nylon fiber material involved in this embodiment of the invention comes from Dongguan Dongcheng VIVI Wire & Tape Processing Plant;

[0041] The silver-plated 200D nylon fiber is a commercially available product from Qingdao Tianyin Textile Technology Co., Ltd.; the silver plating thickness is 1.0 ± 0.2 μm.

[0042] The ionic functional fiber is made by wet spinning of 15% TPU and 30% EMIM TFSI ionic liquid.

[0043] The above three types of fabrics are, but not limited to, those mentioned above.

[0044] Example 1:

[0045] The overall structure of the all-fiber fabric sensor of the present invention is as follows: Figure 1 As shown, it includes a front corner interlocking structure 1 and a rear corner interlocking structure 2, with a lower electrode layer 4, a lower spacer layer 7, a functional layer 5, an upper spacer layer 6, and an upper electrode layer 3 distributed between them from bottom to top.

[0046] The upper electrode layer 4 is located 0.5 mm above the upper spacer layer 6; the functional layer 5 is located 0.5 mm between the upper spacer layer 6 and the lower spacer layer 7; and the lower electrode layer 4 is located 0.5 mm below the lower spacer layer 7. These five layers are connected on the left by a front corner interlocking structure 1 and on the right by a rear corner interlocking structure 2.

[0047] The upper electrode layer 3 and the lower electrode layer 4, the functional layer and the upper spacer layer 6 and the lower spacer layer 6 have the same dimensions, which are 3cm long and 3cm wide.

[0048] The front corner interlocking structure 1, the rear corner interlocking structure 2, the upper spacer layer 6, and the lower spacer layer 7 are all made of 200D nylon fiber as warp and weft yarn; the functional layer 5 is made of 200D nylon fiber as warp yarn and 200D ion functional fiber as weft yarn; the upper electrode layer 4 and the lower electrode layer 5 are made of partially silver-plated 200D nylon fiber.

[0049] The upper spacer layer hole 6 and the lower spacer layer hole 7 are 2mm*2mm in size and their projections overlap; the row spacing between adjacent spacer layer holes is 2mm; the column spacing is 2mm; the total area of ​​the holes accounts for 40% of the area of ​​the spacer layer.

[0050] Electrode 8 in upper electrode layer 3 is positioned directly above the projection of the spacer hole in upper spacer layer 6 and has the same size; electrode 8 in lower electrode layer 4 is positioned directly below the projection of the spacer hole in lower spacer layer 7 and has the same size; upper electrode layer 4 and lower electrode layer 5 include multiple arrayed fabric electrode units, with each row of electrode units connected by continuous silver-plated nylon fiber warp yarns 8 to form row conductors; each column of electrode units is formed by silver-plated nylon fiber weft yarns entangled or interwoven to form column conductors, together constituting a row-column addressing signal acquisition loop. The electrode units in upper electrode layer 4 and lower electrode layer 5 are electrically connected by embedded silver-plated nylon conductors, realizing multi-level contact between electrode-functional layer-electrode to form an arrayed signal acquisition loop.

[0051] The front corner interlocking structure 1 and the rear corner interlocking structure 2 are 0.5cm*3cm in size;

[0052] The electrode sizes of the upper electrode layer 4 and the lower electrode layer 5 are adjustable, and the hole sizes of the upper spacer layer 6 and the lower spacer layer 7 are adjustable to meet the physiological signal detection needs of different human body parts.

[0053] The all-fiber fabric sensor of this invention is specifically implemented using a "flattening-weaving-restoration" weaving process. First, the yarn is wound according to the total number of warp threads, followed by threading and reeding operations, and finally weft insertion and beat-up. During the weaving process, the warp yarns need to be sorted after passing through the reed, ensuring consistent tension of the yarns in the same layer through yarn combing. Given the differences in yarn usage among the functional layer, electrode layer, and spacer layer during weaving, to maintain tension balance across the five layers, the electrode layer warp yarns are individually connected to the warp beam via springs. The spacer layer and functional layer yarns are sequentially bound and fixed from top to bottom and from the middle to both ends according to the layer number. The electrode layer warp yarns are made of nylon; the weft yarns are made of silver-plated nylon; the functional layer warp yarns are made of nylon; the weft yarns are made of ion-functionalized yarn; and both the warp and weft yarns of the spacer layer fabric are made of nylon.

[0054] (1) A 10-page heddle frame with a five-layer structure is required. The heddle is threaded in the same direction; nylon yarn is used as the warp yarn for both the upper and lower spacer layers. The laboratory loom is equipped with a 16-page heddle frame, which can meet the weaving requirements of this all-fiber fabric sensor. Because the spacer layer has a mesh-like perforated structure, the 3rd, 4th, 7th and 8th heddle frames are left empty every two sets during threading, laying the foundation for the subsequent formation of the perforated structure.

[0055] (2) The selection of reed tooth specifications is crucial to avoiding yarn tangling and ensuring the stability of the fabric structure. In this implementation, a steel reed of 100 reeds / 10cm was used, with each reed tooth being threaded through one loop. The reed threading method adopted the straight threading method according to the plain weave design. If the reed size is too large, it will lead to increased warp wear, increased hairiness, and yarn tangling, affecting the shedding operation; if the reed size is too small, it will easily lead to insufficient warp density and uneven arrangement, affecting the flatness of the fabric. Each layer and the bonding layer of the three-dimensional fabric can be regarded as an independent weave layer. All samples used a reed size of 100 reeds / 10cm.

[0056] (3) The total number of warp threads is determined by the number of warp yarns in each layer, the fabric width, the reed number, and the number of threads inserted into each reed. The required total number of warp threads can be accurately calculated based on the given fabric structure parameters. Input the preset pattern diagram into the semi-automatic loom, and weave according to the machine process parameters to finally obtain a full-fiber fabric sensor with different electrode sizes and different spacing layer thicknesses.

[0057] (4) The weaving of the spacer layer borrows from the "warp-interlacing" method in kesi (silk tapestry) technology, where the weft yarn does not run through the entire width but only interlaces with some of the warp yarns to form holes. The size of the holes is precisely controlled by adjusting the number of warp yarns and the frequency of weft interlacing. During weaving, the electrode layer uses separate shuttles for weft insertion. The functional layer uses one shuttle for weft insertion. The spacer layer uses separate shuttles for weft insertion, and weft insertion is not performed on warp yarns that are not threaded through heddles. The structure of the mesh holes can be customized by adjusting the number of weft insertions. When the yarn is mounted on the loom, the tension of the warp yarns should be moderate, with the appropriate tension of the spacer layer as the standard: excessive tension will cause the holes to enlarge and deviate from the design; too little tension will easily lead to smaller holes, yarn tangling, and uneven surface. Uneven tension of individual yarns can be finely adjusted by hanging weights. After weaving, the fabric is removed from the loom and subjected to finishing processes such as yarn breakage treatment, cleaning and stain removal, inspection and repair, and folding and packaging to ensure the integrity and performance of the fabric.

[0058] The "flattening-weaving-reduction" process specifically includes the following steps.

[0059] Silver-plated nylon fibers are equilibrated for 24 hours at 25±2℃ and 65±5% relative humidity to avoid electrode resistance drift caused by uneven tension.

[0060] The ion-functional fibers were equilibrated for 24 hours at 25±2℃ and 65±5% relative humidity to avoid capacitive performance drift caused by uneven tension.

[0061] The temperature in the weaving workshop is controlled at 22±3℃ and the humidity at 60±5%RH to reduce static electricity buildup and yarn fuzz.

[0062] The warp tension is controlled at 0.25–0.35 cN / tex, and the weft tension is 0.18–0.22 cN / tex to ensure the stability of the electrode layer and spacer layer structure;

[0063] The clarity of the hole edges is controlled by adjusting the weft insertion force (0.6–1.0 N / weft), thus preventing hole collapse or electrode fiber breakage.

[0064] After weaving, the fabric is gently rinsed in 40°C deionized water for 10 minutes to remove static electricity and oil introduced during the weaving process, and then dried in 60°C hot air for 30 minutes to restore the fabric's three-dimensional thickness and elasticity.

[0065] Figure 2 , Figure 3 and Figure 4 This is a schematic diagram of the electrode layer, spacer layer, and functional layer structure of an all-fiber fabric sensor. The weaving process requires 40 sets of warp yarns and consists of three steps:

[0066] First, the interlaced electrode layer is formed by the warp and weft yarns;

[0067] Secondly, a perforated structure is formed in the spacer layer by using the "warp-through weft-discontinuity" method according to the preset aperture size;

[0068] Then, the interlaced warp and weft yarns of the functional layer form the functional layer;

[0069] Finally, the electrode layer, spacer layer, and functional layer are connected by weft insertion to form an integral structure with a three-dimensional interlocking structure, such as... Figure 3 As shown. By adjusting the number of warp yarn groups or threads, weaving with different spacing layer apertures can be achieved.

[0070] Among 1-4 spacer layers and 1mm*1mm-4mm*4mm electrodes, the all-fiber fabric sensor exhibits the best performance when it has 1 spacer layer and an electrode size of 2mm*2mm.

[0071] Figure 5 This is a schematic diagram illustrating the principle of different states of multi-level contact in an all-fiber fabric sensor. Initially, the upper and lower electrode arrays are not in contact, and the capacitance signal remains unchanged. As pressure increases, the upper electrode array contacts the lower electrode array through the spacer layer holes, resulting in fiber-to-fiber contact and an increase in capacitance. With continued pressure increase, the upper electrode array contacts the lower electrode array through the spacer layer holes, resulting in yarn-to-yarn contact and a further increase in capacitance. Finally, with increasing pressure, the upper electrode array contacts the lower electrode array through the spacer layer holes, resulting in fabric-to-fabric contact. At this point, the upper electrode array fully contacts the lower electrode array through the spacer layer, and the capacitance signal reaches its peak. When the pressure is removed, the system returns to its initial state. The all-fiber fabric sensor utilizes the synergistic effect of multi-level contact between fibers, yarns, and fabric within a three-dimensional fabric.

[0072] Figures 6-9 It utilizes an LCR meter to test its relative capacitance change performance.

[0073] All electrical performance tests were conducted in a constant temperature and humidity environment (23±1℃, 50±5%RH). The testing instrument was a Tonghui TH2830 precision LCR meter. Pressure loading was performed using an XLD-100E single-column microcomputer-controlled universal testing machine with a loading rate of 1mm / min and a pressure range of 1–10000kPa. Cyclic durability tests were conducted for 10,000 cycles at a constant pressure of 1000kPa.

[0074] Figure 6 The capacitance-pressure curves shown exhibit a highly linear relationship in the range of 1–10000 kPa (R0). 2 =0.998), indicating that the sensor has good sensitivity and stability over an extremely wide pressure range;

[0075] Figure 7The results show that the capacitance change curves highly overlap in 5 repeated load-unload cycles, indicating that the sensor has good repeatability and low hysteresis.

[0076] Figure 8 The results show that the capacitive response is basically consistent under different loading rates of 1–5 mm / min, verifying its real-time response capability to dynamic pressure, and making it suitable for fast motion capture scenarios such as gait and gesture.

[0077] Figure 9 Demonstrates good durability under 10,000 load-unload cycles.

[0078] Without compromising the comfort of wearing gloves, a sensor made entirely of fiber fabric is woven into a glove. Once worn, the glove makes contact with the functional layer via an array of electrodes from the spacer layer and electrode layer. The mechanical signal generated by the contact between the upper electrode, functional layer, and lower electrode enables non-invasive monitoring of human movement.

[0079] Example 2:

[0080] The other steps are the same as in Example 1, except that the thickness of the spacer layer is changed from 1 layer to 2 layers.

[0081] The obtained material properties have a sensitivity of 2 kPa in the range of 0-2000 kPa. -1 Approximately; sensitivity is 10 kPa in the 2100 kPa-8000 kPa range. -1 The sensitivity is approximately 8 kPa within the 8100 kPa-10000 kPa range. -1 about;

[0082] Example 3:

[0083] The other steps are the same as in Example 1, except that the thickness of the spacer layer is changed from 1 layer to 3 layers.

[0084] The obtained material properties have a sensitivity of 1 kPa in the range of 0-2000 kPa. -1 Approximately; sensitivity is 8 kPa in the 2100 kPa-8000 kPa range. -1 The sensitivity is approximately 6 kPa in the 8100 kPa-10000 kPa range. -1 about;

[0085] Example 4:

[0086] The other steps are the same as in Example 1, except that the thickness of the spacer layer is changed from 1 layer to 4 layers.

[0087] The obtained material properties have a sensitivity of 1 kPa in the range of 0-2000 kPa. -1 Approximately; sensitivity is 6 kPa in the 2100 kPa-8000 kPa range. -1The sensitivity is approximately 4 kPa in the 8100 kPa-10000 kPa range. -1 about;

[0088] Example 5:

[0089] The other steps are the same as in Example 1, except that the size of the spacer layer pores and the size of the electrode layer electrodes are replaced with 1mm*1mm instead of 2mm*2mm; the resulting material properties have too low sensitivity linearity in the range of 0-5000kPa.

[0090] Example 6:

[0091] The other steps are the same as in Example 1, except that the size of the spacer layer pores and the size of the electrode layer electrodes are replaced with 3mm*3mm instead of 2mm*2mm; the linearity of the obtained material properties sensitivity saturates at 5000-10000kPa.

[0092] Example 7:

[0093] The other steps are the same as in Example 1, except that the size of the spacer layer pores and the size of the electrode layer electrodes are replaced with 4mm*4mm instead of 2mm*2mm; the linearity of the obtained material properties saturates at 5000-10000kPa.

[0094] As can be seen from the above embodiments, this invention is the first to integrate a "three-dimensional woven structure" with an "electrode-functional layer-electrode mechanism," achieving multi-level contact between electrodes, functional layers, and electrodes through the fabric structure itself, eliminating the need for additional hydrogel or conductive adhesive layers and solving the problems of easy shedding, dehydration, and poor durability of traditional gel layers. It proposes an integrated "flattening-weaving-reduction" molding process, simultaneously constructing the electrode layer, functional layer, spacer layer, and encapsulation layer during the weaving process, achieving spatial registration of the electrode-hole-functional layer-hole-electrode, avoiding interface mismatch and performance degradation caused by subsequent lamination or adhesive bonding. By adjusting the warp density and weft interlacing process parameters, sub-millimeter-level synchronous control of hole size and electrode size is achieved, solving the signal crosstalk problem caused by "electrode-hole alignment deviation" in high-density arrays. By introducing "embedded silver-plated fibers as conductors" as a row and column addressing structure, an array-based signal acquisition loop without external conductors is realized within the fabric plane, improving system integration and wearability comfort.

[0095] The signal electrode layer is made of highly conductive silver-plated nylon fiber through a textile process, which has good electrical properties and mechanical flexibility. The functional layer is made of ion-functional yarn and nylon fiber through a textile process. The spacer layer is made of nylon fiber and is formed by warp knitting to form a pore array structure with a regular square shape. While ensuring the overall structure's breathability and elasticity, it provides a stable multi-level contact mechanism for the electrode-functional layer-electrode interface.

[0096] This sensor integrates the electrode layer, functional layer, and spacer layer using three-dimensional textile technology, forming a composite functional textile with structural integrity, breathability, and elastic recovery properties. During sensing, the electrodes establish a multi-level contact interface with the fabric through the porous structure in the spacer layer, significantly improving the stability and signal-to-noise ratio of electrical signal acquisition. Low-impedance signal transmission is achieved between the electrodes and the counter electrode via embedded silver-plated fiber wires, effectively suppressing motion artifacts.

[0097] Matters not covered in this invention are common knowledge.

Claims

1. A sensor structure made entirely of fiber fabric, characterized in that, It includes a front corner interlocking structure, a rear corner interlocking structure, and a middle section. The middle section has a lower electrode layer, a lower spacer layer, a functional layer, an upper spacer layer, and an upper electrode layer distributed from bottom to top. The two sides of each layer in the middle section are connected to the front corner interlocking structure and the rear corner interlocking structure, respectively. The upper and lower spacer layers are matrix-distributed with spacer layer holes, the size of which is 1-4mm × 1-4mm; the row spacing between adjacent spacer layer holes is 2-4mm; the column spacing is 2-4mm; and the total area of ​​the holes accounts for 30%-70% of the area of ​​the spacer layers. The projections of the spacer holes in the upper and lower spacer layers, and the electrodes in the upper and lower electrode layers overlap. The front and rear corner interlocking structures are made of nylon fibers, with warp and weft yarns as the main components; the horizontal width of the corner interlocking structure is 2-5mm. The electrode layer is made of nylon fiber as warp yarn, and only the weft yarn located directly below the projection of the spacer layer holes is silver-plated nylon yarn; the rest are nylon yarn. The spacer layer is made of nylon fibers as warp and weft yarns; The functional layer is made of nylon fiber as warp and ion-functional fiber as weft; The upper electrode layer is located 0.5mm-1mm above the upper spacer layer, and the lower electrode layer is located 0.5mm-1mm below the lower spacer layer; the functional layer is located between the upper and lower spacers, with a distance of 0.5mm-1.5mm from both the upper and lower spacers. The electrode layer, functional layer, and spacer layer have the same dimensions, which are 1.5-2.5 cm in length and 1.5-2.5 cm in width. The silver plating layer in the silver-plated nylon yarn has a thickness of 1.0 ± 0.2 μm; The nylon fibers in the upper and lower electrode layers, upper and lower spacer layers, functional layers, front corner interlocking structure and rear corner interlocking structure are the same or different in size, ranging from 150D to 250D. The diameter of the ion-functionalized fibers is 150D-250D; The thicknesses of the upper electrode layer, lower electrode layer, upper spacer layer, lower spacer layer, and functional layer are all 0.5mm-1mm; The method for fabricating the all-fiber fabric sensor structure includes the following steps: First, the interlaced electrode layer is formed by the warp and weft yarns; the interlaced functional layer is formed by the warp and weft yarns. Secondly, a perforated structure is formed in the spacer layer by using the "warp-through weft-discontinuity" method according to the preset aperture size; Finally, the upper and lower electrode layers, functional layers, and upper and lower spacer layers are connected by weft insertion to form an overall structure with a three-dimensional angular interlocking structure, spacer layers, and electrode layers. The sensor operates on the following principle: initially, the upper and lower electrode arrays are not in contact, and the capacitance signal remains unchanged. As pressure increases, the upper electrode array contacts the lower electrode array through the spacer layer holes, causing fiber-to-fiber contact and increasing the capacitance signal. With continued pressure increase, the upper electrode array contacts the lower electrode array through the spacer layer holes, causing yarn-to-yarn contact and further increasing the capacitance signal. Finally, with increasing pressure, the upper electrode array contacts the lower electrode array through the spacer layer holes, causing fabric-to-fabric contact, at which point the upper electrode array fully contacts the lower electrode array through the spacer layer, and the capacitance signal reaches its peak value. When the pressure is removed, the system returns to its initial state.

2. The application of the all-fiber fabric sensor structure as described in claim 1, characterized in that, It can be used for one or more applications in gesture recognition, pressure distribution detection, electromyography signal acquisition, or heart rate variability monitoring.

Images