Stepped three-dimensional embroidery stress sensor and manufacturing method thereof

Abstract

A stepped three-dimensional embroidery stress sensor comprises ball columns and ball rows which are vertically and transversely staggered and mutually separated, the first high column, the third high column, the fifth high column and the seventh high column comprise a plurality of high balls which are sequentially arranged at intervals in the vertical direction, the second middle column and the sixth middle column comprise a plurality of middle balls which are sequentially arranged at intervals in the vertical direction, and the fourth low column comprises a plurality of low balls which are sequentially arranged at intervals in the vertical direction. Each ball row comprises a high ball, a middle ball, a high ball, a low ball, a high ball, a middle ball and a high ball which are sequentially arranged at intervals; adjacent high balls in a single ball row are connected through a transverse conductive wire, and the high balls at the end part in the single ball row are correspondingly connected with the high balls at the end part in the adjacent ball row through a vertical conductive wire; a middle ball or a low ball is embroidered on each transverse conductive wire in a surrounding manner, and the transverse conductive wires are in contact with part of the conductive wires used by the middle balls or the low balls; and the top heights of the high, medium and low balls are sequentially reduced. According to the design, the nonlinear segmented response pressure with obvious turning points can be realized, the preparation cost is low, the efficiency is high, and large-scale preparation can be realized.

Description

Technical Field

[0001] This invention relates to a nonlinear piecewise response pressure sensor, belonging to the field of nonlinear pressure sensors, and is applicable to smart wearables, medical electronics, human-computer interaction interfaces, overload detection or safety mechanisms. In particular, it relates to a stepped three-dimensional embroidery stress sensor and its manufacturing method. Background Technology

[0002] Currently, most pressure sensors aim for linear changes in pressure response. However, in certain applications, such as smart homes, it is necessary to achieve non-linear, piecewise changes in pressure response. As a result, non-linear piecewise response pressure sensors have emerged.

[0003] For example, Guan et al. fabricated flexible piezoresistive sensors with wide-range pressure measurements based on a graded nest-like architecture, realizing a resistance response curve pattern in three linear regions, as shown in Figure 1. However, its piecewise response characteristics are not obvious (the gray curve is the original experimental data, and the other line segments are the fitted curves). The overall trend of the curve is very flat. When the force changes, it is difficult to accurately determine the threshold of the corresponding force by the slope. In particular, it is difficult to accurately distinguish the key points (inflection points) in the corresponding threshold region.

[0004] For example, Shuai et al. designed a pressure sensor based on a micro pyramid array and a silver nanowire-PDMS composite electrode (Highly Sensitive Flexible Pressure Sensor Based on SilverNanowiresEmbedded Polydimethylsiloxane Electrode with Microarray Structure), achieving a two-segment capacitive response curve. However, the inflection point of the rate change and the segmented response characteristics were not obvious.

[0005] Therefore, the two research methods mentioned above are not very accurate in adapting to multi-threshold scenarios, such as smart pillows and smart mattresses, because the segmented response is not obvious.

[0006] The applicant, General Motors Global Technology Operations, Inc., filed a Chinese invention patent application with application number 200910206185.0 on June 9, 2010, disclosing a pressure sensor with a nonlinear characteristic curve. The sensor includes a body with an interface, a membrane hermetically disposed in a cavity adjacent to the interface, and a sensing element communicating with the membrane. This design achieves high resolution in both low and high pressure regions by measuring the amount of membrane tortuosity; for example, it can have a sensor resolution of approximately 1 bar at approximately 5 to approximately 25 bar (low pressure) and approximately 10 bar at approximately 500 to approximately 900 bar (high pressure). However, it still has the following drawbacks: This design only achieves high pressure resolution in two clearly separated low-pressure and high-pressure regions; it does not obtain a continuous piecewise response curve with a clear inflection point, and it still falls short of meeting current requirements.

[0007] The information disclosed in this background section is intended only to enhance understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to overcome the defects and problems of existing technologies that cannot achieve nonlinear segmented response pressure with obvious inflection points, and to provide a stepped three-dimensional embroidery stress sensor and its manufacturing method that can achieve nonlinear segmented response pressure with obvious inflection points.

[0009] To achieve the above objectives, the technical solution of the present invention is: a stepped three-dimensional embroidery stress sensor, comprising a high column, a middle column, a high column, a low column, a high column, a middle column, and a high column seven arranged at intervals in sequence. Each of the high columns includes multiple high balls arranged at intervals in a vertical direction. Each of the middle columns includes multiple middle balls arranged at intervals in a vertical direction. The low column includes multiple low balls arranged at intervals in a vertical direction. At the same time, it is configured into multiple rows of balls spaced apart in a horizontal direction. Each row of balls includes high balls, middle balls, high balls, low balls, high balls, middle balls, and high balls arranged at intervals in a vertical direction. The high balls are embroidered with high-conductivity wire, the medium balls with medium-conductivity wire, and the low balls with low-conductivity wire, with the resistance of the high-conductivity wire, medium-conductivity wire, and low-conductivity wire decreasing sequentially. The outer side of the high ball at the beginning of the first column is connected to the outer conductor of the beginning, and the outer side of the high ball at the end of the seventh column is connected to the outer conductor of the end. Adjacent high balls in each row are connected by horizontal conductors. The high balls at the beginning or end of a single row are connected to the high balls at the beginning or end of the adjacent row by vertical conductors. Each horizontal conductive wire is wrapped with a middle conductive wire to form a middle ball, or wrapped with a low conductive wire to form a low ball, and the horizontal conductive wire is in contact with a portion of its corresponding middle or low conductive wire. The top heights of the high ball, medium ball, and low ball decrease sequentially, and the bottoms of the high ball, medium ball, and low ball are all embedded and connected within the same flexible insulating layer.

[0010] The flexible insulating layer is made of silicone rubber.

[0011] The high conductivity wire is carbon fiber conductive wire or PEDOT:PSS coated / composite sewing thread, the medium conductivity wire is stainless steel fiber conductive wire or CNT / graphene sewing thread, and the low conductivity wire is silver fiber conductive wire or copper fiber conductive wire. The initial external conductive wire, the final external conductive wire, the horizontal conductive wire, and the vertical conductive wire are all carbon fiber conductive wires or PEDOT:PSS coated / composite sewing thread.

[0012] The high conductivity wire is a carbon fiber conductive wire, the medium conductivity wire is a stainless steel fiber conductive wire, and the low conductivity wire is a silver fiber conductive wire.

[0013] The fineness of the high conductivity wire is 120D / 2, the fineness of the medium conductivity wire is 120D / 3, and the fineness of the low conductivity wire is 210D / 3.

[0014] The high ball has an inner second ball inside, and the inner second ball has an inner first ball inside. Both the inner first ball and the inner second ball are made of inner layer sewing thread, which can be any one or any combination of polyester sewing thread, natural fiber sewing thread, synthetic fiber sewing thread, and mixed fiber sewing thread.

[0015] Above the stepped three-dimensional embroidery stress sensor is an inverted body, which is obtained by flipping another stepped three-dimensional embroidery stress sensor by 180 degrees, and the state of the flexible insulating layer in the inverted body is either present or removed. The tops of the high-ranking spheres in the first, third, fifth, and seventh columns of the stepped three-dimensional embroidery stress sensor are in contact with the bottoms of the high-ranking spheres in the first, third, fifth, and seventh columns of the inverted body, respectively. The middle and low spheres in the stepped three-dimensional embroidery stress sensor are in one-to-one correspondence with the middle and low spheres in the inverted body.

[0016] A method for manufacturing the above-mentioned stepped three-dimensional embroidery stress sensor, the method comprising the following steps: Step 1: First, use non-woven water-soluble fabric as the base fabric, and then use highly conductive thread to embroider multiple high balls on the base fabric to obtain one high column, three high columns, five high columns, and seven high columns. At this time, the initial outer conductive thread, the final outer conductive thread, the horizontal conductive thread, and the vertical conductive thread all use highly conductive thread, and the top and bottom of the high balls are located above and below the base fabric respectively. Step 2: Using the horizontal conductive line as the axis, use the medium conductive line to embroider a medium ball around the horizontal conductive line, or use the low conductive line to embroider a low ball around the horizontal conductive line. The top and bottom of the medium ball and the low ball are located above and below the base fabric respectively, thus obtaining two columns of medium, six columns of medium, and four columns of low. Step 3: First, a fluid is coated on one side of the base fabric until all the high, medium, and low spheres on the base fabric are wrapped by the fluid. Then, the fluid is allowed to solidify to form a flexible insulating layer to obtain a blank. The blank is then placed in clean water to dissolve it and remove the base fabric, thereby obtaining a stepped three-dimensional embroidery stress sensor.

[0017] In the first step, before embroidering the high ball, first embroider the inner ball at the predetermined position of the high ball using the inner layer of sewing thread, then embroider the inner second ball around the inner first ball, and then embroider the high ball around the inner second ball.

[0018] In the third step, the fluid is silicone rubber; The coating method is as follows: First, the base fabric and its high 1st column, middle 2nd column, high 3rd column, low 4th column, high 5th column, middle 6th column, and high 7th column are laid flat in the square mold. Then, liquid silicone rubber is introduced into the mold so that the silicone rubber is coated on the top surface of the base fabric until all the high, middle, and low spheres on the top surface of the base fabric are wrapped. Then, the fluid is allowed to solidify to form a flexible insulating layer to obtain a blank. Finally, the blank is taken out of the mold.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention discloses a stepped three-dimensional embroidery stress sensor and its manufacturing method, comprising a flexible insulating layer and a series of columns arranged sequentially at intervals: a high column, a middle column, a high column, a low column, a high column, a middle column, and a high column. Each high column consists of multiple high spheres arranged vertically at intervals; each middle column consists of multiple middle spheres arranged vertically at intervals; and each low column consists of multiple low spheres arranged vertically at intervals. The high, middle, and low spheres are arranged laterally in multiple rows of spaced-apart balls, each row comprising high, middle, high, low, high, middle, and high spheres arranged sequentially at intervals. The outer side of the high sphere at the beginning of the high column is connected to the outer conductive wire. One end is connected, and the other end of the initial outer conductive line extends outward. The outer side of the high ball at the end of the seven columns is connected to one end of the final outer conductive line, and the other end of the final outer conductive line extends outward. Adjacent high balls in each ball row are connected by horizontal conductive lines. The high balls at the beginning or end of a single ball row are connected to the high balls at the beginning or end of the adjacent ball row by vertical conductive lines. In addition, each horizontal conductive line is wrapped with a middle conductive line to form a middle ball, or wrapped with a low conductive line to form a low ball, and the horizontal conductive line is in contact with a part of its corresponding middle or low conductive line. In the entire sensor, the top height of the high ball, middle ball, and low ball decreases in sequence. In application, the initial outer conductive line passes through all the high, middle, and low spheres, horizontal conductive lines, and vertical conductive lines before connecting with the final outer conductive line to form a basic circuit. Subsequently, a downward pressure plane is applied from the top of the sensor. The plane first contacts the top of the high sphere. As the plane moves downward, the high sphere is flattened, and the contact between the high conductive lines in the high sphere gradually increases and becomes tighter, increasing the conductive path and reducing the resistance of the high sphere. The total resistance of the basic circuit also decreases. As the pressure plane continues to move downward, the middle sphere is also flattened, and more and more middle conductive lines in the middle sphere come into contact with the horizontal conductive lines. The contact between the middle conductive lines also gradually increases, increasing the conductive path and reducing the resistance of the middle sphere. The total resistance of the basic circuit decreases again. Then, as the plane continues to move downward, the low sphere is also flattened, and more and more low conductive lines in the low sphere come into contact with the horizontal conductive lines. The contact between the low conductive lines also gradually increases, increasing the conductive path and reducing the resistance of the low sphere. The total resistance of the basic circuit decreases once again. Overall, as the pressure plane gradually moves downward, the total resistance of the basic circuit experiences three significant decreases, and the rate of resistance change has two obvious inflection points, exhibiting a clear step-like decrease, thus achieving a nonlinear change in pressure response; therefore, this invention can achieve a nonlinear segmented pressure response with obvious inflection points.

[0020] 2. In the stepped three-dimensional embroidery stress sensor and its manufacturing method of the present invention, the high ball, medium ball, and low ball are all embroidered with corresponding high, medium, and low conductive wires, and the resistance of the high, medium, and low conductive wires decreases sequentially. This design makes the resistance change trend of the conductive wire consistent with the height change trend of each ball, so as to achieve a more obvious stepped resistance change rate, thereby making the segmented response characteristics of the sensor more obvious and making the slope of resistance change in each stage more different; therefore, the present invention can make the nonlinear segmented response pressure more obvious.

[0021] 3. In the present invention, a stepped three-dimensional embroidery stress sensor and its manufacturing method, the high conductivity wire is preferably carbon fiber conductive wire, the medium conductivity wire is stainless steel fiber conductive wire, and the low conductivity wire is silver fiber conductive wire. The reason for this is as follows: First, there are no mature commercial lines available for purchasing PEDOT:PSS coated / composite sewing thread and CNT / graphene sewing thread on the market, which is not suitable for mass production. On the other hand, carbon fiber conductive thread, stainless steel fiber conductive thread, and silver fiber conductive thread have stable performance, mature commercial lines available on the market, and reasonable prices, making them suitable for large-scale production and the best materials for manufacturing this sensor. Secondly, copper fiber conductive wires are prone to oxidation, and some people are allergic to copper and nickel conductive wires, but very few people are allergic to silver fibers, and silver fibers have certain antibacterial functions, which is an advantage when applied to smart textiles. Furthermore, the resistance changes significantly among carbon fiber conductive wire, stainless steel fiber conductive wire, and silver fiber conductive wire. Specifically, the resistance of silver fiber is approximately 255 Ω / m, the resistance of stainless steel fiber is approximately 1100 Ω / m, and the resistance of carbon fiber is approximately 5*10 Ω / m. 8 Ω / m, which is very conducive to producing obvious piecewise responses; Therefore, this invention not only generates a significant nonlinear piecewise response, but also has low preparation cost, high efficiency, and can be mass-produced.

[0022] 4. In the stepped three-dimensional embroidery stress sensor and its manufacturing method of the present invention, the preferred fineness of the high conductivity wire is 120D / 2, the fineness of the medium conductivity wire is 120D / 3, and the fineness of the low conductivity wire is 210D / 3. The reason is that each fineness is compatible with the material of the conductive wire and is the optimal fineness that can be used for that material. If the conductive wire is too thin, it is easy to break during the embroidery process. If the conductive wire is too thick, it is easy to wear down the conductive wire during the embroidery process. The small fibers formed by wear can also easily integrate into the product, affecting the overall conductive path. In addition, if the conductive wire is too thick, it is easy to mismatch the eye diameter of the sewing machine needle, reducing the embroidery efficiency. Therefore, the fineness of the conductive wire specified in the present invention can not only ensure the smooth progress of the embroidery, but also avoid affecting the conductive path.

[0023] 5. In the present invention, a stepped three-dimensional embroidery stress sensor and its manufacturing method, the flexible insulating layer is preferably made of silicone rubber, for the following reasons: First, silicone rubber is easy to coat during manufacturing and also facilitates the molding and fixing after coating; Secondly, silicone rubber has significant elasticity, which allows it to better conform to the object being tested during use, resulting in more accurate pressure monitoring results. Therefore, this invention not only facilitates pressure monitoring during bonding, but also improves manufacturing efficiency. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the response curve of an existing flexible piezoresistive sensor under pressure.

[0025] Figure 2 This is a three-dimensional structural diagram of the present invention in the end face direction.

[0026] Figure 3 This is a three-dimensional structural diagram of the present invention viewed from the side.

[0027] Figure 4 This is a three-dimensional structural diagram of the present invention viewed from above.

[0028] Figure 5 This is a schematic diagram of the internal structure of the high ball in this invention.

[0029] Figure 6 This is a schematic diagram of the internal structure of the sphere in this invention.

[0030] Figure 7 This is a schematic diagram of the internal structure of the low-profile sphere in the invention.

[0031] Figure 8 This is a top view of the embroidered sphere after the invention is completed.

[0032] Figure 9 This is a diagram showing the process of sewing high balls according to the present invention.

[0033] Figure 10 This is a schematic diagram of the structure after all the balls are embroidered on the base fabric in this invention.

[0034] Figure 11 This is a schematic diagram of the structure of the blank in this invention.

[0035] Figure 12 This is a schematic diagram of the structure after the base fabric is removed by water in this invention.

[0036] Figure 13 This is a schematic diagram of the response curve of the present invention under pressure.

[0037] Figure 14This is a schematic diagram of the pressure changes of the stacked structure after the inverted body is included in this invention.

[0038] Figure 15 yes Figure 14 A schematic diagram of the response curve under pressure.

[0039] In the diagram: 1. High column 1; 2. Middle column 2; 3. High column 3; 4. Low column 4; 4. Low ball; 41. Low conductive line; 42. High column 5; 6. Middle column 6; 6. Middle ball; 61. Middle conductive line; 62. High column 7; 7. High ball; 71. High conductive line; 72. Inner second ball; 73. Inner first ball; 74. Inner sewing thread; 75. Initial outer conductive line; 8. Final outer conductive line; 81. Horizontal conductive line; 82. Vertical conductive line; 83. Flexible insulating layer; 9. Ball row; 10. Inverted buckle body; 11. Base fabric; 12. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] See Figure 1 — Figure 15 A stepped three-dimensional embroidery stress sensor is disclosed, comprising a high column 1, a middle column 2, a high column 3, a low column 4, a high column 5, a middle column 6, and a high column 7 arranged at intervals. Each column of the high column 1, high column 3, high column 5, and high column 7 includes multiple high balls 71 arranged at intervals along the vertical direction. Each column of the middle column 2 and middle column 6 includes multiple middle balls 61 arranged at intervals along the vertical direction. The low column 4 includes multiple low balls 41 arranged at intervals along the vertical direction. Simultaneously, multiple ball rows 10 are arranged horizontally, each ball row 10 including high balls 71, middle balls 61, high balls 71, low balls 41, high balls 71, middle balls 61, and high balls 71 arranged at intervals. The high ball 71 is embroidered with a high conductive wire 72, the medium ball 61 is embroidered with a medium conductive wire 62, and the low ball 41 is embroidered with a low conductive wire 42. The resistance of the high conductive wire 72, the medium conductive wire 62, and the low conductive wire 42 decreases in sequence. The outer side of the high ball 71 located at the beginning of the first column 1 is connected to the beginning outer conductive wire 8, and the outer side of the high ball 71 located at the end of the seventh column 7 is connected to the end outer conductive wire 81. Adjacent high balls 71 in each ball row 10 are connected by a horizontal conductive wire 82. The high ball 71 at the beginning or end of a single ball row 10 is connected to the high ball 71 at the beginning or end of the adjacent ball row 10 by a vertical conductive wire 83. Each horizontal conductive wire 82 is surrounded by a middle conductive wire 62 to form a middle ball 61, or surrounded by a low conductive wire 42 to form a low ball 41, and the horizontal conductive wire 82 is in contact with a portion of its corresponding middle conductive wire 62 or low conductive wire 42. The top heights of the high ball 71, the middle ball 61, and the low ball 41 decrease sequentially, and the bottoms of the high ball 71, the middle ball 61, and the low ball 41 are all embedded and connected within the same flexible insulating layer 9.

[0042] The flexible insulating layer 9 is made of silicone rubber.

[0043] The high conductivity wire 72 is a carbon fiber conductive wire or a PEDOT:PSS coated / composite sewing thread; the medium conductivity wire 62 is a stainless steel fiber conductive wire or a CNT / graphene sewing thread; and the low conductivity wire 42 is a silver fiber conductive wire or a copper fiber conductive wire. The initial external conductive wire 8, the final external conductive wire 81, the horizontal conductive wire 82, and the vertical conductive wire 83 are all carbon fiber conductive wires or PEDOT:PSS coated / composite sewing thread.

[0044] The high conductivity wire 72 is a carbon fiber conductive wire, the medium conductivity wire 62 is a stainless steel fiber conductive wire, and the low conductivity wire 42 is a silver fiber conductive wire.

[0045] The high conductivity wire 72 has a fineness of 120D / 2, the medium conductivity wire 62 has a fineness of 120D / 3, and the low conductivity wire 42 has a fineness of 210D / 3.

[0046] The high ball 71 has an inner second ball 73 inside, and the inner second ball 73 has an inner first ball 74 inside. Both the inner first ball 74 and the inner second ball 73 are embroidered with inner layer sewing thread 75. The inner layer sewing thread 75 is any one or any combination of polyester sewing thread, natural fiber sewing thread, synthetic fiber sewing thread, and mixed fiber sewing thread.

[0047] Above the stepped three-dimensional embroidery stress sensor is an inverted body 11, which is obtained by flipping another stepped three-dimensional embroidery stress sensor by 180 degrees, and the flexible insulating layer 9 in the inverted body 11 is either present or removed. The top of the high ball 71 in the first column 1, third column 3, fifth column 5, and seventh column 7 of the stepped three-dimensional embroidery stress sensor is in contact with the bottom of the high ball 71 in the first column 1, third column 3, fifth column 5, and seventh column 7 of the inverted body 11. The middle ball 61 and the low ball 41 in the stepped three-dimensional embroidery stress sensor are in one-to-one correspondence with the middle ball 61 and the low ball 41 in the inverted body 11.

[0048] A method for manufacturing the above-mentioned stepped three-dimensional embroidery stress sensor, the method comprising the following steps: Step 1: First, use non-woven water-soluble fabric as base fabric 12, and then use high-conductivity thread 72 to embroider multiple high balls 71 on base fabric 12 to obtain high column 1, high column 3, high column 5, and high column 7. At this time, the initial external conductive thread 8, the final external conductive thread 81, the horizontal conductive thread 82, and the vertical conductive thread 83 all use high-conductivity thread 72, and the top and bottom of the high balls 71 are located above and below the base fabric 12 respectively. Step 2: Using the horizontal conductive wire 82 as the axis, use the medium conductive wire 62 to embroider a medium ball 61 around the horizontal conductive wire 82, or use the low conductive wire 42 to embroider a low ball 41 around the horizontal conductive wire 82. The top and bottom of the medium ball 61 and the low ball 41 are located above and below the base fabric 12, respectively, thus obtaining the middle two columns 2, the middle six columns 6, and the low four columns 4. Step 3: First, a fluid is coated on one side of the base fabric 12 until all the high spheres 71, medium spheres 61, and low spheres 41 on one side of the base fabric 12 are wrapped by the fluid. Then, the fluid is allowed to solidify to form a flexible insulating layer 9 to obtain a blank. The blank is then placed in clean water to dissolve it and remove the base fabric 12, thereby obtaining a stepped three-dimensional embroidery stress sensor.

[0049] In the first step, before embroidering the high ball 71, an inner ball 74 is first embroidered at the preset position of the high ball 71 using inner sewing thread 75, then an inner ball 73 is embroidered around the inner ball 74, and then the high ball 71 is embroidered around the inner ball 73.

[0050] In the third step, the fluid is silicone rubber; The coating method is as follows: First, the base fabric 12 and its high column 1, middle column 2, high column 3, low column 4, high column 5, middle column 6, and high column 7 are laid flat in the square mold. Then, liquid silicone rubber is introduced into the mold so that the silicone rubber is coated on the top surface of the base fabric 12 until all the high balls 71, middle balls 61, and low balls 41 on the top surface of the base fabric 12 are wrapped. Then, the fluid is allowed to solidify to form a flexible insulating layer 9 to obtain a blank. Finally, the blank is taken out of the mold.

[0051] Example 1: See Figure 1 — Figure 15A stepped three-dimensional embroidery stress sensor, comprising a series of columns 1 (highest), 2 (middle), 3 (highest), 4 (lowest), 5 (highest), 6 (middleest), and 7 (highest, in this embodiment, a 7x7 array) arranged at intervals. Each column of columns 1, 3, 5, and 7 includes multiple high spheres 71 arranged vertically at intervals. Each column of columns 2 and 6 includes multiple middle spheres 61 arranged vertically at intervals. The lower column 4 includes multiple... The ball 41 is arranged vertically at intervals, and horizontally it forms multiple ball rows 10 that are spaced apart. Each ball row 10 includes a high ball 71, a medium ball 61, a high ball 71, a low ball 41, a high ball 71, a medium ball 61, and a high ball 71 arranged at intervals. The high ball 71 is embroidered with high-conductivity wire 72 (preferably carbon fiber conductive wire), the medium ball 61 is embroidered with medium-conductivity wire 62 (preferably stainless steel fiber conductive wire), and the low ball 41 is embroidered with low-conductivity wire 42 (preferably silver fiber conductive wire). The high-conductivity wire 71, medium ball 61, and high ball 71 are arranged vertically at intervals. The resistance of conductive wire 62 and low-conductivity wire 42 decreases sequentially; the outer side of the high ball 71 located at the beginning of the first column 1 is connected to the initial outer conductive wire 8, and the outer side of the high ball 71 located at the end of the seventh column 7 is connected to the final outer conductive wire 81. Adjacent high balls 71 in each ball row 10 are connected by horizontal conductive wire 82. The high ball 71 at the beginning or end of a single ball row 10 is connected to the high ball 71 at the beginning or end of the adjacent ball row 10 by vertical conductive wire 83. The initial outer conductive wire 8, the final outer conductive wire 81, and the horizontal conductive wire 82 are connected by vertical conductive wire 83. The conductive wires 82 and vertical conductive wires 83 are both carbon fiber conductive wires; each horizontal conductive wire 82 is surrounded by a middle conductive wire 62 to form a middle ball 61, or surrounded by a low conductive wire 42 to form a low ball 41, and the horizontal conductive wire 82 is in contact with a portion of its corresponding middle conductive wire 62 or low conductive wire 42; the top heights of the high ball 71, middle ball 61, and low ball 41 decrease sequentially, and the bottoms of the high ball 71, middle ball 61, and low ball 41 are all embedded and connected within the same flexible insulating layer 9 (the flexible insulating layer 9 is made of silicone rubber).

[0052] A method for manufacturing the above-mentioned stepped three-dimensional embroidery stress sensor includes the following steps: Step 1: First, use non-woven water-soluble fabric as the base fabric 12, then use highly conductive wire 72 to embroider multiple high-quality balls 71 on the base fabric 12 to obtain high-quality ball 1, high-quality ball 3, high-quality ball 5, and high-quality ball 7 (e.g., high-quality ball 1, high-quality ball 3, high-quality ball 5, high-quality ball 7). Figure 5 and Figure 8 As shown), at this time, the initial external conductive line 8, the final external conductive line 81, the horizontal conductive line 82, and the vertical conductive line 83 all use high conductive line 72, and the top and bottom of the high ball 71 are located above and below the base fabric 12 respectively. Step 2: Using the horizontal conductive wire 82 as the axis, embroider a central ball 61 around the horizontal conductive wire 82 (e.g., ...). Figure 6 (As shown) Alternatively, a low-conductivity wire 42 can be embroidered around the horizontal conductive wire 82 to form a low-ball 41 (as shown). Figure 7 As shown), the top and bottom of the middle ball 61 and the low ball 41 are located above and below the base cloth 12 respectively, thus obtaining the middle second column 2, the middle sixth column 6, and the low fourth column 4; Step 3: First, apply the base fabric 12 to one side (e.g., ...). Figure 10 (As shown) The fluid is coated until all the high spheres 71, medium spheres 61, and low spheres 41 on one side of the base fabric 12 are covered by the fluid. Then the fluid is allowed to solidify to form a flexible insulating layer 9 to obtain a blank (as shown). Figure 11 (As shown), then the blank is placed in clean water to dissolve it, in order to clean and remove the base fabric 12, thereby obtaining a stepped three-dimensional embroidery stress sensor (as shown). Figure 12 (As shown).

[0053] like Figure 13 As shown, when the above-mentioned stepped three-dimensional embroidery stress sensor is subjected to single-layer pressure measurement, three distinct resistance changes with different slopes can be obtained, achieving a nonlinear piecewise response.

[0054] Example 2: The basic content is the same as in Example 1, except that: like Figure 5 , Figure 8 and Figure 9 As shown, the inner ball 71 is provided with an inner second ball 73, and the inner second ball 73 is provided with an inner first ball 74. The inner first ball 74 and the inner second ball 73 are both made of inner layer sewing thread 75. The inner layer sewing thread 75 is any one or any combination of polyester sewing thread, natural fiber sewing thread, synthetic fiber sewing thread, and mixed fiber sewing thread.

[0055] Example 3: The basic content is the same as in Example 1, except that: Above the stepped three-dimensional embroidery stress sensor is an inverted body 11, which is obtained by flipping another stepped three-dimensional embroidery stress sensor 180 degrees. The flexible insulating layer 9 in the inverted body 11 is present (the flexible insulating layer 9 can also be removed, leaving only the individual balls; furthermore, the balls do not need to be connected, and can be separated from each other). The tops of the high balls 71 in the first column 1, third column 3, fifth column 5, and seventh column 7 of the stepped three-dimensional embroidery stress sensor are in contact with the bottoms of the high balls 71 in the first column 1, third column 3, fifth column 5, and seventh column 7 of the inverted body 11. The middle balls 61 and low balls 41 in the stepped three-dimensional embroidery stress sensor correspond one-to-one with the middle balls 61 and low balls 41 in the inverted body 11.

[0056] like Figure 15 As shown, when the above-mentioned stacked material is subjected to a pressure test, three distinct resistance changes with different slopes can be obtained, achieving a nonlinear piecewise response.

[0057] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A stepped three-dimensional embroidery stress sensor, characterized in that: The stepped three-dimensional embroidery stress sensor includes a high column (1), a middle column (2), a high column (3), a low column (4), a high column (5), a middle column (6), and a high column (7) arranged at intervals. Each column of the high column (1), high column (3), high column (5), and high column (7) includes multiple high balls (71) arranged at intervals along the vertical direction. Each column of the middle column (2) and middle column (6) includes multiple middle balls (61) arranged at intervals along the vertical direction. The low column (4) includes multiple low balls (41) arranged at intervals along the vertical direction. At the same time, it is configured into multiple ball rows (10) arranged at intervals along the horizontal direction. Each ball row (10) includes high balls (71), middle balls (61), high balls (71), low balls (41), high balls (71), middle balls (61), and high balls (71) arranged at intervals along the vertical direction. The high ball (71) is embroidered with high conductive wire (72), the medium ball (61) is embroidered with medium conductive wire (62), and the low ball (41) is embroidered with low conductive wire (42). The resistance of the high conductive wire (72), medium conductive wire (62), and low conductive wire (42) decreases in sequence. The outer side of the high ball (71) at the beginning of the first column (1) is connected to the outer conductive wire (8), and the outer side of the high ball (71) at the end of the seventh column (7) is connected to the outer conductive wire (81). Adjacent high balls (71) in each ball row (10) are connected by horizontal conductive wire (82). The high ball (71) at the beginning or end of a single ball row (10) is connected to the high ball (71) at the beginning or end of the adjacent ball row (10) by vertical conductive wire (83). Each horizontal conductive wire (82) is surrounded by a middle conductive wire (62) to form a middle ball (61), or surrounded by a low conductive wire (42) to form a low ball (41), and the horizontal conductive wire (82) is in contact with a portion of its corresponding middle conductive wire (62) or low conductive wire (42). The top heights of the high ball (71), the middle ball (61), and the low ball (41) decrease sequentially, and the bottoms of the high ball (71), the middle ball (61), and the low ball (41) are all embedded and connected in the same flexible insulating layer (9).

2. The stepped three-dimensional embroidery stress sensor according to claim 1, characterized in that: The flexible insulating layer (9) is made of silicone rubber.

3. A stepped three-dimensional embroidery stress sensor according to claim 1 or 2, characterized in that: The high conductivity wire (72) is a carbon fiber conductive wire or a PEDOT:PSS coated / composite sewing thread, the medium conductivity wire (62) is a stainless steel fiber conductive wire or a CNT / graphene sewing thread, and the low conductivity wire (42) is a silver fiber conductive wire or a copper fiber conductive wire. The initial external conductive wire (8), the final external conductive wire (81), the horizontal conductive wire (82), and the vertical conductive wire (83) are all carbon fiber conductive wires or PEDOT:PSS coated / composite sewing thread.

4. A stepped three-dimensional embroidery stress sensor according to claim 3, characterized in that: The high conductivity wire (72) is a carbon fiber conductive wire, the medium conductivity wire (62) is a stainless steel fiber conductive wire, and the low conductivity wire (42) is a silver fiber conductive wire.

5. A stepped three-dimensional embroidery stress sensor according to claim 1 or 2, characterized in that: The fineness of the high conductivity wire (72) is 120D / 2, the fineness of the medium conductivity wire (62) is 120D / 3, and the fineness of the low conductivity wire (42) is 210D / 3.

6. A stepped three-dimensional embroidery stress sensor according to claim 1 or 2, characterized in that: The high ball (71) has an inner second ball (73) inside, and the inner second ball (73) has an inner first ball (74) inside. The inner first ball (74) and the inner second ball (73) are both made of inner sewing thread (75). The inner sewing thread (75) is any one or any combination of polyester sewing thread, natural fiber sewing thread, synthetic fiber sewing thread, and mixed fiber sewing thread.

7. A stepped three-dimensional embroidery stress sensor according to claim 1 or 2, characterized in that: A buckle (11) is provided above the stepped three-dimensional embroidery stress sensor. The buckle (11) is obtained by flipping another stepped three-dimensional embroidery stress sensor by 180 degrees. The state of the flexible insulating layer (9) in the buckle (11) is either present or removed. The top of the high ball (71) in the first column (1), third column (3), fifth column (5), and seventh column (7) of the stepped three-dimensional embroidery stress sensor is in contact with the bottom of the high ball (71) in the first column (1), third column (3), fifth column (5), and seventh column (7) of the inverted body (11). The middle ball (61) and low ball (41) in the stepped three-dimensional embroidery stress sensor correspond one-to-one with the middle ball (61) and low ball (41) in the inverted body (11).

8. A method for manufacturing a stepped three-dimensional embroidery stress sensor as described in claim 1 or 2, characterized in that... The manufacturing method includes the following steps: Step 1: First, use non-woven water-soluble fabric as the base fabric (12), and then use high-conductivity wire (72) to embroider multiple high balls (71) on the base fabric (12) to obtain high column 1 (1), high column 3 (3), high column 5 (5), and high column 7 (7). At this time, the initial external conductive wire (8), the final external conductive wire (81), the horizontal conductive wire (82), and the vertical conductive wire (83) all use high-conductivity wire (72), and the top and bottom of the high balls (71) are located above and below the base fabric (12) respectively. Step 2: Using the horizontal conductive wire (82) as the axis, use the medium conductive wire (62) to embroider a medium ball (61) around the horizontal conductive wire (82), or use the low conductive wire (42) to embroider a low ball (41) around the horizontal conductive wire (82). The top and bottom of the medium ball (61) and the low ball (41) are located above and below the base fabric (12) respectively, thus obtaining the middle two columns (2), the middle six columns (6), and the low four columns (4). Step 3: First, coat one side of the base fabric (12) with a fluid until all the high spheres (71), medium spheres (61), and low spheres (41) on one side of the base fabric (12) are wrapped with the fluid. Then, wait for the fluid to solidify to form a flexible insulating layer (9) to obtain a blank. Then, put the blank into clean water to dissolve it in order to clean and remove the base fabric (12) and thus obtain a stepped three-dimensional embroidery stress sensor.

9. The method for manufacturing a stepped three-dimensional embroidery stress sensor according to claim 8, characterized in that: In the first step, before embroidering the high ball (71), the inner ball (74) is first embroidered at the preset position of the high ball (71) using the inner sewing thread (75), then the inner second ball (73) is embroidered around the inner first ball (74), and then the high ball (71) is embroidered around the inner second ball (73).

10. The method for manufacturing a stepped three-dimensional embroidery stress sensor according to claim 8, characterized in that: In the third step, the fluid is silicone rubber; The coating method is as follows: First, the base fabric (12) and its high column (1), middle column (2), high column (3), low column (4), high column (5), middle column (6), and high column (7) are laid flat in the square mold. Then, liquid silicone rubber is introduced into the mold so that the silicone rubber is coated on the top surface of the base fabric (12) until all the high balls (71), middle balls (61), and low balls (41) on the top surface of the base fabric (12) are wrapped. Then, the fluid solidifies to form a flexible insulating layer (9) to obtain a blank. Then, the blank is taken out of the mold.

Images