Fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain and preparation method of fishing net-shaped liquid metal flexible sensor

Abstract

The invention relates to a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain and a preparation method, the sensor comprises an elastic main body and liquid metal, the liquid metal is composed of more than one double-S closed fishing net-shaped single-lattice liquid metal, the elastic main body is internally provided with a fishing net-shaped channel matched with the liquid metal, and the elastic main body is internally provided with a plurality of grooves matched with the liquid metal. The liquid metal is located in the fishing net-shaped channel, the two ends of the liquid metal are connected with wires, and the wires extend out of the surface of the elastic body. According to the invention, the problem that the detection and identification of the tensile forces in different directions can be realized by adopting a plurality of sensor combinations is solved, the detection and identification of the tensile forces in different directions can be completely and independently realized, and the anisotropic characteristic is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid metal sensors, and in particular relates to a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain and a preparation method thereof. Background Art

[0002] Sensor technology plays a vital role in various fields, from healthcare to industrial production, and even smart devices in daily life, all require efficient and accurate sensors to sense the environment and provide data support. A tactile sensor is a device that can sense changes in force or pressure on the surface of an object. By converting these forces or pressures into electrical signals, it can sense the touch, shape, hardness and other characteristics of the object. In the fields of automation, robotics, healthcare, virtual reality and the gaming industry, the application of tactile sensors has become an important means to improve product performance and user experience, among which resistive sensors are becoming more and more widely used in tactile sensors. As an important type of sensor, traditional resistive sensors are widely used in contact and non-contact measurements, but their rigid structure limits their applicability in flexible, wearable and curved surface applications.

[0003] Liquid metals are a class of materials with unique advantages. They are metals with melting points not exceeding the melting point of aluminum, including mercury, cesium, gallium, rubidium, potassium, sodium, etc. Due to their excellent electrical conductivity, high surface tension, flexible deformability and low toxicity, they are widely regarded as ideal for manufacturing flexible strain sensors with high ductility and reliability. This type of strain sensor plays an indispensable role in health monitoring, soft robotics, medical operations and flexible wearable devices. The versatility of its design enables the sensor to exhibit differentiated responsiveness in multiple directions, which is particularly critical for wearable electronics to accurately track multi-dimensional movements of the human body.

[0004] Although a new type of anisotropic liquid metal flexible strain sensor has appeared on the market, this sensor does not exist independently. Its essence is still a combination of multiple isotropic sensors. Specifically, an isotropic sensor for measuring the size of the strain, and two vertically placed linear sensors, which are used to capture the direction of the strain, to achieve anisotropy. However, this method requires a combination of multiple sensors to achieve the required anisotropy, which not only increases production costs, but also brings challenges in the integration process. Its essence is still multiple isotropies, and it is impossible to truly achieve independent anisotropy of sensors. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain and a preparation method thereof, and to achieve anisotropy by changing the variation trend of resistance in different directions.

[0006] The present invention provides a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain, comprising an elastic body and liquid metal, wherein the liquid metal is composed of one or more double S-shaped closed fishing net-shaped monomer liquid metals, a fishing net-shaped channel matching the liquid metal is provided in the elastic body, the liquid metal is located in the fishing net-shaped channel, both ends of the liquid metal are connected with wires, and the wires extend out of the surface of the elastic body.

[0007] Preferably, the liquid metal is type I liquid metal, and the type I liquid metal is composed of two or more interconnected monomer liquid metals, and the combination thereof is in the form of two rows with left-right mirror symmetry.

[0008] Preferably, the liquid metal is type II liquid metal, which is composed of two or more interconnected monomer liquid metals, and the combination is in the form of two rows with left and right mirror symmetry and one end translated upward by 0.5 times the height of the monomer liquid metal.

[0009] Preferably, the elastic body comprises an elastic bottom layer and an elastic top layer tightly fitted on the top of the elastic bottom layer, the fishnet-shaped channel is arranged on the bottom surface of the elastic top layer, and the liquid metal is arranged on the top surface of the elastic bottom layer.

[0010] Preferably, the length of the long sides at both ends of the monomer liquid metal is 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

[0011] Preferably, the elastic bottom layer and the elastic top layer are both made of fully cured PDMS, and the thickness of the elastic bottom layer is equal to the thickness of the elastic top layer. The elastic bottom layer and the elastic top layer are made of fully cured PDMS, and the elastic top layer is tightly attached to the top of the elastic bottom layer, so that the metal liquid will not flow out of the fishnet-shaped channel, and the sealing and fitting stability of the elastic body are ensured. The thickness of the elastic bottom layer is equal to the thickness of the elastic top layer, which can minimize the influence of the outside world on the liquid metal.

[0012] Preferably, the conductor is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0013] Preferably, the cross section of the elastic body is a rectangle. Designing the cross section of the elastic body to be a rectangle not only allows the elastic body to be stretched smoothly in all directions, but also simplifies the processing process and improves production efficiency.

[0014] Preferably, the cross section of the fishnet-shaped channel is rectangular. Designing the cross section of the fishnet-shaped channel to be rectangular not only facilitates the stretching of the liquid metal body in all directions in the channel, but also simplifies the processing process.

[0015] A method for preparing a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain comprises the following steps: S1: Make the elastic body mold by 3D printing technology; S2: PDMS main agent and curing agent are prepared in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic main mold. The pouring is stopped at the half height of the elastic main mold, and then placed in a vacuum box to remove bubbles and heat and cure to form an elastic bottom layer; S3: treating the solidified elastic base layer with oxygen plasma, and then applying the liquid metal to the upper surface of the elastic base layer by roller coating; S4: Use a UV laser marking machine to carve on the surface of the liquid metal to form more than one connected double S closed fishing net-shaped monomer liquid metal, forming an elastic bottom layer and liquid metal composite; S5: PDMS main agent and curing agent are mixed again in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic main body mold. After the elastic main body mold is filled, pouring is stopped, and then placed in a vacuum box for debubbling and heating and curing, and then taken out of the mold to form a composite of the elastic main body and the liquid metal; S6: Insert two wires into the two ends of the fishing net-shaped channel and connect them to the two ends of the liquid metal, and extend them out of the elastic top surface.

[0016] The present invention has the following technical effects: 1. When the elastic body is subjected to external force, the fishing net-like channel in the elastic body changes with the change of the elastic body, and the liquid metal changes with the change of the fishing net-like channel. Since the fishing net-like channel and the liquid metal match to form a double S closed fishing net, when the elastic body is subjected to longitudinal tensile force, the longitudinal length of the liquid metal in the fishing net-like channel gradually increases, and the cross-sectional area gradually decreases, resulting in a continuous increase in resistance; when the elastic body is subjected to transverse tensile force, the transverse width of the long sides of the liquid metal at both ends of the fishing net-like channel continues to increase, and the cross-sectional area continues to increase, but the length of the liquid metal of the connecting wire remains almost unchanged, and the trend of cross-sectional area change is much greater than the trend of length change, so the resistance continues to decrease; it can detect transverse changes and longitudinal changes, solves the problem of needing to use a combination of multiple sensors to realize detection and identification of tensile forces in different directions, can realize detection and identification of tensile forces in different directions completely independently, and has the characteristics of anisotropy.

[0017] 2. The double S closed fishing net structure of the monomer liquid metal improves its signal stability, making it more effective in detecting tensile forces and strains in different directions.

[0018] 3. The monomer liquid metal in the liquid metal can detect the tensile force in different directions within 15% strain. By arraying the monomer liquid metal in the liquid metal longitudinally and transversely, the detection and identification of tensile force in different directions within a larger strain range can be achieved.

[0019] 4. The elastic bottom layer and the elastic top layer are made by fully solidifying the PDMS, and the elastic top layer is tightly attached to the top of the elastic bottom layer to ensure that the metal liquid does not flow out of the fishing net-like channel, thereby ensuring the sealing and fitting stability of the elastic body; 5. Since the long side length of a single cell of liquid metal in the liquid metal is greater than the width of the transverse "S" curve, the change in cross-sectional area is much greater than the change in length during transverse stretching, and the change in length is much greater than the change in cross-sectional area during longitudinal stretching. Since the resistance calculation formula is R=ρl / s, where R is the resistance, ρ is the conductivity, l is the length of the liquid metal, and s is the cross-sectional area of ​​the liquid metal, the resistance gradually decreases during transverse stretching, and gradually increases during longitudinal stretching. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of Example 1; Figure 2 It is a schematic diagram of the top view of the structure of Example 1; Figure 3 ΔR / R0-Strain curve diagram of transverse stretching and longitudinal stretching of Example 1; Figure 4 is a stress distribution diagram of transverse stretching of Example 1; Figure 5 This is the stress distribution diagram of the longitudinal stretching of Example 1; Figure 6 It is a schematic diagram of the top view of the structure of Example 2; Figure 7 It is a schematic diagram of the top view structure of Example 3; Figure 8 ΔR / R0-Strain curve diagram of transverse stretching of Example 2 and Example 3; Fig. 9 ΔR / R0-Strain curve diagram of longitudinal stretching of Example 2 and Example 3; Fig.10 is a schematic diagram of the top view of the structure of Example 4; Fig.11 is a schematic diagram of the top view of the structure of Example 5; Fig.12ΔR / R0-Strain curve diagram of transverse stretching of Example 4 and Example 5; Fig.13 ΔR / R0-Strain curve of longitudinal stretching of Example 4 and Example 5.

[0021] Illustrations: 1. Elastic body; 11. Elastic top layer; 12. Elastic bottom layer; 2. Liquid metal; 21. Monomer liquid metal; 22. Type I liquid metal; 23. Type II liquid metal; 3. Fishnet-like channel; 4. Wire. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings.

[0023] Example 1 like Figure 1 As shown, a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain comprises an elastic body 1 and liquid metal 2, wherein the liquid metal 2 is composed of a double S-shaped closed fishing net-shaped monomer liquid metal 21, wherein a fishing net-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, wherein the liquid metal 2 is located in the fishing net-shaped channel 3, and wires 4 are connected to both ends of the liquid metal 2, wherein the wires 4 extend out of the surface of the elastic body 1. The double S-shaped closed fishing net helps to improve the tensile ductility of the liquid metal 2 and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the overall liquid metal 2. It can also avoid the problem of excessive resistance change rate caused by the breakage of the liquid metal 2 due to excessive local deformation.

[0024] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 tightly fitted on the top of the elastic bottom layer 12 , the fishnet-shaped channel 3 is arranged at the bottom of the elastic top layer 11 , and the liquid metal 2 is arranged on the top of the elastic bottom layer 12 .

[0025] The lengths of the long sides at both ends of the monomer liquid metal 21 are 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

[0026] The elastic bottom layer 12 and the elastic top layer 11 are both made of fully cured PDMS, and the thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11. The elastic bottom layer 12 and the elastic top layer 11 are made of fully cured PDMS, and the elastic top layer 11 is tightly attached to the top of the elastic bottom layer 12, ensuring that the metal liquid will not flow out of the fishnet-shaped channel 3, and ensuring the sealing and fitting stability of the elastic body 1. The thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11, which can minimize the influence of the outside world on the liquid metal 2.

[0027] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0028] The cross section of the elastic body 1 is a rectangle. Designing the cross section of the elastic body 1 to be a rectangle not only allows the elastic body 1 to be stretched smoothly in all directions, but also simplifies the processing process and improves production efficiency.

[0029] The cross section of the fishnet-shaped channel 3 is rectangular. Designing the cross section of the fishnet-shaped channel 3 to be rectangular not only facilitates the stretching of the liquid metal 2 in all directions in the channel, but also simplifies the processing process.

[0030] A method for preparing a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain comprises the following steps: S1: Making a mold of the elastic body 1 by 3D printing technology; S2: PDMS main agent and curing agent are prepared in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic body 1 mold, and the pouring is stopped at the half height of the elastic body 1 mold, and then placed in a vacuum box to remove bubbles and heat and cure to form an elastic bottom layer 12; S3: treating the solidified elastic bottom layer 12 with oxygen plasma, and then applying the liquid metal 2 to the upper surface of the elastic bottom layer 12 by roller coating; S4: using an ultraviolet laser marking machine to carve a double S-shaped closed fishing net-shaped monomer liquid metal 21 on the surface of the liquid metal 2, thereby forming a composite of the elastic bottom layer 12 and the liquid metal 2; S5: PDMS main agent and curing agent are mixed again in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic body 1 mold. After the elastic body 1 mold is filled, pouring is stopped, and then placed in a vacuum box for debubbling and heating and curing, and then taken out of the mold to form a composite of the elastic body 1 and the liquid metal 2; S6: insert two wires 4 into the two ends of the fishing net channel 3 and connect them to the two ends of the liquid metal 2 respectively, and extend them out of the surface of the elastic top layer 11 .

[0031] like Figure 3As shown in the figure, the horizontal axis represents the stretching percentage of the elastic body 1 of the fishing net-shaped liquid metal 2 flexible strain sensor capable of detecting anisotropic strain of this embodiment, and the vertical axis ΔR / R0 represents the resistance change rate of the liquid metal 2 body of the fishing net-shaped liquid metal 2 flexible strain sensor capable of detecting anisotropic strain of this embodiment. It can be seen from the figure that during the transverse stretching process with a strain rate from 0% to 15%, the resistance of the liquid metal 2 decreases monotonically, and during the longitudinal stretching process with a strain rate from 0% to 15%, the resistance of the liquid metal 2 shows a monotonically increasing trend. Therefore, the stability of the monotonic change of resistance in this embodiment during transverse stretching and longitudinal stretching is shown.

[0032] like Figure 4 As shown, when the elastic body 1 is subjected to a lateral tensile force, the lateral width of the long sides of the liquid metal 2 at both ends of the fishing net channel 3 continues to increase, and the cross-sectional area continues to increase, but the length of the liquid metal connecting wire 4 remains almost unchanged, and the cross-sectional area change trend is much greater than the length change trend. Therefore, the resistance continues to decrease.

[0033] like Figure 5 As shown, when the elastic body 1 is subjected to a longitudinal tensile force, the longitudinal length of the liquid metal 2 in the fishnet-shaped channel 3 gradually increases, and the cross-sectional area gradually decreases, resulting in a continuous increase in resistance.

[0034] To sum up, when the elastic body 1 is subjected to external force, the fishing net-shaped channel 3 in the elastic body 1 changes with the change of the elastic body 1, and the liquid metal 2 changes with the change of the fishing net-shaped channel 3. Since the fishing net-shaped channel 3 and the liquid metal 2 match to form a double S closed fishing net, when the elastic body 1 is subjected to longitudinal tensile force, the longitudinal length of the liquid metal 2 in the fishing net-shaped channel 3 gradually increases, and the cross-sectional area gradually decreases, resulting in a continuous increase in resistance; when the elastic body 1 is subjected to transverse tensile force, the transverse width of the long sides of the liquid metal 2 at both ends of the fishing net-shaped channel 3 continues to increase, and the cross-sectional area continues to increase, but the length of the liquid metal of the connecting wire 4 remains almost unchanged, and the trend of the cross-sectional area change is much greater than the trend of the length change. Therefore, the resistance continues to decrease, and it can detect transverse changes and longitudinal changes, which solves the problem of needing to use a combination of multiple sensors to realize the detection and identification of tensile forces in different directions, and can realize the detection and identification of tensile forces in different directions completely independently, and has the characteristics of anisotropy.

[0035] Example 2 like Figure 6As shown, a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain includes an elastic body 1 and liquid metal 2, wherein the liquid metal 2 is composed of two double S-shaped closed fishing net-shaped monomer liquid metals 21, and a fishing net-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, and the liquid metal 2 is located in the fishing net-shaped channel 3, and both ends of the liquid metal 2 are connected with wires 4, and the wires 4 extend out of the surface of the elastic body 1. The double S-shaped closed fishing net helps to improve the tensile ductility of the liquid metal 2 and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the overall pattern. It can also avoid the problem of excessive resistance change rate caused by the breakage of the liquid metal 2 due to excessive local deformation.

[0036] The liquid metal 2 is a type I liquid metal 22, which is composed of two connected monomer liquid metals 21, and the combination is two rows of left and right mirror symmetry. The type I liquid metal 22 has high stretchability and can detect and identify tensile forces in different directions within 25%.

[0037] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 tightly fitted on the top of the elastic bottom layer 12 , the fishnet-shaped channel 3 is arranged at the bottom of the elastic top layer 11 , and the liquid metal 2 is arranged on the top of the elastic bottom layer 12 .

[0038] The lengths of the long sides at both ends of the monomer liquid metal 21 are 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

[0039] The elastic bottom layer 12 and the elastic top layer 11 are both made of fully cured PDMS, and the thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11. The elastic bottom layer 12 and the elastic top layer 11 are made of fully cured PDMS, and the elastic top layer 11 is tightly attached to the top of the elastic bottom layer 12, ensuring that the metal liquid will not flow out of the fishnet-shaped channel 3, and ensuring the sealing and fitting stability of the elastic body 1. The thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11, which can minimize the influence of the outside world on the liquid metal 2.

[0040] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0041] The cross section of the elastic body 1 is a rectangle. Designing the cross section of the elastic body 1 to be a rectangle not only allows the elastic body 1 to be stretched smoothly in all directions, but also simplifies the processing process and improves production efficiency.

[0042] The cross section of the fishnet-shaped channel 3 is rectangular. Designing the cross section of the fishnet-shaped channel 3 to be rectangular not only facilitates the stretching of the liquid metal 2 in all directions in the channel, but also simplifies the processing process.

[0043] A method for preparing a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain comprises the following steps: S1: Making a mold of the elastic body 1 by 3D printing technology; S2: PDMS main agent and curing agent are prepared in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic body 1 mold, and the pouring is stopped at the half height of the elastic body 1 mold, and then placed in a vacuum box to remove bubbles and heat and cure to form an elastic bottom layer 12; S3: treating the solidified elastic bottom layer 12 with oxygen plasma, and then applying the liquid metal 2 to the upper surface of the elastic bottom layer 12 by roller coating; S4: using an ultraviolet laser marking machine to carve on the surface of the liquid metal 2 to form two left-right mirror-symmetrical double S-shaped closed fishing net-shaped monomer liquid metals 21 of type I liquid metal 22, forming a composite of the elastic bottom layer 12 and the liquid metal 2; S5: PDMS main agent and curing agent are mixed again in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic body 1 mold. After the elastic body 1 mold is filled, pouring is stopped, and then placed in a vacuum box for debubbling and heating and curing, and then taken out of the mold to form a composite of the elastic body 1 and the liquid metal 2; S6: insert two wires 4 into the two ends of the fishing net channel 3 and connect them to the two ends of the liquid metal 2 respectively, and extend them out of the surface of the elastic top layer 11 .

[0044] like Figure 8 As shown, the curve Ia represents this embodiment. During the transverse stretching process with a strain rate from 0% to 25%, the resistance of the I-type liquid metal 22 decreases monotonically.

[0045] like Fig. 9 As shown, the curve Ia represents this embodiment. During the longitudinal stretching process with a strain rate from 0% to 25%, the resistance of the I-type liquid metal 22 increases monotonically.

[0046] Example 3 like Figure 7As shown, a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain includes an elastic body 1 and liquid metal 2, wherein the liquid metal 2 is composed of two double S-shaped closed fishing net-shaped monomer liquid metals 21, and a fishing net-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, and the liquid metal 2 is located in the fishing net-shaped channel 3, and both ends of the liquid metal 2 are connected with wires 4, and the wires 4 extend out of the surface of the elastic body 1. The double S-shaped closed fishing net helps to improve the tensile ductility of the liquid metal 2 and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the overall pattern. It can also avoid the problem of excessive resistance change rate caused by the breakage of the liquid metal 2 due to excessive local deformation.

[0047] The liquid metal 2 is type II liquid metal 23, which is composed of two connected monomer liquid metals 21, and the combination is two rows with left and right mirror symmetry and one end translated upward by 0.5 times the height of the monomer liquid metal 21. Type II liquid metal 23 has high stretchability and can realize the detection and identification of tensile forces in different directions within 25%.

[0048] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 tightly fitted on the top of the elastic bottom layer 12 , the fishnet-shaped channel 3 is arranged at the bottom of the elastic top layer 11 , and the liquid metal 2 is arranged on the top of the elastic bottom layer 12 .

[0049] The lengths of the long sides at both ends of the monomer liquid metal 21 are 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

[0050] The elastic bottom layer 12 and the elastic top layer 11 are both made of fully cured PDMS, and the thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11. The elastic bottom layer 12 and the elastic top layer 11 are made of fully cured PDMS, and the elastic top layer 11 is tightly attached to the top of the elastic bottom layer 12, ensuring that the metal liquid will not flow out of the fishnet-shaped channel 3, and ensuring the sealing and fitting stability of the elastic body 1. The thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11, which can minimize the influence of the outside world on the liquid metal 2.

[0051] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0052] The cross section of the elastic body 1 is a rectangle. Designing the cross section of the elastic body 1 to be a rectangle not only allows the elastic body 1 to be stretched smoothly in all directions, but also simplifies the processing process and improves production efficiency.

[0053] The cross section of the fishnet-shaped channel 3 is rectangular. Designing the cross section of the fishnet-shaped channel 3 to be rectangular not only facilitates the stretching of the liquid metal 2 in all directions in the channel, but also simplifies the processing process.

[0054] A method for preparing a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain comprises the following steps: S1: Making a mold of the elastic body 1 by 3D printing technology; S2: PDMS main agent and curing agent are prepared in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic body 1 mold, and the pouring is stopped at the half height of the elastic body 1 mold, and then placed in a vacuum box to remove bubbles and heat and cure to form an elastic bottom layer 12; S3: treating the solidified elastic bottom layer 12 with oxygen plasma, and then applying the liquid metal 2 to the upper surface of the elastic bottom layer 12 by roller coating; S4: using an ultraviolet laser marking machine to carve on the surface of the liquid metal 2 a type II liquid metal 23 consisting of two double S-shaped closed fishing net-shaped monomer liquid metals 21, which are mirror-symmetrical on the left and right and one end of which is translated upward by 0.5 times the height of the monomer liquid metal 21, to form a composite of the elastic bottom layer 12 and the liquid metal 2; S5: PDMS main agent and curing agent are mixed again in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic body 1 mold. After the elastic body 1 mold is filled, pouring is stopped, and then placed in a vacuum box for debubbling and heating and curing, and then taken out of the mold to form a composite of the elastic body 1 and the liquid metal 2; S6: insert two wires 4 into the two ends of the fishing net channel 3 and connect them to the two ends of the liquid metal 2 respectively, and extend them out of the surface of the elastic top layer 11 .

[0055] like Figure 8 As shown, II-a in the curve represents this embodiment. During the transverse stretching process with a strain rate from 0% to 25%, the resistance of the type II liquid metal 23 decreases monotonically.

[0056] like Fig. 9 As shown, II-a in the curve represents this embodiment. During the longitudinal stretching process with a strain rate from 0% to 25%, the resistance of the type II liquid metal 23 increases monotonically.

[0057] Example 4 like Fig.10As shown, a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain includes an elastic body 1 and liquid metal 2, wherein the liquid metal 2 is composed of six double S-shaped closed fishing net-shaped monomer liquid metals 21, and a fishing net-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, wherein the liquid metal 2 is located in the fishing net-shaped channel 3, and both ends of the liquid metal 2 are connected with wires 4, and the wires 4 extend out of the surface of the elastic body 1. The double S-shaped closed fishing net helps to improve the tensile ductility of the liquid metal 2 and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the overall pattern. It can also avoid the problem of excessive resistance change rate caused by the breakage of the liquid metal 2 due to excessive local deformation.

[0058] The liquid metal 2 is a type I liquid metal 22, which is composed of six interconnected monomer liquid metals 21, and the combination is two rows of left and right mirror symmetry. The type I liquid metal 22 has high stretchability and can realize the detection and identification of tensile forces in different directions within a larger range.

[0059] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 tightly fitted on the top of the elastic bottom layer 12 , the fishnet-shaped channel 3 is arranged at the bottom of the elastic top layer 11 , and the liquid metal 2 is arranged on the top of the elastic bottom layer 12 .

[0060] The lengths of the long sides at both ends of the monomer liquid metal 21 are 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

[0061] The elastic bottom layer 12 and the elastic top layer 11 are both made of fully cured PDMS, and the thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11. The elastic bottom layer 12 and the elastic top layer 11 are made of fully cured PDMS, and the elastic top layer 11 is tightly attached to the top of the elastic bottom layer 12, ensuring that the metal liquid will not flow out of the fishnet-shaped channel 3, and ensuring the sealing and fitting stability of the elastic body 1. The thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11, which can minimize the influence of the outside world on the liquid metal 2.

[0062] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0063] The cross section of the elastic body 1 is a rectangle. Designing the cross section of the elastic body 1 to be a rectangle not only allows the elastic body 1 to be stretched smoothly in all directions, but also simplifies the processing process and improves production efficiency.

[0064] The cross section of the fishnet-shaped channel 3 is rectangular. Designing the cross section of the fishnet-shaped channel 3 to be rectangular not only facilitates the stretching of the liquid metal 2 in all directions in the channel, but also simplifies the processing process.

[0065] like Fig.12 As shown, the curve Ib represents this embodiment. During the transverse stretching process with a strain rate from 0% to 30%, the resistance of the I-type liquid metal 22 decreases monotonically.

[0066] like Fig.13 As shown, the curve Ib represents this embodiment. During the longitudinal stretching process with a strain rate from 0% to 30%, the resistance of the I-type liquid metal 22 increases monotonically.

[0067] Example 5 like Fig.11 As shown, a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain includes an elastic body 1 and liquid metal 2, wherein the liquid metal 2 is composed of six double S closed fishing net-shaped monomer liquid metals 21, and a fishing net-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, and the liquid metal 2 is located in the fishing net-shaped channel 3, and both ends of the liquid metal 2 are connected with a wire 4, and the other end of the wire 4 extends out of the surface of the elastic body 1. The double S closed fishing net shape helps to improve the tensile ductility of the liquid metal 2 and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the overall pattern. It can also avoid the problem of excessive resistance change rate caused by the breakage of the liquid metal 2 due to excessive local deformation.

[0068] The liquid metal 2 is type II liquid metal 23, which is composed of six interconnected monomer liquid metals 21, and the combination is two rows of left and right mirror symmetry with one end translated upward by 0.5 times the height of the monomer liquid metal 21. Type II liquid metal 23 has high stretchability and can realize the detection and identification of tensile forces in different directions within a larger range.

[0069] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 tightly fitted on the top of the elastic bottom layer 12 , the fishnet-shaped channel 3 is arranged at the bottom of the elastic top layer 11 , and the liquid metal 2 is arranged on the top of the elastic bottom layer 12 .

[0070] The lengths of the long sides at both ends of the monomer liquid metal 21 are 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

[0071] The elastic bottom layer 12 and the elastic top layer 11 are both made of fully cured PDMS, and the thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11. The elastic bottom layer 12 and the elastic top layer 11 are made of fully cured PDMS, and the elastic top layer 11 is tightly attached to the top of the elastic bottom layer 12, ensuring that the metal liquid will not flow out of the fishnet-shaped channel 3, and ensuring the sealing and fitting stability of the elastic body 1. The thickness of the elastic bottom layer 12 is equal to the thickness of the elastic top layer 11, which can minimize the influence of the outside world on the liquid metal 2.

[0072] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0073] The cross section of the elastic body 1 is a rectangle. Designing the cross section of the elastic body 1 to be a rectangle not only allows the elastic body 1 to be stretched smoothly in all directions, but also simplifies the processing process and improves production efficiency.

[0074] The cross section of the fishnet-shaped channel 3 is rectangular. Designing the cross section of the fishnet-shaped channel 3 to be rectangular not only facilitates the stretching of the liquid metal 2 in all directions in the channel, but also simplifies the processing process.

[0075] like Fig.12 As shown, curve II-b represents this embodiment. During the transverse stretching process with a strain rate from 0% to 30%, the resistance of the type II liquid metal 23 decreases monotonically.

[0076] like Fig.13 As shown, curve II-b represents this embodiment. During the longitudinal stretching process with a strain rate from 0% to 30%, the resistance of the type II liquid metal 23 increases monotonically.

[0077] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain, characterized in that: It includes an elastic body and liquid metal. The liquid metal is composed of more than one interconnected double S-closed fishing net-shaped monomer liquid metal. A fishing net-shaped channel matching the liquid metal is provided in the elastic body. The liquid metal is located in the fishing net-shaped channel. Both ends of the liquid metal are connected with wires, and the wires extend out of the surface of the elastic body.

2. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 1, characterized in that: The liquid metal is type I liquid metal, and the type I liquid metal is composed of more than two interconnected monomer liquid metals, and the combination thereof is in the form of two rows with left-right mirror symmetry.

3. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 1, characterized in that: The liquid metal is type II liquid metal, which is composed of more than two connected monomer liquid metals, and its combination method is two rows with left and right mirror symmetry and one end translated upward by 0.5 times the height of the monomer liquid metal.

4. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to any one of claims 1 to 3, characterized in that: The elastic body comprises an elastic bottom layer and an elastic top layer tightly fitted on the top of the elastic bottom layer, the fishnet-shaped channel is arranged on the bottom surface of the elastic top layer, and the liquid metal is arranged on the top surface of the elastic bottom layer.

5. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to any one of claims 1 to 3, characterized in that: The lengths of the long sides at both ends of the monomer liquid metal are 0.3 mm to 0.5 mm, and the radius of the "S" curve arc in the middle is 0.15 mm to 0.35 mm.

6. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 4, characterized in that: The elastic bottom layer and the elastic top layer are both made of completely cured PDMS, and the thickness of the elastic bottom layer is equal to the thickness of the elastic top layer.

7. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 1, characterized in that: The conducting wire is a copper wire.

8. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 1, characterized in that: The cross section of the elastic body is rectangular.

9. The fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 1, characterized in that: The cross section of the fishnet-shaped channel is rectangular.

10. A method for preparing a fishing net-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to claim 1, characterized in that: It includes the following steps: S1: Make the elastic body mold by 3D printing technology; S2: PDMS main agent and curing agent are prepared in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic main mold. The pouring is stopped at the half height of the elastic main mold, and then placed in a vacuum box to remove bubbles and heat and cure to form an elastic bottom layer; S3: treating the solidified elastic base layer with oxygen plasma, and then applying the liquid metal to the upper surface of the elastic base layer by roller coating; S4: Use a UV laser marking machine to carve on the surface of the liquid metal to form more than one connected double S closed fishing net-shaped monomer liquid metal, forming an elastic bottom layer and liquid metal composite; S5: PDMS main agent and curing agent are mixed again in a mass ratio of 10:1, stirred with a glass rod for 5 minutes, and then poured into the elastic main body mold. After the elastic main body mold is filled, pouring is stopped, and then placed in a vacuum box for debubbling and heating and curing, and then taken out of the mold to form a composite of the elastic main body and the liquid metal; S6: Insert two wires into the two ends of the fishing net-shaped channel and connect them to the two ends of the liquid metal, and extend them out of the elastic top surface.

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