Lantern-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain and preparation method thereof

Abstract

The invention relates to a lantern-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain and a preparation method, the lantern-shaped liquid metal flexible sensor comprises an elastic main body and liquid metal, and the liquid metal is composed of more than one lantern-framework-shaped monomer liquid metal which is formed by connecting a plurality of arcs and internal inclined cross bars and is communicated with the elastic main body. A lantern-shaped channel matched with the liquid metal is arranged in the elastic body, the liquid metal is located in the lantern-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. The sensor has the characteristic of anisotropy, can realize detection and identification of tensile forces in different directions completely independently through one sensor, can realize required anisotropy without adopting a combination of a plurality of sensors, and is rapid and accurate in detection.

Description

Technical Field

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

[0002] With the rapid development of science and technology, flexible resistor sensors, as an innovative sensor, are gradually becoming a research hotspot in scientific research and industry. With its unique flexibility, it provides unprecedented possibilities for various applications.

[0003] As the name implies, a flexible resistor sensor is a resistor sensor with flexibility. It is made of special materials and processes, and can achieve flexibility of bending, twisting and even stretching while maintaining resistance performance. This feature enables it to adapt to various complex and changing environments and forms, bringing unlimited possibilities for its application.

[0004] In terms of structure, flexible resistor sensors are usually composed of conductive materials and flexible substrates. Conductive materials can be metals, carbon nanotubes or special conductive polymers, which are responsible for the conduction of electrical signals. The flexible substrate is the key part to support and protect the conductive material, and common materials include polymer films. These materials are processed and assembled through precise processes to eventually form the flexible resistor sensors we see.

[0005] Its working principle is quite unique. When external forces act on the sensor, such as pressure, bending or stretching, the conductive material inside the sensor will deform, thereby changing its resistance value. This change in resistance value can be accurately measured and recorded, and then converted into an electrical signal or digital information. In this way, changes in the external environment can be sensed and corresponding responses and operations can be made accordingly.

[0006] 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.

[0007] Although a new type of liquid metal flexible strain sensor has been proposed, which has the potential to achieve anisotropy. However, this sensor is composed of at least two liquid metal strain sensors. Specifically, an isotropic sensor for measuring the strain size and two vertically placed linear sensors are used to capture the direction of strain through a multi-sensor combination mode, and to detect and identify strains in different directions. However, this method requires a combination of multiple sensors to achieve the required anisotropy, which not only increases production costs, but also is prone to errors during the integration process, and cannot efficiently provide feedback on strain trends, which is extremely inconvenient. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a lantern-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.

[0009] The present invention provides a lantern-shaped liquid metal flexible sensor capable of detecting multi-dimensional strains, comprising an elastic body and liquid metal, wherein the liquid metal is composed of one or more interconnected monomer liquid metals in the shape of a lantern skeleton formed by a plurality of circular arcs connected to internal inclined horizontal bars, wherein a lantern-shaped channel matching the liquid metal is provided in the elastic body, wherein the liquid metal is located in the lantern-shaped channel, and both ends of the liquid metal are connected to wires, wherein the wires extend out of the surface of the elastic body.

[0010] Preferably, the liquid metal is Type I liquid metal, which is composed of two or more interconnected monomer liquid metals arranged in several rows, and the arrangement is a linear arrangement in which odd-numbered rows are two interconnected monomer liquid metals and even-numbered rows are one monomer liquid metal connected to odd-numbered rows.

[0011] Preferably, the liquid metal is type II liquid metal, which is composed of two or more interconnected monomer liquid metals arranged in a plurality of rows, wherein each row includes two monomer liquid metals and the rows are arranged alternately left and right.

[0012] 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 lantern-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.

[0013] Preferably, the radius of the lantern skeleton arc part in the monomer liquid metal is 1mm to 3mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°. The inclined horizontal bar structure of the monomer liquid metal can make the liquid metal more stable and less prone to breakage during the stretching process, and the inclined horizontal bar can amplify the length change trend of the liquid metal during longitudinal stretching and the cross-sectional area change trend of the liquid metal during transverse stretching.

[0014] 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 closely attached to the top of the elastic bottom layer, so that the metal liquid does not flow out of the lantern-shaped channel, and the sealing and attachment stability of the elastic body are ensured.

[0015] Preferably, the conductive wire is a copper wire.

[0016] Preferably, the cross-section of the elastic body is rectangular.

[0017] Preferably, the cross-section of the lantern-shaped channel is rectangular.

[0018] A method for preparing a lantern-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: Using an ultraviolet laser marking machine to carve on the surface of the liquid metal to form one or more connected lantern skeleton-shaped monomer liquid metals composed of a plurality of arcs connected with internal inclined horizontal bars, forming an elastic bottom layer and a 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 lantern-shaped channel respectively to connect with the two ends of the liquid metal, and extend them out of the surface of the elastic body.

[0019] The present invention has the following technical effects: 1. When the elastic body is subjected to external force, the lantern-shaped channel in the elastic body changes with the change of the elastic body, and the liquid metal changes with the change of the lantern-shaped channel. Since the lantern-shaped channel matches the liquid metal and has a lantern skeleton structure with inclined horizontal bars inside, when the elastic body is subjected to longitudinal tensile force, the longitudinal length of the arc part of the liquid metal in the lantern-shaped channel gradually increases, and the cross-sectional area gradually decreases. The length change of the inclined horizontal bar part is much greater than the width change, resulting in a continuous increase in resistance; when the elastic body is subjected to transverse tensile force, the transverse width of the arc part of the liquid metal in the lantern-shaped channel continues to increase, and the cross-sectional area continues to increase. The length change of the arc part is much smaller than the cross-sectional area change, and the width change of the inclined horizontal bar part is greater than the length change. The overall cross-sectional area change trend of the liquid metal in the lantern-shaped channel is much greater than the length change trend. Therefore, the resistance continues to decrease. It has the characteristics of anisotropy and can realize the detection and identification of tensile forces in different directions completely independently through a sensor. The required anisotropy can be achieved without the combination of multiple sensors, and the detection is fast and accurate.

[0020] 2. The single liquid metal is shaped like a lantern skeleton, which gives the liquid metal a variety of arc curves. These arc curves help to improve its tensile ductility, effectively disperse the deformation transmitted by the elastic body, and enhance the uniform deformation coordination of the entire liquid metal.

[0021] 3. The inclined horizontal bar structure of the monomer liquid metal can make the liquid metal more stable and less likely to break during the stretching process. The inclined horizontal bar can amplify the length change trend of the liquid metal during longitudinal stretching and the cross-sectional area change trend of the liquid metal during transverse stretching. It improves its signal stability and makes it more effective in detecting tensile forces and strains in different directions.

[0022] 4. The monomer liquid metal in the liquid metal can detect the tensile force in different directions within 30% 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.

[0023] 5. 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 to ensure that the metal liquid does not flow out of the lantern-shaped channel, thereby ensuring the sealing and fitting stability of the elastic body.

[0024] 6. Since the monomer liquid metal in the liquid metal is in the shape of a lantern skeleton with inclined horizontal bars inside, the change in cross-sectional area is much greater than the change in length when stretched horizontally, and the change in length is much greater than the change in cross-sectional area when stretched vertically. 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 when stretched horizontally, and gradually increases when stretched vertically. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.12 ΔR / 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.

[0026] 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. Lantern-shaped channel; 4. Wire. DETAILED DESCRIPTION

[0027] 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.

[0028] Example 1 like Figure 1 As shown, a lantern-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 a single liquid metal 21 in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, and a lantern-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, and the liquid metal 2 is located in the lantern-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. Since the single liquid metal 21 is in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, it 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.

[0029] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 that is tightly attached to the top of the elastic bottom layer 12. The lantern-shaped channel 3 is arranged on the bottom surface of the elastic top layer 11, and the liquid metal 2 is arranged on the top surface of the elastic bottom layer 12. The liquid metal 2 is located inside the lantern-shaped channel 3, and the lantern-shaped channel 3 limits the liquid metal 2.

[0030] The radius of the lantern skeleton-shaped arc part in the monomer liquid metal 21 is 1mm to 3mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°. These arcs with rich shapes help to improve its tensile ductility and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the entire liquid metal 2. The inclined horizontal bar structure of the monomer liquid metal 21 can make the liquid metal 2 more stable and less prone to breakage during the stretching process, and the inclined horizontal bars can amplify the length change trend of the liquid metal 2 during longitudinal stretching, and amplify the cross-sectional area change trend of the liquid metal 2 during transverse stretching.

[0031] 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 lantern-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.

[0032] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0033] 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.

[0034] The cross section of the lantern-shaped channel 3 is rectangular. Designing the cross section of the lantern-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.

[0035] A method for preparing a lantern-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 a single liquid metal 21 in the shape of a lantern skeleton consisting of a plurality of circular arcs connected with internal inclined horizontal bars, thereby forming a composite body 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 lantern-shaped channel 3 respectively to connect with the two ends of the liquid metal 2 , and extend out of the surface of the elastic top layer 11 .

[0036] like Figure 3 As shown in the figure, the horizontal axis represents the stretching percentage of the elastic body 1 of the lantern-shaped liquid metal flexible strain sensor capable of detecting anisotropic strain in this embodiment, and the vertical axis ΔR / R0 represents the resistance change rate of the liquid metal 2 body of the lantern-shaped liquid metal flexible strain sensor capable of detecting anisotropic strain in this embodiment. As can be seen from the figure, during the transverse stretching process with a strain rate from 0% to 30%, the resistance of the liquid metal 2 decreases monotonically, and during the longitudinal stretching process with a strain rate from 0% to 30%, the resistance of the liquid metal 2 increases monotonically. Therefore, the stability of the monotonic change of resistance in this embodiment during transverse and longitudinal stretching is shown.

[0037] like Figure 4As shown, when the elastic body 1 is subjected to a lateral tensile force, the lateral width of the arc portion of the liquid metal 2 in the lantern-shaped channel 3 continues to increase, the cross-sectional area continues to increase, the length change of the arc portion is much smaller than the cross-sectional area change, the width change of the inclined horizontal bar portion is greater than the length change, and the overall cross-sectional area change trend of the liquid metal 2 in the lantern-shaped channel 3 is much greater than the length change trend. Therefore, the resistance continues to decrease.

[0038] like Figure 5 As shown, when the elastic body 1 is subjected to longitudinal tensile force, the longitudinal length of the arc portion of the liquid metal 2 in the lantern-shaped channel 3 gradually increases, the cross-sectional area gradually decreases, and the length change of the inclined horizontal strip portion is much greater than the width change, resulting in a continuous increase in resistance.

[0039] To sum up, when the elastic body 1 is subjected to external force, the lantern-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 lantern-shaped channel 3. Since the lantern-shaped channel 3 matches the liquid metal 2 and has a lantern skeleton structure with inclined horizontal bars inside, when the elastic body 1 is subjected to longitudinal tensile force, the longitudinal length of the arc part of the liquid metal 2 in the lantern-shaped channel 3 gradually increases, and the cross-sectional area gradually decreases. The length change of the inclined horizontal bar part is much greater than the width change, resulting in a continuous increase in resistance; when the elastic body 1 is subjected to transverse tensile force, the transverse width of the arc part of the liquid metal 2 in the lantern-shaped channel 3 continues to increase, and the cross-sectional area continues to increase. The length change of the arc part is much smaller than the cross-sectional area change, the width change of the inclined horizontal bar part is greater than the length change, and the overall cross-sectional area change trend of the liquid metal 2 in the lantern-shaped channel 3 is much greater than the length change trend. Therefore, the resistance continues to decrease, which solves the problem of unstable resistance change of the liquid metal 2 in different stretching directions, and can detect transverse and longitudinal changes, with anisotropic characteristics.

[0040] Example 2 like Figure 6 As shown, a lantern-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 interconnected single liquid metals 21 in the shape of lantern skeletons formed by connecting a plurality of circular arcs with internal inclined horizontal bars, wherein a lantern-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, wherein the liquid metal 2 is located in the lantern-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. Since the single liquid metal 21 is in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, it 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.

[0041] The liquid metal 2 is composed of two connected left and right mirror-symmetrical monomer liquid metals 21. It has higher stretchability, can withstand greater strain, and is suitable for environments with greater tensile forces.

[0042] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 that is tightly attached to the top of the elastic bottom layer 12. The lantern-shaped channel 3 is arranged on the bottom surface of the elastic top layer 11, and the liquid metal 2 is arranged on the top surface of the elastic bottom layer 12. The liquid metal 2 is located inside the lantern-shaped channel 3, and the lantern-shaped channel 3 limits the liquid metal 2.

[0043] The radius of the lantern skeleton-shaped arc part in the monomer liquid metal 21 is 1mm to 3mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°. These arcs with rich shapes help to improve its tensile ductility and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the entire liquid metal 2. The inclined horizontal bar structure of the monomer liquid metal 21 can make the liquid metal 2 more stable and less prone to breakage during the stretching process, and the inclined horizontal bars can amplify the length change trend of the liquid metal 2 during longitudinal stretching, and amplify the cross-sectional area change trend of the liquid metal 2 during transverse stretching.

[0044] 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 lantern-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.

[0045] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0046] 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.

[0047] The cross section of the lantern-shaped channel 3 is rectangular. Designing the cross section of the lantern-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.

[0048] A method for preparing a lantern-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 two mirror-symmetrical lantern-shaped monomer liquid metals 21 consisting of a plurality of arcs connected with internal inclined horizontal bars, 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 lantern-shaped channel 3 respectively to connect with the two ends of the liquid metal 2 , and extend out of the surface of the elastic top layer 11 .

[0049] like Figure 8 As shown, curve a is the present embodiment. During the transverse stretching process with a strain rate from 0% to 35%, the resistance of the liquid metal 2 decreases monotonically.

[0050] like Fig. 9 As shown, curve a is the present embodiment. During the longitudinal stretching process with a strain rate from 0% to 35%, the resistance of the liquid metal 2 increases monotonically.

[0051] Example 3 like Figure 7 As shown, a lantern-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 interconnected single liquid metals 21 in the shape of lantern skeletons formed by connecting a plurality of circular arcs with internal inclined horizontal bars, wherein a lantern-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, wherein the liquid metal 2 is located in the lantern-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. Since the single liquid metal 21 is in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, it 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.

[0052] The liquid metal 2 is composed of two connected monomer liquid metals 21, one of which is translated upward by 0.5 times the height and then translated to the right to fit with the other monomer liquid metal 21. It has higher stretchability, can withstand greater strain, and is suitable for environments with greater tensile force.

[0053] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 that is tightly attached to the top of the elastic bottom layer 12. The lantern-shaped channel 3 is arranged on the bottom surface of the elastic top layer 11, and the liquid metal 2 is arranged on the top surface of the elastic bottom layer 12. The liquid metal 2 is located inside the lantern-shaped channel 3, and the lantern-shaped channel 3 limits the liquid metal 2.

[0054] The radius of the lantern skeleton-shaped arc part in the monomer liquid metal 21 is 1mm to 3mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°. These arcs with rich shapes help to improve its tensile ductility and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the entire liquid metal 2. The inclined horizontal bar structure of the monomer liquid metal 21 can make the liquid metal 2 more stable and less prone to breakage during the stretching process, and the inclined horizontal bars can amplify the length change trend of the liquid metal 2 during longitudinal stretching, and amplify the cross-sectional area change trend of the liquid metal 2 during transverse stretching.

[0055] 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 lantern-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.

[0056] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0057] 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.

[0058] The cross section of the lantern-shaped channel 3 is rectangular. Designing the cross section of the lantern-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.

[0059] A method for preparing a lantern-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 lantern-frame-shaped monomer liquid metals 21 consisting of a plurality of arcs connected with internal inclined horizontal bars, wherein one of the monomer liquid metals 21 is translated upward by 0.5 times the height and then translated to the right to fit with the other monomer liquid metal 21, 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 lantern-shaped channel 3 respectively to connect with the two ends of the liquid metal 2 , and extend out of the surface of the elastic top layer 11 .

[0060] like Figure 8 As shown, curve b is this embodiment. During the transverse stretching process with a strain rate from 0% to 35%, the resistance of the liquid metal 2 decreases monotonically.

[0061] like Fig. 9 As shown, curve b is this embodiment. During the longitudinal stretching process with a strain rate from 0% to 35%, the resistance of the liquid metal 2 increases monotonically.

[0062] Example 4 like Fig.10As shown, a lantern-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 eleven interconnected single liquid metals 21 in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, wherein a lantern-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, wherein the liquid metal 2 is located in the lantern-shaped channel 3, and both ends of the liquid metal 2 are connected with wires 4, wherein the wires 4 extend out of the surface of the elastic body 1. Since the single liquid metal 21 is in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, it 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.

[0063] The liquid metal 2 is a type I liquid metal 22, which is composed of eleven interconnected monomer liquid metals 21 arranged in seven rows, and the arrangement is a linear arrangement of two interconnected monomer liquid metals 21 in odd rows and one monomer liquid metal 21 in even rows connected to odd rows. The type I liquid metal 22 can detect and identify tensile forces in different directions within 35%.

[0064] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 that is tightly attached to the top of the elastic bottom layer 12. The lantern-shaped channel 3 is arranged on the bottom surface of the elastic top layer 11, and the liquid metal 2 is arranged on the top surface of the elastic bottom layer 12. The liquid metal 2 is located inside the lantern-shaped channel 3, and the lantern-shaped channel 3 limits the liquid metal 2.

[0065] The radius of the lantern skeleton-shaped arc part in the monomer liquid metal 21 is 1mm to 3mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°. These arcs with rich shapes help to improve its tensile ductility and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the entire liquid metal 2. The inclined horizontal bar structure of the monomer liquid metal 21 can make the liquid metal 2 more stable and less prone to breakage during the stretching process, and the inclined horizontal bars can amplify the length change trend of the liquid metal 2 during longitudinal stretching, and amplify the cross-sectional area change trend of the liquid metal 2 during transverse stretching.

[0066] 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 lantern-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.

[0067] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0068] 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.

[0069] The cross section of the lantern-shaped channel 3 is rectangular. Designing the cross section of the lantern-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.

[0070] like Fig.12 As shown, curve Ia is the present embodiment. During the transverse stretching process with a strain rate from 0% to 35%, the resistance of the I-type liquid metal 22 decreases monotonically.

[0071] like Fig.13 As shown, curve Ia is the present embodiment. During the longitudinal stretching process with a strain rate from 0% to 35%, the resistance of the I-type liquid metal 22 increases monotonically.

[0072] Example 5 like Fig.11 As shown, a lantern-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 interconnected single liquid metals 21 in the shape of lantern skeletons formed by connecting a plurality of circular arcs with internal inclined horizontal bars, wherein a lantern-shaped channel 3 matching the liquid metal 2 is provided in the elastic body 1, wherein the liquid metal 2 is located in the lantern-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. Since the single liquid metal 21 is in the shape of a lantern skeleton formed by connecting a plurality of circular arcs with internal inclined horizontal bars, it 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.

[0073] The liquid metal 2 is a type II liquid metal 23, which is composed of eight interconnected monomer liquid metals 21 arranged in four rows, each row including two monomer liquid metals 21 and the rows are arranged alternately left and right. The type II liquid metal 23 can detect and identify tensile forces in different directions within 35%.

[0074] The elastic body 1 includes an elastic bottom layer 12 and an elastic top layer 11 that is tightly attached to the top of the elastic bottom layer 12. The lantern-shaped channel 3 is arranged on the bottom surface of the elastic top layer 11, and the liquid metal 2 is arranged on the top surface of the elastic bottom layer 12. The liquid metal 2 is located inside the lantern-shaped channel 3, and the lantern-shaped channel 3 limits the liquid metal 2.

[0075] The radius of the lantern skeleton-shaped arc part in the monomer liquid metal 21 is 1mm to 3mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°. These arcs with rich shapes help to improve its tensile ductility and effectively disperse the deformation transmitted by the elastic body 1, while enhancing the uniform deformation coordination of the entire liquid metal 2. The inclined horizontal bar structure of the monomer liquid metal 21 can make the liquid metal 2 more stable and less prone to breakage during the stretching process, and the inclined horizontal bars can amplify the length change trend of the liquid metal 2 during longitudinal stretching, and amplify the cross-sectional area change trend of the liquid metal 2 during transverse stretching.

[0076] 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 lantern-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.

[0077] The conductor 4 is a copper wire, which has low resistivity, good signal conduction performance, easy processing, excellent conductivity and high stability.

[0078] 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.

[0079] The cross section of the lantern-shaped channel 3 is rectangular. Designing the cross section of the lantern-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.

[0080] like Fig.12As shown, curve II-a is the present embodiment. During the transverse stretching process with a strain rate from 0% to 35%, the resistance of the type II liquid metal 23 decreases monotonically.

[0081] like Fig.13 As shown, curve II-a is the present embodiment. During the longitudinal stretching process with a strain rate from 0% to 35%, the resistance of the type II liquid metal 23 increases monotonically.

[0082] 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 lantern-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 one or more interconnected monomer liquid metals in the shape of a lantern skeleton composed of a plurality of circular arcs connected with internal inclined horizontal bars. A lantern-shaped channel matching the liquid metal is provided in the elastic body. The liquid metal is located in the lantern-shaped channel. Both ends of the liquid metal are connected with wires, which extend out of the surface of the elastic body.

2. The lantern-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, which is composed of more than two connected monomer liquid metals arranged in several rows, and the arrangement method is a linear arrangement in which odd-numbered rows are two connected monomer liquid metals and even-numbered rows are one monomer liquid metal connected to odd-numbered rows.

3. The lantern-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 interconnected monomer liquid metals arranged in a plurality of rows, wherein each row includes two monomer liquid metals and the rows are arranged alternately left and right.

4. The lantern-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 lantern-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 lantern-shaped liquid metal flexible sensor capable of detecting multi-dimensional strain according to any one of claims 1 to 3, characterized in that: The radius of the lantern skeleton-shaped arc part in the monomer liquid metal is 1 mm to 3 mm, the angle is 90° to 180°, and the angle of the inclined horizontal bar is 45° to 135°.

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

10. A method for preparing the lantern-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: Using an ultraviolet laser marking machine to carve on the surface of the liquid metal to form one or more connected lantern skeleton-shaped monomer liquid metals composed of a plurality of arcs connected with internal inclined horizontal bars, forming an elastic bottom layer and a 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 lantern-shaped channel respectively to connect with the two ends of the liquid metal, and extend them out of the surface of the elastic body.

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