Thin film strain sensor embedded in special-shaped structural member and preparation method of thin film strain sensor

Abstract

The invention provides a thin film strain sensor embedded in a special-shaped structural member and a preparation method thereof, and the sensor comprises the components of the special-shaped structural member which comprises a structural member bottom layer substrate and a structural member residual part; the resistance strain sensor is embedded between the structural part bottom layer base body and the structural part remaining part; the insulating film is arranged between the structural part bottom layer substrate and the resistance strain sensor; the sensor protection layer covers the upper part of the resistance strain sensor; the electric signal connecting layer is arranged above the resistance strain sensor; the filler is filled between the rest part of the structural part and other parts; the resistance strain sensor is used for outputting corresponding resistance when the special-shaped structural member deforms under the action of physical quantity; and obtaining a strain value under the action of the corresponding physical quantity according to the relation between the sensor resistance and the strain. The resistance strain sensor does not depend on the surface flatness of the device, the service life of the resistance strain sensor is prolonged, and the use scene of the resistance strain sensor is widened.

Description

Technical Field

[0001] This application relates to the field of sensors, specifically to a thin-film strain sensor embedded in an irregularly shaped structural component and its fabrication method. Background Technology

[0002] Resistance strain sensors are devices that convert changes in external strain into changes in resistance, and they have wide applications in metrology. This is because the measurement of most physical quantities, such as force, torque, velocity, and acceleration, can be indirectly obtained by measuring strain, making strain sensors the core of most measuring instruments on the market. Furthermore, they are simple in structure, small in size, stable and reliable in performance, and easy to use. The fabrication of resistance strain sensors generally falls into two categories. One involves purchasing off-the-shelf strain gauges and using special adhesive to attach them to the surface of the elastic body at the location where strain needs to be measured. This method is simple and convenient, but requires a smooth and flat surface for the strain gauge, and is prone to inaccurate placement, thick strain gauge substrates affecting strain transmission, and the adhesive itself is easily affected by the external environment. The other method uses in-situ manufacturing, such as patent CN114414123B, which uses MEMS manufacturing technologies such as photolithography and sputtering to directly generate thin-film strain sensors on the surface of the device where strain needs to be measured. This preparation method has the advantages of high precision, accurate positioning, thin strain substrate, and less susceptibility to environmental influences. However, it has higher requirements for the shape and flatness of the surface of the structural parts and special requirements for the shape of irregular structural parts.

[0003] With the rapid development of the robotics field, achieving more precise robot control requires obtaining force / torque measurements at robot joint motors, end effector contact points, and critical load-bearing structural components. However, these components are often not standard flat planes and operate in complex environments. Existing adhesive strain gauges suffer from creep, hysteresis, and reliability issues, resulting in short lifespans and difficulty in obtaining stable and reliable measurements. Furthermore, the irregular shapes of these structural components make it difficult to directly fabricate thin-film strain sensors on their surfaces for measurement.

[0004] A search revealed a patent with application publication number CN106248266A, which discloses a resistance strain gauge sensor based on 3D printing and its manufacturing method. The manufacturing method includes the following steps: preparing an insulating substrate in the strain region of an elastic element; printing a resistance-sensitive material onto the insulating substrate, with the print head moving relative to the elastic element to print a sensitive grid with a target pattern; and printing conductive lines and conductive contacts connecting the sensitive grid to form a strain gauge. In this patent, the strain sensor is fabricated on the surface of a structure, which places high demands on the shape of the structure's surface, and the strain sensor is easily affected by the external environment. Summary of the Invention

[0005] In view of one of the defects in the prior art, the purpose of this application is to provide a thin-film strain sensor embedded in an irregularly shaped structural component and a method for its fabrication.

[0006] A first aspect of this application provides a thin-film strain sensor embedded in an irregularly shaped structural component, comprising:

[0007] An irregularly shaped structural component, comprising a bottom substrate and a remaining portion thereof, wherein the remaining portion thereof is located above the bottom substrate.

[0008] A resistance strain sensor is embedded between the bottom substrate of the structural component and the remaining part of the structural component;

[0009] An insulating film is disposed between the bottom substrate of the structural component and the resistance strain sensor;

[0010] A sensor protective layer covers the resistance strain sensor.

[0011] An electrical signal connection layer is disposed above the resistance strain sensor and exposed from the upper surface of the irregular structure, for transmitting the electrical signal of the resistance strain sensor to the surface of the irregular structure.

[0012] A filler is placed between the resistance strain sensor, the insulating film, the sensor protective layer, the electrical signal connection layer, and the remaining part of the structural component to enhance the strain transfer effect inside the device.

[0013] The resistance strain sensor is used to output the corresponding resistance when the irregularly shaped structural component deforms under the action of a physical quantity; the strain value under the action of the corresponding physical quantity is obtained according to the relationship between the sensor resistance and the strain.

[0014] Optionally, the material of the resistance strain sensor is any one of NiCr, CuNi, and Karma alloy.

[0015] Optionally, the electrical signal connection layer is a metal block, which is inserted into the opening of the remaining part of the structure. The side surface of the metal block is provided with an insulating layer. The bottom of the metal block is connected to the resistance strain sensor, and the top of the metal block is exposed from the remaining part of the structure.

[0016] Optionally, a thin-film temperature sensor is also embedded between the bottom substrate of the structure and the remaining part of the structure.

[0017] A second aspect of this application provides a method for fabricating the aforementioned thin-film strain sensor embedded in an irregularly shaped structural component, comprising:

[0018] The underlying substrate of structural components is prepared using additive manufacturing technology;

[0019] An insulating film is prepared on the bottom substrate of the structural component;

[0020] A resistance strain sensor is formed at a stress-sensitive location on the upper surface of the insulating film;

[0021] A sensor protective layer is covered on the resistance strain sensor, and the lead electrodes are exposed by etching.

[0022] Additive manufacturing technology is used on the surface of the bottom substrate of the structural component to manufacture the remaining part of the structural component;

[0023] An opening is pre-drilled on the surface of the remaining part of the irregularly shaped structural component to pour out all the metal powder inside the device cavity;

[0024] A metal block is provided as an electrical signal connection layer. The metal block is inserted through the opening so that the bottom of the metal block contacts the lead electrode of the resistance strain sensor.

[0025] Filler is injected into the space between the insulating film, the resistance strain sensor, the electrical signal connection layer, the sensor protective layer and the remaining part of the structural component through the opening, and then cured at high temperature to obtain a thin film strain sensor embedded in the irregular structural component.

[0026] Optionally, the preparation of the underlying substrate of the structural component using additive manufacturing technology includes: obtaining a flat elastomer surface by printing as the underlying substrate of the structural component;

[0027] The method of using additive manufacturing technology on the surface of the bottom substrate of the structural component to manufacture the remaining part of the structural component includes: avoiding the insulating film area, and using bridging technology to perform additive manufacturing of the remaining part of the structural component on the bottom substrate of the structural component.

[0028] Optionally, a resistance strain sensor is formed at a stress-sensitive location on the upper surface of the insulating film, comprising:

[0029] Patterning is achieved at the stress-sensitive region on the upper surface of the insulating film using any one of the following methods: mask sputtering, mask etching, or lift-off; then, an alloy-sensitive material is sputtered to obtain a resistance strain sensor.

[0030] Optionally, an adhesive layer is provided beneath the alloy-sensitive material.

[0031] Optionally, the insulating film and the sensor protective layer are obtained by spin coating and high-temperature curing.

[0032] The thin-film strain sensor embedded in the irregularly shaped structure provided in this application has no requirements for the flatness of the device surface, making the strain sensor independent of the device surface flatness; the strain sensor embedded in the device is not easily affected by the external environment, which enhances the service life of the strain sensor and broadens its application scenarios.

[0033] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0034] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0035] Figure 1 This is a schematic diagram of a thin-film strain sensor embedded in an irregularly shaped structural member according to an exemplary embodiment.

[0036] Figure 2 This is a flowchart illustrating a method for fabricating a thin-film strain sensor embedded in an irregularly shaped structural component according to an exemplary embodiment;

[0037] In the diagram: 1 is the bottom substrate of the structural component, 2 is the insulating film, 3 is the resistance strain sensor, 4 is the electrical signal connection layer, 5 is the sensor protective layer, and 6 is the remaining part of the structural component. Detailed Implementation

[0038] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0039] Reducing the dependence of resistance strain sensors on the shape and flatness of structural components, increasing their service life, and expanding their application scenarios are pressing technical problems that need to be solved in this field. Based on the above problems, this application provides a thin-film strain sensor embedded in an irregularly shaped structural component to address these issues.

[0040] Reference Figure 1As shown, in one embodiment of this application, a thin-film strain sensor embedded in an irregularly shaped structural component includes an irregularly shaped structural component, a resistance strain sensor 3, an insulating film 2, a sensor protective layer 5, an electrical signal connection layer 4, and a filler. The irregularly shaped structural component includes a bottom substrate 1 and a remaining portion 6, with the remaining portion 6 located above the bottom substrate 1. The resistance strain sensor 3 is embedded between the bottom substrate 1 and the remaining portion 6. The insulating film 2 is disposed between the bottom substrate 1 and the resistance strain sensor 3. The sensor protective layer 5 covers the resistance strain sensor 3. The electrical signal connection layer 4 is located above the resistance strain sensor 3 and protrudes from the upper surface of the irregular structure, i.e., the upper surface of the remaining part 6 of the structure, to transmit the electrical signal of the resistance strain sensor 3 to the surface of the irregular structure. The filler is filled between the resistance strain sensor 3, the insulating film 2, the sensor protective layer 5, the electrical signal connection layer 4 and the remaining part 6 of the structure to enhance the strain transmission effect inside the device. The resistance strain sensor 3 is used to output the corresponding resistance when the irregular structure deforms under the action of a physical quantity. The strain value under the action of the corresponding physical quantity is obtained according to the relationship between the sensor resistance and the strain.

[0041] Specifically, the insulating film 2 supports the resistance strain sensor 3 and provides electrical insulation. The sensor protective layer 5 protects the entire sensor from external influences. Filler material is used to fill the remaining structural components 6 between the sensor and other parts, enhancing the transmission of internal strain and improving mechanical strength and other properties. When the substrate deforms under the influence of an unknown physical quantity, this deformation is transmitted to the embedded strain sensing chip. Based on the resistance strain effect, the resistance strain sensor 3 outputs the resistance under the influence of the unknown physical quantity. The strain value under the influence of the corresponding physical quantity is obtained based on the relationship between the sensor resistance and the strain.

[0042] Compared to existing technologies (such as CN106248266A), the thin-film strain sensor in this application embodiment is embedded inside the additively manufactured structure, with only the electrical connection points exposed on the surface. Therefore, the strain sensor is less susceptible to the influence of the external environment, has no requirements on the shape of the structure surface, and is easier to integrate and manufacture multiple sensors.

[0043] In the above embodiments of this application, the resistance strain sensor 3 is embedded in the irregularly shaped structural component, that is, embedded inside the device. There is no requirement for the flatness of the device surface, so the resistance strain sensor 3 is not dependent on the flatness of the device surface. The resistance strain sensor 3 embedded inside the device is not easily affected by the external environment, which enhances the service life of the resistance strain sensor 3 and broadens its application scenarios.

[0044] In order to output the corresponding resistance when the irregularly shaped structural component deforms under the action of an unknown physical quantity, in some specific embodiments of this application, considering that different sensitive materials have different resistivity, temperature coefficient of resistance (TCR), sensitivity (GF) and coefficient of linear expansion, the material of the resistance strain sensor 3 is any one of NiCr, CuNi and Karma alloy, depending on the specific scenario and performance requirements.

[0045] Specifically, the resistance strain sensor 3 is a metal fabricated using a mask sputtering method. The thickness of the resistance strain sensor 3 is 200–900 nm.

[0046] In the embodiments described above, an alloy sensitive material with a high strain sensitivity coefficient is used to obtain the output resistance when an irregularly shaped structural component undergoes deformation.

[0047] To reduce the lateral effect of the resistance strain sensor 3, a transition grid structure is used at the bending point. Since the magnitude of the resistance change is related to the width and length of the metal pattern in the direction of force, to reduce the resistance change after force is applied in the non-sensitive direction, the length of the metal at the connection of the grid wires in the sensitive direction needs to be minimized, and its width increased. In this embodiment, the width of the metal pattern at the connection is 4 to 5 times the width of the grid wire in the sensitive direction, and the length is approximately 3 to 4 times the width of the grid wire in the sensitive direction. Furthermore, to ensure electrical connection, square lines or arc lines are used to connect the grid wires of the resistance strain sensor in the sensitive direction. These measures can reduce the influence of structural deformation in the non-sensitive direction on the resistance value of the resistance strain sensor 3.

[0048] Specifically, the shape of the resistance strain sensor 3 is designed according to the measurement requirements, and can be arc-shaped, elongated, or other shapes.

[0049] In order to achieve the output of resistance, in some specific embodiments of this application, the electrical signal connection layer 4 is a metal block. The metal block is inserted into the opening of the remaining part 6 of the structural component. The side surface of the metal block is provided with an insulating layer. The bottom of the metal block is connected to the resistance strain sensor 3, and the top protrudes from the remaining part 6 of the structural component.

[0050] In order to achieve the integration of multiple sensors, in some specific embodiments of this application, a thin-film temperature sensor is also embedded between the bottom substrate 1 of the structural component and the remaining part 6 of the structural component.

[0051] It should be noted that, depending on the specific measurement requirements, other types of sensors can be embedded between the bottom substrate 1 of the structural component and the remaining part 6 of the structural component to achieve the integration of more sensors.

[0052] The sensor in the above embodiments of this application, through its embedded design, makes the resistance strain sensor 3 independent of the surface flatness of the device, reducing the influence of the external environment on the strain sensor chip, extending its service life, and enabling its application in force / torque measurement of irregularly shaped parts in multiple fields, thus broadening its application scope. Furthermore, a thin-film temperature sensor can be embedded in structural components to achieve multi-sensor integration, further expanding application scenarios. It features long lifespan and high integration.

[0053] Another embodiment of this application provides a method for fabricating the above-mentioned thin-film strain sensor embedded in an irregularly shaped structural component, referring to... Figure 2 As shown, the method includes the following steps:

[0054] S1. Prepare the underlying substrate 1 of the structural component using additive manufacturing technology;

[0055] S2. Prepare an insulating film 2 on the bottom substrate 1 of the structural component;

[0056] S3. A resistance strain sensor 3 is formed at a stress-sensitive location on the upper surface of the insulating film 2;

[0057] S4. Cover the resistance strain sensor 3 with the sensor protective layer 5, and expose the lead electrodes (PAD part) by etching.

[0058] S5. Using additive manufacturing technology on the surface of the bottom substrate 1 of the structural component, the remaining part 6 of the structural component is manufactured.

[0059] S6. When manufacturing the remaining part 6 of the irregular structure, a pre-reserved opening is made on the surface to pour out all the metal powder that was not used in the additive manufacturing of the device cavity through the pre-reserved opening.

[0060] S7. Provide a metal block as an electrical signal connection layer 4. Insert the metal block through the opening so that the bottom of the metal block contacts the lead electrode of the resistance strain sensor 3. Thus, the electrical signal of the resistance strain sensor 3 is transmitted to the surface of the structural component through the electrical signal connection layer 4.

[0061] S8. Liquid filler is injected from the opening into the space between the insulating film 2, the resistance strain sensor 3, the electrical signal connection layer 4, the sensor protective layer 5 and the remaining part of the structural component 6, and then cured at high temperature to obtain a thin film strain sensor embedded in the irregular structural component.

[0062] The above embodiments of this application feature an embedded strain / force sensing chip, which is realized using micro-nano fabrication technology and has the characteristics of small size and fast response speed. The sensor is fabricated inside the device, and there are no requirements for the surface shape and flatness of the structural parts, which can realize strain / force measurement of irregular structural parts. It is not easily affected by the external environment and has an extremely long service life.

[0063] Compared to existing technologies (such as CN106248266A), the embodiments of this application use photolithography, sputtering and other processes to prepare the resistance-sensitive material, which can accurately locate the position of the sensitive gate, prepare a denser and thinner sensitive gate, and have better electrical performance.

[0064] To achieve additive manufacturing of irregularly shaped structural components, in some specific embodiments of this application, additive manufacturing technology is used to prepare the bottom substrate 1 of the structural component, including: obtaining a flat elastomer surface by printing as the bottom substrate 1 of the structural component; and using additive manufacturing technology on the surface of the bottom substrate 1 of the structural component to manufacture the remaining part 6 of the structural component, including: avoiding the insulating film area, placing the bottom substrate 1 of the structural component horizontally on the additive manufacturing platform, uniformly spreading a layer of metal powder on the surface of the bottom substrate 1 of the structural component, melting the metal powder using additive manufacturing technology, and combining it with the metal on the surface of the bottom substrate 1 of the structural component, and using the above-mentioned additive manufacturing bridging technology to perform additive manufacturing of the remaining part 6 of the structural component.

[0065] Specifically, in S1, a suitable internal plane of the structural component is selected. When the additive manufacturing completes the printing of this plane, the semi-finished device is taken out and the plane on which the resistance strain sensor 3 needs to be fabricated is polished.

[0066] In the above embodiments of this application, the bottom substrate 1 and the remaining part 6 of the structural component adopt additive manufacturing technology: first, the partial shape of the device is printed to obtain a flat elastomer surface, and an insulating film 2 is prepared on the surface, a resistance strain sensor 3 and a sensor protective layer 5 are prepared in the stress-sensitive part; then, avoiding the insulating film area, additive manufacturing is continued on the bottom substrate 1 of the structural component through bridging technology to complete the manufacturing of the entire device.

[0067] In order to fabricate the resistance strain sensor 3, in some specific embodiments of this application, the resistance strain sensor 3 is formed on the stress-sensitive part of the upper surface of the insulating film 2, including: patterning the resistance strain sensor on the stress-sensitive part of the upper surface of the insulating film 2 using any one of mask sputtering, mask etching, or lift-off methods; and then sputtering a layer of alloy sensitive material to obtain the resistance strain sensor 3.

[0068] In order to enhance the bonding force between the sensor and the underlying substrate 1 of the structural component, in some specific embodiments of this application, an adhesive layer is provided below the alloy sensitive material.

[0069] Specifically, Cr acts as the adhesive layer, with a thickness of 10 nm to 30 nm. The thickness of the sensitive materials CuNi, Karma alloy, and NiCr is 200 to 900 nm.

[0070] In the embodiments described above, Cr is used as the adhesive layer, which can effectively enhance the bonding force between the sensor and the substrate.

[0071] In S7, specifically, the metal block used for the electrical signal connection layer 4 is surface-oxidized to form an insulating layer. Then, the top and bottom of the metal block are polished, and the metal block is inserted through the pre-reserved opening on the surface of the additive manufacturing. The bottom of the metal block contacts the lead electrode of the resistance strain sensor 3, and the electrical signal of the resistance strain sensor 3 is transmitted to the surface of the remaining part 6 of the structural component through the electrical signal connection layer 4.

[0072] In order to prepare the insulating substrate and / or sensor protective layer, in some specific embodiments of this application, the insulating film 2 and the sensor protective layer 5 are obtained by spin coating and high-temperature curing.

[0073] Specifically, depending on the application requirements, the insulating film 2 can be made of ordinary insulating medium or high temperature resistant insulating material, such as inorganic high temperature resistant electrical insulating film. During the post-processing after additive manufacturing, the insulating properties of the film remain unchanged.

[0074] The inorganic thin film formed by spin coating and high-temperature curing in the above embodiments of this application has good insulation and strain transfer rate, as well as high corrosion resistance.

[0075] The above embodiments of this application can achieve the integration of multiple sensors by repeating the fabrication process of the resistance strain sensor 3, the electrical signal connection layer 4, and the sensor protective layer 5 on the insulating film 2, and embedding other sensors such as film temperature inside the structural component.

[0076] The sensor fabrication method described in the above embodiments of this application combines micro-nano fabrication technology and additive manufacturing technology. It allows for stopping the fabrication of irregularly shaped structural parts at a certain cross-section, fabricating the thin-film sensor using micro-nano fabrication, and then completing the remaining fabrication. This solves the problem of traditional thin-film strain gauge fabrication technology being highly dependent on the surface shape of the structural parts, providing a new solution for measuring force / torque in irregularly shaped structural parts. The thin-film strain sensor proposed in the above embodiments of this application has strong applicability, is not easily affected by the external environment, and has broad application prospects.

[0077] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0078] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0080] In the description of the embodiments in this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0081] The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0082] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A thin-film strain sensor embedded in an irregularly shaped structural component, characterized in that, include: An irregularly shaped structural component, comprising a bottom substrate and a remaining portion thereof, wherein the remaining portion thereof is located above the bottom substrate. A resistance strain sensor is embedded between the bottom substrate of the structural component and the remaining part of the structural component; An insulating film is disposed between the bottom substrate of the structural component and the resistance strain sensor; A sensor protective layer covers the resistance strain sensor. An electrical signal connection layer is disposed above the resistance strain sensor and exposed from the upper surface of the irregular structure, for transmitting the electrical signal of the resistance strain sensor to the surface of the irregular structure. A filler is placed between the resistance strain sensor, the insulating film, the sensor protective layer, the electrical signal connection layer, and the remaining part of the structural component to enhance the strain transfer effect inside the device. The resistance strain sensor is used to output the corresponding resistance when the irregularly shaped structural component deforms under the action of a physical quantity; the strain value under the action of the corresponding physical quantity is obtained according to the relationship between the sensor resistance and the strain.

2. The thin-film strain sensor embedded in an irregularly shaped structural component according to claim 1, characterized in that, The material of the resistance strain sensor is any one of NiCr, CuNi, and Karma alloy.

3. The thin-film strain sensor embedded in an irregularly shaped structural component according to claim 1, characterized in that, The electrical signal connection layer is made of a metal block, which is inserted into the opening of the remaining part of the structure. The side surface of the metal block is provided with an insulating layer. The bottom of the metal block is connected to the resistance strain sensor, and the top protrudes from the remaining part of the structure.

4. The thin-film strain sensor embedded in an irregularly shaped structural component according to claim 1, characterized in that, A thin-film temperature sensor is also embedded between the bottom substrate of the structural component and the remaining part of the structural component.

5. A method for fabricating a thin-film strain sensor embedded in an irregularly shaped structural component as described in any one of claims 1-4, characterized in that, include: The underlying substrate of structural components is prepared using additive manufacturing technology; An insulating film is prepared on the bottom substrate of the structural component; A resistance strain sensor is formed at a stress-sensitive location on the upper surface of the insulating film; A sensor protective layer is covered on the resistance strain sensor, and the lead electrodes are exposed by etching. Additive manufacturing technology is used on the surface of the bottom substrate of the structural component to manufacture the remaining part of the structural component; An opening is pre-drilled on the surface of the remaining part of the irregularly shaped structural component to pour out all the metal powder inside the device cavity; A metal block is provided as an electrical signal connection layer. The metal block is inserted through the opening so that the bottom of the metal block contacts the lead electrode of the resistance strain sensor. Filler is injected into the space between the insulating film, the resistance strain sensor, the electrical signal connection layer, the sensor protective layer and the remaining part of the structural component through the opening, and then cured at high temperature to obtain a thin film strain sensor embedded in the irregular structural component.

6. The method for fabricating a thin-film strain sensor embedded in an irregularly shaped structural component according to claim 5, characterized in that, The preparation of the underlying substrate of the structural component using additive manufacturing technology includes: obtaining a flat elastomer surface by printing as the underlying substrate of the structural component; The method of using additive manufacturing technology on the surface of the bottom substrate of the structural component to manufacture the remaining part of the structural component includes: avoiding the insulating film area, and using bridging technology to perform additive manufacturing of the remaining part of the structural component on the bottom substrate of the structural component.

7. The method for fabricating a thin-film strain sensor embedded in an irregularly shaped structural component according to claim 5, characterized in that, A resistance strain sensor is formed at a stress-sensitive location on the upper surface of the insulating film, comprising: Patterning is achieved at the stress-sensitive region on the upper surface of the insulating film using any one of the following methods: mask sputtering, mask etching, or lift-off; then, an alloy-sensitive material is sputtered to obtain a resistance strain sensor.

8. The method for fabricating a thin-film strain sensor embedded in an irregularly shaped structural component according to claim 7, characterized in that, An adhesive layer is provided beneath the alloy sensitive material.

9. The method for fabricating a thin-film strain sensor embedded in an irregularly shaped structural component according to claim 5, characterized in that, The insulating film and the sensor protective layer are obtained by spin coating and high-temperature curing.

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