Integrated embedded optical fiber sensing multi-material multifunctional structure additive manufacturing method

Abstract

The invention relates to the field of multi-material multifunctional additive manufacturing, in particular to a multi-material multifunctional structure additive manufacturing method integrated with embedded optical fiber sensing, which is used for constructing a coupling space structure integrated with optical fiber sensing, wire and micro-channel heat exchange in a matrix to realize electric conduction and heat conduction functions and temperature and strain sensing integrated manufacturing. Comprising the following steps: 1, designing a space coupling structure, and carrying out structural design by adopting a suspension support optimization algorithm; secondly, the forming area is divided into a plurality of collaborative subdomains, a central controller generates a multi-mechanical-arm movement track based on time-space double constraints, and multi-arm collaborative operation is executed based on slice data; the first multi-degree-of-freedom mechanical arm carries an FDM spray head and is responsible for printing a polymer matrix and a runner wall surface; and the second multi-degree-of-freedom mechanical arm carries the FDM spray head to follow the track of the first multi-degree-of-freedom mechanical arm, and when the temperature of the base body is higher than the glass transition temperature, the wire and the optical fiber are pressed into the base body to form a component.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of multi-material and multi-functional additive manufacturing, and more particularly to a multi-material and multi-functional structure additive manufacturing method integrated with embedded optical fiber sensing. BACKGROUND

[0002] Fused deposition modeling (FDM) is one of the most widely used 3D printing technologies, which is to heat thermoplastic filaments to a molten state, then extrude through a nozzle and stack layer by layer to form a three-dimensional entity. With the advantages of low equipment cost, simple operation, and various material selection, this technology has rapidly popularized in the fields of industrial design, education, medical treatment, and consumer electronics.

[0003] However, the traditional FDM process is limited by a single material supply system, and each layer can only deposit one homogeneous material, resulting in a single characteristic in mechanics, heat, electricity, etc. It is difficult to meet the differentiated needs of component strength and heat exchange, electrical conductivity, etc. in complex service environments, and it is also impossible to realize multi-functional integration such as embedded circuit and flow channel, and real-time monitoring of structural state. With the urgent demand for structural and functional integrated components in aerospace, robotics, personalized medical treatment, and other high-end equipment scenarios, it is inevitable to develop additive manufacturing technology that can realize multi-material on-demand point printing, multi-functional integration, and parallel printing in the same printing process.

[0004] On the other hand, optical fiber sensing is based on the change of light transmission characteristics in optical fiber to perceive external physical quantities. When temperature, stress, and other external factors act on the optical fiber, they will cause changes in optical parameters such as intensity, phase, wavelength, or polarization state of light waves. By demodulating these changes, accurate monitoring of the measured quantities can be achieved, which has advantages such as anti-electromagnetic interference and high sensitivity compared to electrical principle sensors. There are cases in engineering where optical fibers are used to monitor structural temperature, strain, and other parameters, but the installation method of optical fibers is mainly surface pasting and pre-embedded placement, which may cause poor contact between the optical fiber and the base material and reduce measurement accuracy. SUMMARY

[0005] The present application provides a multi-material and multi-functional structure additive manufacturing method integrated with embedded optical fiber sensing, which can construct a coupling space structure integrated with optical fiber sensing, metal wire conduction, and micro-channel heat exchange inside the base body, and realize integrated manufacturing of conduction, heat conduction, temperature, and strain sensing.

[0006] The above-mentioned purpose is achieved by the following technical solutions:

[0007] A multi-material and multi-functional structure integrated with embedded optical fiber sensing, comprising a base body, a micro-channel arranged on the base body, a wire located in the base body and accompanying the micro-channel, and an optical fiber located at the hetero-material combination interface of the base body and the wire.

[0008] Optionally, the material of the base is polylactic acid or polyether ether ketone, the wire is metal, carbon nanotube fiber or conductive polymer, and the fiber is a polyimide-coated fiber.

[0009] Optionally, the wire and the micro-channel are arranged in parallel, that is, the wire extends in parallel with the axis of the micro-channel, and the spacing is constant; or the wire and the micro-channel are arranged in a spiral.

[0010] Optionally, the wire has a diameter of 50-150 μm; the micro-channel has an inner diameter of 1-3 mm; the spacing between the wire and the micro-channel is 0.5-2 mm; the fiber has an outer diameter of 125-150 μm, and is embedded along an S-shaped, spiral or three-dimensional grid path at the heterogeneous material bonding interface, and the radius of curvature is not less than 10 mm.

[0011] Optionally, when the wire has a longitudinal intersection, a through hole is provided on the base to connect the wires of the adjacent layers or cross layers, and the through hole is filled with a conductive medium.

[0012] Optionally, the conductive medium is silver paste.

[0013] Optionally, the base is provided with a fluid inlet, a fluid outlet and a standard interface in communication with the micro-channel, and the standard interface is an electrical interface connected with the wire or an optical fiber interface connected with the fiber.

[0014] The above-mentioned additive manufacturing method of the multi-material multi-functional structure integrated with embedded optical fiber sensing includes the following steps:

[0015] Step 1: Design a spatial coupling structure and use a suspended support optimization algorithm to design the structure;

[0016] Step 2: Divide the forming area into multiple cooperative sub-domains, generate a motion trajectory based on time-space double constraints, and perform a multi-printing device cooperative operation based on slice data;

[0017] The first printing device is responsible for printing the polymer base and the channel wall; the second printing device follows the trajectory of the first printing device and presses the wire and the fiber into the base when the temperature of the base is above the glass transition temperature to form a multi-material multi-functional structure integrated with embedded optical fiber sensing.

[0018] Optionally, step 3: manufacture a fiber interface flange, an electrical spring-pin hybrid connector and a fluid quick plug base on the surface of the component; the interface area is made of polyether ether ketone (PEEK) / carbon fiber (CF) composite material to improve mechanical strength and realize anti-plugging; after printing, the flatness is ensured to be ≤0.02 mm;

[0019] Optionally, step 4: anneal the component to eliminate residual stress.

[0020] Optionally, step five: OTDR test is performed on the optical fiber network to locate the loss point and record the initial wavelength-temperature / strain coefficient; four-wire method resistance test is performed on the conductive circuit to establish a resistance-temperature calibration curve; water pressure sealing test is performed on the flow channel to ensure that the leakage rate meets the requirements, and the linear response of the optical fiber sensing network to temperature and strain R²>0.99 and the no-leakage performance of the micro flow channel under 0.5 MPa water pressure are confirmed, and finally a qualified multi-material multifunctional structure integrated with embedded optical fiber sensing is obtained.

[0021] The multi-material multifunctional structure integrated with embedded optical fiber sensing has the following beneficial effects:

[0022] In the formed high polymer matrix, a spatial coupling structure of "micro flow channel-metal wire-optical fiber" is formed; for the micro flow channel overhanging structure, a self-supporting section design is adopted to cooperate with multi-arm variable angle printing to prevent the top from collapsing; the metal wire and the millimeter-level micro flow channel adopt a companion layout, and the fluid medium embedded circuit in the micro flow channel is used for active thermal management; the optical fiber is embedded at the interface of the heterogeneous material combination of the polymer matrix and the metal wire, forming a full life cycle sensing network for monitoring the interlayer stress and interface temperature of the structure; and the optical fiber interface, electrical interface and fluid inlet and outlet are integrally printed on the surface of the component, realizing the integration of the four functions of bearing-sensing-conducting-heat exchange.

[0023] The additive manufacturing method of the multi-material multifunctional structure integrated with embedded optical fiber sensing has the following beneficial effects:

[0024] 1. Deep coupling of "structure-function" is realized: instead of simply embedding wires and flow channels into the matrix, the present application creates a "micro flow channel accompanied by metal wire" topology, which directly uses the micro flow channel as a heat sink for embedded high-power circuits, effectively solving the problem of internal heat accumulation in closed composite structures leading to matrix softening failure.

[0025] 2. The problem of "splitting" of the interface of heterogeneous materials is solved: through the time and space coordination process of multiple mechanical arms, the optical fiber and the metal wire are simultaneously implanted when the matrix is in the best molten viscous state, realizing "in-situ metallurgical bonding" or "microscopic physical interlocking" of heterogeneous materials. Unlike traditional single-nozzle printing, the present method controls the operation timing of each mechanical arm to ensure that the embedding operation of materials other than the matrix, such as metal wires or / and optical fibers, occurs within a specific "thermal window period" (melting point ± 5℃) after the matrix material is printed, and uses the residual heat of the matrix to realize in-situ hot sealing without the need for additional adhesives. Compared with traditional cold post-embedding, this process significantly improves the interlayer bonding strength.

[0026] 3. Endow the structure with the perception ability throughout the whole life cycle: The embedded optical fiber is located at the most failure-prone heterogeneous material interface, which not only monitors the residual stress in the manufacturing process, but also provides in-situ data of temperature (-50℃~200℃), strain (±5000με) and vibration during the service period of the component, serving as the "nervous system" of the structure.

[0027] 4. Significantly improve the manufacturing efficiency and integration: Truly realize "design is manufacturing", simplify the assembly of traditional discrete devices with more than ten processes into one-time additive manufacturing process, greatly reduce the volume and weight of complex mechatronic systems such as aerospace and satellite support. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic view of the multi-material multifunctional structure of the application integrated with embedded optical fiber sensing;

[0029] Figure 2 is a structural schematic view of the in-situ embedded optical fiber sensing network;

[0030] Figure 3 is a structural schematic view of the in-situ embedded optical fiber sensing network;

[0031] Figure 4 is a structural schematic view of the micro-channel for heat dissipation;

[0032] Figure 5 is a schematic view of the component surface standard interface of the application, such as optical fiber, electrical, fluid interface;

[0033] Figure 6 is a schematic view of the multi-degree-of-freedom mechanical arm, FDM nozzle and wire conveying mechanism included in the multi-degree-of-freedom collaborative additive manufacturing system;

[0034] Figure 7 is a structural schematic view of the FDM nozzle of the application;

[0035] Figure 8 is a schematic view of the printing component heat treatment and calibration experiment of the application;

[0036] Figure 9 is a schematic view of the system integration and function verification of the application.

[0037] BRIEF DESCRIPTION OF DRAWINGS: 1. Multi-material multifunctional structure integrated with embedded optical fiber sensing; 101. Base; 102. Micro-channel; 103. Wire; 104. Through hole; 105. Optical fiber; 106. Standard interface; 2. FDM nozzle; 201. Shell; 202. Heating block; 203. Screw; 204. Throat pipe; 205. Melt cavity; 206. Nozzle; 3. Multi-degree-of-freedom mechanical arm; 4. Wire conveying mechanism. DETAILED DESCRIPTION

[0038] A multi-material multifunctional structure 1 integrated with embedded optical fiber sensing, referring to Figures 1 to 4 , comprising a base body 101, a micro-channel 102, a wire 103 and an optical fiber 105 are arranged in the base body 101, and the micro-channel 102, the wire 103 and the optical fiber 105 form a spatial coupling structure.

[0039] Specifically, the material of the base body 101 is polylactic acid (PLA) or polyether ether ketone (PEEK); the wire 103 can adopt annealed copper wire, silver-coated aluminum wire, carbon nanotube fiber or conductive polymer wire, etc. which has the properties of electric conductivity and thermal conductivity.

[0040] The wire 103 is located beside the micro-channel 102, forming an embedded circuit and a companion heat dissipation structure, that is, in the plane (XY plane) perpendicular to the printing accumulation direction (Z axis), the center of the wire 103 and the outer edge of the pipe wall of the micro-channel 102 maintain a certain horizontal distance; or in three-dimensional space, the wire 103 closely follows the outer wall profile of the micro-channel 102 for equidistant envelope design; in this way, the fluid medium in the micro-channel 102 can be used for in-situ thermal management of the electrified wire 103, and on the other hand, signal transmission can also be realized.

[0041] The diameter of the wire 103 is 50-150μm; the inner diameter of the micro-channel 102 is 1-3mm; the spacing of the wire 103 path planning beside the micro-channel 102 is 0.5-2mm;

[0042] Embodiment 1 of the companion heat dissipation: the wire 103 and the micro-channel 102 are in parallel distribution, that is, the extension direction of the wire 103 is parallel to the axis of the micro-channel 102, and the spacing is kept constant.

[0043] Embodiment 2 of the companion heat dissipation: the wire 103 and the micro-channel 102 are in spiral winding distribution. That is, the wire 103 is spirally coiled around the outer wall of the micro-channel 102 with the micro-channel 102 as the center axis, and the crossing of the wires 103 at different heights needs to be designed as a layered jumper structure. That is, the wires 103 arranged at different printing layer heights are connected through the through hole 104 in the Z axis direction. The through hole 104 is a reserved vertical hole for connecting the wires 103 of adjacent layers or across layers, realizing the three-dimensional interconnection of the wires 103.

[0044] The through hole 104 is filled with conductive silver paste to avoid short circuit of the same layer wire 103. The silver paste has very low resistivity and good fluidity, can fully fill the interlayer micropores left by 3D printing, and after solidification can significantly reduce the interlayer contact resistance, ensuring the stability of signal transmission and the efficiency of heat dissipation.

[0045] The optical fiber 105 is embedded at the heterogeneous material interface of the substrate 101 and the wire 103 to form a full life cycle sensing network for monitoring interlaminar stress and interface temperature of the structure. The optical fiber 105 has a polyimide coating with an outer diameter of 125-150 μm. As a reinforcing phase and sensing unit, it is embedded along the S-shaped, spiral-shaped or three-dimensional grid-shaped path at the heterogeneous material interface with a curvature radius not less than 10 mm.

[0046] The substrate 101 can be provided with a standard interface 106, such as a fluid inlet connected to the micro-channel 102, a fluid outlet, an electrical interface connected to the wire 103, and an optical fiber interface connected to the optical fiber 105, to realize the integration of the bearing-sensing-conducting-heat exchange functions.

[0047] The manufacturing method of the above-mentioned multi-material multi-functional structure 1 integrated with embedded optical fiber sensing includes the following steps:

[0048] Step one: design a spatial coupling structure, use a cantilever support optimization algorithm for structure design, use the rapid cooling characteristics of the polymer material substrate 101 to prevent the top of the flow channel from collapsing and ensure the sealing of the flow channel;

[0049] The wire 103 is an annealed copper wire with a diameter of 100 μm; the micro-channel 102 has an inner diameter of 2 mm; the wire 103 is planned along the side of the micro-channel 102, and the distance between them is 1.5 mm, forming an embedded circuit;

[0050] After the wire 103 is embedded in the substrate 101, the wetting bonding area formed by the contact between the surface of the wire 103 and the substrate 101 is the interface of the two. The optical fiber 105 is arranged along the tangent direction or the main stress direction of the bonding area / interface to capture the interface stress caused by the mismatch of the thermal expansion coefficient to the greatest extent.

[0051] Step two: a multi-degree-of-freedom collaborative additive manufacturing system can be used, which includes two multi-degree-of-freedom mechanical arms 3 carrying FDM printing nozzles 2. The forming area is divided into multiple collaborative sub-domains, and the central controller generates the motion trajectories of the two multi-degree-of-freedom mechanical arms 3 based on "time-space double constraints". Based on the slicing data, the two multi-degree-of-freedom mechanical arms 3 are cooperatively operated for printing, so that the trajectories of the two FDM printing nozzles 2 are the same.

[0052] One of the FDM print heads 2 is only responsible for spraying the raw material of the melted substrate 101, which is used to build the substrate 101 and the micro-channel 102; the FDM print head 2 of the second mechanical arm is responsible for spraying the wire 103 and the optical fiber 105 coated with the melted substrate material. When the temperature of the substrate 101 is above the glass transition temperature (window period of melting point ± 5°C), the wire 103 and the optical fiber 105 are pressed into the substrate 101 to form a component. In this way, by strictly calculating the time difference of the two multi-degree-of-freedom mechanical arms 3 by the central controller, it is ensured that the subsequent embedding action occurs at the moment when the substrate 101 still has sufficient wetness and viscosity, so as to realize the tight wrapping of the metal wire 103, the optical fiber 105 and the substrate 101, and avoid the generation of cold joints.

[0053] Further, the multi-degree-of-freedom mechanical arm 3 can adopt a six-axis industrial robot arm, preferably a UR5 series CB3 model robot arm of the URAO robot company. The wire feeding mechanism 4 is fixed at the third joint (large arm section) of each multi-degree-of-freedom mechanical arm 3, and the wire 103 and the optical fiber 105 need to be wound on two material trays with dampers respectively, which are installed on the mechanical arm base through a 3D printing support. The wire passes through a polytetrafluoroethylene conduit to synchronize the feeding of the optical fiber 105 and the wire 103 into the throat pipe 204 at a speed of 0.1-1mm / s with constant tension. Among them, the tension of 0.05-0.2N ensures the position accuracy of the optical fiber in the complex three-dimensional path and prevents micro-bending loss.

[0054] The FDM print head 2 includes a shell 201, a heating block 202 is installed inside the shell 201, and the heating block 202 can be an electric heating element or a medium that guides heat from a heat source into the shell 201. A first flow channel and a second flow channel are provided on the shell 201, a first screw 203 is provided in the first flow channel, and a second screw 203 is provided in the second flow channel. The top of the two screws 203 is driven to rotate by a group of synchronous gear sets, and is driven to rotate by a micro high-torque stepping motor fixed above the shell 201, so as to realize the quantitative extrusion of the raw material of the substrate. A throat pipe 204 for guiding the optical fiber and the metal wire is provided between the first flow channel and the second flow channel. At this time, the first flow channel and the second flow channel form a Y-shaped three-way flow channel, and the three-way flow channel is also a molten pool, i.e. a melting cavity 205. The bottom of the throat pipe 204 is in communication with the converging flow channel, and the wire 103 and the optical fiber 105 are guided into the converging flow channel. When the first screw and the second screw rotate, the melted raw material of the substrate 101 can be transported to the converging flow channel to coat the wire 103 and the optical fiber 105 to form a composite wire. The bottom of the heat dissipation shell 201 is fixedly connected and communicated with a nozzle 206, a narrow and narrow wire channel is formed in the nozzle 206, the wire channel coincides with the axis of the throat pipe 204 to guide the composite wire to be extruded from the bottom of the nozzle 206.

[0055] Step three: the fiber interface flange, electrical spring-pin hybrid connector and fluid quick plug base are manufactured on the surface of the component in a conformal manner; the interface area is made of high-filled polyether ether ketone (PEEK) / carbon fiber (CF) composite material to improve mechanical strength and realize anti-plugging; after printing, the interface is CNC micro-milled to ensure that the flatness is less than or equal to 0.02 mm, and the reliability of optical, electrical and fluid connection is ensured to improve the sealed connection with external equipment.

[0056] Step four: the component is annealed in a 120℃ nitrogen furnace for 2h to eliminate residual stress.

[0057] Step five: the optical fiber network is tested by OTDR to locate the loss point and record the initial wavelength-temperature / strain coefficient; the conductive circuit is tested by four-wire method resistance test to establish the resistance-temperature calibration curve; the flow channel is tested by water pressure sealing test to ensure that the leakage rate meets the requirements. Connect the test equipment (such as Figure 8 、 Figure 9 ), confirm the linear response of the optical fiber sensing network to temperature and strain (R²>0.99), and the no-leakage performance of the micro-flow channel under 0.5MPa water pressure, and finally obtain a qualified printed component with multiple materials and multiple functions, i.e. a multi-material and multi-functional structure 1 integrated with embedded optical fiber sensing.

[0058] Step five: the printed component is connected to external laser light source, optical detector, data acquisition card, programmable power supply and cooling liquid circulating pump through standard interface 106 to build an integrated experimental platform of bearing-sensing-conducting-heat exchange; under the combined conditions of static load, cyclic thermal shock and vibration, the comprehensive performance of simultaneously realizing structural bearing, temperature monitoring, strain monitoring, electrical conduction and electrical signal transmission, and micro-flow channel heat exchange is verified.

[0059] In order to verify the effectiveness of the "coupling structure" and "cooperative process" proposed in the present application, the following comparative experiments are carried out:

[0060] Example 1: the multi-material and multi-functional structure 1 integrated with embedded optical fiber sensing obtained by the above manufacturing method is removed, and the diameter 100μm copper wire and the inner diameter 2mm micro-flow channel are arranged in a spiral manner with a spacing of 0.5mm.

[0061] Comparative example 1: the same wire is directly embedded in the polymer matrix without accompanying flow channel.

[0062] Results: the surface equilibrium temperature of the wire in the example is maintained at 45℃, and the resistance value is stable; while the temperature of the wire in the comparative example rises to 120℃ within 2 minutes, resulting in local softening of the matrix and melting of the circuit. This proves the necessity of the "micro-flow channel-wire" coupling structure proposed in the present application in the manufacturing of high-density electronic devices.

[0063] Further verify the interface bonding strength:

[0064] Comparative Example 2: Traditional single-jet step printing (print a layer -> pause -> lay a line -> cover).

[0065] Results: The interfacial shear strength of the heterogeneous material interface layer of the sample of the embodiment reaches 42 MPa, reaching more than 90% of the strength of the pure PEEK matrix, and the optical fiber signal transmission loss is low (<0.02 dB / m); and the shear strength of the comparative example is only 25 MPa due to the obvious cold joint caused by "cold waiting", and the optical fiber is prone to micro-bending loss. This proves that the synergistic manufacturing process of the present application can effectively solve the interface splitting problem of multi-material structure.

Claims

1. A multi-material, multi-functional structure integrating embedded fiber optic sensing, characterized in that, It includes a substrate, microchannels disposed on the substrate, conductors located within the substrate and accompanying the microchannels, and optical fibers located at the interface between the heterogeneous materials of the substrate and the conductors.

2. The multi-material, multi-functional structure for integrated embedded fiber optic sensing according to claim 1, characterized in that, The substrate is made of polylactic acid or polyetheretherketone, the conductor is made of metal, carbon nanotube fiber or conductive polymer, and the optical fiber is made of polyimide coated optical fiber.

3. The multi-material, multi-functional structure for integrated embedded fiber optic sensing according to claim 1, characterized in that, The conductors and microchannels are distributed in parallel, that is, the direction of the conductors is parallel to the axis of the microchannels and the spacing is kept constant; or, the conductors and microchannels are distributed in a spiral winding pattern.

4. The multi-material, multi-functional structure for integrated embedded fiber optic sensing according to claim 1, characterized in that, The conductor diameter is 50-150μm; the microchannel inner diameter is 1-3mm; the distance between the conductor and the microchannel is 0.5-2mm; the optical fiber outer diameter is 125-150μm, and it is embedded in the interface of heterogeneous materials along an S-shaped, spiral, or three-dimensional mesh path with a curvature radius of not less than 10 mm.

5. The multi-material, multi-functional structure for integrated embedded fiber optic sensing according to claim 1, characterized in that, When conductors cross longitudinally, through holes are provided on the substrate to connect conductors in adjacent layers or across layers, and the through holes are filled with conductive medium.

6. The multi-material, multi-functional structure for integrated embedded fiber optic sensing according to claim 5, characterized in that, The conductive medium is silver paste.

7. The multi-material, multi-functional structure for integrated embedded fiber optic sensing according to claim 1, characterized in that, The substrate is provided with a fluid inlet and a fluid outlet that are connected to the microchannel, an electrical interface that connects to the wire, and an optical fiber interface that connects to the optical fiber.

8. The additive manufacturing method for multi-material, multi-functional structures with integrated embedded fiber optic sensing as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Design the spatial coupling structure and use the suspension support optimization algorithm for structural design; Step 2: Divide the forming area into multiple collaborative subdomains, generate motion trajectories based on time-space dual constraints, and execute collaborative operations of multiple printing devices based on slice data; The first printing device is responsible for printing the polymer matrix and the flow channel walls; the second printing device follows the trajectory of the first printing device and presses the wires and optical fibers into the matrix when the matrix temperature is above the glass transition temperature to form a multi-material, multi-functional structure with integrated embedded optical fiber sensing.

9. The additive manufacturing method according to claim 8, characterized in that, it further... include: Step 3: Conformally manufacture the fiber optic interface flange, electrical spring-pin hybrid connector, and fluid quick-connect base on the component surface; the interface area uses polyetheretherketone (PEEK) / carbon fiber (CF) composite material to improve mechanical strength and achieve anti-mating and unmating; after printing, ensure flatness ≤0.02 mm; Step 4: Anneal the multi-material, multi-functional structure with integrated embedded fiber optic sensing to eliminate residual stress.

10. The additive manufacturing method according to claim 9, characterized in that, it further... include: Step 5: Perform OTDR testing on the fiber optic network, locate the loss point, and record the initial wavelength-temperature / strain coefficient; Four-wire resistance testing was performed on the conductive circuit to establish a resistance-temperature calibration curve; a water pressure sealing test was performed on the flow channel to ensure that the leakage rate meets the requirements, confirming that the linear response of the fiber optic sensing network to temperature and strain R²>0.99, and the leak-free performance of the microchannel under 0.5MPa water pressure, finally obtaining a qualified multi-material, multi-functional structure for integrated embedded fiber optic sensing.

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