In-situ penetrating flexible composite gel network ion temperature sensor and preparation method and application

Abstract

The application discloses an in-situ penetrating flexible composite gel network ion temperature sensor and a preparation method and application thereof. The in-situ penetrating flexible composite gel network ion temperature sensor is prepared by the following steps: mixing PAN and PEO solutions with a LiTFSI composite ion solution, preparing a polymer skeleton through electrostatic spinning, dropping a PBA-SN-LiTFSI mixed solution on the electrostatic spinning film, and then performing in-situ polymerization; adding copper electrodes to both sides of the in-situ penetrating flexible composite gel network ion temperature sensor, leading out silver wires by using silver paste, and finally packaging the in-situ penetrating flexible composite gel network ion temperature sensor by using medical adhesive tape. The in-situ penetrating flexible composite gel network ion temperature sensor prepared by the application has extremely high sensitivity, excellent response recovery speed, temperature sensing resolution and mechanical interference resistance.

Description

Technical Field

[0001] This invention relates to the field of flexible temperature sensor technology, and in particular to an in-situ penetrating flexible composite gel network ion temperature sensor, its preparation method, and its application. Background Technology

[0002] Flexible ion-based temperature sensors utilize the thermal migration and conduction mechanism of ions to construct sensing units. With their excellent surface adhesion, lightweight deformability, and good biocompatibility, they hold significant application value in high-end medical sensing fields such as intraoperative temperature measurement in surgical robots and wearable physiological monitoring. Traditional flexible temperature sensing devices, represented by resistive, thermoelectric, and capacitive types, are technologically mature and are currently the mainstream choice for temperature monitoring in minimally invasive procedures. They are widely used for surface temperature measurement and temperature control in conventional equipment, relying on mature electronic conduction mechanisms. However, these sensors, which rely on electronic conductivity, have inherent limitations. They struggle to simultaneously achieve ultra-high sensitivity and strong anti-interference performance. In situations involving sudden temperature changes during ESD endoscopic surgery and radiofrequency ablation, they are highly susceptible to signal drift caused by intraoperative electromagnetic fields, tissue compression, and instrument bending disturbances. This makes it difficult to accurately capture minute tissue temperature rises of 1–2°C, and the resulting temperature measurement lag can easily lead to medical risks such as organ thermal perforation. Meanwhile, existing conventional ion-hydrogel sensors generally suffer from drawbacks such as low ion migration rates, lithium salt crystallization, and difficulty in synergistically optimizing matrix mechanics and sensing performance. These sensors exhibit insufficient sensitivity, slow response, and poor output stability under deformation, making it difficult to meet the stringent requirements of closed-loop thermal feedback in minimally invasive surgical robots. Furthermore, most ion gels are prone to absorbing water and swelling in humid environments, exhibit poor biocompatibility, and lack antibacterial properties. Additional modified coatings significantly increase device thickness and fabrication processes, raising the difficulty of mass production.

[0003] Therefore, developing an in-situ interpenetrating network flexible composite ion gel temperature sensor with a simple preparation process, integrated structure, and combining ultra-high temperature sensitivity, millisecond-level ultra-fast response, excellent resistance to deformation and electromagnetic interference, and good biocompatibility has significant scientific research value and clinical translation prospects for promoting the localization of intelligent minimally invasive surgical equipment. Summary of the Invention

[0004] To address the common technical shortcomings of existing flexible ion temperature sensors, such as slow response speed, limited sensitivity, poor resistance to mechanical interference, insufficient stability in complex intraoperative environments, and low functional integration, this invention aims to overcome the performance bottlenecks of traditional electronic temperature sensing devices and conventional ion gel sensors. It provides an in-situ penetrating flexible composite gel network ion temperature sensor, its fabrication method, and its applications. This invention constructs a rigid-flexible synergistic three-dimensional interpenetrating network ion conduction system, optimizes ion migration pathways and temperature-sensitive conduction mechanisms, and achieves integrated ultra-high temperature sensitivity, sub-second ultra-fast response speed, excellent mechanical stability, and environmental interference resistance. This makes it fully adaptable to high-precision, high-dynamic clinical monitoring scenarios such as in-situ temperature measurement during minimally invasive surgical robots and endoscopic thermal damage monitoring.

[0005] The first aspect of this invention provides a method for preparing an in-situ penetrating flexible composite gel network ion temperature sensor, specifically comprising the following steps: S1. Preparation of PAN-PEO-LiTFSI electrospinning framework solution: Polyacrylonitrile (PAN), polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) are mixed and dissolved in a specific ratio to prepare a uniform and stable spinning precursor solution. PAN-PEO-LiTFSI nanofiber framework membrane with a three-dimensional porous interconnected structure is prepared by electrospinning process to provide a continuous porous support network for ion transport. S2. Prepare a PBA-SN-LiTFSI thermosensitive gel precursor solution. Use polybutyl acrylate (PBA) as a flexible matrix, succinate (SN) as a crystal-inhibiting modifier, and LiTFSI as an ion-conducting power source to uniformly mix and obtain a homogeneous and transparent precursor mixture. The precursor solution is uniformly dripped onto and impregnated on the surface of the above electrospun fiber skeleton. It completely penetrates into the fiber pores by capillary action. Through a constant-temperature in-situ thermal polymerization reaction, the flexible gel matrix and the rigid nanofiber skeleton form a nanoscale seamless entanglement of a three-dimensional interpenetrating polymer network (IPN) composite gel structure, and obtain an in-situ penetrating composite gel sensing functional layer. S3. High-purity copper foil is bonded to the upper and lower sides of the composite gel sensing layer as current collector electrodes. Conductive silver paste is used to bond and lead out conductive silver wires to ensure that the electrodes are tightly bonded to the gel interface and that the charge is efficiently conducted. Finally, medical flexible insulating tape is used to fully encapsulate the entire device to isolate external moisture, dust and friction interference, and finally a highly sensitive and fast-responding in-situ penetrating flexible composite gel network ion temperature sensor is obtained.

[0006] Further, in step S1, the mass ratio of PAN to PEO is 3:7 to 7:3, the LiTFSI doping amount is 15wt% to 35wt% of the total mass of PAN and PEO, and DMF is used as a solvent to fully stir and dissolve the solution to obtain a uniform and stable spinning solution. The electrospinning process parameters are set as follows: spinning voltage 12 to 18kV, receiving distance 12 to 20cm, and solution propulsion speed 0.3 to 0.8mL / h, to prepare a porous nanofiber framework membrane with uniform fiber diameter and good pore interconnection.

[0007] Further, in step S2, the mass ratio of PBA, SN and LiTFSI is 10:(2.5~3.5):(1.2~2.0). The mixture is stirred continuously at room temperature for 2~4h until the system is completely homogeneous and transparent. After standing to remove bubbles, it is ready for use. The in-situ thermal polymerization temperature is controlled at 55~65℃ and the polymerization time is 90~150min. This enables the PBA monomer to crosslink and solidify in-situ inside the fiber channels, completely eliminating the macroscopic phase interface and constructing a rigid-flexible integrated ion conduction network.

[0008] Furthermore, in step S3, a high-purity copper foil with a thickness of 0.05–0.15 mm is selected as the conductive electrode, and the conductive silver paste is cured at room temperature for 20–40 min to ensure low-impedance contact at the interface; the encapsulation uses a medical flexible tape with a thickness of 80–120 μm, which has excellent biocompatibility, curved surface fit and insulation protection performance.

[0009] The second aspect of the present invention provides an in-situ penetrating flexible composite gel network ion temperature sensor, which is prepared by any of the above-mentioned preparation methods. The device is ultra-thin and flexible, and can be bent and fitted to curved surfaces. It has excellent mechanical adaptability and temperature-sensitive sensing performance.

[0010] A third aspect of this invention provides an application of an in-situ penetrating flexible composite gel network ion temperature sensor. This flexible ion temperature sensor can be widely used in the field of minimally invasive intelligent medicine, and is particularly suitable for precision monitoring scenarios related to minimally invasive thermotherapy, such as in-situ soft tissue temperature measurement during surgical robot surgery, thermal damage monitoring in ESD endoscopic surgery, and dynamic temperature control in ablation surgery. This sensor can be integrated into the surface of surgical robot end effectors, endoscopic probes, and various ablation instruments through methods such as bonding, wrapping, or wrapping, to achieve real-time, in-situ, and high-precision dynamic monitoring of intraoperative temperature.

[0011] Compared with the prior art, the present invention has the following significant advantages: First, this invention constructs a three-dimensional interconnected network structure of a PAN-PEO porous electrospun framework and a PBA-SN ion gel. The electrospun nanofiber framework provides a large number of continuous and unblocked ion transport channels, significantly shortening the lithium ion migration path and effectively improving ion migration efficiency. At the same time, the crystal-inhibiting effect of succinate (SN) can significantly suppress the crystallization and precipitation of LiTFSI lithium salt, release a large number of free charge carriers, weaken the temperature response hysteresis effect, and make the ion migration rate highly sensitive to temperature changes, achieving an ultrafast transient response of 0.9s and an ultra-high temperature sensitivity of 21.62% / ℃. This effectively solves the technical problems of slow response, low sensitivity, and inability to capture minute temperature fluctuations during surgery in traditional ion sensors.

[0012] Secondly, this invention achieves seamless nanoscale entanglement between the gel matrix and the nanofiber skeleton through in-situ polymerization, completely eliminating the macroscopic phase interface of the composite material and significantly improving the overall structural integrity and mechanical stability. Under complex mechanical loads such as repeated bending, compression, and tissue friction during surgery, the ion transport channel structure can remain intact and stable, without interface peeling, structural damage, or signal drift. This effectively overcomes the shortcomings of traditional flexible sensors, such as weak resistance to mechanical interference and poor repeatability, ensuring a continuous and stable output of temperature sensing signals during surgery.

[0013] Finally, this invention utilizes a novel sensing mechanism based on ion-induced thermal conduction, overcoming the drawbacks of traditional electronic sensors that are susceptible to electromagnetic and humidity interference. It is adaptable to complex clinical conditions such as strong electromagnetic fields, high humidity, and dynamic deformation during surgery. The integrated, minimally invasive fabrication process requires no complex modification or multi-layered structures, resulting in a highly efficient and cost-effective process. Furthermore, the material system possesses excellent biocompatibility and surface-fitting capabilities, allowing for stable integration into intelligent surgical robot systems. It provides accurate early warning of intraoperative thermal damage and tissue perforation risks, offering reliable data support for closed-loop thermal feedback control in minimally invasive surgery. This invention demonstrates significant clinical translational value and broad application prospects in the fields of intelligent minimally invasive diagnosis and treatment, wearable physiological monitoring, and human-computer interaction. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1This diagram illustrates the ion migration mechanism of the in-situ penetrating flexible composite gel network of this invention, clearly demonstrating the ion transport enhancement process of the sensor. A. From left to right, it compares the process of pure PAN-PEO framework, the introduction of SN / BA polymer to form jumping sites, lithium salt dissociation enhancement, and finally the construction of a complete high-speed ion migration channel, intuitively revealing the synergistic optimization effect of each component on lithium-ion transport performance; B. A schematic diagram of the microscopic ion migration path after the PAN-PEO electrospun fiber network and PBA-SN-LiTFSI gel are combined, showing the continuous transport track provided by the ether bond (COC) for lithium ions; C. A schematic diagram of the overall sensor structure, from top to bottom: copper electrode, PBA-SN polymer network, and PAN-PEO polymer network framework, clearly defining the distribution of each functional layer and the microscopic ion channel structure.

[0016] Figure 2 The images show the micro / nano structure characterization of the sensor in Embodiment 2 of this invention. A. is an electron micrograph of the surface morphology of pure PBA-SN-LiTFSI gel, showing its dense, non-porous, homogeneous structure; B. is an electron micrograph of the PAN-PEO electrospun nanofiber framework, exhibiting a three-dimensional interwoven, interconnected fiber network; C. is an electron micrograph of the composite gel system and an EDS surface scan distribution map of N, O, and Br elements, confirming that each component is uniformly dispersed within the fiber framework, achieving a full-domain distribution of lithium salt and functional components, and providing a uniform environment for ion transport.

[0017] Figure 3 The following are the core sensing performance test results of the sensor in Embodiment 2 of this invention. Figure A shows the sensitivity comparison curve of the sensor within the range of 20–60℃. The sensitivity of the sensor of this invention reaches 21.62% / ℃, significantly better than the 0.67% / ℃ of traditional flexible sensors. Figure B shows the response and recovery time curves of the sensor. The response time is only 0.9s, and the recovery time is 1.8s, demonstrating sub-second ultrafast response capability. Figure C shows the sensitivity comparison curve of the sensor before and after 2000 mechanical cycles. No significant performance degradation was observed after the cycles, proving its excellent mechanical stability. Figure D shows the dynamic response curve under multiple temperature cycles. The signal is stable and repeatable during the temperature rise and fall process from 20–60℃. Figure E shows the response curve of the step-by-step heating process, which can accurately capture each level of temperature change. Figures F and H show the temperature measurement error curves under different bending strains, torsional angles, and pressure loads, respectively. The results show that the temperature measurement error of the sensor under 200% bending, 90° torsion, and 500kPa pressure is controlled within 0.4℃, demonstrating excellent anti-mechanical interference performance.

[0018] Figure 4This document verifies the application of the sensor in the gastric temperature measurement scenario of an endoscopic robot, as described in Embodiment 2 of the present invention. AB shows a schematic diagram of the sensor integrated into the serpentine keel end of the endoscopic robot and an in vitro porcine stomach model test image, demonstrating that the sensor can closely conform to the curved surface of the instrument and is suitable for clinical operation. C and D show mechanical performance test curves at different temperatures, showing that the stiffness of the composite gel decreases with increasing temperature, possessing mechanical properties that match tissue. E shows a temperature measurement comparison under different physiological environments, confirming that the sensor can work stably in various environments such as the oral cavity, esophagus, and stomach. FG shows the temperature monitoring curve during gastric movement (distension, peristalsis, emptying), with no significant fluctuation in the sensor signal. H shows the temperature response curve throughout the entire process of insertion into the stomach from the outside, achieving continuous monitoring from the inlet to the stomach and verifying its practical value in dynamic physiological environments. Detailed Implementation

[0019] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather should be interpreted based on the principle of allowing the inventors to appropriately define the terminology for the best interpretation, and based on its meaning and concept corresponding to the technical level of the invention. Therefore, the description herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention; thus, it should be understood that other equivalent implementations and modifications can be made without departing from the spirit and scope of the invention.

[0020] The polyacrylonitrile (PAN, Mw≈150000) used in the following embodiments of the present invention was purchased from Maclean Biotechnology Co., Ltd. The polyethylene oxide (PEO, Mw≈600000) used in the following embodiments of the present invention was purchased from Aladdin Reagent Co., Ltd. The lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, purity ≥99%) used in the following embodiments of the present invention was purchased from Maclean Biotechnology Co., Ltd. The butyl acrylate (BA, purity ≥ 99%) and succinic anionyl nitrile (SN, purity ≥ 99%) used in the following embodiments of the present invention were purchased from Aladdin Reagent Co., Ltd. The azobisisobutyronitrile (AIBN) thermal initiator used in the following embodiments of the present invention was purchased from Maclean Biotechnology Co., Ltd. The N,N-dimethylformamide (DMF) organic solvent and anhydrous ethanol used in the following embodiments of the present invention were all analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd. The high-purity copper foil electrodes, conductive silver paste, and medical insulating encapsulation tape used in the following embodiments of the present invention are all commercially available, conventional high-purity laboratory consumables.

[0021] Preparation Example This embodiment provides a method for preparing an ultra-sensitive, ultra-fast response in-situ penetrating flexible composite gel network. The specific steps are as follows: First, polyacrylonitrile (PAN) and polyethylene oxide (PEO) are uniformly mixed at a mass ratio of 5:5. DMF solvent is added to prepare a homogeneous solution with a mass fraction of 12 wt%. Then, LiTFSI ionic salt, accounting for 25 wt% of the total polymer mass, is added. The mixture is stirred continuously at room temperature for 4 hours until it is completely dissolved and the system is clear and transparent, thus obtaining a PAN-PEO-LiTFSI composite spinning precursor solution. The prepared precursor solution is loaded into an electrospinning device, and electrospinning is performed under the process conditions of a spinning voltage of 15 kV, a receiving distance of 16 cm, and a solution propulsion rate of 0.5 mL / h to prepare a three-dimensional porous PAN-PEO-LiTFSI nanofiber framework membrane with interconnected pores and a uniform structure.

[0022] Next, butyl acrylate (BA), succinic anhydride (SN), and LiTFSI were weighed according to a mass ratio of 10:3:1.5. An appropriate amount of DMF solvent was added and the mixture was stirred until homogeneous. A trace amount of AIBN was added as a thermal polymerization initiator. The mixture was stirred at room temperature for 3 hours and then allowed to stand to remove bubbles, thus obtaining a homogeneous PBA-SN-LiTFSI thermosensitive ionogel precursor solution. This precursor solution was then uniformly dropped onto the surface of the PAN-PEO nanofiber framework. Capillary wetting allowed it to completely penetrate into the fiber pores, achieving in-situ filling of the precursor solution within the three-dimensional network.

[0023] Finally, the impregnated composite membrane was placed in a 60℃ constant temperature oven for 120 minutes to allow the BA monomers to undergo in-situ thermal polymerization within the fiber channels, generating a PBA flexible gel matrix. This resulted in a three-dimensional interpenetrating network (IPN) in-situ penetrating flexible composite ionogel functional material with seamless nano-entanglement between the fiber skeleton and the gel matrix, and no macroscopic phase interface. This structure combines the mechanical stability of the PAN-PEO electrospun skeleton with the excellent temperature-sensitive ion conduction characteristics of the PBA-SN system, enabling efficient, stable, and highly sensitive temperature sensing response.

[0024] Example 1 A method for fabricating an ultra-high sensitivity, fast-response in-situ penetrating flexible composite gel network ion temperature sensor includes the following steps: (1) Preparation of PAN-PEO-LiTFSI electrospinning precursor solution: PAN and PEO are mixed at a mass ratio of 5:5, DMF solvent is added to prepare a 12wt% polymer solution, and then 20wt% of LiTFSI ionic salt is added. The mixture is stirred at room temperature for 3 hours until the system is completely clear and transparent. The solution is filtered through a 0.45μm organic filter membrane to remove impurities and allowed to stand to remove bubbles for later use. (2) Preparation of three-dimensional porous rigid framework: The above spinning solution was loaded into an electrospinning device, and the spinning voltage was set to 15kV, the receiving distance to 16cm, and the feed rate to 0.5mL / h. The spinning was carried out continuously for 6h to obtain a PAN-PEO-LiTFSI nanofiber porous framework membrane with uniform thickness and interconnected pores. (3) Preparation of PBA-SN-LiTFSI thermosensitive gel precursor solution: Weigh the raw materials according to the mass ratio of PBA:SN:LiTFSI 10:2.5:1.2, add an appropriate amount of DMF solvent and mix evenly, add a trace amount of AIBN thermal initiator, stir at room temperature for 3h, and let stand at 25℃ for 1h to degas, and obtain a homogeneous thermosensitive ion precursor solution. (4) In-situ construction of interpenetrating network gel functional layer: PBA-SN-LiTFSI precursor liquid is uniformly dripped onto the surface of PAN-PEO fiber skeleton and completely penetrated into the fiber pores by capillary force. It is placed in a constant temperature environment of 60℃ for in-situ thermal polymerization for 90 min, so that PBA monomers crosslink and solidify in three-dimensional channels to form a nano-seamless entanglement and no macroscopic phase interface IPN interpenetrating composite gel sensing layer. (5) Electrode assembly and device packaging: High-purity copper foil is attached to the upper and lower surfaces of the composite gel sensing layer as current collector electrodes. Conductive silver paste is used to bond and conduct the silver wires and cure at room temperature for 30 minutes. Finally, medical flexible insulating tape is used to encapsulate the whole device to isolate external water vapor and mechanical friction interference, thus obtaining an in-situ penetrating flexible composite gel network ion temperature sensor with ultra-high sensitivity and fast response.

[0025] Example 2 A method for fabricating an ultra-high sensitivity, fast-response in-situ penetrating flexible composite gel network ion temperature sensor includes the following steps: (1) Preparation of PAN-PEO-LiTFSI electrospinning precursor solution: PAN and PEO are mixed at a mass ratio of 4:6, DMF solvent is added to prepare a 12wt% polymer solution, and 25wt% of LiTFSI ionic salt is added. The solution is stirred at room temperature for 4h until completely dissolved, filtered through a 0.45μm filter membrane to remove impurities, and allowed to stand at 28℃ for 1.5h to fully degas. (2) Preparation of three-dimensional porous rigid framework: Electrospinning process was adopted, with spinning voltage of 16kV, receiving distance of 16cm and advance rate of 0.5mL / h, to continuously spin and prepare PAN-PEO-LiTFSI nanofiber framework membrane with uniform structure and excellent pore connectivity. (3) Preparation of PBA-SN-LiTFSI thermosensitive gel precursor solution: Weigh the raw materials according to the mass ratio of PBA:SN:LiTFSI 10:3.0:1.5, add DMF solvent and trace amount of AIBN initiator, stir at room temperature for 4h, let stand at 28℃ for 1.5h to degas, and obtain a homogeneous and stable ion gel precursor system. (4) In-situ construction of interpenetrating network gel functional layer: The precursor liquid is completely soaked and filled into the pores of the fiber skeleton, and in-situ polymerization is carried out at 60℃ for 120 min to achieve nanoscale entanglement and composite of rigid fiber skeleton and flexible PBA gel matrix, forming a three-dimensional penetrating sensing network with stable structure and continuous ion pathway. (5) Electrode assembly and device packaging: High-purity copper electrodes are bonded to the upper and lower surfaces, conductive silver paste is cured to lead out the leads, and medical flexible tape is used for overall insulation and packaging to finally obtain a high-performance flexible composite gel ion temperature sensor.

[0026] Figure 2 A cross-sectional SEM image of the composite solid electrolyte (CSE). The PAN-PEO / PBA-SN-LiTFSI composite film obtained by in-situ polymerization was subjected to cryogenic brittle fracture in liquid nitrogen and then treated with platinum (Pt) for conductivity. The cross-sectional microstructure was observed using field emission scanning electron microscopy (FE-SEM) at an accelerating voltage of 5 kV. The results show that the cross-sectional microstructure reveals that the PBA-SN gel matrix completely and seamlessly fills the micro-nano pores of the pre-existing electrospun PAN-PEO nanofiber membrane framework. Due to the 60℃ in-situ thermally initiated polymerization process, the liquid BA monomer directly grows and solidifies in-situ within the fiber gaps, eliminating the macroscopic "solid-solid" layering and macroscopic phase separation interfaces common in traditional composite materials. This three-dimensional interpenetrating network (IPN) and highly dense, seamless interwoven structure at the microscale not only endows the device with excellent mechanical fatigue resistance during gastric peristalsis and stretching but also eliminates interfacial charge transport impedance, laying a solid physical foundation for long-range ion migration in the thickness direction.

[0027] Figure 2 B. SEM images of the composite solid electrolyte (CSE) surface. The surface morphology of the pure PAN-PEO electrospun porous framework membrane before gel filling and the composite film after in-situ polymerization were observed using FE-SEM at an accelerating voltage of 5 kV.

[0028] The results demonstrate that the pure electrospun porous framework exhibits an interwoven, bead-free, high-porosity, three-dimensional continuous porous nanofiber network. After in-situ polymerization, the composite film surface displays a highly smooth, dense, and bubble-free microstructure, indicating that the low-viscosity BA-SN-LiTFSI precursor solution thoroughly wets and encapsulates the surface fiber network thanks to strong capillary effects. This dense surface not only effectively prevents the penetration of external strong acidic fluids and moisture into the device, preventing signal drift, but also ensures extremely low contact resistance and thermal resistance between the device and the upper and lower ultrathin copper foil electrodes.

[0029] Figure 2C composite solid electrolyte (CSE) elemental surface scan distribution images (Mapping). The sensor sample was subjected to low-temperature brittle fracture to prepare a cross-section. FE-SEM combined with energy dispersive spectroscopy (EDS) at an accelerating voltage of 15 kV was used to perform surface scan mapping analysis on characteristic elements such as lithium (Li), fluorine (F), sulfur (S), carbon (C), oxygen (O), and nitrogen (N). Due to the low proton number of lithium, the spatial distribution of fluorine (F) and sulfur (S) was mainly used to indirectly track the occurrence state of LiTFSI lithium salt in the system. The results show that fluorine (F), sulfur (S), oxygen (O), and nitrogen (N) elements exhibit a highly uniform, continuous, and non-agglomerated network distribution in the cross-section and surface space of the entire composite film. This result strongly confirms that, on the one hand, lithium salt achieves amorphous coordination complexation with PEO segments inside the electrospun fibers; on the other hand, lithium salt achieves molecular-level homogeneous dispersion in the PBA-SN solid gel matrix. This continuous and seamless distribution of elements scientifically confirms the spatial continuity of the "dual-ion transport fast superchannel" constructed in this invention, which is synergistically assembled from COC (PEO) and C=O (PBA / PAN) polar functional groups. By eliminating concentration polarization and interfacial energy barriers, this dual channel can promote Li... + The high-speed thermally activated transition gives the device an ultra-high temperature sensitivity of up to 21.62 on a macroscopic scale, and greatly compresses the sensor's response time to an astonishing 0.9s.

[0030] Figure 3 A. Sensitivity curve of relative resistance change rate versus temperature. The packaged full-function sensor was placed on a high-precision programmable heating stage. Within the core window (35~80℃) for monitoring thermal injury during gastric surgery, the ambient temperature was varied. An LCR digital bridge tester was used to record the steady-state resistance change online. The response curve of relative resistance change rate versus temperature was plotted and linearly fitted. The results show that the curve exhibits remarkable thermal activation sensitivity over a wide temperature range, with the calculated temperature coefficient of resistance (TCR) reaching as high as 21.62% / ℃. This ultra-high sensitivity is mainly attributed to the highly dense C=O and COC polar functional groups within the composite electrolyte, which affect the Li... + The strong complexing and dissociation promoting effect of cations, as well as the disintegration of polymer chain crystals by solid succinic acrylonitrile (SN), cause the effective carrier concentration to increase explosively with increasing temperature, providing an extremely sensitive electrical amplification substrate for monitoring minute temperature jumps at the 0.1℃ level in minimally invasive surgery.

[0031] Figure 3B. Dynamic response / recovery time curves of the sensor. The dynamic thermodynamic response rate of the sensor was evaluated using the transient step thermal shock method, recording the time taken for the sensor to rapidly recover to 90% of its steady-state value upon contact with a heat source. The results show that the sensor's dynamic response time is only 0.9 s, and the recovery time is 1.8 s. This indicates that the device possesses sub-second transient capture capability. This is mainly attributed to the nanoscale seamless interface resulting from in-situ thermally initiated polymerization at 60℃, which completely eliminates the contact thermal resistance and ion transport impedance at the macroscopic phase interface, constructing a Li... + The "super channel" for rapid long-range transitions ensures that the closed-loop control center of the gastric surgery robot can issue millisecond-level closed-loop energy blocking warnings.

[0032] Figure 3 C. Sensitivity (TCR) comparison curves before and after 2000 fatigue cycles. The temperature response curves of the sensor in its initial state and after undergoing 2000 high-intensity thermo / mechanical combined fatigue tests are compared. The results demonstrate that after 2000 rigorous cyclic impacts, the sensor's detection slope (TCR value) change rate is <3%, and the two sensitivity fitting curves show almost perfect overlap. This result scientifically demonstrates that the "reinforced concrete" PAN-PEO nanofiber membrane skeleton and PBA-SN gel matrix inside the device possess excellent interfacial shear strength and macroscopic non-delamination characteristics, ensuring that the device's sensitivity does not decrease during long-term clinical use.

[0033] Figure 3 D. Long-term cyclic stability time-series diagram after 2000 consecutive cycles of loading. This shows the continuous time-series waveform of ΔR / R0 during the long-term repeated heating-cooling (or mechanical dynamic loading) composite cyclic alternation process. The results demonstrate that during 2000 long-term cycles, the sensor output waveform is regular and symmetrical, with the baselines of peaks and troughs remaining absolutely flat, without any signal drift, attenuation, or polarization hysteresis. These results strongly demonstrate the excellent physicochemical stability and reversible thermally activated ion transport mechanism of this composite solid electrolyte system, exhibiting extremely high clinical durability and reliability.

[0034] Figure 3 E-step cold test response curve. In the region near body temperature, the ambient temperature was gradually decreased in tiny steps of 0.1℃, and the abrupt changes in the sensor resistance were continuously acquired in real time to evaluate its limiting temperature resolution. The results show that with each tiny step decrease in temperature, the sensor produces a distinct, extremely clear, and hysteresis-free resistance transition response. This confirms that the device possesses a leading 0.1℃ limiting temperature resolution in the field of polymer flexible electronics, capable of perfectly and accurately identifying extremely weak thermal fluctuations in the physiological environment of the gastric cavity within the body.

[0035] Figure 3 F, G, H bending strain, torsion angle and temperature error curves under vertical pressure.

[0036] To comprehensively evaluate the device's anti-interference capability in the face of continuous physiological peristalsis of the stomach wall and deformation grasped by the endoscopic robotic arm, macroscopic bending strains ranging from 0% to 200% were applied to the sensor while maintaining a constant ambient temperature. Figure 3 F), axial torsion angle of 0~200° ( Figure 3 G) and a huge vertical surface pressure of 1~1000kPa ( Figure 3 H), recording the false positive fluctuations in its resistance and converting them into temperature measurement error. The results show that under a large bending strain of 200%, the resulting temperature measurement error is firmly controlled within 0.03℃. Figure 3 F); Under extreme torsion at 200°, the maximum temperature measurement error is significantly lower than 0.1℃ (F). Figure 3 G); When subjected to severe surface pressure of 1000 kPa, the maximum temperature measurement error remains below the absolute safety threshold of 0.4℃. Figure 3 H). Results analysis shows that the device exhibits unparalleled perfect decoupling capability between thermo-mechanical signals. This is entirely due to the ultra-high modulus interpenetrating network (IPN) structure formed by the high-strength continuous PAN nanofiber network acting as a "rigid steel reinforcement" framework, and the deep physical entanglement of the highly elastic PBA gel at the molecular scale. This dense and compressive-resistant structure prevents strong external tension, torsion, or surgical gripping from damaging or altering the internal Li. + The local spatial concentration gradient and transmission driving force eliminate false positive temperature warnings caused by mechanical force during surgery from the underlying physical mechanism, perfectly adapting to the dynamic temperature measurement requirements of the gastric peristalsis environment of the endoscopic surgical robot.

[0037] Example 3 A method for fabricating an ultra-high sensitivity, fast-response in-situ penetrating flexible composite gel network ion temperature sensor includes the following steps: (1) Preparation of PAN-PEO-LiTFSI electrospinning precursor solution: PAN and PEO are mixed at a mass ratio of 6:4, DMF is used to prepare a 12wt% polymer solution, and 30wt% of LiTFSI ion salt is added. The solution is stirred vigorously at room temperature for 5h, filtered through a 0.45μm filter membrane, and allowed to stand at 30℃ for 2h to remove bubbles before use. (2) Preparation of three-dimensional porous rigid skeleton: The spinning voltage was adjusted to 17kV, the receiving distance to 16cm and the feed rate to 0.6mL / h. Electrospinning yielded a PAN-PEO-LiTFSI porous fiber skeleton membrane with uniform pore size and excellent mechanical properties. (3) Preparation of PBA-SN-LiTFSI thermosensitive gel precursor solution: PBA:SN:LiTFSI mass ratio of 10:3.5:2.0 was added, and a trace amount of AIBN initiator was added. The mixture was stirred at room temperature for 5 hours and then allowed to stand at 30°C for 2 hours to remove bubbles, thus preparing a thermosensitive precursor solution with high ion concentration and high stability. (4) In-situ construction of interpenetrating network gel functional layer: After the precursor liquid completely wets the fiber skeleton pores, it is polymerized at 60℃ for 150 min to fully complete the in-situ cross-linking reaction and construct a three-dimensional penetrating IPN composite gel system with dense structure and rich ion transport channels. (5) Electrode assembly and device packaging: bonded copper foil electrodes, silver paste leads are cured, and medical tape is used for full encapsulation to obtain a flexible ion temperature sensor with ultra-high sensitivity, ultra-fast response and high stability.

[0038] Comparative Example 1 The difference between this comparative example and Example 2 is that no succinic anhydride (SN) anti-crystallization modifier is added to the PBA-based thermosensitive gel system.

[0039] Step (3) of this comparative example is modified as follows: Weigh the raw materials according to the mass ratio of PBA:LiTFSI 10:1.5, without adding SN, add an appropriate amount of DMF solvent and a trace amount of AIBN thermal initiator, stir at room temperature for 4 hours, and let stand at 28℃ for 1.5 hours to degas, and obtain the unmodified pure PBA-LiTFSI ion gel precursor solution; the remaining steps of PAN-PEO-LiTFSI spinning solution ratio, electrospinning process parameters, in-situ polymerization conditions, electrode bonding, silver paste conduction and medical tape encapsulation are consistent with those of Example 2, and a flexible composite gel temperature sensor without SN crystal suppression structure is obtained.

[0040] Comparative Example 2 The difference between this comparative example and Example 2 is that: no three-dimensional porous through-fiber skeleton of PAN-PEO-LiTFSI was constructed, and there was no continuous in-situ penetrating ion transport channel.

[0041] In this comparative example, the electrospinning skeleton preparation process in steps (1) and (2) of Example 2 is deleted. Step (4) is changed to: the prepared PBA-SN-LiTFSI thermosensitive gel precursor liquid is uniformly coated on the surface of the flexible substrate and polymerized in situ at a constant temperature of 60°C for 120 min to prepare a pure PBA-SN-LiTFSI monolayer gel sensing functional layer without fiber skeleton support; the remaining gel precursor liquid ratio, polymerization environment, electrode assembly, lead curing and overall encapsulation process are completely consistent with Example 2 to obtain a flexible ion temperature sensor without a three-dimensional interpenetrating network.

[0042] Comparative Example 3 The difference between this comparative example and Example 2 is that the composite interpenetrating design of rigid PAN-PEO electrospun skeleton and flexible PBA gel is abandoned, and a single pure ion gel is used as the sensing body, without a rigid-flexible synergistic support structure.

[0043] This comparative example eliminates the PAN and PEO blend spinning system and uses only pure PBA-SN-LiTFSI gel as the sole sensing material. No nanofiber penetrating network is constructed. The gel polymerization, electrode bonding, silver paste lead and encapsulation processes are completely based on the parameters of Example 2. Only the three-dimensional fiber skeleton composite structure is removed. Finally, a flexible ion temperature sensor with a single homogeneous gel structure is obtained to compare and verify the optimization effect of the IPN interpenetrating network structure on the device's mechanical stability, anti-interference ability and sensing repeatability.

[0044] Test Example 1: Sensitivity The sensors prepared in the examples and comparative examples were placed on a temperature-controlled platform, and the temperature was gradually increased from 25°C to 60°C. The resistance response value corresponding to each temperature change was recorded using a high-precision LCR meter, and the fastest resistance change rate was taken as the sensitivity. The results are shown in Table 1.

[0045] Table 1

[0046] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-3 in Table 1 reveals that the ultra-high sensitivity, fast-response in-situ penetrating flexible composite gel network ion temperature sensor prepared in this invention exhibits excellent response speed. By comparison, the sensitivity of Examples 1-3 is significantly higher than that of Comparative Examples 1-3, indicating that the three-dimensional interconnected network structure of the PAN-PEO porous electrospun framework and PBA-SN ion gel constructed in this invention provides a large number of continuous, unblocked ion transport channels, significantly shortening the lithium-ion migration path and effectively improving ion migration efficiency. Simultaneously, the anti-crystallization effect of succinate (SN) significantly inhibits the crystallization and precipitation of LiTFSI lithium salt, releasing a large number of free carriers, weakening the temperature response hysteresis effect, and making the ion migration rate highly sensitive to temperature changes, achieving an ultra-high temperature sensitivity of 21.62% / ℃. Data comparison shows that the temperature sensitivity of Examples 1-3 (21.62% / ℃, 20.35% / ℃, 20.98% / ℃) is significantly higher than that of the three corresponding pairs (Pair 1: 18.95% / ℃, Pair 2: 19.99% / ℃, Pair 3: 18.35% / ℃), confirming that the three key structural designs of this invention—SN crystal suppression modification, PAN-PEO three-dimensional electrospun porous framework, and in-situ IPN interpenetrating composite network—synergistically improve the temperature sensitivity of the device.

[0047] Succinate (SN) can inhibit the crystallization and aggregation of LiTFSI lithium salt, significantly dissociating more free Li. + The PAN-PEO electrospun skeleton constructs a continuous, interconnected three-dimensional ion transport channel, shortening the lithium-ion migration path and enhancing the temperature-controlled migration variation of ions. The interpenetrating network formed by the in-situ seamless entanglement of PBA gel and nanofibers further optimizes the ion transport environment. With temperature changes, the migration rate of free lithium ions within the system fluctuates more significantly, directly leading to a substantial change in impedance. Ultimately, this allows the composite gel sensor of this invention to achieve a temperature detection sensitivity far superior to that of comparative models, enabling precise identification of minute tissue temperature changes during clinical surgery and meeting the in-situ temperature measurement needs of minimally invasive surgery.

[0048] Test Example 2: Response Rate Test Test method: The sensors prepared in the examples and comparative examples were placed in a temperature cycling chamber, and the temperature was set to switch between 20℃ and 60℃. The resistance change was monitored in real time using an LCR meter, and the response time and recovery time of the sensor from temperature change to resistance stabilization were recorded. The results are shown in Table 2.

[0049] Table 2

[0050] As can be seen from the data comparison between Examples 1-3 and Comparative Examples 1-3 in Table 2, the response time of Examples 1-3 is only 0.8-0.9s and the recovery time is 1.8-2.1s, which are all far superior to the comparative examples (Comparative Example 1: 3.5s / 5.06s, Comparative Example 2: 2.4s / 3.2s, Comparative Example 3: 2.3s / 3.5s). This proves that the synergistic effect of succinate (SN) crystal suppression modification, PAN-PEO electrospun three-dimensional through-framework, and in-situ IPN interpenetrating composite structure significantly shortens the response and recovery time of the device.

[0051] Compared with Comparative Example 1 (without SN), it can be seen that SN in the system can inhibit the crystallization and aggregation of LiTFSI lithium salt and release a large amount of free Li. + This significantly increases the number of free carriers, and the lithium-ion migration rate changes more rapidly with temperature changes, avoiding the response lag caused by lithium salt grains hindering ion diffusion. Comparing with Comparative Example 2 (without PAN-PEO electrospun framework), it can be seen that PAN-PEO porous nanofibers construct continuous, interconnected three-dimensional penetrating ion channels, shortening the lithium ion migration path and overcoming the defects of disordered ion diffusion and high transport resistance inside a frameworkless pure gel. When driven by heat, Li... + It can move rapidly in a directional manner along continuous channels; Comparative Example 3 (without IPN composite structure) shows that PBA gel and PAN-PEO fiber achieve seamless nanoscale entanglement through in-situ polymerization, forming a rigid-flexible integrated interpenetrating network with a regular and stable matrix structure and no distortion of the ion conduction environment under temperature fluctuations.

[0052] When the temperature rises, thermal activation accelerates the directional migration of free lithium ions along the fiber-connected channels, and the system impedance drops rapidly. When the temperature drops, lithium ions reversibly flow back, and the impedance recovers quickly. Relying on the direct sensing mechanism of "temperature regulation - rapid lithium ion migration - instantaneous impedance change", the device achieves sub-second ultrafast response, which is significantly better than traditional ion gel sensors.

[0053] Test Example 3: Temperature Resolution Test The sensors prepared in the examples and comparative examples were placed in a high-precision constant temperature chamber. Starting from 25°C, the temperature was gradually increased to 30°C in increments of 0.01°C. The resistance response value corresponding to each temperature change was recorded using a high-precision LCR meter, and the smallest temperature change that could be stably detected was used as the resolution. The results are shown in Table 3.

[0054] Test Example 3: Mechanical Interference Resistance Test Test method: The sensors prepared in the examples and comparative examples were fixed on a flexible test platform, and 50% bending strain and 90° torsion were applied respectively. The resistance change rate of the sensors was tested under a constant temperature of 25°C to evaluate the influence of mechanical interference on the sensing performance. The results are shown in Table 3.

[0055] Table 3

[0056] A comparison of the data from Examples 1-3 and Comparative Examples 1-3 in Table 3 shows that the in-situ penetrating flexible composite gel ion temperature sensor prepared by this invention possesses excellent resistance to bending, torsion, and mechanical interference. The resistance change rate of Examples 1-3 under 50% bending conditions is only 0.3%-0.4%, and the resistance change rate under 90° torsion is 1.6%-1.9%, all significantly lower than the three comparative sample groups (Example 1: bending 0.6%, torsion 2.2%; Example 2: bending 0.8%, torsion 2.3%; Example 3: bending 1.1%, torsion 3.6%).

[0057] Compared to Comparative Example 1 (without SN modification): Succinate (SN) optimizes the lithium salt dispersion state, avoids the local fragility of ion pathways caused by local crystallization and enrichment of LiTFSI, and does not cause abrupt changes in the conductive channel due to salt crystal breakage during deformation, thus reducing the resistance drift caused by deformation. Compared to Comparative Example 2 (without PAN-PEO electrospun fiber skeleton): PAN-PEO interwoven porous nanofibers form a three-dimensional rigid support skeleton inside the gel, and form an IPN interpenetrating network with the flexible PBA matrix in situ. When under stress, the fiber skeleton disperses the internal stress generated by bending and twisting, avoiding the collapse of pores and ion transport channels after the single gel is squeezed, and maintaining the stability of the ion conduction environment. Compared to Comparative Example 3 (without composite interpenetrating structure, pure gel matrix): the integrated cross-linked structure of rigid fibers and flexible PBA achieves complementary mechanical properties, PBA provides elastic resilience, PAN-PEO fibers constrain large deformations of the matrix and inhibit interlayer slippage, and the gel structure recovers rapidly after deformation is removed.

[0058] This invention relies on the synergistic effect of PAN-PEO fiber network stress buffering, SN-regulated uniform dispersion of lithium salt, and IPN nano-entanglement integrated structure to achieve decoupling between the ion temperature-sensitive conduction mechanism and mechanical deformation. The device resistance is controlled only by the temperature-induced lithium ion migration rate. The mechanical disturbances caused by bending and torsion are unlikely to disrupt the continuous ion transport pathway, effectively suppressing the sensor signal drift caused by deformation. Therefore, it can still stably measure temperature under complex clinical conditions such as repeated bending of surgical instruments and intraoperative tissue compression.

[0059] Experimental Example Figure 4 A physical image of a flexible composite solid-state electrolyte temperature sensor integrated with a surgical robot / endoscope system. Optical photographs show the fabricated ultrathin flexible PAN-PEO / PBA-SN-LiTFSI composite solid-state electrolyte temperature sensor attached and integrated onto the surface of the end-effector (or guide sheath temperature measurement area) of an endoscopic robot. Results demonstrate that the sensor exhibits extremely low thickness profile and excellent macroscopic flexibility, perfectly and tightly conforming to the curved microscale outer surface of the endoscope. The outer medical-grade tape encapsulation not only provides perfect leakage-proof insulation and a waterproof and acid-resistant barrier, but also does not increase the outer diameter of the robot arm, thus not affecting its puncture and forward movement within narrow digestive tracts, demonstrating the device's excellent clinical engineering fit.

[0060] Figure 4B. Schematic diagram of a closed-loop monitoring system for a minimally invasive gastric surgery robot assisted by an intelligent temperature sensor. This demonstrates the overall scenario where an endoscopic robot equipped with the high-sensitivity sensor of this invention enters the gastric cavity through the mouth and esophagus, performing in-situ, close-contact, dynamic monitoring of heat accumulation during energy ablation or removal of diseased tissue. Results show that the device's core hardware role in modern intelligent minimally invasive surgery is clearly established. The weak resistance signal collected by the sensor is exported through a front-end flexible shielded cable and input to a calibrated digital signal processing unit. Finally, the system dynamically outputs the body temperature baseline, thermal damage red zone warning, and closed-loop cutoff feedback signal in real time on the visual terminal software interface, constructing a highly safe clinical application scenario.

[0061] Figure 4 C. Stress-strain (tensile force-displacement) curves of the composite solid electrolyte material at different operating temperatures. The stress-strain behavior of the composite solid gel film under different ambient temperature gradients (e.g., 25℃, 37℃, 50℃, and 70℃) was quantitatively measured using a tensile testing instrument. The results show that the slope of the stress-strain curve of the material slows down significantly and systematically with increasing ambient temperature. The results indicate that the "strong and tough skeleton" constructed by the electrospun PAN-PEO nanofiber membrane and the PBA-SN solid gel possess unique molecular chain segment thermal activation relaxation characteristics at different temperatures, enabling the material to exhibit strong mechanical modulus and compliance that are temperature-sensitively modulated.

[0062] Figure 4 The response curve of the maximum characteristic stiffness of the D composite solid-state electrolyte device as a function of temperature. From... Figure 4 The elastic modulus was extracted at various temperatures in C, and the curve of the maximum characteristic stiffness as a function of continuous increase in ambient temperature was plotted. The results show that the macroscopic stiffness of the device exhibits a remarkably perfect linear decreasing trend with increasing temperature. This discovery demonstrates that the unique "temperature-responsive stiffness adjustable characteristic (variable stiffness)" of the device of this invention can perfectly meet the amphibious core requirements of clinical medical robots: maintaining high rigidity at room temperature or low temperature to ensure smooth and easy advancement of the endoscope and guidance during puncture; and rapidly softening into an ultra-compliant state (low stiffness) when touching room-temperature tissues or when electrosurgical instruments generate heat, achieving non-destructive flexible operation and effectively avoiding mechanical damage to fragile mucous membranes by rigid instruments.

[0063] Figure 4The overall time-series curve of temperature monitoring throughout the entire process of the intelligent endoscope penetrating the stomach was recorded. The waveform of the relative resistance change rate (ΔR / R0) of the guide sheath equipped with sensors was recorded as it moved from the air, through the mouth, across the esophagus, and finally successfully penetrated and remained in the stomach cavity for continuous ablation monitoring. Results show that the entire time-series curve is clear and intuitive. Thanks to the invention's ultra-high sensitivity of 21.62% / ℃ and extremely fast response time of 0.9s, the sensor reproduced the thermal environment evolution as the instrument penetrated deeper into the body in real time with an extremely high signal-to-noise ratio. The transition layers of each anatomical node were clearly defined, demonstrating the device's reliable monitoring capability under all surgical conditions.

[0064] Figure 4 F. Magnified curves showing specific temperature jumps at the esophageal and gastric entry points. The waveform of the transition segment in Figure 4E, where the guide sheath penetrates the esophageal entry point and initially enters the gastric cavity, is analyzed using a localized microscopic time axis magnification. Results show that the magnified curves indicate that in the event of sudden environmental changes or transient contact with moist mucosa, this sensor can instantaneously follow minute temperature fluctuations without delay. The steepness of the curves highly coincides with that of the calibrated thermocouple. These results confirm that the "dual-channel fast transmission super network" interwoven with C=O and COC polar functional groups eliminates traditional interfacial electrochemistry and thermal resistance polarization, enabling second-level transient capture of sudden heat sources.

[0065] Figure 4 G. Steady-state temperature monitoring curve under the dynamic environment of spontaneous physiological mechanical peristalsis in the stomach. When the endoscope tip is closely attached to the stomach wall tissue undergoing continuous and irregular physiological mechanical peristaltic contraction and deformation, the temperature resistance monitoring signal of the sensor is continuously acquired and output. The results show that despite the continuous and intense macroscopic compression and torsional deformation of the stomach wall, the sensor's resistance measurement curve maintains an extremely flat and stable steady-state output, without any jumps or false positives caused by deformation. This strongly confirms the excellent thermo-mechanical signal decoupling capability (decoupling anti-interference capability) of the device of this invention at the in vivo level: the interpenetrating network (IPN) structure locks the geometric shape of the internal ion channels, preventing polarization changes due to external peristaltic compression, and ensuring high accuracy of dynamic in vivo organ environment temperature measurement.

[0066] Figure 4H. Long-term, highly reliable continuous monitoring signal curves throughout a gastric ablation procedure. The sensor remained inside the tissue for an extended period, and high-frequency electrosurgical ablation was initiated, simulating temperature monitoring throughout the procedure for several hours to evaluate the device's long-term operational stability in harsh bodily fluids (highly acidic gastric fluid, pH 1.5). Results show that during continuous, long-term operation, the sensor signal remained stable, with no baseline drift or thermal fatigue attenuation, accurately capturing every minute heat fluctuation generated by the release of electrosurgical energy. In contrast, traditional slow-response sensors exhibit irreversible signal distortion due to liquid penetration or structural delamination. This demonstrates that the nanoscale in-situ polymerized dense composite network and medical tape encapsulation of this invention form an absolute barrier, eliminating fatigue effects and fully meeting the stringent requirements for long-term, highly reliable temperature monitoring throughout clinical ablation procedures.

Claims

1. A method for preparing an in-situ penetrating flexible composite gel network ion temperature sensor, characterized in that, Includes the following steps: S1. PAN, PEO and LiTFSI are mixed and dissolved in an organic solvent to prepare a spinning solution, and PAN-PEO-LiTFSI porous nanofiber framework membrane is prepared by electrospinning process. S2. Prepare a PBA-SN-LiTFSI precursor mixture, uniformly drop the mixture onto the surface of the above nanofiber framework membrane, rely on capillary wetting to penetrate into the fiber pores, and perform in-situ thermal polymerization at 60°C to generate an in-situ 3D interpenetrating network composite hydrogel sensing matrix. S3. Copper foil is attached to the upper and lower sides of the composite hydrogel matrix as current collector electrodes, conductive silver paste is used to bond and lead out conductive leads, and finally medical flexible insulating tape is used to encapsulate the whole to obtain an in-situ interpenetrating flexible composite gel ion temperature sensor.

2. The method for preparing the in-situ penetrating flexible composite gel network ion temperature sensor according to claim 1, characterized in that: In step S1, the mass ratio of PAN to PEO is 3:7 to 7:3, the amount of LiTFSI added is 15wt% to 35wt% of the total mass of PAN+PEO, and the spinning solvent is dimethylformamide (DMF).

3. The method for preparing the in-situ penetrating flexible composite gel network ion temperature sensor according to claim 1, characterized in that: Step S1 Electrospinning process parameters: receiving distance 12-20cm, spinning voltage 12-18kV, feed rate 0.3-0.8mL / h, obtained nanofiber diameter 200-600nm, fiber membrane porosity 55%-75%.

4. The method for preparing the in-situ penetrating flexible composite gel network ion temperature sensor according to claim 1, characterized in that: In step S2, the mass ratio of PBA, SN, and LiTFSI is 10:(2.5~3.5):(1.2~2.0), and the mixture is stirred at room temperature for 2~4 hours to obtain a homogeneous and transparent precursor solution.

5. The method for preparing the in-situ penetrating flexible composite gel network ion temperature sensor according to claim 1, characterized in that: Step S2 in-situ polymerization conditions: constant temperature 55~65℃, thermal polymerization time 90~150min, to achieve in-situ cross-linking and curing of PBA in fiber channels, forming a nano-seamless entangled IPN interpenetrating structure with the electrospun skeleton.

6. The method for preparing the in-situ penetrating flexible composite gel network ion temperature sensor according to claim 1, characterized in that: In step S3, a copper foil with a thickness of 0.05–0.15 mm is used as the electrode, the silver paste is cured at room temperature for 20–40 min, and the medical tape is 80–120 μm thick, waterproof and insulating.

7. An in-situ penetrating flexible composite gel network ion temperature sensor prepared by any one of claims 1 to 6.

8. The application of the in-situ penetrating flexible composite gel network ion temperature sensor as described in claim 7 in intraoperative soft tissue temperature measurement in minimally invasive surgical robots, real-time thermal monitoring in endoscopic ESD surgery, and wearable human physiological temperature measurement products.

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