Tactile temperature co-sensor comprising a flexible substrate material and method of making the same

Abstract

The application discloses a kind of haptic temperature synergic sensor comprising flexible substrate material and preparation method thereof.Sensor includes flexible substrate, arrayed haptic sensing unit and multilayer heterostructure temperature-sensitive layer, multilayer heterostructure temperature-sensitive layer is alternately stacked by pressure-sensitive material layer, thermosensitive material layer and conductive material layer and so on Heterogeneous materials can realize the synergic perception of temperature and pressure.By reasonably designing the material properties and interface structure of each layer, the response performance of the sensor to multiple physical quantities is improved.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, specifically to a tactile temperature co-sensor comprising a flexible substrate material and its preparation method. Background Technology

[0002] In the field of modern intelligent sensing technology, arrayed tactile sensors have been widely used in robotics, smart wearable devices, medical testing, and many other fields. However, traditional arrayed tactile sensors often only sense single physical quantities such as pressure. With the continuous expansion of intelligent application scenarios, for example, when a robot grasps a hot object, it not only needs to sense pressure to adjust its grasping force but also needs to monitor temperature in real time to prevent component damage. In smart wearable devices, simultaneously acquiring skin surface pressure and temperature data is crucial for health monitoring. Therefore, multifunctional sensors capable of simultaneously sensing temperature and pressure have become a research hotspot. However, simply adding a temperature-sensitive layer to a sensor to achieve temperature measurement presents many problems, such as poor compatibility between the temperature-sensitive layer and the original tactile sensing unit, leading to severe signal interference; unreasonable multi-layer structure design causing temperature and pressure signals to couple and be difficult to separate accurately; and traditional processing techniques cannot accurately fabricate micro-nano-scale functional layers, resulting in slow sensor response and low measurement accuracy. Existing technical solutions are insufficient to meet the need for efficient and coordinated sensing of temperature and pressure, necessitating a new technical solution to address these issues and improve sensor performance and application range. Summary of the Invention

[0003] To address the shortcomings of traditional sensors, such as insufficient electrical stability of silicone rubber materials and the lack of ductility despite excellent electrical properties, this invention discloses a tactile temperature co-sensor comprising a flexible substrate material and its fabrication method. This achieves co-sensing of temperature and pressure, expanding the sensor's functional range. The multi-layered heterogeneous structure design, combined with appropriate material selection and process control, effectively improves the sensor's sensitivity, measurement accuracy, and response speed to temperature and pressure.

[0004] In a first aspect, this application provides a tactile temperature-sensitive sensor comprising a flexible substrate material, including: a flexible substrate, an arrayed tactile sensing unit, and a multilayer heterostructure temperature-sensitive layer; the arrayed tactile sensing unit is disposed on the flexible substrate, and the multilayer heterostructure temperature-sensitive layer is disposed on top of the arrayed tactile sensing unit; the multilayer heterostructure temperature-sensitive layer is formed by alternating stacking of at least three nanofilms of different materials, the nanofilms being grown on the flexible substrate by molecular beam epitaxy or chemical vapor deposition, for achieving coordinated sensing of temperature and pressure. In one embodiment, the single-layer thickness of the multilayer heterostructure temperature-sensitive layer is 5nm to 50nm, prepared using molecular beam epitaxy or chemical vapor deposition, and the material combination includes, but is not limited to, metals, semiconductors, insulators, semiconductor heterojunctions, or oxide / nitride composite systems.

[0005] In one embodiment, the multilayer heterogeneous temperature-sensitive layer, by designing the thickness ratio of each layer and the density of interface defects, achieves a temperature response sensitivity ≥0.1% / ℃ and a pressure response sensitivity ≥10kPa. -1 .

[0006] In one embodiment, the arrayed tactile sensing unit includes piezoresistive, piezoelectric, or capacitive sensing sub-units distributed in a matrix, each sub-unit corresponding to an independent multilayer heterostructure temperature-sensitive layer region.

[0007] In one embodiment, a signal decoupling module is further included, which is electrically connected to the arrayed tactile sensing unit and the multilayer heterostructure temperature-sensitive layer, for separating the coupled signals of temperature and pressure.

[0008] Secondly, the present invention also provides a method for fabricating a sensor, comprising: alternately depositing nanofilms of different materials on the flexible substrate using micro-nano fabrication technology to form the multilayer heterostructure thermosensitive layer, wherein the thickness of a single layer is controlled to be 5nm to 50nm by the deposition time; and fabricating the arrayed tactile sensing units on the surface of the flexible substrate or the thermosensitive layer, wherein the arrayed distribution of the units is achieved by a patterning process.

[0009] In one embodiment, the material interface of the multilayer heterogeneous temperature-sensitive layer is optimized by in-situ annealing at a temperature of 200°C to 800°C for 10 minutes to 2 hours to reduce interface stress and improve signal response speed.

[0010] In one embodiment, an insulating layer with a thickness of 1 nm to 10 nm is prepared between the arrayed tactile sensing unit and the multilayer heterostructure thermosensitive layer using atomic layer deposition technology.

[0011] In one embodiment, the top layer material of the multilayer heterostructure temperature-sensitive layer is a transparent conductive oxide, and the bottom layer material is a highly thermally conductive metal, forming an integrated structure of "thermal conduction-sensing-electrical conductivity".

[0012] In one embodiment, the method further includes a step of temperature-pressure cross-calibration of the sensor, which achieves independent calculation of the two physical quantities by establishing a multidimensional response model.

[0013] The tactile temperature co-sensor and its fabrication method, provided by this invention, offer significant advantages. By constructing a multilayer structure from heterogeneous materials such as a pressure-sensitive layer, a thermosensitive layer, and a conductive layer, synergistic sensing of temperature and pressure is achieved, expanding the sensor's functional range. The multilayer heterogeneous structure design, combined with appropriate material selection and process control, effectively improves the sensor's response sensitivity, measurement accuracy, and response speed to temperature and pressure. The inclusion of an insulating transition layer and signal processing circuitry enhances the compatibility between the sensor's functional layers, reduces the impact of interlayer interactions on performance, and achieves accurate separation of coupled signals. Furthermore, the use of micro-nano fabrication techniques such as molecular beam epitaxy and chemical vapor deposition ensures the precise fabrication of the multilayer structure, guaranteeing the consistency and stability of the sensor's performance. In the field of robotic tactile sensing, this sensor can help robots more accurately perceive the temperature and pressure of objects they grasp, improving operational flexibility and safety. In smart wearable devices, it can monitor real-time changes in temperature and pressure on the human skin surface, providing rich data support for health monitoring and human-computer interaction, and has broad application prospects. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a tactile temperature co-sensing sensor structure comprising a flexible substrate material, provided in an embodiment of this application.

[0015] Figure 2 This is a flowchart illustrating the operational steps of the tactile temperature co-sensing transmission method comprising a flexible substrate material provided in this application embodiment. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as being processed sequentially, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. A process can be terminated when its operation is completed, but it may also have additional steps not included in the drawings. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0017] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0018] In existing technologies, arrayed tactile sensors are widely used in robotics, smart wearable devices, medical testing, and many other fields in the field of modern intelligent sensing technology. However, traditional arrayed tactile sensors often only sense single physical quantities such as pressure. With the continuous expansion of intelligent application scenarios, when robots grasp high-temperature objects, it is not only necessary to sense pressure to adjust the grasping force, but also to monitor the temperature in real time to avoid damage to components. In smart wearable devices, simultaneously acquiring skin surface pressure and temperature data is crucial for health monitoring. Therefore, multifunctional sensors capable of simultaneously sensing temperature and pressure have become a research hotspot. However, simply adding a temperature-sensitive layer to a sensor to achieve temperature measurement has many problems, such as poor compatibility between the temperature-sensitive layer and the original tactile sensing unit, leading to severe signal interference; unreasonable multi-layer structure design, causing temperature and pressure signals to be coupled and difficult to separate accurately; and traditional processing technology cannot accurately fabricate micro-nano-scale functional layers, resulting in slow sensor response speed and low measurement accuracy. Existing technical solutions are insufficient to meet the needs of efficient and coordinated sensing of temperature and pressure, and a new technical solution is urgently needed to solve the above problems and improve the performance and application range of sensors.

[0019] Therefore, this application proposes a tactile temperature co-sensor comprising a flexible substrate material and its fabrication method. The sensor includes a flexible substrate, an array of tactile sensing units, and a multilayer heterogeneous temperature-sensitive layer. This multilayer heterogeneous temperature-sensitive layer is composed of alternating layers of heterogeneous materials such as pressure-sensitive materials, thermosensitive materials, and conductive materials, enabling co-sensing of temperature and pressure. By rationally designing the material properties and interface structure of each layer, the sensor's response performance to various physical quantities is improved. Furthermore, the corresponding fabrication process is disclosed, employing micro-nano fabrication techniques such as molecular beam epitaxy and chemical vapor deposition to ensure the precise construction of the multilayer structure. This invention has broad application prospects in fields such as robotic tactile sensing and intelligent wearable devices.

[0020] This embodiment provides a detailed description of an arrayed multilayer heterogeneous tactile temperature sensor incorporating a flexible substrate material and its fabrication method, in order to achieve the technical solution described in the claims. First, the overall structure of the sensor includes a flexible substrate, an arrayed tactile sensing unit, and a multilayer heterogeneous temperature-sensitive layer. The flexible substrate, serving as the basic support structure of the sensor, can be either a silicon flexible substrate or a flexible polyimide flexible substrate. Silicon flexible substrates possess good mechanical stability and processing adaptability, making them suitable for traditional rigid sensors; flexible polyimide flexible substrates, on the other hand, endow the sensor with bendable characteristics, meeting the requirements of flexible electronic devices.

[0021] An array of tactile sensing units is mounted on a flexible substrate. Taking a piezoresistive tactile sensing subunit as an example, each subunit consists of a sensitive resistor and an electrode. The sensitive resistor is made of doped silicon. The pattern of the sensing subunit is defined on the flexible substrate using photolithography, and then the silicon material is doped using ion implantation to form a sensitive region with a piezoresistive effect. The electrode is made of aluminum or copper and is fabricated using sputtering and photolithography etching processes to achieve electrical connection with the sensitive resistor. Multiple piezoresistive tactile sensing subunits are arranged in a matrix to form an array of tactile sensing units, enabling precise sensing of pressure in different areas.

[0022] The multilayer heterogeneous temperature-sensitive layer is the core component for achieving coordinated temperature and pressure sensing. It consists of at least three heterogeneous material layers: a pressure-sensitive material layer, a thermistor material layer, and a conductive material layer. The pressure-sensitive material layer is also made of silicon-doped material, whose piezoresistive effect converts changes in external pressure into changes in resistance. The thermistor material layer uses vanadium oxide thin film, which exhibits significant temperature-resistance characteristics and can sense changes in ambient temperature. The conductive material layer uses graphene thin film or silver nanowire thin film, utilizing their excellent conductivity to achieve efficient transmission of electrical signals. Each material layer is alternately grown on a flexible substrate or an array of tactile sensing units using molecular beam epitaxy or chemical vapor deposition methods.

[0023] In molecular beam epitaxy (MBE), a flexible substrate is placed in a growth chamber under ultra-high vacuum conditions. The intensity and orientation of the molecular beams of each element are precisely controlled, allowing them to grow layer by layer on the surface of the flexible substrate. Chemical vapor deposition (CVD) involves introducing reactive gases into a reaction chamber. Under high temperature or plasma excitation, the gas molecules undergo a chemical reaction, depositing a thin film on the surface of the flexible substrate. During growth, process parameters such as growth temperature, gas flow rate, and beam intensity are strictly controlled to ensure the thickness and quality of each nanofilm layer. The materials are stacked alternately in the order of pressure-sensitive material layer, conductive material layer, and thermosensitive material layer, forming a multilayer heterostructure thermosensitive layer. To enhance the compatibility between the multilayer heterostructure thermosensitive layer and the arrayed tactile sensing unit, an insulating transition layer is set between them. The material used is silicon dioxide or silicon nitride, prepared using atomic layer deposition (ALD) technology, with its ultrathin thickness of 1-5 nm precisely controlled, effectively isolating electrical interference between different functional layers.

[0024] The sensor is also equipped with a signal processing circuit, which is located at the bottom of the flexible substrate or integrated inside the chip. The signal processing circuit is connected to the arrayed tactile sensing unit and the multilayer heterogeneous temperature-sensitive layer via metal wires or conductive vias. This circuit has functions of signal amplification, filtering, A / D conversion, and separation and calculation of temperature and pressure signals. When the sensor is subjected to external pressure and temperature, the arrayed tactile sensing unit and the multilayer heterogeneous temperature-sensitive layer generate corresponding electrical signal changes. After receiving these signals, the signal processing circuit separates the coupled temperature and pressure signals using a preset algorithm and model, ultimately outputting accurate temperature and pressure measurement results.

[0025] Regarding the sensor fabrication method, a selected flexible substrate is first provided. If it is a silicon flexible substrate, its surface needs to be cleaned and polished to remove surface impurities and oxide layers; if it is a flexible polyimide substrate, surface activation treatment is required to enhance the adhesion of subsequent thin film deposition. Next, an array of tactile sensing units is fabricated on the flexible substrate using photolithography and etching processes. During photolithography, photoresist is spin-coated onto the surface of the flexible substrate, exposed through a mask to induce a photochemical reaction in the photoresist, followed by development and etching steps to form the required electrode and sensitive resistor patterns.

[0026] Subsequently, multilayer heterostructure temperature-sensitive layers were alternately grown on a flexible substrate or a pre-fabricated arrayed tactile sensing unit using molecular beam epitaxy or chemical vapor deposition. During growth, the growth parameters of each layer were strictly controlled, such as the growth temperature and gas flow rate of the vanadium oxide temperature-sensitive material layer, to ensure the crystallinity and performance of the film. After growth, the multilayer heterostructure temperature-sensitive layers underwent high-temperature annealing to improve the crystal structure and interfacial properties of the material and enhance interlayer bonding.

[0027] Finally, the signal processing circuit is electrically connected to the arrayed tactile sensing unit and the multilayer heterogeneous temperature-sensitive layer, achieving reliable electrical connection through wire bonding or flip-chip technology. After connection, the sensor is encapsulated using epoxy resin or silicone or other encapsulation materials to protect the internal structure of the sensor from external environmental influences, while ensuring physical contact and signal transmission between the sensor and the outside world.

[0028] As a supporting carrier, the flexible substrate of a sensor directly affects the growth quality of subsequent functional layers and the overall device stability due to its material properties and surface treatment process. For rigid sensor systems, flexible silicon substrates, with their diamond cubic crystal structure, exhibit excellent mechanical strength (elastic modulus up to 190 GPa) and thermal stability (coefficient of thermal expansion of only 2.6 × 10⁻⁶). -6 / ℃), can maintain dimensional stability in a temperature range of -50℃ to 150℃, and is suitable for high-precision industrial measurement scenarios. In practical applications, single-crystal silicon wafers with (100) crystal orientation are preferred, and the thickness is controlled between 500μm and 1mm. This thickness range avoids mechanical deformation caused by excessive thinness and prevents thermal resistance effects introduced by excessive thickness. The surface cleaning process adopts the RCA standard process: first, organic contaminants are removed by a mixture of dilute sulfuric acid and hydrogen peroxide (volume ratio 4:1), then the native oxide layer is etched with hydrofluoric acid buffer (1:50 dilution), and finally ultrasonically cleaned with deionized water and dried with nitrogen to ensure that the surface particle contamination density is <5 particles / mm 2 .

[0029] In the field of flexible electronics, polyimide flexible substrates are relied upon to meet the fit requirements of wearable devices. Commercially available polyimide films (such as DuPont Kapton) are selected with thicknesses ranging from 50μm to 100μm, exhibiting an elongation at break >100% and withstanding over 100,000 bending cycles with a radius >5mm without failure. Surface activation treatment employs inductively coupled plasma (ICP) technology, using an oxygen flow rate of 50sccm and a radio frequency power of 100W for 30 seconds. This introduces hydroxyl (-OH) and carboxyl (-COOH) groups onto the flexible substrate surface through oxygen free radical bombardment, increasing the surface energy from 42mN / m to 68mN / m, significantly enhancing the adhesion of subsequently deposited metal or ceramic films. Experiments show that the interfacial bonding strength between the untreated polyimide flexible substrate and the silica film is only 1.2N / cm, which increases to 5.8N / cm after plasma treatment, effectively preventing interlayer delamination failure.

[0030] The core of a piezoresistive tactile sensing unit is converting mechanical stress into changes in electrical resistance. Its performance depends on the piezoresistive coefficient of the sensitive material and the structural design. Each sensing sub-unit adopts a square layout with a side length of 20μm. This size balances spatial resolution and fabrication feasibility. Structures smaller than 10μm face limitations in photoresist resolution, while those larger than 50μm lead to a decrease in integration density. The unit spacing is set at 50μm. Based on finite element analysis (FEA) results: when the spacing is less than 30μm, the stress field overlap rate of adjacent units is >30%, leading to crosstalk errors; greater than 80μm reduces the number of sensing points per unit area, affecting the accuracy of pressure distribution reconstruction. A 100×100μm 5×5 matrix arrangement is used. 2 For example, the spatial resolution of an array reaches 5 points / mm. 2 It can distinguish 0.1 N / cm 2 The pressure gradient change. In the ion implantation process, boron ions (B...) + With 80keV energy and 1×10 15 ions / cm 2 Dosage was injected into a silicon substrate to form a doped layer with a depth of 200 nm. The doping concentration was verified to be 10⁻⁶ by secondary ion mass spectrometry (SIMS). 18 Up to 10 19 cm -3 This concentration range results in a piezoresistive coefficient π of silicon material. 44 Reaching 100×10 -11 Pa -1 This represents an improvement of two orders of magnitude over intrinsic silicon. To suppress temperature drift, a bridge structure is used for the sensing resistor, with four varistors distributed across the four arms of a Wheatstone bridge. Differential amplification is employed to improve the common-mode rejection ratio caused by temperature to over 80dB. Actual measurements show that this structure exhibits a zero-point drift of <0.05% FS within a temperature range of 0℃ to 80℃, meeting the accuracy requirements of industrial-grade sensors.

[0031] The multilayer heterostructure design of the temperature-sensitive layer follows the principle of "functional layering - signal coupling - interface optimization". The piezoresistive material layer uses a p-type boron-doped single-crystal silicon (100) thin film with a thickness of 200 nm to 500 nm. A (100) preferred orientation is formed through magnetron sputtering combined with annealing to maximize the piezoresistive effect along the

[110] crystal orientation. The boron concentration is 10%. 19 cm -3At this time, the piezoresistive sensitivity factor of the thin film is GF=50, which is 3 times higher than that of amorphous piezoresistive materials. The thermistor material layer is a rutile vanadium oxide (VO2) thin film, which is grown on a sapphire substrate using CVD technology. The reaction gases are VO(OC2H5)3 and oxygen at a flow ratio of 1:10, and a 150nm thick film is formed by deposition at 500℃ for 2 hours. The VO2 thin film prepared under these conditions undergoes a metal-insulator phase transition at 68℃, and the resistance change rate before and after the phase transition is >3 orders of magnitude. Moreover, the temperature coefficient of resistance in the room temperature range (25℃±10℃) reaches 0.8% / ℃, which is significantly better than that of traditional thermistor materials.

[0032] Graphene films were grown on copper foil substrates via chemical vapor deposition. The 4-inch wafer-level films exhibited a sheet resistance of <100 Ω / □ and a transmittance of >90%, making them suitable for transparent sensor designs. Silver nanowire films were prepared using a template method. The nanowires, with a diameter of 80 nm and a length of 50 μm, formed a conductive network with a conductivity of 5 × 10⁻⁶ at a thickness of 100 nm. 6 The structure exhibits a tensile strength of S / m and can withstand 50% tensile deformation without failure. The stacking order of the three-layer structure has been optimized through thermodynamic simulation: the combination of pressure-sensitive layer (silicon-based), conductive layer (graphene), and thermistor layer (VO2) exhibits interlayer thermal stress <10MPa under a pressure of 100kPa and a temperature load of 50℃, which is far below the yield strength of the material (yield strength of silicon-based thin films >100MPa), effectively preventing interface cracking. A 5nm thick amorphous silicon dioxide transition layer is introduced at the interface. By adjusting the sputtering power, the oxygen-silicon ratio is continuously varied from 1.8 to 2.2, forming a gradient refractive index interface, reducing phonon scattering efficiency by 40% and improving thermal signal transmission efficiency.

[0033] The insulating transition layer was prepared using atomic layer deposition (ALD) with tetraethoxysilane (TEOS) and ozone as precursors, reacting at a substrate temperature of 150°C. The deposition thickness was 0.1 nm per cycle, precisely controlled to a target thickness of 1-5 nm. The silica film prepared using this process achieved a density of 2.2 g / cm³. 3 The breakdown field strength is >10MV / cm, and the dielectric loss at 100kHz is <0.01, effectively isolating the leakage current between the tactile unit and the temperature-sensitive layer (measured leakage current <1pA). To address the high-frequency noise coupling problem, a 50nm thick tungsten metal shielding layer is embedded in the transition layer to form an LC filter structure, improving the noise suppression rate above 10MHz to 95%.

[0034] The signal processing circuit employs System-in-Package (SiP) technology, integrating a low-noise amplifier (LNA, noise figure <1dB), a 24-bit Δ-Σ A / D converter (AD7746), and a field-programmable gate array (FPGA) onto a 2mm×2mm chip. The LNA utilizes chopper stabilization technology to reduce 1 / f noise from 100nV / √Hz to 5nV / √Hz. The A / D converter is equipped with a programmable gain amplifier (PGA, gain range 1-128), adaptable to input signal ranges from 0.1mV to 10V. The signal decoupling algorithm is based on Independent Component Analysis (ICA). By constructing a pressure-temperature response matrix, real-time blind source separation is achieved using the FastICA algorithm, with a separation accuracy >99.5%. Under excitation at 10kPa pressure and 30℃ temperature, the decoupled pressure signal error is <0.5%, and the temperature signal error is <0.2℃, meeting the accuracy requirements of medical-grade sensors.

[0035] The packaging process employs a "sandwich" structure: a 200μm thick polyimide buffer layer at the bottom, a 1mm thick thermally conductive silicone layer (thermal conductivity 2.5W / (m·K)) in the middle, and a 50μm thick PTFE wear-resistant layer at the top. This design enables the sensor to withstand 10N / mm² of wear. 2 Under pressure, the flexible substrate deforms by less than 5 μm, and the temperature signal transmission delay is less than 10 ms. The surface anti-oxidation coating uses an atomic layer deposition alumina film; a thickness of 50 nm is sufficient to reduce water vapor permeability to 1 × 10⁻¹² g / (cm²). 2 ·s), significantly improving the sensor's lifespan in a high humidity environment of 95% RH (performance degradation <5% after 1000 hours of actual testing).

[0036] Key process nodes in the fabrication process are controlled in a closed-loop manner: Chemical mechanical polishing (CMP) of the silicon flexible substrate uses a laser scattering instrument to monitor surface roughness in real time. When Ra > 0.2 nm, the polishing pressure (5-15 kPa) and slurry flow rate (50-100 mL / min) are automatically adjusted. During molecular beam epitaxy of vanadium oxide thin films, the crystallization state of the film is monitored in situ using reflected high-energy electron diffraction (RHEED). When the half-width at half-maximum (FWHM) of the diffraction spot is > 0.5°, beam current adjustment is triggered. Annealing is performed in a vacuum tube furnace, with a heating rate of 5°C / min to 550°C and a holding time of 30 minutes. Thermocouple arrays are used to monitor the temperature uniformity within the furnace (±2°C) to ensure sufficient atomic diffusion at the interlayer interfaces. Statistical process control (SPC) analysis shows that the process capability index Cpk of the key process parameters is > 1.67, ensuring a device yield > 95%.

[0037] The optimized sensor was characterized using a standard testing platform. Under combined excitation by a pressure testing unit (range 0-1 MPa, accuracy 0.05% FS) and a temperature control chamber (range -40℃ to 125℃, resolution 0.1℃), the sensor achieved a pressure sensitivity of 15 kPa. -1 It exhibits a temperature sensitivity of 0.8% / ℃ and a response time of <5ms (10%-90% rise time). In 100,000 cyclic loading tests, the zero-point drift is <0.1% FS and the full-scale drift is <0.3% FS, demonstrating excellent long-term stability.

[0038] This sensor has already been applied in industrial robot tactile gloves, acquiring real-time temperature distribution and contact pressure maps of workpiece surfaces via a 10×10 array, successfully solving the problems of force control and thermal damage early warning when gripping high-temperature workpieces (200℃). In the medical field, flexible sensors integrated into smart bandages can simultaneously monitor wound pressure and temperature changes, providing multi-dimensional data support for wound healing. With advancements in micro-nano fabrication technology and materials science, the sensor's structural design can be further expanded to multimodal sensing (such as humidity and strain coupling measurement), and through integration with flexible circuit boards and wireless transmission modules, it will drive the development of next-generation intelligent sensing systems towards miniaturization, integration, and intelligence.

[0039] refer to Figure 2 Secondly, the present invention also provides a method for fabricating a sensor, comprising: alternately depositing nanofilms of different materials on the flexible substrate using micro-nano fabrication technology to form the multilayer heterostructure thermosensitive layer, wherein the thickness of a single layer is controlled to be 5nm to 50nm by the deposition time; and fabricating the arrayed tactile sensing units on the surface of the flexible substrate or the thermosensitive layer, wherein the arrayed distribution of the units is achieved by a patterning process.

[0040] In one embodiment, the material interface of the multilayer heterogeneous temperature-sensitive layer is optimized by in-situ annealing at a temperature of 200°C to 800°C for 10 minutes to 2 hours to reduce interface stress and improve signal response speed.

[0041] In one embodiment, an insulating layer with a thickness of 1 nm to 10 nm is prepared between the arrayed tactile sensing unit and the multilayer heterostructure thermosensitive layer using atomic layer deposition technology.

[0042] In one embodiment, the top layer material of the multilayer heterostructure temperature-sensitive layer is a transparent conductive oxide, and the bottom layer material is a highly thermally conductive metal, forming an integrated structure of "thermal conduction-sensing-electrical conductivity".

[0043] In one embodiment, the method further includes a step of temperature-pressure cross-calibration of the sensor, which achieves independent calculation of the two physical quantities by establishing a multidimensional response model.

[0044] This invention provides an arrayed multilayer heterogeneous tactile temperature co-sensing sensor and its fabrication method, which offer significant advantages. By constructing a multilayer structure from heterogeneous materials such as pressure-sensitive, thermosensitive, and conductive layers, co-sensing of temperature and pressure is achieved, expanding the sensor's functional range. The multilayer heterogeneous structure design, combined with appropriate material selection and process control, effectively improves the sensor's response sensitivity, measurement accuracy, and response speed to temperature and pressure. The inclusion of an insulating transition layer and signal processing circuitry enhances the compatibility between the sensor's functional layers, reduces the impact of interlayer interactions on performance, and achieves accurate separation of coupled signals. Furthermore, the use of micro-nano fabrication techniques such as molecular beam epitaxy and chemical vapor deposition ensures the precise fabrication of the multilayer structure, guaranteeing the consistency and stability of the sensor's performance. In the field of robotic tactile sensing, this sensor can help robots more accurately sense the temperature and pressure of objects they grasp, improving operational flexibility and safety. In smart wearable devices, it can monitor real-time changes in temperature and pressure on the human skin surface, providing rich data support for health monitoring and human-computer interaction, and has broad application prospects.

[0045] Through the above technical solution, this application solves the problem of insufficient synergy between micro and macro structures caused by inaccurate parameter control during the construction of multi-level structures in flexible substrate materials. By adjusting key parameters in real time and providing visual feedback, it ensures that the mechanical support direction of nanofibers is precisely matched with the stress transmission path of macro-periodic units, eliminating abrupt changes in interfacial stress between structural levels, thereby improving the fatigue resistance of flexible substrate materials during repeated stretching. Through deep synergistic optimization of materials, structure, and process, this solution achieves breakthroughs in key indicators such as sensor sensitivity, reliability, and environmental adaptability, providing an engineering solution for multi-physical quantity fusion sensing in complex scenarios, and possessing significant technological innovation value and industrial application potential.

[0046] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application. The scope of this application is determined by the scope of the claims.

Claims

1. A tactile temperature-coordinated sensor comprising a flexible substrate material, characterized in that, include: The system comprises a flexible substrate, an arrayed tactile sensing unit, and a multilayer heterostructure thermosensitive layer. The arrayed tactile sensing unit is disposed on the flexible substrate, and the multilayer heterostructure thermosensitive layer is disposed on top of the arrayed tactile sensing unit. The multilayer heterostructure thermosensitive layer is composed of at least three layers of nanofilms of different materials stacked alternately. The nanofilms are grown on the flexible substrate by molecular beam epitaxy or chemical vapor deposition to achieve coordinated sensing of temperature and pressure. An amorphous silica transition layer with a gradient refractive index is provided between the multilayer heterostructure thermosensitive layer and the arrayed tactile sensing unit. The oxygen-silicon ratio of the amorphous silica transition layer varies continuously from 1.8 to 2.

2. The multilayer heterostructure thermosensitive layer is stacked alternately in the order of pressure-sensitive layer-conductive layer-thermal-sensitive layer. After thermodynamic simulation optimization, the interlayer thermal stress of this stacked structure is < 10 MPa under a pressure of 100 kPa and a temperature load of 50 °C. The thickness of a single layer of the multilayer heterostructure temperature-sensitive layer is 5nm to 50nm. It is prepared by molecular beam epitaxy or chemical vapor deposition. The material combination includes metal, semiconductor, insulator, semiconductor heterojunction or oxide-nitride composite system. The multilayer heterogeneous temperature-sensitive layer, by designing the thickness ratio of each layer and the density of interface defects, achieves a temperature response sensitivity ≥0.1% / ℃ and a pressure response sensitivity ≥10kPa⁻¹.

2. The tactile temperature-coordinated sensor according to claim 1, characterized in that, The arrayed tactile sensing unit includes piezoresistive, piezoelectric, or capacitive sensing sub-units distributed in a matrix, with each sub-unit corresponding to an independent multilayer heterostructure temperature-sensitive layer region.

3. The tactile temperature-coordinated sensor according to claim 1, characterized in that, It also includes a signal decoupling module, which is electrically connected to the arrayed tactile sensing unit and the multilayer heterostructure temperature-sensitive layer, and is used to separate the coupled signals of temperature and pressure.

4. A method for preparing a tactile temperature-coordinated sensor as described in any one of claims 1-3, characterized in that, include: The multilayer heterostructure temperature-sensitive layer is formed by alternately depositing nanofilms of different materials on a flexible substrate using micro-nano fabrication technology, wherein the thickness of a single layer is controlled to be 5nm to 50nm by the deposition time. The arrayed tactile sensing units are fabricated on the surface of the flexible substrate or temperature-sensitive layer, and the arrayed distribution of the units is achieved through a patterning process.

5. The preparation method according to claim 4, characterized in that, The material interface of the multilayer heterogeneous temperature-sensitive layer is optimized through in-situ annealing, with an annealing temperature of 200℃~800℃ and a time of 10min~2h, in order to reduce interface stress and improve signal response speed.

6. The preparation method according to claim 5, characterized in that, An insulating layer with a thickness of 1 nm to 10 nm is prepared between the arrayed tactile sensing unit and the multilayer heterostructure thermosensitive layer using atomic layer deposition technology.

7. The preparation method according to claim 4, characterized in that, The top layer of the multilayer heterostructure temperature-sensitive layer is made of a transparent conductive oxide, and the bottom layer is made of a highly thermally conductive metal.

8. The preparation method according to claim 4, characterized in that, It also includes a step of temperature-pressure cross-calibration of the sensor, and achieves independent solution of the two physical quantities by establishing a multidimensional response model.

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