A pressure-temperature dual-mode sensor and its preparation method and application

Abstract

The present invention provides a pressure-temperature dual-mode sensor, its preparation method, and its application. The pressure-temperature dual-mode sensor utilizes a pressure sensing layer designed as a rectangular array of gradient-tilted magnetic pillars. Due to the gradient variations in length and position of the magnetic pillars and their tilted layout, the gradient-tilted magnetic pillar array creates a unique magnetic field gradient in space. This magnetic field gradient enables the pressure-temperature dual-mode sensor to respond linearly or relatively uniformly to external stimuli of varying magnitudes, broadening the range of pressure testing and effectively addressing the problems of stress concentration in other microstructures and uncertainty and limited measurement range caused by overlapping large structures. Furthermore, the pressure sensing layer and the temperature sensing layer are tested in layers, avoiding crosstalk between temperature and pressure signals and further improving the detection accuracy and precision of the pressure-temperature dual-mode sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible sensors, and in particular to a pressure-temperature dual-mode sensor and a preparation method and application thereof. Background Art

[0002] Existing flexible pressure sensor fabrication techniques typically require combining soft materials with different elastic moduli to achieve high sensitivity and a wide range, ensuring both high sensitivity and a wide range. Furthermore, to cope with complex physical environments, multiple signals must be processed simultaneously. Many multi-mode sensors leave this multi-signal processing to back-end circuitry and algorithms, significantly increasing the complexity of these processes. Traditional multi-mode sensors, which combine multiple materials, often experience some degree of signal interference.

[0003] However, this flexible thin film sensor with multiple sensitive materials stacked on top of each other has the following problems: first, it will greatly increase the volume of the sensor, affecting the flexibility and assembly of the thin film material; second, it will be difficult to control the ratio of each material in this multi-material stacked sensor, resulting in different sensor performance and poor product uniformity; third, there are other pressure sensors with surface microstructures (cones, prisms, cylinders, etc.), but this inevitably leads to stress concentration, the microstructure part is always subject to the greatest force, and larger microstructures undergo cross-overlapping; fourth, multi-mode sensors have signal interference problems, which greatly affects sensor performance.

[0004] Therefore, there is an urgent need for a pressure-temperature dual-mode sensor and its preparation method and application to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a pressure-temperature dual-mode sensor and its preparation method and application, so as to solve the technical problems of the existing pressure-temperature dual-mode sensor in that the pressure test range is too small and the test accuracy is too low.

[0006] To solve the above technical problems, the present invention first provides a pressure-temperature dual-mode sensor, comprising a base layer, a flexible micro-nano coil assembly, an adhesive layer, and a temperature sensing layer stacked in sequence. A pressure sensing layer is provided on a surface of the temperature sensing layer away from the base layer. The pressure sensing layer is an array of gradient-inclined magnetic pillars distributed in a rectangular array.

[0007] The gradient-inclined magnetic column array comprises a plurality of magnetic column groups spaced apart along a first direction, each magnetic column group comprising a plurality of magnetic columns spaced apart and having different lengths along a second direction, the second direction being perpendicular to the first direction; and the lengths of the plurality of magnetic columns within each magnetic column group gradually increase or decrease along the second direction.

[0008] Preferably, the inclination angles of the plurality of magnetic pillars and the plane where the temperature sensing layer is located are equal, and the inclination angle is greater than or equal to 15° and less than or equal to 55°.

[0009] Preferably, the bottom diameter of the magnetic column is 0.5 mm to 1.5 mm; the distance between two adjacent magnetic columns is 0.5 mm to 1.5 mm; and the length of the magnetic column is 0.5 mm to 3.5 mm.

[0010] Preferably, the material of the base layer is soft silicone; and the material of the adhesive layer is silicone adhesive.

[0011] Preferably, along the direction from the base layer to the temperature sensing layer, the flexible micro-nano coil assembly includes a coil base, a first micro-nano coil layer, an intermediate insulating layer, a second micro-nano coil layer and a coil packaging layer stacked in sequence;

[0012] The coil base and coil encapsulation layer are both made of polyimide, and the intermediate insulating layer is made of an insulating polymer. Preferably, the first micro-nano coil layer is connected to a first electrode, and the second micro-nano coil layer is connected to a second electrode. The first and second electrodes are used to connect to an external pressure measurement signal for pressure testing; the temperature sensing layer is connected to a third and fourth electrodes. The third and fourth electrodes are used to connect to an external temperature measurement signal for temperature testing.

[0013] Preferably, the temperature sensing layer is prepared by squeezing a temperature-sensitive solution consisting of a mixture of a temperature-sensitive material and soft silicone into a mold via a syringe; the temperature-sensitive material includes any one of vanadium oxide, Pedot:pss and graphene.

[0014] Preferably, the pressure sensing layer is prepared by pouring a magnetic solution consisting of a mixture of magnetic powder particles and soft silicone into a 3D printing mold and then performing reverse molding; the mass fraction of the magnetic powder particles in the magnetic solution is 10% to 90%; and the magnetic powder particles are neodymium iron boron magnetic powder.

[0015] Accordingly, the present invention further provides a method for preparing the pressure-temperature dual-mode sensor as described in any one of the above items, the method comprising:

[0016] S1, preparing a flexible micro-nano coil assembly on the substrate;

[0017] S2, bonding the temperature sensing layer to the flexible micro-nano coil assembly through an adhesive layer;

[0018] S3, forming a gradient tilted magnetic column array distributed in a rectangular array on the temperature sensing layer to obtain a pressure-temperature dual-mode sensor.

[0019] Correspondingly, the present invention further provides an application of any of the above pressure-temperature dual-mode sensors or the pressure-temperature dual-mode sensor prepared by the above preparation method in robots and wearable electronic products.

[0020] The present invention provides a pressure-temperature dual-mode sensor, a method for preparing the sensor, and its application, unlike existing technologies. The sensor utilizes a pressure sensing layer configured as a rectangular array of gradient-tilted magnetic pillars. The gradient-tilted magnetic pillar array, characterized by its gradient length and position and tilted layout, creates a unique magnetic field gradient in space. When the sensor is operating, this magnetic field gradient causes it to respond linearly or evenly to external stimuli of varying magnitudes. This response exhibits a regular, pressure-matching trend based on the magnetic field gradient. This eliminates the effects of overlap between the magnetic pillars and enables the sensor to output accurate pressure signals over a wide pressure range. This broadens the pressure measurement range and effectively addresses the problems of stress concentration in other microstructures and the uncertainty and limited measurement range caused by overlapping large structures. At the same time, the pressure sensing layer and the temperature sensing layer are tested in layers, which avoids the problem of crosstalk between temperature signals and pressure signals, and further improves the detection accuracy and precision of the pressure-temperature dual-mode sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a pressure-temperature dual-mode sensor provided in Example 1 of the present invention;

[0022] Figure 2 Schematic diagram of an explosion of the pressure-temperature dual-mode sensor provided in Example 1 of the present invention;

[0023] Figure 3 A schematic diagram illustrating the connection between the gradient tilted magnetic column array and the temperature sensing layer in the pressure-temperature dual-mode sensor provided in Example 1 of the present invention;

[0024] Figure 4 A process flow chart of a method for preparing a pressure-temperature dual-mode sensor provided in Example 1 of the present invention;

[0025] In the accompanying drawings: 100 - pressure-temperature dual-mode sensor; 10 - base layer; 20 - flexible micro-nano coil assembly; 21 - coil base; 22 - first micro-nano coil layer; 23 - intermediate insulating layer; 24 - second micro-nano coil layer; 25 - coil packaging layer; 30 - adhesive layer; 40 - temperature sensing layer; 50 - pressure sensing layer; 51 - magnetic column. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a pressure-temperature dual-mode sensor 100 and its preparation method and application, so as to solve the technical problems of the existing pressure-temperature dual-mode sensor 100, such as too small pressure test range and too low test accuracy.

[0028] The present application will now be further described with reference to specific embodiments.

[0029] Example 1:

[0030] See also Figures 1 to 3 Embodiment 1 of the present invention first provides a pressure-temperature dual-mode sensor 100, comprising a base layer 10, a flexible micro-nano coil assembly 20, an adhesive layer 30, and a temperature sensing layer 40 stacked in sequence. A pressure sensing layer 50 is disposed on a surface of the temperature sensing layer 40 away from the base layer 10. The pressure sensing layer 50 is a gradient-inclined magnetic column array distributed in a rectangular array.

[0031] The gradient-inclined magnetic column array comprises a plurality of magnetic column groups spaced apart along a first direction D1. Each magnetic column group comprises a plurality of magnetic columns 51 spaced apart and having different lengths along a second direction D2. The second direction D2 is perpendicular to the first direction D1. The lengths of the plurality of magnetic columns 51 within each magnetic column group gradually decrease along the second direction D2.

[0032] In Example 1 of the present invention, the pressure-temperature dual-mode sensor 100 exhibits a clear layered structure from bottom to top, comprising, in order, a base layer 10, a flexible micro-nano coil assembly 20, an adhesive layer 30, and a temperature sensing layer 40. Furthermore, a pressure sensing layer 50 is located above the temperature sensing layer 40. This layered arrangement allows each component to have a specific function, and they work together to achieve dual-mode pressure and temperature measurement.

[0033] Specifically, the base layer 10 serves as the bottommost supporting structure, providing certain stability and basic physical properties for the entire pressure-temperature dual-mode sensor 100; wherein, the material of the base layer 10 is preferably soft silicone; soft silicone is selected as the material, and soft silicone has good flexibility, deformability and certain elasticity, and can adapt to different usage environments and the surface shape of the object being measured, while providing a stable attachment basis for the upper layers, thereby preventing the overall structure of the pressure-temperature dual-mode sensor 100 from being easily damaged.

[0034] In Example 1 of the present invention, along the direction from the base layer 10 to the temperature sensing layer 40, the flexible micro-nano coil assembly 20 includes a coil base 21, a first micro-nano coil layer 22, an intermediate insulating layer 23, a second micro-nano coil layer 24, and a coil packaging layer 25 stacked in sequence;

[0035] The coil substrate 21 and the coil packaging layer 25 are both made of polyimide, and the intermediate insulating layer 23 is made of insulating polymer. The first micro-nano coil layer 22 and the second micro-nano coil layer 24 are both MEMS (Micro-Electro-Mechanical Systems) coils.

[0036] Specifically, coil substrate 21 not only provides physical support but also, to a certain extent, influences the thermal conductivity, electrical insulation, and other properties of the entire flexible micro-nano coil assembly 20. Its smooth surface provides an excellent foundation for the subsequent fabrication and attachment of the first micro-nano coil layer 22, ensuring that the first micro-nano coil layer 22 can be evenly and stably laid on top, facilitating the realization of precise electromagnetic characteristics.

[0037] Specifically, the core function of the intermediate insulating layer 23 is to provide insulation isolation between the first micro-nano coil layer 22 and the second micro-nano coil layer 24, and can perform electrical connection and signal transmission respectively according to actual needs, providing a guarantee for achieving more complex and more precise electromagnetic functions.

[0038] Specifically, the coil encapsulation layer 25 acts as a "protective shell", encapsulating the entire flexible micro-nano coil assembly 20, so that the assembly can operate normally in different usage environments, whether it is a relatively harsh industrial environment or a special environment such as the human body, reducing the interference and damage to its performance caused by external factors.

[0039] Specifically, both the first micro-nano coil layer 22 and the second micro-nano coil layer 24 are MEMS coils, whose dimensions are at the micro-nano level, typically on the micron or even nanometer scale. This allows them to perform functions such as electromagnetic induction within a very small space, making them ideally suited for integration into the flexible micro-nano coil assembly 20, meeting the development needs of miniaturization and integration. They are also highly sensitive, able to keenly sense subtle changes in physical quantities such as external magnetic fields and generate corresponding electromagnetic induction changes. For example, in magnetic field detection applications, they can accurately capture weak magnetic field fluctuations and convert them into electrical signal outputs, which is crucial for high-precision measurement and detection applications.

[0040] Furthermore, the first micro-nano coil layer 22 and the second micro-nano coil layer 24 are fabricated in a mirror-symmetrical manner to increase the output power of the pressure test signal of the pressure-temperature dual-mode sensor 100. Preferably, the flexible micro-nano coil assembly 20 can also utilize a single-layer, multi-turn micro-nano coil. However, a single-layer, multi-turn micro-nano coil may result in too low an output power of the pressure test signal of the pressure-temperature dual-mode sensor 100, making detection by the back-end circuit difficult. Therefore, it is recommended that the number of micro-nano coil layers in the flexible micro-nano coil assembly 20 be two or more. Furthermore, when combined with an external gradient-tilted magnetic column array, the first micro-nano coil layer 22 and the second micro-nano coil layer 24 can jointly sense the magnetic field changes caused by pressure changes, converting these magnetic field changes into electrical signals, thereby achieving functions such as pressure measurement. Compared to a single-layer MEMS coil, this dual-layer configuration often improves measurement accuracy and reliability.

[0041] In Example 1 of the present invention, the bonding layer 30 uses a silicone adhesive. This material can effectively bond the flexible micro-nano coil assembly 20 and the temperature sensing layer 40 together. It has good bonding performance. Moreover, since it is also a silicone material, it has good compatibility with the adjacent soft silicone base layer 10 in chemical and physical properties, thereby ensuring the stability of the connection between the layers and the overall sealing of the sensor.

[0042] In Example 1 of the present invention, the temperature sensing layer 40 is prepared by squeezing a temperature-sensitive solution consisting of a mixture of a temperature-sensitive material and soft silicone into a mold via a syringe; the temperature-sensitive material includes any one of vanadium oxide, Pedot:pss (a composite of poly (3,4-ethylenedioxythiophene) and poly (4-styrene sulfonate)), and graphene, and in Example 1 of the present invention, Pedot:pss is preferably used.

[0043] Specifically, the temperature sensing layer 40 is connected to a third electrode and a fourth electrode, and the third electrode and the fourth electrode are used to receive an external temperature measurement signal to perform temperature testing.

[0044] Furthermore, the principle of the temperature sensing layer 40 used in the pressure-temperature dual-mode sensor 100 provided by the present invention for temperature testing is as follows:

[0045] The sensing mechanism of the temperature sensing layer 40 involves the contact resistance of the third and fourth electrodes, as well as the bulk resistance of the temperature sensing layer 40. When the temperature changes, the resistance of the temperature-sensitive material changes, causing the bulk resistance of the temperature sensing layer 40 to change. However, because the temperature sensing layer 40 is connected to the third and fourth electrodes, the contact resistance between the two layers remains stable. Therefore, when an external force is applied to the temperature sensing layer 40, the pressure has minimal effect on the bulk and contact resistances of the temperature sensing layer 40. The temperature sensing layer 40 does not respond to external pressure, but only to temperature changes.

[0046] In the first embodiment of the present invention, a pressure sensing layer 50 is provided on a surface of the temperature sensing layer 40 away from the base layer 10. The pressure sensing layer 50 is a gradient tilted magnetic column array distributed in a rectangular array.

[0047] The gradient-inclined magnetic column array includes a plurality of magnetic column groups spaced apart along a first direction D1, each magnetic column group includes a plurality of magnetic columns 51 spaced apart and having different lengths along a second direction D2, and the second direction D2 is perpendicular to the first direction D1; the lengths of the plurality of magnetic columns 51 in each magnetic column group decrease gradually along the second direction D2.

[0048] Specifically, the principle of the pressure-temperature dual-mode sensor 100 provided by the present invention using the pressure sensing layer 50 and the flexible micro-nano coil assembly 20 to perform pressure testing in collaboration is as follows:

[0049] The pressure sensing layer 50 utilizes a gradient-tilted magnetic column array arranged in a rectangular array. It comprises multiple magnetic column groups spaced apart along a first direction D1. Each magnetic column group comprises multiple magnetic columns 51 spaced apart along a second direction D2 (perpendicular to the first direction D1) and with decreasing lengths. The magnetic columns 51 are also tilted at a specific angle relative to the plane of the temperature sensing layer 40. When external pressure is applied to the pressure sensing layer 50, the magnetic columns 51 are subjected to stress, altering their internal magnetic domain structure. This stress changes magnetic parameters such as the magnetic permeability and magnetic moment of the columns 51, thereby altering the magnetic field they generate. Furthermore, the pressure and resulting magnetic field changes vary depending on the position, length, and tilt angle of the magnetic columns 51. For example, the magnetic columns 51 at the edge of the array and those at the center experience different magnetic field changes due to the different forces acting on them.

[0050] When the magnetic field of the magnetic pillars 51 of the pressure sensing layer 50 changes due to pressure, the magnetic flux passing through the MEMS coils (first micro-nano coil layer 22 and second micro-nano coil layer 24) in the flexible micro-nano coil assembly 20 changes accordingly. According to Faraday's law of electromagnetic induction, when the magnetic flux passing through a closed coil changes, an induced electromotive force is generated at both ends of the coil.

[0051] The magnetic field gradient formed by the gradient-tilted magnetic column array of the pressure sensing layer 50 enables the magnetic field changes of the magnetic columns 51 at different positions to complement and cooperate with each other when the pressure changes. Even a slight pressure change can be reflected as a noticeable difference in the magnetic flux and induced electromotive force of the flexible micro-nano coil assembly 20, thereby improving the resolution and accuracy of the pressure measurement, avoiding the situation where small pressure changes cannot be accurately captured due to the uniform and indifferent magnetic field, and realizing accurate measurement of a wide range of pressure values.

[0052] Furthermore, the first micro-nano coil layer 22 is connected to a first electrode, and the second micro-nano coil layer 24 is connected to a second electrode. These electrodes are used to connect to an external pressure measurement signal, conveniently collecting the generated induced electromotive force (EMF) signal and transmitting it to subsequent measurement circuits or processing equipment. By analyzing, calibrating, and performing related conversion operations on the collected electrical signal, the externally applied pressure can be inferred based on the corresponding relationship between the electrical signal and pressure, ultimately realizing the pressure test function and completing the coordinated pressure measurement process between the pressure sensing layer 50 and the flexible micro-nano coil assembly 20.

[0053] In Example 1 of the present invention, the test pressure part in the pressure-temperature dual-mode sensor 100 is a self-powered sensor that does not require external power supply and therefore consumes no energy; the test temperature part in the pressure-temperature dual-mode sensor 100 is a piezoresistive sensor that relies on resistance changes and requires external power supply.

[0054] Specifically, the pressure sensing layer 50 is prepared by a 3D printing process using a magnetic solution consisting of a mixture of magnetic powder particles and soft silica gel; the mass fraction of the magnetic powder particles in the magnetic solution is 10% to 90%, preferably 70%; the magnetic powder particles are preferably neodymium iron boron magnetic powder.

[0055] Furthermore, neodymium iron boron (NdFeB) was chosen as the material for the magnetic powder particles because it is a high-performance permanent magnet. It possesses high remanence, coercivity, and a large maximum magnetic energy product. Remanence means that even after the external magnetic field is removed, the material retains a strong magnetic field. This allows the pressure sensing layer 50 to maintain a relatively stable and strong magnetic field environment even without continuous external magnetic field excitation. This creates a magnetic field of sufficient strength for the pressure sensing layer 50. This strong magnetic foundation allows for significant magnetic field changes to be detected during subsequent pressure measurements.

[0056] Furthermore, when the mass fraction of magnetic powder particles is less than 10%, while the overall magnetic solution has relatively good fluidity, facilitating subsequent 3D printing operations, and the resulting pressure sensing layer 50 is highly flexible, allowing it to better adapt to various surface shapes and certain applications requiring deformation, the relatively small amount of magnetic powder results in a relatively weak magnetic field strength. When subjected to pressure, the magnetic field may change only slightly, which, to a certain extent, affects the sensitivity of pressure measurement, potentially requiring only relatively large pressure changes to produce a recognizable signal change. As the mass fraction of magnetic powder particles increases, approaching 70%, the magnetic field strength significantly increases, and the magnetic field change under pressure becomes more pronounced, which helps improve the accuracy of pressure measurement and the minimum detectable pressure change, thereby increasing sensitivity. However, excessively high magnetic powder content (greater than 70%) can lead to poor fluidity of the magnetic solution, making it more difficult to extrude the material from the nozzle during 3D printing, potentially causing nozzle clogging. Furthermore, the resulting pressure sensing layer 50 becomes less flexible, becoming relatively brittle and susceptible to damage such as cracking when subjected to external forces, impacting its service life and applicability.

[0057] Specifically, the multiple magnetic pillars 51 are tilted at equal angles relative to the plane of the temperature sensing layer 40, with the tilt angle being greater than or equal to 15° and less than or equal to 55°. When the magnetic pillars 51 are tilted, the direction of the magnetic field they generate is no longer simply perpendicular or parallel to a plane, but instead forms a specific tilted orientation in space. For example, compared to magnetic pillars 51 placed perpendicular to a plane, the magnetic field lines generated by tilted magnetic pillars 51 extend and bend along the tilted direction in space. Multiple magnetic pillars 51 are arranged at the same tilt angle, and their magnetic fields overlap and influence each other, forming a complex and regular magnetic field distribution pattern around and above the entire pressure sensing layer 50. This distribution plays a key role in the subsequent realization of the pressure measurement function.

[0058] Furthermore, when the tilt angle is less than 20°, the magnetic pillar 51 is too close to the plane of the temperature sensing layer 40, resulting in a small change in magnetic flux. Consequently, the output pressure signal of the pressure-temperature dual-mode sensor 100 is too small, or even undetectable. This also causes compression and overlap of the magnetic pillars, reducing the accuracy and precision of pressure measurements. When the tilt angle is greater than 40°, the magnetic pillar 51 is too far from the MEMS coil, and the upward bend angle of the magnetic pillar 51 is too small. Consequently, the output pressure signal of the pressure-temperature dual-mode sensor 100 is too small, or even undetectable. Therefore, based on the structural parameters of the magnetic pillar 51 and the output parameters of the pressure-temperature dual-mode sensor 100, under the existing device parameters, the first embodiment of the present invention determines that the two distinguishable signals generated by the pressure-temperature dual-mode sensor 100 during bidirectional bending are optimal when the tilt angle is 35°.

[0059] Specifically, the spacing between adjacent magnetic pillars 51 is 0.5 mm to 1.5 mm, preferably 1 mm. Excessively large spacing between adjacent magnetic pillars 51 results in a bulky device and inconvenience. However, too small a spacing between adjacent magnetic pillars 51 can lead to overlapping of the pillars during bending, resulting in minimal magnetic flux change. This results in a weak output pressure signal from the pressure-temperature dual-mode sensor 100.

[0060] Specifically, the bottom diameter of the magnetic column 51 is 0.5 mm to 1.5 mm, preferably 1 mm; the length of the magnetic column 51 is 0.5 mm to 3.5 mm.

[0061] Furthermore, when the base diameter is smaller, such as approaching 0.5mm, the magnetic field generated by the magnetic pillar 51 is relatively more concentrated in a smaller area around it, and the magnetic field changes are more "steep" in space, that is, the magnetic field gradient is more obvious, which helps improve the resolution of the pressure-temperature dual-mode sensor 100 for small pressure changes and can more accurately sense subtle pressure fluctuations. On the other hand, the magnetic field distribution generated by the magnetic pillar 51 with a larger base diameter is relatively flatter and more uniform. Under higher pressure or when detecting a wide range of pressure changes, its stable magnetic field characteristics can ensure that the overall magnetic field changes remain within the range that can be accurately detected and analyzed, helping to widen the pressure measurement range. Therefore, the appropriate selection of the base diameter size can balance the magnetic field uniformity and gradient to meet different pressure measurement requirements.

[0062] Furthermore, as the length of the magnetic column 51 increases, the distribution of its internal magnetic domains and the intensity of the magnetic field generated to the outside will also change. Generally speaking, within a certain range, the longer the length, the stronger the magnetic field strength may be, but at the same time, the gradient of the change in magnetic field strength along the length direction will also be more complex. For example, under the action of pressure, the difference in magnetic field changes at different length positions will be more significant, which provides more detailed information for accurately measuring pressure by detecting magnetic field changes, helping to improve the accuracy and resolution of measurements, especially for the detection of small pressure changes. For shorter magnetic columns 51, the change in magnetic field intensity is relatively simple and direct, and may be more suitable in some application scenarios where the measurement accuracy requirements are not particularly high and more emphasis is placed on overall stability and simple response relationships.

[0063] Accordingly, see Figures 1 to 4 Embodiment 1 of the present invention further provides a method for preparing a pressure-temperature dual-mode sensor 100 as described above, which realizes a flexible sensor that satisfies both high sensitivity and a wide range by designing a gradient tilted magnetic column array, and specifically comprises the following steps:

[0064] S10 , preparing a flexible micro-nano coil assembly 20 on the base layer 10 .

[0065] Specifically, step S10 further includes:

[0066] A flexible micro-nano coil assembly 20 is prepared on the base layer 10. The flexible micro-nano coil assembly 20 includes, from bottom to top, a coil base 21, a first micro-nano coil layer 22, an intermediate insulating layer 23, a second micro-nano coil layer 24, and a coil packaging layer 25, which are stacked in sequence. The high-density flexible micro-nano coil assembly 20 is prepared by methods such as photolithography, etching, and electroplating. The specific method is shown in Chinese invention patent ZL202311264390.9. The key dimensions, number of turns, and number of layers of the MEMS coil can be designed according to the actual needs of signal output and the accuracy of process equipment, and will not be repeated here.

[0067] S20 , bonding the temperature sensing layer 40 to the flexible micro-nano coil assembly 20 through the bonding layer 30 .

[0068] Specifically, step S20 further includes:

[0069] First, a temperature-sensitive solution obtained by mixing a temperature-sensitive material and soft silicone is poured into a mold to prepare a temperature sensing layer 40 ; then, the temperature sensing layer 40 is bonded to the flexible micro-nano coil assembly 20 through the adhesive layer 30 .

[0070] Furthermore, the temperature-sensitive material can be a temperature-stable material, such as vanadium oxide, Pedot:pss, or graphene. This can be achieved by spin coating or spray coating, or by mixing the temperature-sensitive material with soft silicone to form a temperature-sensitive solution. The specific thickness of the temperature sensing layer 40 depends on the design of the pressure-temperature dual-mode sensor 100.

[0071] S30 , forming a gradient tilted magnetic column array distributed in a rectangular array on the temperature sensing layer 40 to obtain a pressure-temperature dual-mode sensor 100 .

[0072] Specifically, step S30 further includes:

[0073] First, the corresponding gradient tilted magnetic column array area is designed according to the size of the flexible micro-nano coil assembly 20 designed in advance in step S20, and the corresponding gradient structure 3D printing mold is prepared by the 3D printing molding method; then, the magnetic solution obtained by mixing magnetic powder particles and soft silicone is squeezed into the gradient structure 3D printing mold through a syringe to prepare a gradient tilted magnetic column array distributed in a rectangular array; finally, the prepared gradient tilted magnetic column array is assembled with the temperature sensing layer 40 to finally obtain the pressure-temperature dual-mode sensor 100.

[0074] Specifically, through experimental exploration, it was found that the length and tilt angle of the gradient tilted magnetic column array: the tilted magnetic column cannot be designed to be too long, otherwise it will easily cause problems such as tilting and falling to the ground and easily cross-contact with other magnetic columns; the tilted magnetic column cannot be designed to be too short, otherwise the magnetic flux passing through the MEMS coil will be insufficient.

[0075] In this step, the overall dimensions of the gradient-tilted magnetic pillar array are 1 cm x 1 cm. Through experimental exploration, the specific dimensions of the gradient-tilted magnetic pillar array are as follows: the gradient-tilted magnetic pillar array consists of a 4 x 4 array, with the bottom diameter of the magnetic pillars 51 being 1 mm. The lengths of the multiple magnetic pillars 51 in each magnetic pillar group along the second direction D2 are 3.5 mm, 2.5 mm, 1.5 mm, and 0.5 mm, respectively. Each magnetic pillar 51 is tilted at a 35° angle relative to the temperature sensing layer 40. The spacing between adjacent magnetic pillars 51 is 1 mm.

[0076] The present invention provides a gradient tilted magnetic column array that compensates for the contact area during the sequential contact of the magnetic columns 51 from high to low, thereby achieving the design requirement of a wide range. The high uniformity between the pressure-temperature dual-mode sensors 100 comes from the excellent batch-to-batch consistency of the gradient structure mold prepared by the manufacturing process based on 3D printing. When the magnetic column 51 of the top gradient tilted magnetic column array is stimulated externally, the magnetic flux of the magnetic column 51 close to the MEMS coil increases successively, which is the main reason for the increase in the induced electromotive force when the pressure tactile sensor measures the pressure value. At the same time, the temperature sensitive layer changes its resistance value due to the change in temperature through the temperature sensitive material, and a separate lead is used for measurement, avoiding interference with the pressure measurement signal.

[0077] Different from the prior art, the present invention has the following beneficial effects:

[0078] 1. Expanding the pressure test range of the pressure-temperature dual-mode sensor 100: The present invention designs the pressure sensing layer 50 into a gradient tilted magnetic column array, so that the pressure-temperature dual-mode sensor 100 can be tested over a wide range, effectively solving the stress concentration problem of other pressure sensing microstructures and the problem of uncertainty and small measurement range caused by large structure overlap. As the size of the external stimulus changes, the output signal gradually increases.

[0079] 2. Multi-mode sensor for precise multi-signal measurement: Existing sensors, due to the stacking of different sensitive layers, require externally fabricated electrodes for signal measurement, leading to signal interference and a cumbersome production process. This also requires specialized back-end circuitry and algorithms for data processing. The present invention reduces signal crosstalk by separating the temperature sensing layer 40 and the pressure sensing layer 50 for layered measurement, improving sensor signal accuracy and eliminating redundant back-end steps.

[0080] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For any details not described in individual embodiments, reference may be made to the description in other embodiments.

[0081] The above embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A pressure-temperature dual-mode sensor, characterized in that: The invention comprises a base layer, a flexible micro-nano coil assembly, an adhesive layer and a temperature sensing layer stacked in sequence. A pressure sensing layer is provided on a surface of the temperature sensing layer away from the base layer. The pressure sensing layer is a gradient tilted magnetic column array distributed in a rectangular array. The gradient-inclined magnetic column array comprises a plurality of magnetic column groups spaced apart along a first direction, each magnetic column group comprising a plurality of magnetic columns spaced apart and having different lengths along a second direction, the second direction being perpendicular to the first direction; and the lengths of the plurality of magnetic columns within each magnetic column group gradually increase or decrease along the second direction.

2. The pressure-temperature dual-mode sensor according to claim 1, characterized in that: The inclination angles of the plurality of magnetic pillars and the plane where the temperature sensing layer is located are equal, and the inclination angle is greater than or equal to 15° and less than or equal to 55°.

3. The pressure-temperature dual-mode sensor according to claim 1, characterized in that: The bottom diameter of the magnetic column is 0.5 mm to 1.5 mm; the distance between two adjacent magnetic columns is 0.5 mm to 1.5 mm; and the length of the magnetic column is 0.5 mm to 3.5 mm.

4. The pressure-temperature dual-mode sensor according to claim 1, characterized in that: The material of the base layer is soft silicone; the material of the adhesive layer is silicone adhesive.

5. The pressure-temperature dual-mode sensor according to claim 1, characterized in that: Along the direction from the base layer to the temperature sensing layer, the flexible micro-nano coil assembly includes a coil base, a first micro-nano coil layer, an intermediate insulating layer, a second micro-nano coil layer and a coil packaging layer stacked in sequence; The coil substrate and the coil packaging layer are both made of polyimide, and the middle insulating layer is made of insulating polymer.

6. The pressure-temperature dual-mode sensor according to claim 5, characterized in that: The first micro-nano coil layer is connected to a first electrode, the second micro-nano coil layer is connected to a second electrode, and the first electrode and the second electrode are used to connect an external pressure measurement signal for pressure testing; the temperature sensing layer is connected to a third electrode and a fourth electrode, and the third electrode and the fourth electrode are used to connect an external stable measurement signal for temperature testing.

7. The pressure-temperature dual-mode sensor according to claim 1, characterized in that: The temperature sensing layer is prepared by squeezing a temperature-sensitive solution consisting of a mixture of a temperature-sensitive material and soft silica gel into a mold via a syringe; the temperature-sensitive material includes any one of vanadium oxide, Pedot:pss and graphene.

8. The pressure-temperature dual-mode sensor according to claim 1, characterized in that: The pressure sensing layer is prepared by pouring a magnetic solution consisting of a mixture of magnetic powder particles and soft silicone into a 3D printing mold and then performing reverse molding; the mass fraction of the magnetic powder particles in the magnetic solution is 10% to 90%; and the magnetic powder particles are neodymium iron boron magnetic powder.

9. A method for preparing a pressure-temperature dual-mode sensor according to any one of claims 1 to 8, characterized in that: The method comprises: S1, preparing the flexible micro-nano coil assembly on the base layer; S2, bonding the temperature sensing layer to the flexible micro-nano coil assembly through the bonding layer; S3, forming a gradient tilted magnetic column array distributed in a rectangular array on the temperature sensing layer to obtain the pressure-temperature dual-mode sensor.

10. Application of the pressure-temperature dual-mode sensor prepared by the preparation method according to claim 9 in robots and wearable electronic products.

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