Capacitance-resistance two-in-one flexible sensor, test system and preparation method

Abstract

The invention relates to the technical field of sensors, in particular to a capacitance-resistance two-in-one flexible sensor, a test system and a preparation method. The flexible sensor comprises a first electrode layer, a second electrode layer and a dielectric layer, the dielectric layer is located between the first electrode layer and the second electrode layer; the dielectric layer comprises composite resin and flexible conductive microspheres dispersed in the composite resin; when the pressure applied to the flexible sensor is smaller than or equal to the critical pressure, the first electrode layer and the second electrode layer are in a disconnected state; when the pressure applied to the flexible sensor is larger than the critical pressure, the flexible conductive microspheres form a conduction path in the dielectric layer, and the first electrode layer and the second electrode layer are connected through the conduction path and are in a conduction state. According to the technical scheme, the flexible sensor is simple in structural design, and cost reduction is facilitated.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a flexible sensor combining capacitance and resistance, a testing system, and a fabrication method. Background Technology

[0002] In the era of artificial intelligence, electronic skin (flexible sensors) is the most critical component of embodied intelligence. It is the core key for intelligent entities to evolve from virtual digital brains into embodied subjects that can interact deeply and securely with the physical world.

[0003] The technical principles behind electronic skin commonly include capacitive, resistive, piezoelectric, and Hall effect sensors, each with its own advantages and disadvantages. Capacitive sensors are sensitive to slight touch and proximity, and have low power consumption, but they are prone to complex signal processing and have a small measurement range. Resistive sensors have a simple structure, low cost, and can measure relatively large pressures, but their sensitivity is relatively low. Piezoelectric sensors have excellent dynamic response, can sense high-frequency vibrations and instantaneous pressure without external power supply, but they cannot measure static forces and their output signal is easily affected by temperature. Hall effect sensors can achieve non-contact operation, but their structure is complex and they are susceptible to magnetic field interference. Currently, the mainstream methods on the market are capacitive and resistive sensors, each with its own advantages and disadvantages and suitable for different scenarios.

[0004] Capacitive-resistive composite electronic skin cleverly combines the advantages of both. It utilizes capacitive sensing to achieve highly sensitive touch, micro-pressure, and proximity detection, while employing resistive sensing to measure a wider range of pressures, even maintaining stable output under high pressure. This composite structure not only broadens the sensor's dynamic detection range but also effectively improves measurement accuracy and reliability through the mutual complementarity and verification of the two signals. It also enhances resistance to environmental interference, making it an efficient strategy for achieving multifunctional, high-performance electronic skin. CN105606270B discloses a capacitive-resistive composite flexible sensor, which uses a capacitive layer and a resistive layer arranged vertically on a flexible substrate. The capacitive layer senses tactile information, while the resistive layer senses pressure information, with the capacitive layer positioned above the resistive layer. This invention effectively combines the advantages of both resistive and capacitive sensors, distinguishing the tactile force of capacitance while incorporating the large range and stability of resistance. However, this invention achieves its effect by stacking two structures, resulting in a complex structure, greater thickness, and higher cost. Summary of the Invention

[0005] To solve the above-mentioned technical problems, or at least partially solve them, the present invention provides a flexible sensor combining capacitance and resistance, a testing system, and a preparation method, which simplifies the design of the flexible sensor structure and helps to reduce costs.

[0006] In a first aspect, the present invention provides a flexible sensor combining capacitance and resistance, comprising:

[0007] The electrode layer comprises a first electrode layer, a second electrode layer, and a dielectric layer; the dielectric layer is located between the first electrode layer and the second electrode layer; the dielectric layer includes a composite resin and flexible conductive microspheres dispersed in the composite resin.

[0008] When the pressure applied to the flexible sensor is less than the critical pressure, the first electrode layer and the second electrode layer are disconnected; when the pressure applied to the flexible sensor is greater than or equal to the critical pressure, the flexible conductive microspheres form a conductive path in the dielectric layer, and the first electrode layer and the second electrode layer are connected through the conductive path and are in a conductive state.

[0009] In some embodiments, the flexible conductive microsphere includes a central elastomer and a conductive layer; the conductive layer covers the surface of the central elastomer.

[0010] In some embodiments, the material forming the central elastomer is any one of polystyrene, silicone, butyl rubber, and acrylic acid.

[0011] In some embodiments, the material forming the conductive layer is any one of nano-gold, nano-silver, nano-carbon, nano-copper, and carbon nanotubes.

[0012] In some embodiments, the composite resin is formed by mixing a resin and a curing agent.

[0013] In some embodiments, the first electrode layer and the second electrode layer are copper foil or aluminum foil;

[0014] Alternatively, the first electrode layer and the second electrode layer are formed by printing conductive paste onto a substrate.

[0015] Secondly, the present invention also provides a sensor testing system, comprising:

[0016] The flexible sensor that combines capacitance and resistance as described in the first aspect;

[0017] A signal detection element, wherein both the first electrode layer and the second electrode layer are connected to the signal detection element.

[0018] In some embodiments, the sensor testing system further includes:

[0019] First test line and second test line;

[0020] The first test line is fixedly connected to the first electrode layer, and the second test line is fixedly connected to the second electrode layer;

[0021] The first test line and the second test line are used to connect to the signal detection element.

[0022] Thirdly, the present invention also provides a method for fabricating a flexible sensor, used to fabricate the flexible sensor as described in the first aspect; the fabrication method includes:

[0023] Fabrication of a first electrode layer, a second electrode layer, and a dielectric material;

[0024] The dielectric material is scraped onto one side of the first electrode layer and cured for a first preset time;

[0025] The second electrode layer is placed over the side of the first electrode layer coated with dielectric material and cured for a second preset time to form a dielectric layer between the first electrode layer and the second electrode layer.

[0026] In some embodiments, the preparation of the dielectric material includes:

[0027] We provide resins, curing agents, and flexible conductive microspheres;

[0028] The resin is added to the curing agent and stirred for a third preset time to form a composite resin;

[0029] The flexible conductive microspheres are added to the composite resin and stirred for a fourth preset time to form the dielectric material.

[0030] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0031] The flexible sensor provided in this invention includes: a first electrode layer, a second electrode layer, and a dielectric layer; the dielectric layer is located between the first and second electrode layers; the dielectric layer includes a composite resin and flexible conductive microspheres dispersed in the composite resin; when the pressure applied to the flexible sensor is less than a critical pressure, the first and second electrode layers are disconnected; when the pressure applied to the flexible sensor is greater than or equal to the critical pressure, the flexible conductive microspheres form a conductive path in the dielectric layer, and the first and second electrode layers are connected through the conductive path and are in a conductive state. Therefore, by setting a flexible sensor formed by the first electrode layer, the second electrode layer, and the dielectric layer, switching between capacitive and resistive sensors can be achieved to sense tactile and pressure information. This flexible sensor has a simple structural design, which helps to reduce costs. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a flexible sensor combining capacitance and resistance provided in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of another flexible sensor combining capacitance and resistance provided in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of a sensor testing system provided in an embodiment of the present invention;

[0037] Figure 4 This is a schematic flowchart illustrating a method for fabricating a flexible sensor according to an embodiment of the present invention.

[0038] Among them, 11 is the first electrode layer; 12 is the dielectric layer; 13 is the second electrode layer; 121 is the composite resin; 122 is the flexible conductive microsphere; 01 is the central elastomer; 02 is the conductive layer; 14 is the first test line; 15 is the second test line; and 16 is the signal detection element. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0041] The flexible sensor provided in this invention includes: a first electrode layer, a second electrode layer, and a dielectric layer; the dielectric layer is located between the first and second electrode layers; the dielectric layer includes a composite resin and flexible conductive microspheres dispersed in the composite resin; when the pressure applied to the flexible sensor is less than a critical pressure, the first and second electrode layers are disconnected; when the pressure applied to the flexible sensor is greater than or equal to the critical pressure, the flexible conductive microspheres form a conductive path in the dielectric layer, and the first and second electrode layers are connected through the conductive path and are in a conductive state. Therefore, by setting a flexible sensor formed by the first electrode layer, the second electrode layer, and the dielectric layer, switching between capacitive and resistive sensors can be achieved to sense tactile and pressure information. This flexible sensor has a simple structural design, which helps to reduce costs.

[0042] The following description, in conjunction with the accompanying drawings, provides an exemplary account of the flexible sensor combining capacitance and resistance, the testing system, and the fabrication method provided in the embodiments of the present invention.

[0043] Figure 1 This is a schematic diagram of the structure of a flexible sensor combining capacitance and resistance, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another flexible sensor combining capacitance and resistance provided in an embodiment of the present invention. Figure 1 The flexible sensor shown is in a state below the critical pressure. Figure 2 The flexible sensor shown is in a state at or above the critical pressure.

[0044] like Figure 1 and Figure 2 As shown, the flexible sensor includes: a first electrode layer 11, a second electrode layer 13, and a dielectric layer 12; the dielectric layer 12 is located between the first electrode layer 11 and the second electrode layer 13; the dielectric layer 12 includes a composite resin 121 and flexible conductive microspheres 122 dispersed in the composite resin 121.

[0045] When the pressure applied to the flexible sensor is less than the critical pressure, the first electrode layer 11 and the second electrode layer 13 are disconnected; when the pressure applied to the flexible sensor is greater than or equal to the critical pressure, the flexible conductive microspheres 122 form a conductive path in the dielectric layer 12, and the first electrode layer 11 and the second electrode layer 13 are connected through the conductive path and are in a conductive state.

[0046] Specifically, in this embodiment of the invention, the flexible sensor is configured as a two-in-one structure, which is formed by a first electrode layer 11, a second electrode layer 13, and a dielectric layer 12. When the flexible sensor is subjected to a force less than the critical pressure, i.e., when the force is small, the flexible conductive microspheres 122 do not contact each other, or the flexible conductive microspheres 122 are not connected to the first electrode layer 11, or the flexible conductive microspheres 122 are not connected to the second electrode layer 13. This achieves a disconnect between the first electrode layer 11 and the second electrode layer 13, meaning that the upper and lower electrodes of the flexible sensor are not conductive. At this time, the flexible sensor is a capacitive sensor.

[0047] When the flexible sensor is subjected to a force greater than or equal to the critical pressure, i.e., when the force is relatively large, the flexible conductive microspheres 122 move and come into contact with each other and with the upper and lower electrodes, thereby forming a conductive path between the first electrode layer 11 and the second electrode layer 13. This achieves a conductive state between the first electrode layer 11 and the second electrode layer 13, meaning that the upper and lower electrodes of the flexible sensor are conductive, and the flexible sensor functions as a resistive sensor. Furthermore, when the flexible sensor is a resistive sensor, as the force increases, the flexible conductive microspheres 122 make more contacts, and the resistance of the resistive sensor decreases.

[0048] Therefore, the flexible sensor combining capacitance and resistance in this embodiment of the invention can switch between capacitive and resistive sensors. The capacitive sensor is used to sense tactile information (smaller pressure), and the resistive sensor is used to sense pressure information (greater pressure).

[0049] In existing technologies, a capacitor layer and a resistive layer are arranged vertically on a flexible substrate. The capacitor layer is used to sense tactile information, and the resistive layer is used to sense pressure information. The capacitor layer is located above the resistive layer, effectively combining the advantages of both resistive and capacitive sensors. It can distinguish the tactile force of capacitance while also combining the large range and stability of resistance. However, this is achieved by stacking the two structures together, resulting in a complex structure, a relatively thick layer, and high cost. Compared to existing technologies, the embodiments of the present invention, by setting a flexible sensor formed by a first electrode layer 11, a second electrode layer 13, and a dielectric layer 12, can switch between capacitive and resistive sensors to sense both tactile and pressure information. This flexible sensor has a simple structure design, which can reduce design costs.

[0050] In some embodiments, such as Figure 1 or Figure 2 As shown, the flexible conductive microsphere 122 includes a central elastic body 01 and a conductive layer 02; the conductive layer 02 covers the surface of the central elastic body 01.

[0051] Specifically, by setting the flexible conductive microspheres 122 to include a central elastic body 01 and a conductive layer 02, when the dielectric layer 12 is subjected to external pressure and reaches a critical pressure, the flexible conductive microspheres 122 can move and contact each other, and the flexible conductive microspheres 122 can be connected, thereby forming a conductive path between the first electrode layer 11 and the second electrode layer 13, so as to realize that the first electrode layer 11 and the second electrode layer 13 are in a conductive state.

[0052] In some embodiments, such as Figure 1 or Figure 2 As shown, the material forming the central elastomer 01 is any one of polystyrene, silicone, butyl rubber, and acrylic acid.

[0053] Polystyrene, being lightweight and highly elastic, easily deforms under stress and quickly returns to its original shape after the external force is removed. It also exhibits good chemical stability and is unlikely to react with the conductive layer. Using polystyrene as the central elastomer allows the conductive layer to deform and contact under pressure, and to rapidly rebound after the pressure is released, ensuring the "repeatable deformation-recovery" performance of the flexible conductive microspheres.

[0054] Silicone exhibits excellent elasticity, can withstand large deformations, is resistant to high and low temperatures (-50℃~200℃), is resistant to aging, has strong chemical inertness, and excellent flexibility, making it suitable for repeated compression and rebound scenarios. Using silicone as a central elastomer allows it to maintain its performance under long-term stress cycles while adapting to different environmental conditions (such as temperature variations).

[0055] Butyl rubber, in particular, exhibits excellent elasticity, airtightness, aging resistance, and a stable molecular structure, making it resistant to oxidation or corrosion and allowing for rapid deformation recovery under stress. Using butyl rubber as the central elastomer can enhance the structural stability of flexible conductive microspheres while ensuring elasticity (especially in long-term use or complex environments, preventing loss of elasticity due to aging or oxidation).

[0056] Acrylic acid, in particular, possesses flexibility and excellent elasticity, allowing for adjustments to its elastic parameters to meet specific requirements. Using acrylic acid as a central elastomer enables designs with varying "stress-conduction" sensitivities.

[0057] Therefore, polystyrene, silicone, butyl rubber and acrylic acid share common properties such as good elasticity, strong deformation recovery ability and high chemical stability, and can be used to prepare the central elastomer in this embodiment.

[0058] In some embodiments, the central elastomer may also be made of other materials known to those skilled in the art, which will not be described in detail or limited herein.

[0059] In some embodiments, such as Figure 1 or Figure 2As shown, the material forming the conductive layer 02 is any one of nano-gold, nano-silver, nano-carbon, nano-copper, and carbon nanotubes.

[0060] Among them, nano-gold, nano-silver, nano-carbon, nano-copper and carbon nanotubes have excellent electrical conductivity and can be easily and uniformly coated on the surface of the central elastomer 01 at the nanoscale to form a continuous conductive layer 02.

[0061] In some embodiments, such as Figure 1 or Figure 2 As shown, composite resin 121 is formed by mixing resin and curing agent. Specifically, composite resin 121 is formed by mixing and stirring the resin and curing agent evenly.

[0062] In some embodiments, such as Figure 1 or Figure 2 As shown, the first electrode layer 11 and the second electrode layer 13 can be copper foil or aluminum foil.

[0063] In some embodiments, such as Figure 1 or Figure 2 As shown, the first electrode layer 11 and the second electrode layer 13 can be formed by printing conductive paste onto the substrate.

[0064] Specifically, the conductive paste is first prepared in proportion and adjusted to a consistency suitable for printing; the paste is then printed onto a designated area of ​​the substrate according to a preset pattern using printing equipment; the printed substrate is then heated (or irradiated with ultraviolet light) to allow the solvent to evaporate, the adhesive to cure, and the conductive filler to be firmly fixed, forming the first electrode layer 11 and the second electrode layer 13.

[0065] In some embodiments, the first electrode layer 11 and the second electrode layer 13 can also be made of silver nanowires to form transparent electrodes, and the embodiments of the present invention are not specifically limited here.

[0066] Based on the above embodiments, the present invention also provides a sensor testing system. Figure 3 This is a schematic diagram of a sensor testing system provided in an embodiment of the present invention. Figure 3 As shown, the sensor testing system includes a signal detection element 16 and a flexible sensor combining capacitance and resistance as described in the above embodiment, and therefore has the same or similar beneficial effects, which will not be elaborated here.

[0067] like Figure 1 or Figure 2 As shown, both the first electrode layer 11 and the second electrode layer 13 are connected to the signal detection element 16. In this way, the signal detection element 16 can acquire the capacitance signal or resistance signal of the flexible sensor, so as to obtain the corresponding capacitance value or resistance value based on the capacitance signal or resistance signal.

[0068] There is a first preset relationship between the capacitance value and the corresponding pressure value, and a second preset relationship between the resistance value and the corresponding pressure value. These first and second preset relationships can be pre-defined and obtained. Therefore, once the capacitance or resistance value is obtained, the corresponding pressure value can be determined based on the aforementioned first and second preset relationships.

[0069] For example, the signal detection element 16 is an LCR meter, through which the capacitance or resistance value of the flexible sensor can be obtained.

[0070] In some embodiments, such as Figure 3 As shown, the sensor testing system also includes:

[0071] First test line 14 and second test line 15;

[0072] The first test line 14 is fixedly connected to the first electrode layer 11, and the second test line 15 is fixedly connected to the second electrode layer 13; the first test line 14 and the second test line 15 are used to connect to the signal detection element 16.

[0073] Specifically, a first test line 14 is soldered onto the first electrode layer 11, and a second test line 15 is soldered onto the second electrode layer 13. After connecting the first test line 14 and the second test line 15 to the signal detection element 16, the capacitance or resistance value of the flexible sensor can be obtained.

[0074] Based on the above embodiments, the present invention also provides a method for preparing a flexible sensor, which is used to prepare a flexible sensor as described in the above embodiments. Therefore, it has the same or similar beneficial effects, which will not be elaborated here.

[0075] Figure 4 This is a schematic flowchart illustrating a method for fabricating a flexible sensor according to an embodiment of the present invention. Figure 4 As shown, the preparation method includes:

[0076] S301. Prepare the first electrode layer, the second electrode layer, and the dielectric material.

[0077] Specifically, this step involves preparing the first electrode layer, the second electrode layer, and the dielectric material to prepare for S302.

[0078] In some embodiments, the first electrode layer, the second electrode layer, and the dielectric material can be prepared in advance and used directly.

[0079] S302. Apply dielectric material to one side of the first electrode layer and pre-cur it for a first preset time.

[0080] Specifically, in this step, the dielectric material is coated on one side surface of the first electrode layer, and then the dielectric material is pre-cured.

[0081] S303. The second electrode layer is placed over the side of the first electrode layer on which the dielectric material is coated, and cured for a second preset time, so that the dielectric material forms a dielectric layer between the first electrode layer and the second electrode layer.

[0082] Specifically, in this step, the second electrode layer is placed over the side of the first electrode layer on which the dielectric material is coated, and then cured for a second preset time, after which the dielectric material is cured.

[0083] In some embodiments, the preparation of the dielectric material includes:

[0084] We provide resins, curing agents, and flexible conductive microspheres;

[0085] The resin is added to the curing agent and stirred for a third preset time to form a composite resin.

[0086] Flexible conductive microspheres are added to the composite resin and stirred for a fourth preset time to form a dielectric material.

[0087] The following is an exemplary description of how to fabricate the flexible sensor according to an embodiment of the present invention.

[0088] Example 1

[0089] Take 8 grams of PDMS resin, add 0.5 grams of curing agent and stir evenly. Then add 1.5 grams of flexible conductive microspheres and stir evenly to form a dielectric material. The flexible conductive microspheres can be ps@Au. Next, coat the dielectric material onto one side of the first electrode layer (which can be a 2*2cm copper foil), controlling the thickness of the dielectric material to be 20µm. Pre-cur at 80 degrees Celsius for 30 minutes. Then, attach the second electrode layer (which can be a 2*2cm copper foil) to the side of the first electrode layer coated with the dielectric material, and cure at 100 degrees Celsius for 1 hour to prepare the flexible sensor described in this embodiment of the invention. Afterwards, a first test line can be soldered onto the first electrode layer, and a second test line can be soldered onto the second electrode layer for convenient testing.

[0090] The flexible sensor prepared in Example 1 was tested with an LCR meter and found to have an initial capacitance of 0.81 nF and an initial resistance of 100 MΩ. It was in an insulated state and could sense tactile pressure. When the pressure was greater than the critical pressure of 30 kPa, the resistance rapidly decreased to 10 kΩ. When the pressure increased from 30 kPa to 500 kPa, the resistance slowly decreased from 10 kΩ to 100 Ω.

[0091] Example 2

[0092] 7.53 grams of PDMS resin were mixed with 0.47 grams of curing agent and stirred until homogeneous. Then, 2 grams of flexible conductive microspheres were added and stirred until homogeneous to form a dielectric material. The flexible conductive microspheres could be ps@Au. Next, the dielectric material was coated onto one side of the first electrode layer (which could be a 2*2cm copper foil), controlling the thickness of the dielectric material to be 20µm. It was then pre-cured at 80 degrees Celsius for 30 minutes. Then, the second electrode layer (which could be a 2*2cm copper foil) was attached to the side of the first electrode layer coated with the dielectric material, and cured at 100 degrees Celsius for 1 hour to prepare the flexible sensor described in this embodiment of the invention. Furthermore, a first test line could be soldered onto the first electrode layer, and a second test line could be soldered onto the second electrode layer for convenient testing.

[0093] The flexible sensor prepared in Example 2 was tested with an LCR meter and found to have an initial capacitance of 0.84 nF and an initial resistance of 100 MΩ. It was in an insulated state and could sense tactile pressure. When the pressure was greater than the critical pressure of 10 kPa, the resistance rapidly decreased to 9.5 kΩ. When the pressure increased from 10 kPa to 500 kPa, the resistance slowly decreased from 9.5 kΩ to 50 Ω.

[0094] The factors influencing the critical pressure of flexible sensors are shown below. For example, Table 1 shows the mass fraction of 10µm flexible conductive microspheres in the dielectric material and their corresponding critical pressures.

[0095] Table 1

[0096] Mass fraction of conductive microspheres (%) Critical pressure (kPa) 0 2000 5 1515 10 930 15 30 20 10 21.6 0

[0097] For example, Table 2 shows the mass fraction of 5 μm flexible conductive microspheres in the dielectric material and the corresponding critical pressure.

[0098] Table 2

[0099] Mass fraction of conductive microspheres (%) Critical pressure (kPa) 0 2000 5 1215 10 770 14 35 16 15 17 0

[0100] For example, Table 3 shows the mass fraction of 100 nm flexible conductive microspheres in the dielectric material and the corresponding critical pressure.

[0101] Table 3

[0102] Mass fraction of conductive microspheres (%) Critical pressure (kPa) 0 2000 5 1350 10 850 14 40 16 18 17 0

[0103] Therefore, as shown in Tables 1, 2, and 3, the critical pressure of the sensor is related to the diameter of the flexible conductive microspheres and the mass fraction of the flexible conductive microspheres in the dielectric material.

[0104] It should be noted that when the diameter of the flexible conductive microsphere is less than half the thickness of the dielectric layer, the percolation critical volume fraction is about 16.5%. As the diameter of the flexible conductive microsphere increases, the percolation critical volume fraction gradually increases to about 21%. If a diameter greater than half the thickness is selected, the microsphere may directly penetrate the dielectric layer and form physical contact, which may easily lead to an initial short circuit. Therefore, it is preferable to use flexible conductive microspheres with a diameter less than half the thickness of the dielectric layer.

[0105] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0106] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions as those in the present invention.

Claims

1. A flexible sensor combining capacitance and resistance, characterized in that, include: First electrode layer, second electrode layer, and dielectric layer; The dielectric layer is located between the first electrode layer and the second electrode layer; the dielectric layer comprises a composite resin and flexible conductive microspheres dispersed in the composite resin; When the pressure applied to the flexible sensor is less than the critical pressure, the first electrode layer and the second electrode layer are disconnected; when the pressure applied to the flexible sensor is greater than or equal to the critical pressure, the flexible conductive microspheres form a conductive path in the dielectric layer, and the first electrode layer and the second electrode layer are connected through the conductive path and are in a conductive state.

2. The flexible sensor combining capacitance and resistance according to claim 1, characterized in that, The flexible conductive microspheres include a central elastomer and a conductive layer; the conductive layer covers the surface of the central elastomer.

3. The flexible sensor combining capacitance and resistance according to claim 2, characterized in that, The material forming the central elastomer is any one of polystyrene, silicone, butyl rubber, and acrylic acid.

4. The flexible sensor combining capacitance and resistance according to claim 2, characterized in that, The material forming the conductive layer is any one of nano-gold, nano-silver, nano-carbon, nano-copper, and carbon nanotubes.

5. The flexible sensor combining capacitance and resistance according to claim 1, characterized in that, The composite resin is formed by mixing resin and curing agent.

6. The flexible sensor combining capacitance and resistance according to claim 1, characterized in that, The first electrode layer and the second electrode layer are copper foil or aluminum foil; Alternatively, the first electrode layer and the second electrode layer are formed by printing conductive paste onto a substrate.

7. A sensor testing system, characterized in that, include: The flexible sensor combining capacitance and resistance as described in any one of claims 1-6; A signal detection element, wherein both the first electrode layer and the second electrode layer are connected to the signal detection element.

8. The sensor testing system according to claim 7, characterized in that, Also includes: First test line and second test line; The first test line is fixedly connected to the first electrode layer, and the second test line is fixedly connected to the second electrode layer; The first test line and the second test line are used to connect to the signal detection element.

9. A method for fabricating a flexible sensor, characterized in that, A method for fabricating a flexible sensor as described in any one of claims 1-6; the fabrication method includes: Fabrication of a first electrode layer, a second electrode layer, and a dielectric material; The dielectric material is scraped onto one side of the first electrode layer and pre-cured for a first preset time. The second electrode layer is placed over the side of the first electrode layer coated with dielectric material and cured for a second preset time to form a dielectric layer between the first electrode layer and the second electrode layer.

10. The preparation method according to claim 9, characterized in that, The preparation of the dielectric material includes: We provide resins, curing agents, and flexible conductive microspheres; The resin is added to the curing agent and stirred for a third preset time to form a composite resin; The flexible conductive microspheres are added to the composite resin and stirred for a fourth preset time to form the dielectric material.

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