Flexible touch sensor and thin film and manufacturing method thereof

Abstract

The invention discloses a flexible touch sensor and a thin film and a manufacturing method thereof, relates to the field of bionic sensors, and is used for improving the sensing sensitivity of electronic skin. Uniformly mixing the neodymium-iron-boron magnetic powder with a silicone rubber matrix according to a mass ratio of 2: 3 to obtain magnetic silica gel; the magnetic silica gel is subjected to mold building, curing, demolding and magnetizing treatment in sequence, and the flexible touch sensor film is obtained. According to the preparation method, the flexible touch sensor film which is high in magnetic field uniformity, high in sensitivity, controllable in sensitivity, high in magnetic response performance, high in magnetic transmission efficiency and high in physical consistency can be efficiently prepared.

Description

Technical Field

[0001] This invention relates to the field of biomimetic sensing technology, and in particular to a flexible tactile sensor film, a flexible tactile sensor, and methods for manufacturing both. Background Technology

[0002] Electronic skin (also known as flexible tactile sensor film), as a flexible sensing material with tactile sensing capabilities, has broad application prospects in fields such as robotics interaction and wearable devices. Its core requirements lie in possessing high sensitivity, good flexibility compatibility, stable magnetic field output, and controllable sensing performance to adapt to the tactile detection requirements of different scenarios.

[0003] In known technologies, electronic skin often uses a composite of magnetic materials and flexible substrates to prepare magnetic field sources, but this approach has the following problems: 1. Severe agglomeration of magnetic particles leads to uneven magnetic field distribution, causing signal drift and reducing detection accuracy; 2. Magnetic matrix (usually magnetic silicone mixed with magnetic particles and silicone rubber matrix) either has poor dispersibility or insufficient magnetic field strength, making it difficult to balance dispersibility and detection signal-to-noise ratio. 3. Electronic skin has low performance stability. Summary of the Invention

[0004] The purpose of this invention is to provide a flexible tactile sensor, its thin film, and its manufacturing method to address all or part of the problems mentioned above, thereby improving the sensitivity of electronic skin sensing.

[0005] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides a method for fabricating a flexible tactile sensor thin film, comprising: Neodymium iron boron magnetic powder and silicone rubber matrix are uniformly mixed at a mass ratio of 2:3 to obtain magnetic silicone. The magnetic silicone is sequentially molded, cured, demolded, and magnetized to obtain a flexible tactile sensor film.

[0006] In a second aspect, the present invention also provides a flexible tactile sensor film, which is prepared by the above-described flexible tactile sensor film manufacturing method.

[0007] In a third aspect, the present invention also provides a method for manufacturing a flexible tactile sensor, comprising: The aforementioned flexible tactile sensor film is adhered to the tactile sensor base.

[0008] In a fourth aspect, the present invention also provides a flexible tactile sensor, which is prepared by the above-described method for manufacturing a flexible tactile sensor.

[0009] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This invention achieves the following significant effects through optimized selection of raw materials (neodymium iron boron magnetic powder + silicone rubber matrix), formulation (2:3 mass ratio), and process design: 1. Improved magnetic field uniformity: By designing a mixing mass ratio of NdFeB magnetic powder to silicone rubber matrix of 2:3, and further optimizing the dispersant, the problem of magnetic powder agglomeration is solved, resulting in uniform magnetic powder dispersion with no tendency to agglomerate, uniform magnetic field distribution in the thin film, and small signal drift.

[0010] 2. High sensitivity: The prepared flexible tactile sensor film has a resolution of up to 0.005N and a minimum sensing weight of 0.5g, meeting the requirements for high-precision tactile detection.

[0011] 3. Controllable sensitivity: By selecting different types of silicone rubber substrates, a wide range of adjustment can be achieved, including resolution of 0.005N-0.1N, minimum sensing weight of 0.5g-10g, and maximum force of 1.2N-15N, to adapt to different application scenarios.

[0012] 4. Improved magnetic response performance: Through the directional alignment process, the surface magnetic field of the flexible tactile sensor film at the center can be increased to 11mT-13mT after magnetization. The magnetic signal intensity is high, the signal-to-noise ratio is excellent, and the detection sensitivity is significantly improved.

[0013] 5. Strong batch consistency: Using 6061 aluminum molds and casting weight control, the size and performance fluctuations of the flexible tactile sensor film in batches are small, and the batch production qualification rate is high.

[0014] 6. Improved process efficiency: Aluminum molds require no release agent, and curing time is between 30 minutes and 4 hours, significantly improving production efficiency. Furthermore, vacuum defoaming and repeated magnetization ensure product quality.

[0015] 7. High magnetic transmission efficiency: By adding iron-nickel alloy powder to the raw materials, or by adhering a permalloy film to the bottom surface of the flexible tactile sensor film, the magnetic field of neodymium iron boron magnetic powder is concentrated, which enhances the magnetic field change transmitted to the Hall sensor, thereby enhancing the magnetic field sensing sensitivity. Attached Figure Description

[0016] The present invention will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a flowchart illustrating the implementation process of a flexible tactile sensor thin film fabrication method.

[0017] Figure 2 This is a schematic diagram of the mold structure.

[0018] Figure 3This is a schematic diagram of a "magnet-mold-magnet" sandwich structure.

[0019] Figure 4 This is a flowchart of a method for manufacturing a flexible tactile sensor in one embodiment, where the dashed boxes represent optional steps.

[0020] Figure 5 This is a cross-sectional view of a flexible tactile sensor in one embodiment.

[0021] In the figure, 1-aluminum mold, 2-slot, 3-magnetic cube, 4-flexible tactile sensor film, 5-tactile sensor base. Detailed Implementation

[0022] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0023] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0024] Based on research and analysis, the known electronic skin fabrication processes have the following shortcomings: (1) Magnetic particles have extremely high surface energy and are prone to spontaneous aggregation due to van der Waals forces and magnetic forces, resulting in uneven magnetic field distribution, signal drift, and reduced detection accuracy; (2) The mixing ratio of magnetic particles and flexible matrix is ​​not optimized. Either the proportion of magnetic powder is too high, resulting in poor dispersibility, or the proportion is too low, resulting in insufficient magnetic field strength. It is difficult to balance dispersibility and detection signal-to-noise ratio. (3) The mechanical properties (modulus, hardness, etc.) of flexible substrates are fixed, and the sensing sensitivity is uncontrollable, making it difficult to adapt to the resolution and force range requirements in different scenarios. (4) The sample weight and thickness were inconsistent during the preparation process, and the performance fluctuated greatly during mass production; the magnetic powder was not sufficiently magnetized, and the magnetic response sensitivity was insufficient. (5) Process problems such as residual bubbles and difficulty in demolding during the curing process further affect the performance stability and production efficiency of electronic skin.

[0025] To address one or more of the above-mentioned shortcomings, this application proposes a method for fabricating a flexible tactile sensor film. The aim is to improve the sensing sensitivity and stability of electronic skin by optimizing the selection of raw materials, mixing ratios, process parameters, or auxiliary means, and on this basis, improve its preparation efficiency and consistency in mass production.

[0026] The implementation process of the flexible tactile sensor thin film fabrication method of this application includes: Neodymium iron boron magnetic powder and silicone rubber matrix were uniformly mixed at a mass ratio of 2:3 to obtain magnetic silicone. The magnetic silicone was then sequentially molded, defoamed, cured, demolded, and magnetized to obtain a flexible tactile sensor film 4.

[0027] like Figure 1 As shown, in one optional embodiment, the method for fabricating a flexible tactile sensor film specifically includes the following process steps: S1. Raw material preparation.

[0028] A 2:3 mass ratio of neodymium iron boron magnetic powder to a silicone rubber matrix was prepared. With this material selection and mixing ratio, after thorough and uniform mixing, the surface magnetic field at the center of the flexible tactile sensor film 4 was 7-9 mT, and the magnetic field strength could be stably detected by a Hall sensor. Furthermore, the magnetic powder was uniformly dispersed in the silicone rubber matrix without agglomeration affecting local performance. However, using other mass ratios with the same material selection did not achieve the same effect. For example, changing the mass ratio of neodymium iron boron magnetic powder to silicone rubber matrix to 3:2 increased the surface magnetic field at the center of the flexible tactile sensor film 4 to 12-15 mT; however, the magnetic powder easily agglomerated after mixing. Similarly, changing the mass ratio of neodymium iron boron magnetic powder to silicone rubber matrix to 1:1 increased the surface magnetic field at the center of the flexible tactile sensor film 4 to 10-12 mT, again resulting in easy agglomeration of the magnetic powder after mixing. Therefore, by mixing neodymium iron boron magnetic powder and silicone rubber matrix in a 2:3 mass ratio, the magnetic powder agglomeration phenomenon can be effectively solved while ensuring the magnetic strength of the center surface of the flexible tactile sensor film 4.

[0029] For example, after preparing a calibrated electronic level and preheating to zero, weigh out 4g of neodymium iron boron magnetic powder, 3g of component A silica gel, and 3g of component B silica gel. For larger-scale preparations, increase the prepared raw materials proportionally. Pour all weighed raw materials into the planetary mixer jar.

[0030] Regarding the selected raw materials, the key parameters of the neodymium iron boron magnetic powder selected in the above embodiments are as follows: Average particle size of magnetic powder: 5 micrometers; Coercivity: 710 kA / m~780 kA / m (resistance to demagnetization, preventing signal drift). Because the electronic skin is frequently bent and compressed, it is equivalent to continuously applying mechanical stress and a demagnetizing field to the magnetic powder. High coercivity helps resist demagnetization and prevent signal drift. Remanence: 838-878 mT (provides a strong magnetic signal, improving the signal-to-noise ratio). High remanence is equivalent to a strong magnetic signal, which is easier to detect by Hall sensors or magnetoresistive elements, thus improving the signal-to-noise ratio.

[0031] For the silicone rubber matrix, in one optional embodiment, its component A is: vinyl silicone oil / base adhesive, and its component B is polymethylhydrosiloxane / curing agent containing Si-H bonds.

[0032] Furthermore, this application also considers the controllability of sensing sensitivity. Therefore, in one optional embodiment, the silicone rubber substrate is of type Ecoflex 0010, Ecoflex 0030, Ecoflex 0050, Dragon skin 10NV, Dragon skin 20NV, or Dragon skin 25NV. With different selections, the flexible tactile sensor film 4 will ultimately achieve different sensing and mechanical properties, as detailed in Table 1.

[0033] Table 1. Selection Table for Silicone Rubber Matrix

[0034] The sensitivity of the sensor can be adjusted by selecting different types of silicone rubber with varying moduli. For example, the correspondence between some performance requirements and the selection criteria is as follows: High sensitivity requirements (resolution 0.005N, minimum sensing weight 0.5g): Ecoflex 0010 is recommended; For medium sensitivity and high elongation at break requirements (resolution 0.01N, elongation at break 980%): Ecoflex0050 is recommended. For high stress range requirements (maximum stress 15N, tear strength 139pli): Dragon skin 25NV is selected.

[0035] Although the magnetic silicone obtained by the above material selection and mass ratio no longer exhibits magnetic powder agglomeration, in order to further reduce the tendency of magnetic powder agglomeration and further improve the magnetic field uniformity of the flexible tactile sensor film 4, in an optional embodiment, a dispersant is added to the mixture (i.e., the mixture formed together with the neodymium iron boron magnetic powder and the silicone rubber matrix, the order of preparation of each component is not limited, and the same applies below) during the raw material preparation stage.

[0036] Specifically, the additional dispersant is an epoxy-based silane coupling agent diluted with anhydrous ethanol at a dilution ratio of 1:10 (volume ratio). For example, in the preparation of the above-mentioned raw materials of 4g NdFeB magnetic powder, 3g silica gel of component A, and 3g silica gel of component B, the prepared dispersant is 0.04g diluted epoxy-based silane coupling agent (KH-560) + 0.4g anhydrous ethanol.

[0037] In addition, to enhance the magnetic field sensing capability of the flexible tactile sensor film 4, in an optional embodiment, iron-nickel alloy powder is added to the mixture during the raw material preparation stage (this can be implemented with or without a dispersant). After the mixture is uniformly mixed, the iron-nickel alloy powder, due to its extremely high magnetic permeability, becomes an excellent magnetic field channel. It spontaneously gathers around the magnetic field generated by the NdFeB particles and connects end to end to form a continuous, low magnetic resistance magnetic network. This gathers the diffuse magnetic field of the NdFeB particles, amplifies the change in magnetic flux, and enhances the magnetic field change transmitted to the Hall sensor, thereby improving the detection accuracy of the tactile sensor.

[0038] The mass ratio of NdFeB magnetic powder, silicone rubber matrix, and iron-nickel alloy powder is 2:3:0.2. For example, in the above-mentioned raw material preparation example containing 4g of NdFeB magnetic powder, 3g of component A silicone rubber, and 3g of component B silicone rubber, the added iron-nickel alloy powder is 0.4g (less than 0.4g or slightly more than 0.4g is acceptable, but the mass ratio should not be higher than that of the NdFeB magnetic powder, or only slightly higher). Specifically, the mass ratio of Fe to Ni in the iron-nickel alloy powder is 7:3 (or an approximate ratio), and the particle size can be selected as 1 micrometer to 2 micrometers.

[0039] S2, Mixed processing.

[0040] The neodymium iron boron magnetic powder is thoroughly and uniformly mixed with the silicone rubber matrix (or with the addition of a dispersant and / or iron-nickel alloy powder).

[0041] According to the above embodiment, the tank containing the raw materials is fixed in the clamp of the planetary mixer, and then preparation for mixing is carried out.

[0042] In one alternative implementation, a two-step mixing mechanism is used to mix the raw materials: Step 1: Mix the ingredients at a low speed of 300 rpm for 3 minutes; Step 2: Continue mixing the raw materials at high speed for 4 minutes using shear force generated at 1000 rpm.

[0043] After the raw materials are mixed, magnetic silicone is obtained in which magnetic powder is uniformly dispersed in the silicone rubber matrix, and the magnetic powder has a weak tendency to agglomerate.

[0044] S3, Formwork (casting in molds).

[0045] After obtaining the magnetic silicone (colloid), inject the magnetic silicone into the mold to form the shape.

[0046] To improve preparation efficiency, in one optional embodiment, an aluminum mold 1, such as a 6061 aluminum mold (hereinafter referred to as aluminum mold 1), is selected. This mold can prepare up to nine films at a time. Figure 2As shown. More importantly, the aluminum mold 1 can be directly demolded after curing without the need for a release agent, which greatly improves the efficiency of film preparation.

[0047] In scenarios involving the batch preparation of multiple thin films, to control the consistency of each film, it is essential to ensure that the quality of each film is identical during the casting of magnetic silicone.

[0048] For example, when casting magnetic silicone, the mold is placed on an electronic balance. After the balance is zeroed, magnetic silicone is poured into slot 2 of the mold. This process is repeated for each film, and the mass of magnetic silicone cast for each film is the same, for example, 2.15g, 3mm thick, and 20mm×20mm in size. After the magnetic silicone is cast into the mold, it self-levels due to its surface tension. In this way, multiple films of the same mass can be cast simultaneously to ensure the consistency of batch film production.

[0049] For batch production processes that do not require maintaining film consistency, such as scenarios where the production of films of different sizes / thicknesses is requested, the quality of each casting can be controlled according to the requirements.

[0050] S4. Defoaming treatment.

[0051] Due to the mixing or casting of raw materials, air bubbles may form inside the cast film, which can affect the working stability and sensing sensitivity of the flexible tactile sensor film 4. Therefore, it is preferable to perform defoaming treatment on the cast film. Of course, if the influence of air bubbles is not considered, or if the raw material mixing and casting process is strictly controlled, the defoaming treatment step can be omitted, or the defoaming treatment can be designed into the raw material mixing stage, that is, during or after the raw material mixing process.

[0052] As an optional implementation method, defoaming treatment is divided into two types: Method 1: During the injection of magnetic silicone into the mold, defoaming is achieved by vibrating the mold. This method is mainly effective for larger air bubbles.

[0053] Method 2: After injecting the magnetic silicone into the mold, place the mold in a vacuum environment for defoaming treatment. This method can eliminate smaller air bubbles simultaneously.

[0054] In one alternative implementation of Method 2, the mold is placed in a vacuum container sealed with Vaseline. The internal pressure of the vacuum container is -0.6 MPa, and the defoaming treatment time is 10 minutes. The pressure and time are adjustable. When using Method 2 for defoaming treatment, there is no restriction on whether or not Method 1 is used.

[0055] S5. Curing treatment.

[0056] After the magnetic silicone is cast, or after defoaming treatment, the colloidal film needs to be cured into a flexible film. The curing process is usually achieved by heating the entire mold at a constant temperature.

[0057] For example, the mold is placed in a 70-degree Celsius constant temperature heating chamber and kept at that temperature for 3 hours to allow the film to solidify. Afterward, it is cooled to room temperature with the heating chamber.

[0058] In addition, in order to further improve the detection sensitivity of the flexible tactile sensor film 4, in one optional embodiment, the magnet and the mold are combined into a "magnet-mold-magnet" sandwich structure before the curing process, and then placed together in a heating chamber for curing.

[0059] The magnets on opposite sides of the mold can orient the magnetic powder in the film, thereby increasing the magnetic field strength at the center of the flexible tactile sensor film 4 after magnetization (to 11mT~13mT), significantly improving the magnetic response sensitivity of the flexible tactile sensor film 4.

[0060] As an optional implementation, the selected magnet is a magnetic block array composed of multiple magnetic cube blocks 3. The magnetic cube blocks 3 are evenly arranged. For example, as... Figure 3 As shown, 32 pieces are selected (other quantities are acceptable, but 2×k is preferred). 2 k is a positive integer representing the number of magnetic cube blocks 3 on one side. The N50 (other options are possible) magnetic cube blocks 3, measuring 6mm × 6mm × 6mm, consist of 4 blocks (4 blocks per side) × 4 = 16 blocks arranged in a magnetic block array on one side, providing a total of 32 magnetic cube blocks 3 on both sides. The 16 blocks on one side (and other quantities are similar) can be connected into a single unit by a corresponding frame for easy stacking and fixing.

[0061] S6. Demolding process.

[0062] The cured film is demolded from the mold. Taking the aluminum mold 1 used in the previous article as an example, the film can be directly demolded and removed after curing without the need for a release agent.

[0063] S7. Magnetization treatment.

[0064] Only after the demolded film is magnetized can a stable magnetic field be formed.

[0065] In one optional embodiment, a single-stage magnetization method is used to magnetize the thin film. The magnetization voltage is 2000V, and during magnetization, it is ensured that the thin film and the magnetizing head are in close contact and aligned. Magnetization is repeated several times (usually 2-3 times) with short intervals between each repetition. After magnetization, the surface magnetism at the center of the flexible tactile sensor thin film 4 is 7mT-9mT. If magnets are added to both sides of the mold during the curing process, the surface magnetism at the center of the flexible tactile sensor thin film 4 after magnetization can reach 11mT-13mT.

[0066] Furthermore, to further enhance the magnetic focusing ability of the film and thus improve the sensing sensitivity, in one optional embodiment, after magnetizing the film, a permalloy film is adhered to the bottom surface of the flexible tactile sensor film 4. This permalloy film has the same dimensions as the flexible tactile sensor film 4, for example, 20mm × 20mm, but its thickness is significantly smaller than that of the flexible tactile sensor film 4 (3mm), for example, the thickness of the permalloy film is 0.05mm (or a similar value), and the alloy grade is 1J85. The permalloy film is adhered to the bottom surface of the flexible tactile sensor film 4 using Giant Arrow 988A silicone as an adhesive. Giant Arrow 988A silicone maintains excellent elasticity after curing, meeting the flexibility requirements of electronic skin. As a flexible, sheet-like, non-closed magnetic conductive layer, the permalloy film is tightly bonded to the flexible tactile sensor film 4. When it deforms synchronously with the flexible tactile sensor film 4, it gathers the dispersing magnetic field of neodymium iron boron magnetic powder, enhancing the magnetic field changes transmitted to the Hall sensor.

[0067] It should be noted that adding iron-nickel alloy powder to the raw materials, or adhering a permalloy film to the bottom surface of the magnetized flexible tactile sensor film 4, can both serve to concentrate the magnetic field of neodymium iron boron magnetic powder. One of the two methods can be optimized, or they can be used simultaneously. The two methods are not mutually exclusive and can simultaneously improve the detection sensitivity of the flexible tactile sensor film 4.

[0068] The flexible tactile sensor film fabrication method provided in the above embodiments or their optional embodiments can produce a flexible tactile sensor film 4 with high sensing sensitivity, stable sensing performance, and strong mechanical properties. This flexible tactile sensor film 4 is also the subject of protection claimed in this application.

[0069] Furthermore, based on the concept of this application, this embodiment also provides a method for fabricating a flexible tactile sensor. This method involves adhering the prepared flexible tactile sensor film 4 to a tactile sensor base 5, thus completing the fabrication of the flexible tactile sensor. The adhesive can still be Giant Arrow 988A silicone. The tactile sensor base 5 can be a general / known magnetic sensor base; it is not the focus of this application's improvement on the flexible tactile sensor. Its principle is to locate one or more of the deformation position, direction, and amplitude of the flexible tactile sensor film 4 by detecting changes in the magnetic field.

[0070] Using the above method, a flexible tactile sensor with high detection sensitivity and stable detection performance can be prepared. This flexible tactile sensor is also the object of protection claimed in this application.

[0071] The process flow of the technical solution provided in this application is described below with two examples.

[0072] Example 1 A method for fabricating a high-precision flexible tactile sensor, such as Figure 4 As shown, it includes the following steps: Step 1: Turn on the calibrated electronic balance to preheat it, and then zero the balance.

[0073] Step 2: Weigh 4g of neodymium iron boron magnetic powder using a plastic spoon, and weigh 3g of component A silicone (vinyl silicone oil, base adhesive) and 3g of component B silicone (polymethylhydrosiloxane containing Si-H bonds, curing agent) using a Pasteur pipette. The silicone rubber matrix model is Ecoflex 0010. Pour all the raw materials into the container of the planetary mixer, and fix the container containing the raw materials in the clamp of the planetary mixer.

[0074] Step 3: First, mix the raw materials at a low speed of 300 rpm for 3 minutes, and then mix at a high speed of 1000 rpm for 4 minutes to ensure that the neodymium iron boron magnetic powder is evenly mixed in the silicone rubber matrix.

[0075] Step 4: Pour the mixed magnetic silicone into an aluminum mold 1 made of 6061 stainless steel. Due to the properties of the mold material, no release agent is needed; the silicone can be easily demolded after curing. This mold can produce 9 films at a time, each film measuring 20mm x 20mm and 3mm in thickness.

[0076] Step 5: After pouring, the magnetic silicone will level itself in the mold due to surface tension. If there are large air bubbles (such as those visible to the naked eye), they can be defoamed by gently vibrating the mold.

[0077] Step 6: To ensure the physical consistency of each film, when pouring the mixed magnetic silicone, place the mold on a balance. After zeroing the balance, start pouring the mixed magnetic silicone into the mold, ensuring that the weight of each film is 2.15g. This step should be done as quickly as possible to avoid the additional magnetic silicone from not fully integrating with the original magnetic silicone.

[0078] Step 7: Place the mold filled with magnetic silicone into a vacuum container to defoam for 10 minutes. White petroleum jelly is needed to keep the vacuum container sealed, and the pressure inside the vacuum container should be maintained at -0.6 MPa.

[0079] Step 8: Turn on the constant temperature heating box and preheat it to 70℃. Place the mold with the magnetic silicone into the constant temperature heating box and keep it at that temperature for 3 hours to allow the magnetic silicone to cure.

[0080] Step 9: After the magnetic silicone has cured, it is cooled to room temperature in the heating chamber, and then the film is removed.

[0081] Step 10: Magnetize the thin film using a magnetizer to obtain the flexible tactile sensor thin film 4, which provides the magnetic field source in the tactile sensor. During the magnetization process, ensure that the surface of the thin film is completely in contact with and aligned with the magnetizing head, and that the position and direction of each magnetization are consistent. Magnetization can be repeated 2-3 times (with short intervals between each repetition) to ensure that all magnetic powder is fully magnetized. The magnetization method is unipolar magnetization, the magnetization voltage is 2000V, and the surface magnetic field at the center of the magnetized flexible tactile sensor thin film 4 is 7mT-9mT.

[0082] Thus, a highly sensitive and stable flexible tactile sensor film 4 can be prepared. The prepared flexible tactile sensor film 4 has a resolution of 0.005N and a minimum sensing weight of 0.5g. If other performance requirements are needed, other silicone rubber substrates can be selected with reference to Table 1.

[0083] Step 11: Adhere the magnetic flexible tactile sensor film 4, which has been filled with magnetic tape, to the tactile sensor base 5 using Giant Arrow 988A silicone adhesive. This silicone adhesive can still maintain its elasticity after curing and can conform to the flexibility of the skin.

[0084] Through the above steps, a flexible tactile sensor can be fabricated, and its structure is as follows: Figure 5 As shown.

[0085] Example 2 A method for fabricating a high-precision flexible tactile sensor is disclosed. This method is largely the same as the method described in the previous embodiment, with the only optimization being that a uniform weak magnetic field is applied during the curing stage between steps 7 and 8 to orient the NdFeB particles and improve magnetic response sensitivity. That is, before the curing process, the following steps are added: Prepare 32 6mm×6mm×6mm magnetic cube blocks 3 (N50). Arrange the magnetic cube blocks 3 in a 4×4 pattern to form two large blocks of magnets. Combine the two magnets and the mold filled with magnetic silicone into a "magnet-mold-magnet" sandwich structure. Then, in step 8, place the entire sandwich structure into a constant temperature heating box.

[0086] In this embodiment, due to the above optimization steps, the surface magnetism at the center of the magnetized flexible tactile sensor film 4 can reach 11mT-13mT.

[0087] As for other preferred embodiments, such as adding a dispersant to the raw materials, or adding iron-nickel alloy powder to the raw materials, or adhering a permalloy film to the bottom surface of the flexible tactile sensor film 4, they can be implemented based on any of the above embodiments, and will not be listed one by one in this application.

[0088] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method for fabricating a flexible tactile sensor film, characterized in that, include: Neodymium iron boron magnetic powder and silicone rubber matrix are uniformly mixed at a mass ratio of 2:3 to obtain magnetic silicone. The magnetic silicone is sequentially molded, cured, demolded, and magnetized to obtain a flexible tactile sensor film.

2. The method for fabricating a flexible tactile sensor film as described in claim 1, characterized in that, Before mixing the neodymium iron boron magnetic powder with the silicone rubber matrix, a dispersant is added to the mixture of neodymium iron boron magnetic powder and silicone rubber matrix.

3. The method for fabricating a flexible tactile sensor film as described in claim 1 or 2, characterized in that, Before curing, the magnet and the mold into which the magnetic silicone is injected are combined into a "magnet-mold-magnet" sandwich structure and then cured together.

4. The method for fabricating a flexible tactile sensor film as described in claim 3, characterized in that, The magnet is a magnetic block array composed of multiple magnetic cube blocks.

5. The method for fabricating a flexible tactile sensor film as described in claim 1, characterized in that, Before mixing the NdFeB magnetic powder with the silicone rubber matrix, iron-nickel alloy powder is added to the mixture of NdFeB magnetic powder and silicone rubber matrix. The mass ratio of NdFeB magnetic powder, silicone rubber matrix and iron-nickel alloy powder is 2:3:0.

2.

6. The method for fabricating a flexible tactile sensor film as described in claim 1 or 5, characterized in that, After magnetization, the process also includes: A permalloy film is adhered to the bottom surface of the flexible tactile sensor film.

7. The method for fabricating a flexible tactile sensor film as described in claim 1, characterized in that, The silicone rubber matrix is ​​of the following model: Ecoflex 0010, Ecoflex 0030, Ecoflex 0050, Dragon skin 10NV, Dragon skin 20NV, or Dragon skin 25NV.

8. A flexible tactile sensor film, characterized in that, The flexible tactile sensor film is prepared by the flexible tactile sensor film manufacturing method according to any one of claims 1-7.

9. A method for manufacturing a flexible tactile sensor, characterized in that, include: The flexible tactile sensor film as described in claim 8 is adhered to the tactile sensor base.

10. A flexible tactile sensor, characterized in that, The flexible tactile sensor is manufactured using the method described in claim 9.

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