Capacitive proximity-pressure composite sensing array for operation safety of inspection robot

Abstract

The invention relates to the technical field of capacitive flexible sensors, in particular to a capacitive approach-pressure composite sensing array for the operation safety of an inspection robot, and the capacitive flexible pressure sensor comprises a first sensing electrode, a first bonding layer, a dielectric layer, a second bonding layer and a second sensing electrode. The first sensing electrode, the first bonding layer, the dielectric layer, the second bonding layer and the second sensing electrode are sequentially stacked and combined from top to bottom to form a sandwich structure. The capacitive flexible proximity sensor is based on the edge effect, and the top electrode is designed to be of a disc structure; as the electrons are non-uniformly distributed on the electrodes and are mainly gathered in the marginal area, the disk structure can enhance the depth and strength of a marginal field, and when an object enters a stronger marginal field, more obvious electric field interference can be generated, so that a capacitance change signal when the object approaches is amplified, and the sensitivity of the flexible proximity sensor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of capacitive flexible sensors, and particularly relates to a capacitive proximity-pressure composite sensing array for inspection robot operation safety. BACKGROUND

[0002] In the early days, power inspection completely relied on manual work, which had problems such as high labor intensity, low efficiency, missed inspection, unstable detection quality, and single method. In contrast, power inspection robots have functions such as all-weather data acquisition, real-time information transmission, intelligent analysis and early warning, and rapid decision feedback, which can replace manual inspection, improve the management level of power equipment, and better guarantee the safe and stable operation of the power grid. The use of power inspection robots is an important means to realize the intelligentization of the power grid and an important direction for the development of future smart grids. Integrating flexible tactile sensors on the work clamp of the power inspection robot can endow the power inspection robot with excellent tactile perception ability, enabling the robot to quickly acquire process information such as pressure, resistance, and jamming during work. These tactile data can help improve the robot's environmental perception and object recognition accuracy, and thus achieve safer and more accurate operation control. Flexible tactile sensors can be divided into two categories according to their functional characteristics: flexible proximity tactile sensors and flexible pressure tactile sensors, which can detect multiple physical parameters such as pressure, distance, vibration, and sliding.

[0003] Flexible proximity sensing technology avoids frequent physical contact, thereby minimizing mechanical wear and tear of the equipment. Among flexible proximity tactile sensors, the common ones are photoelectric, magnetic field, and capacitive types. Capacitive flexible sensors are particularly suitable for integration in robotic tactile fingers for close-range detection due to their fast response capability and excellent anti-interference performance.

[0004] Patent application CN111458753A provides a full-flexible same-plane spiral electrode proximity tactile flexible sensor and a preparation method thereof. The sensor includes a flexible substrate, a base electrode, and a shielding electrode, and has a vertical "sandwich" structure as a whole. The flexible substrate is a circular insulating layer in the middle, has high sensitivity, and has uniform sensitive field proximity tactile sensing performance, providing a feasible design idea for multifunctional electronic skin.

[0005] In the academic paper “Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array” published in the journal Science Advances, Mirza Saquib Sarwar’s team designed a capacitive sensor array. The dielectric layer of the sensor array is PDMS, and the electrode layer is formed by injecting conductive hydrogel into the PDMS cavity. The upper and lower electrode layers are designed as ring-disc structures, which help to improve the strength of the output signal and the proximity sensitivity. The sensor can track the movement of the finger on the sensor array and can detect the positions of multiple fingers within a distance of 20 mm.

[0006] In the academic paper “High-Performance Flexible Capacitive Proximity and Pressure Sensors with Spiral Electrodes for Continuous Human–Machine Interaction” published in the journal ACS Materials Letters, Jinrong Huang’s team designed a capacitive flexible proximity sensor based on a new type of complementary Archimedean spiral electrode, and the dielectric layer uses treated microstructure cross-linked calcium alginate. This structure allows for better sensitivity and better proximity sensing performance, with an increased sensing distance of up to 55 mm.

[0007] Capacitive flexible pressure sensors have the advantages of simple manufacturing process, low cost, high reliability, and are more easily integrated into large-scale arrays. However, capacitive flexible pressure sensors usually exhibit low sensitivity due to limited capacitance and low compressibility of dielectric materials. A new type of pressure sensing mechanism based on the electric double layer (EDL) effect has been developed recently, which has high sensitivity while retaining the advantages of traditional capacitive sensors. Ionic gels or hydrogels as dielectric layers have good ionic conductivity, and combined with the double-layer theory, they can achieve ultra-high sensitivity in flexible pressure sensors.

[0008] Patent application CN120740809A proposes a flexible pressure sensor and a method for preparing the same. A firm chemical bonding interface is constructed between the electrode layer and the ionic elastomer layer of the flexible pressure sensor, and microstructures are introduced on the ionic elastomer layer, which simultaneously have mechanical stability, reliability, and sensitivity. The flexible pressure sensor also has good flexibility and transparency, and can be applied in the fields of humanoid robots, intelligent prostheses, etc.

[0009] The academic paper "Biomimetic nanofiber-iongel composites for flexible pressure sensors with broad range and ultra-high sensitivity" published by Xin Gou's team in the journal Nano Energy draws inspiration from the tactile sensing mechanism and layered structure of human skin, and designs a nanofiber-agar composite material with internal hierarchical stiffness characteristics and surface semi-embedded microstructure by applying electrospinning and droplet injection methods. The sensor made of the material has ultra-high sensitivity, wide pressure range and ultra-strong stability.

[0010] The academic paper "Peptide-enhanced tough, resilient and adhesive eutectogels for highly reliable strain / pressure sensing under extreme conditions" published by Zhang's team in the journal Nature Communications synthesizes peptide-enhanced eutectic gels by introducing alpha-helix "molecular spring" structures into deep eutectic solvents, achieving high tensile / compression, good resilience, excellent fracture toughness, excellent fatigue resistance and strong adhesion. The off-electric flexible sensor can effectively rebound after being stressed, making the sensor highly durable.

[0011] In summary, relevant researchers have carried out a lot of research work around flexible tactile sensors, but there are still problems of low measurement sensitivity and accuracy, poor stability and durability. SUMMARY

[0012] The purpose of the application is to overcome the shortcomings of the prior art. The application provides a dielectric layer material for a capacitive flexible pressure sensor, a dielectric layer, a capacitive flexible pressure sensor and a capacitive flexible proximity sensor.

[0013] Technical scheme: In a first aspect, the application provides a dielectric layer material for a dielectric layer of a capacitive flexible pressure sensor, which is composed of Ad-GO solid 8-11%, MXene 0.3-0.8%, Alg-CD solid 10-15%, glycerol 8-15%, and the balance is deionized water in mass percentage. Ad-GO is a composite material formed by modifying a functional modification group Ad to the surface of graphene GO nanosheet, and Alg-CD is a complex formed by chemical grafting of sodium alginate Alg and beta-cyclodextrin.

[0014] Further, it comprises: When preparing the Ad-GO solid, the components are composed of the following mass percentages: graphene oxide 0.1%~0.3%, acetyl chloride 7%~9%, 1-adamantane carboxylic acid 1%~3%, and the balance is propylene carbonate.

[0015] Furthermore, including: When preparing the Alg-CD solid, the components are composed of the following mass percentages: hexamethylene diisocyanate 6%~10%, β-cyclodextrin 3%~6%, sodium alginate 3%~5%, and the balance is dimethyl sulfoxide.

[0016] Secondly, the present invention also provides a dielectric layer comprising the dielectric layer material described above.

[0017] Thirdly, the present invention also provides a method for preparing a dielectric layer, based on the dielectric layer material described above, comprising the following steps: (1) Sodium alginate and anhydrous dimethyl sulfoxide are mixed and magnetically stirred to form a dispersion of sodium alginate or anhydrous dimethyl sulfoxide; β-cyclodextrin and anhydrous dimethyl sulfoxide are mixed and magnetically stirred to form a β-CD or anhydrous dimethyl sulfoxide solution. Hexamethylene diisocyanate is slowly and dropwise added to the β-CD or anhydrous dimethyl sulfoxide solution and reacted in an oil bath under nitrogen atmosphere to form a CD-HDI solution. (2) The prepared sodium alginate or anhydrous dimethyl sulfoxide dispersion was added to the CD-HDI solution using a constant pressure dropping funnel. The reaction mixture was stirred at a constant temperature and then cooled to room temperature. It was then transferred to a dialysis bag for dialysis. After dialysis, the solution containing Alg-CD polymer in the dialysis bag was freeze-dried to obtain Alg-CD solid product and ground into fine powder. (3) Mix 1-adamantane carboxylic acid and deionized water, add dilute potassium hydroxide solution until neutral, remove water to obtain adamantane solution, dissolve it in propylene carbonate, add acetyl chloride, and stir in an oil bath to generate activated adamantane solution. (4) Graphene oxide and propylene carbonate were ultrasonically treated to form a graphene oxide dispersion. The graphene oxide dispersion was mixed with adamantane solution and magnetically stirred. After the mixture was finished, it was poured into a centrifuge tube to collect the precipitate and washed repeatedly. Finally, it was freeze-dried to obtain Ad-GO solid powder. (5) Dissolve Alg-CD solid powder in deionized water and stir magnetically to form a homogeneous solution. Then add glycerol and stir magnetically until completely mixed to form a homogeneous solution. Mix Ad-GO solid powder, MXene and deionized water and sonicate to form a dispersion. (6) Slowly pour the prepared dispersion into the homogeneous solution, stir, add calcium chloride aqueous solution, and continue stirring until uniformly dispersed to form a mixed solution. Pour the mixed solution onto a glass dish with filter paper, and dry to obtain dielectric layer hydrogel.

[0018] Fourthly, the present invention also provides an adhesive layer material for use on the adhesive layer of a capacitive flexible pressure sensor, wherein the components are composed of the following by mass percentage: 0.5% to 1.5% tris(2-carboxyethyl)phosphine, 0.05% to 0.1% bovine serum albumin, and the balance being deionized water.

[0019] Fifthly, the present invention also provides an adhesive layer, characterized in that the adhesive layer is assembled between an electrode and a dielectric layer, and the adhesive layer contains the adhesive layer material described above.

[0020] In a sixth aspect, the present invention also provides a method for preparing an adhesive layer, based on the adhesive layer material described above, comprising: mixing a certain concentration of bovine serum albumin aqueous solution with a tris(2-carboxyethyl)phosphine aqueous solution, gently shaking to allow the two to react fully, and obtaining an adhesive layer mixed solution.

[0021] In a seventh aspect, the present invention also provides a capacitive flexible pressure sensor, comprising: a first sensing electrode, a first adhesive layer, a dielectric layer, a second adhesive layer, and a second sensing electrode; The first sensing electrode, the first adhesive layer, the dielectric layer, the second adhesive layer, and the second sensing electrode are stacked in sequence from top to bottom to form a sandwich structure, wherein the dielectric layer is the dielectric layer described above, and at least one of the first adhesive layer and the second adhesive layer includes the adhesive layer described above.

[0022] Furthermore, including: The fabrication methods for capacitive flexible pressure sensors include: The adhesive layer mixture solution is spin-coated onto the surfaces of the first and second sensing electrodes to obtain the FPCB electrode. Then, the dielectric layer hydrogel is stacked and assembled with the FPCB electrode to form a sandwich structure. The adhesive layer mixture solution is obtained by the adhesive layer preparation method of claim 8, and the dielectric layer hydrogel is obtained by the dielectric layer preparation method of claim 5.

[0023] Furthermore, including: The upper surface of the first sensing electrode of the capacitive flexible proximity sensor is designed to include two concentric rings.

[0024] Furthermore, including: The system includes the aforementioned capacitive flexible pressure sensor, capacitive flexible proximity sensor, wires, and signal processing module. The first and second sensing electrodes are connected to the wires and then communicate with the signal processing module, which is used to process data generated during the operation of the power inspection robot.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following advantages: 1. Based on the edge effect, the present invention designs the top electrode as a disk structure. Due to the non-uniform distribution of electrons on the electrode and their main concentration in the edge region, this disk structure can enhance the depth and intensity of the edge field. When an object enters the stronger edge field, it will generate more significant electric field interference, thereby amplifying the capacitance change signal when the object approaches and improving the sensitivity of the flexible proximity sensor.

[0026] 2. This invention introduces a sodium alginate network into the dielectric layer. Under pressure, the dynamic ionic bonds of the sodium alginate network break as sacrificial bonds, consuming energy and converting mechanical energy into chemical energy for dissipation, thus preventing stress concentration. Furthermore, the sodium alginate material is modified with cyclodextrin. Through chemical grafting, the hydrophobic cavity structure of cyclodextrin is introduced, enabling sodium alginate to undergo ionic cross-linking while also combining with adamantane to construct a dynamic cross-linked network. This gives the dielectric layer self-healing capabilities and improves the mechanical durability of the sensor.

[0027] 3. This invention introduces filter paper as a substrate. The filter paper is composed of interwoven cellulose fibers, forming a robust micron-level three-dimensional network that acts as a framework. This allows the dielectric layer to effectively resist plastic deformation and provides it with good toughness, thereby improving the stability of the sensor under different loads during long-term operation. This significantly enhances the sensor's durability.

[0028] 4. This invention introduces Mxene, changing the surface microstructure of the dielectric layer to a bulk microstructure. Traditional surface-structured dielectric layers achieve capacitance changes by altering the interfacial contact area; however, this structure is prone to saturation under high voltage, leading to decreased sensitivity. This work, by introducing Mxene, utilizes the reversible breaking and formation of chemical bonds to control ion movement, generating extremely low initial capacitance and extremely high capacitance under pressure. This significant difference in capacitance enables high sensitivity.

[0029] 5. By introducing glycerol and CaCl2 into the dielectric layer, glycerol molecules, rich in hydroxyl groups, can form a hydrogen bond network with water molecules, effectively locking in moisture and slowing down evaporation; CaCl2 has a high ionic potential, thus forming the strongest interaction force with water molecules. The introduction of glycerol and CaCl2 materials enables both intelligent moisture absorption and moisturizing functions, giving the sensor greater durability.

[0030] 6. This invention introduces an adhesive layer. The insulating layer of the FPCB board used for the electrode is usually made of polyimide (PI) film and polyester (polyethylene terephthalate PET) film to isolate the conductive layer and provide electrical insulation performance. Through the functional groups rich in BSA protein, such as amino, carboxyl, and hydroxyl groups, hydrogen bonds are formed with the carbonyl and carboxyl groups of polymer substrates such as PI / PET, thereby constructing a chemical bonding interface between the flexible substrate and the electrode, solving the problem of insufficient bonding strength between the heterogeneous materials interface between the electrode and the dielectric layer.

[0031] 7. This invention uses graphene oxide (GO). Graphene oxide (GO) provides ion channels through the stacked nanoscale gaps. Ions migrate in these smooth, confined two-dimensional spaces with far less resistance than in disordered polymer networks, which can accelerate ion migration and improve the response speed of the sensor. Attached Figure Description

[0032] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is an overall structural diagram of the capacitive proximity-pressure composite sensor array for the safety of inspection robot operations as described in an embodiment of the present invention.

[0033] Figure 2 These are top and bottom views of the upper electrode as described in an embodiment of the present invention.

[0034] Figure 3 This is a sensitivity curve of the capacitive proximity sensor prepared according to an embodiment of the present invention.

[0035] Figure 4 The diagram shows the response time and recovery time of the capacitive proximity sensor prepared for the embodiment of the present invention for approach and distance actions.

[0036] Figure 5 The sensitivity curve of the capacitive flexible pressure sensor prepared for an embodiment of the present invention under a stress change of 50 kPa.

[0037] Figure 6 The stress-capacitance change rate curve of the capacitive flexible pressure sensor prepared for an embodiment of the present invention under a stress range of 180 kPa.

[0038] Figure 7 The normalized change curve of capacitance of the capacitive flexible pressure sensor prepared for an embodiment of the present invention during the pressure loading-unloading process of 1~15N.

[0039] Figure 8 This is a schematic diagram of the tensile stress-strain curves of ionogel membranes prepared with sodium alginate of different masses according to an embodiment of the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1: In a first aspect, this example provides a dielectric layer material for use on the dielectric layer of a capacitive flexible pressure sensor, which is composed of the following by mass percentage: 8%~11% Ad-GO solid, 0.3%~0.8% MXene, 10%~15% Alg-CD solid, 8%~15% glycerol, and the balance being deionized water. Ad-GO is a composite material formed by modifying the functionalized modification group Ad onto the surface of graphene oxide GO nanosheets, and Alg-CD is a composite material formed by chemical grafting sodium alginate Alg and β-cyclodextrin.

[0042] When preparing the Ad-GO solid, the components are composed of the following mass percentages: graphene oxide 0.1%~0.3%, acetyl chloride 7%~9%, 1-adamantane carboxylic acid 1%~3%, and the balance is propylene carbonate.

[0043] When preparing the Alg-CD solid, the components are composed of the following mass percentages: hexamethylene diisocyanate 6%~10%, β-cyclodextrin 3%~6%, sodium alginate 3%~5%, and the balance is dimethyl sulfoxide.

[0044] Secondly, this embodiment also provides a dielectric layer containing the dielectric layer material described above.

[0045] Thirdly, this embodiment also provides a method for preparing a dielectric layer, based on the dielectric layer material described above, comprising the following steps: (1) Sodium alginate and anhydrous dimethyl sulfoxide are mixed and magnetically stirred to form a dispersion of sodium alginate or anhydrous dimethyl sulfoxide; β-cyclodextrin and anhydrous dimethyl sulfoxide are mixed and magnetically stirred to form a β-CD or anhydrous dimethyl sulfoxide solution. Hexamethylene diisocyanate is slowly and dropwise added to the β-CD or anhydrous dimethyl sulfoxide solution and reacted in an oil bath under nitrogen atmosphere to form a CD-HDI solution. (2) The prepared sodium alginate or anhydrous dimethyl sulfoxide dispersion was added to the CD-HDI solution using a constant pressure dropping funnel. The reaction mixture was stirred at a constant temperature and then cooled to room temperature. It was then transferred to a dialysis bag for dialysis. After dialysis, the solution containing Alg-CD polymer in the dialysis bag was freeze-dried to obtain Alg-CD solid product and ground into fine powder. (3) Mix 1-adamantane carboxylic acid and deionized water, add dilute potassium hydroxide solution until neutral, remove water to obtain adamantane solution, dissolve it in propylene carbonate, add acetyl chloride, and stir in an oil bath to generate activated adamantane solution. (4) Graphene oxide and propylene carbonate were ultrasonically treated to form a graphene oxide dispersion. The graphene oxide dispersion was mixed with adamantane solution and magnetically stirred. After the mixture was finished, it was poured into a centrifuge tube to collect the precipitate and washed repeatedly. Finally, it was freeze-dried to obtain Ad-GO solid powder. (5) Dissolve Alg-CD solid powder in deionized water and stir magnetically to form a homogeneous solution. Then add glycerol and stir magnetically until completely mixed to form a homogeneous solution. Mix Ad-GO solid powder, MXene and deionized water and sonicate to form a dispersion. (6) Slowly pour the prepared dispersion into the homogeneous solution, stir, add calcium chloride aqueous solution, and continue stirring until uniformly dispersed to form a mixed solution. Pour the mixed solution onto a glass dish with filter paper, and dry to obtain dielectric layer hydrogel.

[0046] Example 2: In the first aspect, this example provides an adhesive layer material for use on the adhesive layer of a capacitive flexible pressure sensor. The components are composed of the following by mass percentage: 0.5% to 1.5% tris(2-carboxyethyl)phosphine, 0.05% to 0.1% bovine serum albumin, and the balance being deionized water.

[0047] Secondly, this embodiment also provides an adhesive layer, characterized in that the adhesive layer is assembled between the electrode and the dielectric layer, and the adhesive layer contains the adhesive layer material described above.

[0048] Thirdly, this embodiment also provides a method for preparing an adhesive layer, based on the adhesive layer material described above, comprising: mixing a certain concentration of bovine serum albumin aqueous solution with tris(2-carboxyethyl)phosphine aqueous solution, gently shaking to allow the two to react fully, and then obtaining an adhesive layer mixed solution.

[0049] Example 3: In a first aspect, this example provides a capacitive flexible sensor, comprising: a first sensing electrode, a first adhesive layer, a dielectric layer, a second adhesive layer, and a second sensing electrode; The first sensing electrode, the first adhesive layer, the dielectric layer, the second adhesive layer, and the second sensing electrode are stacked in sequence from top to bottom to form a sandwich structure. The dielectric layer is the dielectric layer described in Embodiment 1, and at least one of the first adhesive layer and the second adhesive layer includes the adhesive layer described in Embodiment 2.

[0050] Secondly, the method for fabricating the capacitive flexible sensor provided in this embodiment includes: The adhesive layer mixture solution is spin-coated onto the surfaces of the first and second sensing electrodes to obtain the FPCB electrode. Then, the dielectric layer hydrogel is stacked and assembled with the FPCB electrode to form a sandwich structure. The adhesive layer mixture solution is obtained by the adhesive layer preparation method of claim 8, and the dielectric layer hydrogel is obtained by the dielectric layer preparation method of claim 5.

[0051] In a preferred embodiment, the upper surface of the first sensing electrode is designed to include two concentric annular rings.

[0052] Example 4: This example relates to a capacitive proximity-pressure composite sensor array for the safety of inspection robot operations, comprising an upper electrode, an adhesive layer, a dielectric layer, a lower electrode, a signal processing unit, and an MCU processing unit, forming a flexible capacitive pressure sensor array and a flexible capacitive proximity sensor array.

[0053] The electrode layer of the flexible capacitive pressure sensing unit in the capacitive proximity-pressure composite sensing array includes a first sensing electrode, a second sensing electrode, and a wire. The flexible capacitive pressure sensing unit is located on the FPCB board contact dielectric layer side. The first sensing electrode has a size of 1. cm ×1 cm The second sensing electrode has a size of 4. cm ×4 cm The dielectric layer is composed of a hydrogel with a filter paper matrix containing microstructures as the framework, and the final sensing unit is a 2×2 pressure sensor array.

[0054] The flexible capacitive proximity sensing unit of the capacitive proximity-pressure composite sensing array consists of an electrode unit as the first sensing electrode and a wire. The first sensing electrode is located on the non-contact dielectric layer side of the FPCB board and is designed with an electrode structure, specifically two concentric ring electrodes. The second sensing electrode is the second sensing electrode of the pressure sensing unit, which is concentric with the first sensing electrode. The two rings form a proximity electric field and generate proximity capacitance.

[0055] The dielectric layer of the capacitive proximity-pressure composite sensing array used for the safety of inspection robot operations, wherein when the amphiphilic cyclodextrin-functionalized alginate derivative Alg-CD solid is prepared in step 1, the components are composed of the following by mass percentage: hexamethylene diisocyanate (HDI) 6%~10%, β-cyclodextrin (β-CD) 3%~6%, sodium alginate 3~5%, and the balance is dimethyl sulfoxide (DMSO).

[0056] Furthermore, the dielectric layer of the capacitive proximity-pressure composite sensing array used for the safety of the inspection robot's operation, wherein the dielectric layer is composed of the following components by mass percentage when preparing the Ad-GO solid in step 2: graphene oxide (GO) 0.1%~0.3%, acetyl chloride 7%~9%, 1-adamantane carboxylic acid 1%~3%, and the balance being propylene carbonate (PC).

[0057] Among them, Ad-GO solid is modified onto the surface of graphene oxide (GO) nanosheets by EDC / NHS chemical grafting technology, with AD (such as disulfide bonds, dynamic hydrogen bonds and other functional groups) modified onto the surface to form AD-GO composite material. AD is an abbreviation for "Active / Functional Group", which specifically refers to active groups that can combine with functional groups (such as carboxyl groups, hydroxyl groups and epoxy groups) on the GO surface through chemical reactions.

[0058] Furthermore, the dielectric layer of the capacitive proximity-pressure composite sensor array for the safety of the inspection robot operation is composed of the following components by mass percentage: Ad-GO 8%~11%, MXene 0.3%~0.8%, Alg-CD 10%~15%, glycerol 8%~15%, and the balance being deionized water.

[0059] Alg-CD, short for β-cyclodextrin-grafted sodium alginate (Alg-β-CD), is a complex formed by chemical grafting of sodium alginate (Alginate) and β-cyclodextrin (β-CD).

[0060] Furthermore, in the capacitive proximity-pressure composite sensor array for the safety of inspection robot operations, the adhesive layer comprises the following components by mass percentage: 0.5-1.5% tris(2-carboxyethyl)phosphine (TCEP), 0.05-0.1% bovine serum albumin (BSA), and the remainder being deionized water.

[0061] Furthermore, the method for preparing the hydrogel dielectric layer of the capacitive proximity-pressure composite sensing array includes the following steps: Step 1: Mix sodium alginate and anhydrous dimethyl sulfoxide (DMSO) and stir magnetically to form a sodium alginate / DMSO dispersion. Mix β-cyclodextrin (β-CD) and anhydrous dimethyl sulfoxide and stir magnetically to form a β-CD / DMSO solution. Slowly and dropwise add hexamethylene diisocyanate (HDI) to the β-CD / DMSO solution and react in an oil bath under nitrogen atmosphere to form a CD-HDI solution.

[0062] Subsequently, the prepared sodium alginate / DMSO dispersion was added to the CD-HDI solution using a constant-pressure dropping funnel. The reaction mixture was stirred at a constant temperature and then cooled to room temperature before being transferred to a dialysis bag for dialysis. After dialysis, the solution containing the Alg-CD polymer in the dialysis bag was freeze-dried to obtain the Alg-CD solid product, which was then ground into a fine powder and stored in a dry environment.

[0063] CD-HDI solution is a composite material or solution system formed by cyclodextrin (such as β-cyclodextrin) and hexamethylene diisocyanate (HDI), belonging to a type of polyurethane functional composite material.

[0064] Step 2: Mix 1-adamantane carboxylic acid and deionized water, add dilute potassium hydroxide solution to 7.0, remove water to obtain an adamantane solution, dissolve it in propylene carbonate, add acetyl chloride, and stir in an oil bath to generate an activated adamantane solution. Ultrasonically treat graphene oxide and propylene carbonate to form a stable and homogeneous dispersion. Then, mix the graphene oxide dispersion and the adamantane solution, and stir magnetically. After completion, pour the mixture into a centrifuge tube to collect the precipitate, and repeat the washing process. Finally, freeze-dry to obtain Ad-GO solid powder and store in a dry environment.

[0065] Step 3: Dissolve Alg-CD solid powder in deionized water and stir magnetically to form a homogeneous solution. Then add glycerol and stir magnetically until completely mixed into a homogeneous solution. Mix Ad-GO solid powder, MXene, and deionized water, and sonicate to form a stable and homogeneous dispersion. Subsequently, slowly pour the prepared dispersion into the homogeneous solution, stir rapidly for 5 minutes, add CaCl2 aqueous solution, and continue stirring until uniformly dispersed. Pour the mixture onto a glass dish lined with filter paper and dry for 4 hours to obtain a dielectric hydrogel.

[0066] In this embodiment, Mxene is a type of two-dimensional transition metal carbide, nitride, or carbonitride, obtained by selectively removing the A layer (such as aluminum or silicon) from the MAX phase precursor through chemical etching.

[0067] Step 4: Mix 2 mg / mL BSA aqueous solution with pH=5, 50 mM tris(2-carboxyethyl)phosphine (TCEP) aqueous solution, gently shake to allow it to react fully, spin-coat the mixed solution onto the electrode, and then assemble the dielectric layer hydrogel with the designed FPCB electrode into an upper electrode-dielectric layer-lower electrode to form a sandwich structure, thus obtaining a capacitive proximity-pressure composite sensing array.

[0068] Specifically, the capacitive proximity-pressure composite sensor array for the safety of inspection robot operations in this embodiment is fabricated according to the following steps: Step 1: Preparation of β-cyclodextrin-modified sodium alginate powder 2 g of sodium alginate and 30 g of anhydrous dimethyl sulfoxide (DMSO) were mixed and magnetically stirred at 60 °C until the sodium alginate was fully dissolved to form a highly viscous gel dispersion. 2.4 g of β-cyclodextrin (β-CD) was dissolved in 20 g of anhydrous DMSO and magnetically stirred at 50 °C until completely dissolved. Then, 4.6 g of hexamethylene diisocyanate (HDI) was slowly and dropwise added to the β-CD / DMSO solution using a constant-pressure dropping funnel. The mixture was placed in a 60 °C oil bath and reacted at a constant temperature under a nitrogen atmosphere for four hours to form a CD-HDI solution. Subsequently, the prepared sodium alginate / DMSO gel dispersion was added to the CD-HDI solution at a slow, controllable rate of 1 g / min using a constant-pressure dropping funnel, while the system was vigorously stirred at 60 °C during the addition to ensure sufficient contact. After completion, the reaction mixture was stirred at 60°C under nitrogen protection for 24 hours to ensure that the hydroxyl groups on the sodium alginate molecular chain reacted fully with CD-HDI to complete the grafting. After the reaction, the solution was cooled to room temperature and transferred to a dialysis bag with a molecular weight cutoff of 12-14 kDa, ensuring that the large Alg-CD polymer chains could not pass through the dialysis membrane. The bag was then placed in a large amount of deionized water for dialysis purification for 7 days, with the dialysis fluid changed 2-3 times a day to thoroughly remove DMSO solvent, unreacted HDI, β-CD, and other small molecule byproducts. After dialysis, the solution containing the Alg-CD polymer in the dialysis bag was poured into a petri dish and pre-frozen overnight in an ultra-low temperature freezer at -80°C. Then, it was transferred to a freeze dryer for freeze-drying for at least 48 hours to obtain a white, fluffy, spongy Alg-CD solid product. Finally, the product was ground into a fine powder and stored in a dry environment at 4°C to avoid moisture absorption, and was prepared for subsequent hydrogel preparation.

[0069] Step 2: Preparation of adamantane-modified graphene oxide powder 2 g of 1-adamantane carboxylic acid and 50 g of deionized water were mixed, and a 0.1% potassium hydroxide solution was added dropwise using a dropper. The pH of the solution was monitored with a pH meter until it reached 7.0, at which point the addition was stopped, converting the inert carboxylic acid (R-COOH) into a reactive carboxylate (R-COO⁻K⁺). The water was then completely removed using a rotary evaporator to obtain the potassium salt of adamantane carboxylic acid, which was completely dissolved in 60 g of propylene carbonate. 10 g of acetyl chloride was added, and the mixture was placed in a 60°C oil bath and stirred continuously for 24 hours to generate an activated adamantane solution. 0.2 g of graphene oxide and 50 g of propylene carbonate were weighed and ultrasonically treated at 120 W pulse mode with 2-second intervals and 3-second intervals in a 10°C ice-water bath to form a stable and homogeneous dispersion. Subsequently, the graphene oxide dispersion and the adamantane solution were mixed and magnetically stirred at 60°C for 12 hours to allow the functional groups on the graphene oxide sheet surface to undergo a complete esterification grafting reaction with the adamantane intermediate. After the reaction was completed, the mixture was poured into a centrifuge tube, and more than 100 grams of deionized water was added to precipitate the product. The precipitate was then collected by centrifugation at 8000 rpm for 10 minutes. This washing process of adding water and centrifugation was repeated 5 times to thoroughly remove propylene carbonate, unreacted raw materials and byproducts. Finally, the washed precipitate was freeze-dried to obtain Ad-GO solid powder, which was stored in a dry environment at 4°C for subsequent use.

[0070] Step 3: Preparation of dielectric layer hydrogel Weigh 0.6 g of Alg-CD solid powder and dissolve it in 2 g of deionized water. Stir magnetically at 50 °C to form a homogeneous solution. Add 0.5 g of glycerol and stir magnetically at 50 °C until completely mixed into a homogeneous solution. Take 0.5 g of Ad-GO solid powder and 0.03 g of MXene, mix them with 1 g of deionized water, and sonicate at 120 W pulse mode with 2 s intervals and 3 s intervals in a 10 °C ice-water bath to form a stable and homogeneous dispersion. Then, slowly pour the prepared dispersion into the homogeneous solution, stir rapidly for 5 minutes, add 0.5 g of 0.1 wt% CaCl2 aqueous solution, and continue stirring at 30 °C until uniformly dispersed. Pour the mixture onto a glass dish containing filter paper and dry in a 50 °C drying oven for 4 hours to obtain a dielectric hydrogel.

[0071] Step 4: Prepare the adhesive layer and assemble the sensor. 1 gram of 2 mg / mL BSA solution was mixed with 1 gram of 14 mg / mL tris(2-carboxyethyl)phosphine (TCEP) aqueous solution at pH=5. After gentle shaking to allow the reaction to proceed, the mixed solution was spin-coated onto the electrode. After standing at room temperature for 1 hour, an adhesive layer was formed on the electrode. Then, the upper electrode-adhesive layer-dielectric layer-adhesive layer-lower electrode were assembled to form a sandwich structure, resulting in a capacitive proximity-pressure composite sensing array.

[0072] Comparative Example 1: (If Alg is changed from 2 grams to 1 gram, while the weight of other components remains unchanged, the mass percentage of Alg will decrease to approximately 1.7%) Step 1: Preparation of β-cyclodextrin-modified sodium alginate powder 1 gram of sodium alginate and 30 grams of anhydrous dimethyl sulfoxide (DMSO) were mixed and magnetically stirred at 60°C until the sodium alginate was fully dissolved to form a highly viscous gel dispersion. 2.4 grams of β-cyclodextrin (β-CD) were dissolved in 20 grams of anhydrous DMSO and magnetically stirred at 50°C until completely dissolved. Then, 4.6 grams of hexamethylene diisocyanate (HDI) were slowly and dropwise added to the β-CD / DMSO solution using a constant-pressure dropping funnel. The mixture was placed in a 60°C oil bath and reacted at a constant temperature under a nitrogen atmosphere for four hours to form a CD-HDI solution. Subsequently, the prepared sodium alginate / DMSO gel dispersion was added to the CD-HDI solution at a slow, controllable rate of 1 gram per minute using a constant-pressure dropping funnel. During the addition, the system was vigorously stirred at 60°C to ensure sufficient contact. After completion, the reaction mixture was stirred at 60°C under nitrogen protection for 24 hours to ensure that the hydroxyl groups on the sodium alginate molecular chain reacted fully with CD-HDI to complete the grafting. After the reaction, the solution was cooled to room temperature and transferred to a dialysis bag with a molecular weight cutoff of 12-14 kDa, ensuring that the large Alg-CD polymer chains could not pass through the dialysis membrane. The bag was then placed in a large amount of deionized water for dialysis purification for 7 days, with the dialysis fluid changed 2-3 times a day to thoroughly remove DMSO solvent, unreacted HDI, β-CD, and other small molecule byproducts. After dialysis, the solution containing the Alg-CD polymer in the dialysis bag was poured into a petri dish and pre-frozen overnight in an ultra-low temperature freezer at -80°C. Then, it was transferred to a freeze dryer for freeze-drying for at least 48 hours to obtain a white, fluffy, spongy Alg-CD solid product. Finally, the product was ground into a fine powder and stored in a dry environment at 4°C to avoid moisture absorption, and was prepared for subsequent hydrogel preparation.

[0073] Step 2: Preparation of adamantane-modified graphene oxide powder 2 g of 1-adamantane carboxylic acid and 50 g of deionized water were mixed, and a 0.1% potassium hydroxide solution was added dropwise using a dropper. The pH of the solution was monitored with a pH meter until it reached 7.0, at which point the addition was stopped, converting the inert carboxylic acid (R-COOH) into a reactive carboxylate (R-COO⁻K⁺). The water was then completely removed using a rotary evaporator to obtain the potassium salt of adamantane carboxylic acid, which was completely dissolved in 60 g of propylene carbonate. 10 g of acetyl chloride was added, and the mixture was placed in a 60°C oil bath and stirred continuously for 24 hours to generate an activated adamantane solution. 0.2 g of graphene oxide and 50 g of propylene carbonate were weighed and ultrasonically treated at 120 W pulse mode with 2-second intervals and 3-second intervals in a 10°C ice-water bath to form a stable and homogeneous dispersion. Subsequently, the graphene oxide dispersion and the adamantane solution were mixed and magnetically stirred at 60°C for 12 hours to allow the functional groups on the graphene oxide sheet surface to undergo a complete esterification grafting reaction with the adamantane intermediate. After the reaction was completed, the mixture was poured into a centrifuge tube, and more than 100 grams of deionized water was added to precipitate the product. The precipitate was then collected by centrifugation at 8000 rpm for 10 minutes. This washing process of adding water and centrifugation was repeated 5 times to thoroughly remove propylene carbonate, unreacted raw materials and byproducts. Finally, the washed precipitate was freeze-dried to obtain Ad-GO solid powder, which was stored in a dry environment at 4°C for subsequent use.

[0074] Step 3: Preparation of dielectric layer hydrogel Weigh 0.6 g of Alg-CD solid powder and dissolve it in 2 g of deionized water. Stir magnetically at 50 °C to form a homogeneous solution. Add 0.5 g of glycerol and stir magnetically at 50 °C until completely mixed into a homogeneous solution. Take 0.5 g of Ad-GO solid powder and 0.03 g of MXene, mix them with 1 g of deionized water, and sonicate at 120 W pulse mode with 2 s intervals and 3 s intervals in a 10 °C ice-water bath to form a stable and homogeneous dispersion. Then, slowly pour the prepared dispersion into the homogeneous solution, stir rapidly for 5 minutes, add 0.5 g of 0.1 wt% CaCl2 aqueous solution, and continue stirring at 30 °C until uniformly dispersed. Pour the mixture onto a glass dish containing filter paper and dry in a 50 °C drying oven for 4 hours to obtain a dielectric hydrogel.

[0075] Step 4: Prepare the adhesive layer and assemble the sensor. 1 gram of 2 mg / mL BSA solution was mixed with 1 gram of 14 mg / mL tris(2-carboxyethyl)phosphine (TCEP) aqueous solution at pH=5. After gentle shaking to allow the reaction to proceed, the mixed solution was spin-coated onto the electrode. After standing at room temperature for 1 hour, an adhesive layer was formed on the electrode. Then, the upper electrode-adhesive layer-dielectric layer-adhesive layer-lower electrode were assembled to form a sandwich structure, resulting in a capacitive proximity-pressure composite sensing array.

[0076] likeFigure 1 As shown, the capacitive proximity-pressure composite sensor array for the safety of inspection robot operations provided in this embodiment has a sandwich-like structure. It has a hydrogel dielectric layer 3 as the central layer, an adhesive layer 2 and an FPCB electrode 1 on the upper and lower surfaces of the hydrogel dielectric layer, and an electrode layer 4 on the lower surface.

[0077] Figure 2 The top and bottom views of FPCB electrode 1 are shown. The upper surface is a proximity sensing array electrode containing two concentric rings; the lower surface is a 2×2 pressure sensing array formed by sensing units of size 1cm×1cm. Overall, a pressure-proximity composite sensing array is formed to realize proximity sensing when an object approaches and pressure sensing when an object is under load.

[0078] Figure 3 The proximity sensitivity is defined as (ΔC / C0) / Δd. The sensor is approached from a distance of 7cm, and capacitance values ​​are collected every 0.5cm, resulting in the proximity sensing curve shown in the figure. The proximity sensitivity S of this proximity sensor is 13.75cm⁻¹.

[0079] The response speed of proximity sensing is also a key performance indicator that significantly affects the practical application of the sensor. We collected capacitance change curves during the approach and movement away from the sensor at a sampling frequency of 200Hz, such as... Figure 4 As shown, the response time upon approach is 35 ms, while the recovery time upon withdrawal is 50 ms.

[0080] The sensitivity of a pressure sensor is defined as S = (ΔC / C0) / ΔP. A stress of 0~180KPa is applied to the sensor using a ZQ990B tension / compression press, and the sensor capacitance is measured using a TH2829. The results are as follows: Figure 5 As shown in the figure. The results indicate that the sensor can still maintain a high sensitivity of 13.76 kPa⁻¹ under a stress range of 0–180 kPa.

[0081] To evaluate the dynamic response speed of the pressure sensor, a 500g weight (equivalent pressure ~50kPa) was gently placed on the flexible pressure sensor prepared in this embodiment and then quickly released. Figure 6 The figure shows the response time and recovery time of the sensor under a stress change of 50 kPa. The results show that the response time is 54 ms and the recovery time is 49 ms.

[0082] Figure 7The force-capacitance response curves of the capacitive pressure sensor are shown, with applied pressures of 1N, 5N, 10N, and 15N, respectively, representing increases of 5N. The curves demonstrate good resolution of force changes, accurately distinguishing forces of different magnitudes. Furthermore, the peak values ​​of the same force (e.g., 1N, 5N, 10N) are essentially consistent at different time points, indicating that the sensor exhibits stable response characteristics and good cyclic repeatability under repeated force loading.

[0083] To compare the effect of sodium alginate dosage on the mechanical properties of the gel, the sodium alginate dosage was adjusted, and then a flexible ion gel material was prepared and shaped into an ion gel dielectric layer according to the same method described above. The mechanical tensile test was then performed on the material using a ZQ990B tensile press. Figure 8 This is a stress-strain diagram of ionogels prepared with different masses of sodium alginate in an embodiment of the present invention. 1-Alg and 2-Alg represent 1 gram and 2 grams of sodium alginate, respectively. It can be seen that when the sodium alginate content is higher, the tensile strength and elongation at break of the ionogel membrane are significantly improved, indicating excellent mechanical properties.

[0084] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0085] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0086] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0087] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0088] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0089] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A dielectric layer material for a capacitive flexible pressure sensor, characterized in that, The dielectric layer used in capacitive flexible pressure sensors is composed of the following components by mass percentage: 8%~11% Ad-GO solid, 0.3%~0.8% MXene, 10%~15% Alg-CD solid, 8%~15% glycerol, and the balance being deionized water. Ad-GO is a composite material formed by modifying the surface of graphene oxide GO nanosheets with functionalized Ad groups, and Alg-CD is a complex formed by chemical grafting sodium alginate (Alg) and β-cyclodextrin.

2. The dielectric layer material of the capacitive flexible pressure sensor according to claim 1, characterized in that, When preparing the Ad-GO solid, the components are composed of the following mass percentages: graphene oxide 0.1%~0.3%, acetyl chloride 7%~9%, 1-adamantane carboxylic acid 1%~3%, and the balance is propylene carbonate.

3. The dielectric layer material of the capacitive flexible pressure sensor according to claim 1, characterized in that, When preparing the Alg-CD solid, the components are composed of the following mass percentages: hexamethylene diisocyanate 6%~10%, β-cyclodextrin 3%~6%, sodium alginate 3%~5%, and the balance is dimethyl sulfoxide.

4. A dielectric layer of a capacitive flexible pressure sensor, characterized in that, The dielectric layer comprises the dielectric layer material according to any one of claims 1 to 3.

5. A method for fabricating the dielectric layer of a capacitive flexible pressure sensor, characterized in that, Based on the dielectric layer material according to any one of claims 1-3, the method comprises the following steps: (1) Sodium alginate and anhydrous dimethyl sulfoxide are mixed and magnetically stirred to form a dispersion of sodium alginate or anhydrous dimethyl sulfoxide; β-cyclodextrin and anhydrous dimethyl sulfoxide are mixed and magnetically stirred to form a β-CD or anhydrous dimethyl sulfoxide solution. Hexamethylene diisocyanate is slowly and dropwise added to the β-CD or anhydrous dimethyl sulfoxide solution and reacted in an oil bath under nitrogen atmosphere to form a CD-HDI solution. (2) The prepared sodium alginate or anhydrous dimethyl sulfoxide dispersion was added to the CD-HDI solution using a constant pressure dropping funnel. The reaction mixture was stirred at a constant temperature and then cooled to room temperature. It was then transferred to a dialysis bag for dialysis. After dialysis, the solution containing Alg-CD polymer in the dialysis bag was freeze-dried to obtain Alg-CD solid product and ground into fine powder. (3) Mix 1-adamantane carboxylic acid and deionized water, add dilute potassium hydroxide solution until neutral, remove water to obtain adamantane solution, dissolve it in propylene carbonate, add acetyl chloride, and stir in an oil bath to generate activated adamantane solution. (4) Graphene oxide and propylene carbonate were ultrasonically treated to form a graphene oxide dispersion. The graphene oxide dispersion was mixed with adamantane solution and magnetically stirred. After the mixture was finished, it was poured into a centrifuge tube to collect the precipitate and washed repeatedly. Finally, it was freeze-dried to obtain Ad-GO solid powder. (5) Dissolve Alg-CD solid powder in deionized water and stir magnetically to form a homogeneous solution. Then add glycerol and stir magnetically until completely mixed to form a homogeneous solution. Mix Ad-GO solid powder, MXene and deionized water and sonicate to form a dispersion. (6) Slowly pour the prepared dispersion into the homogeneous solution, stir, add calcium chloride aqueous solution, and continue stirring until uniformly dispersed to form a mixed solution. Pour the mixed solution onto a glass dish with filter paper, and dry to obtain dielectric layer hydrogel.

6. An adhesive layer material, characterized in that, The adhesive layer used in capacitive flexible pressure sensors comprises the following components by mass percentage: 0.5%~1.5% tris(2-carboxyethyl)phosphine, 0.05%~0.1% bovine serum albumin, and the remainder being deionized water.

7. An adhesive layer, characterized in that, The adhesive layer is assembled between the electrode and the dielectric layer, and the adhesive layer contains the adhesive layer material of claim 6.

8. A method for preparing an adhesive layer for a capacitive flexible pressure sensor, characterized in that, Based on the adhesive layer material of claim 6, the method comprises: mixing a certain concentration of bovine serum albumin aqueous solution with tris(2-carboxyethyl)phosphine aqueous solution, and gently shaking to allow the two to react fully, thereby obtaining an adhesive layer mixed solution.

9. A capacitive flexible pressure sensor, characterized in that, include: A first sensing electrode, a first adhesive layer, a dielectric layer, a second adhesive layer, and a second sensing electrode; The first sensing electrode, the first adhesive layer, the dielectric layer, the second adhesive layer, and the second sensing electrode are stacked in sequence from top to bottom to form a sandwich structure, wherein the dielectric layer is the dielectric layer of claim 4, and at least one of the first adhesive layer and the second adhesive layer includes the adhesive layer of claim 7.

10. The capacitive flexible pressure sensor according to claim 9, characterized in that, Its preparation methods include: The adhesive layer mixture solution is spin-coated onto the surfaces of the first and second sensing electrodes to obtain the FPCB electrode. Then, the dielectric layer hydrogel is stacked and assembled with the FPCB electrode to form a sandwich structure. The adhesive layer mixture solution is obtained by the adhesive layer preparation method of claim 8, and the dielectric layer hydrogel is obtained by the dielectric layer preparation method of claim 5.

11. The capacitive flexible pressure sensor according to claim 10, characterized in that, The upper surface of the first sensing electrode is designed to include two concentric rings.

12. A capacitive composite sensor array for the operational safety of inspection robots, characterized in that, The device includes a capacitive flexible pressure sensor, a capacitive flexible proximity sensor, a wire, and a signal processing module as described in any one of claims 9-11. The first sensing electrode and the second sensing electrode are respectively connected to the wire and then communicate with the signal processing module. The signal processing module is used to process data generated during the operation of the power inspection robot.

Images