Dual-mode flexible sensor and preparation method thereof, and continuum robot

Abstract

The application discloses a dual-mode flexible sensor, comprising: a plurality of sensing belts, each of which comprises a flexible substrate, a strain sensing electrode, an isolation film, a tactile sensing electrode and a sensing belt film connected in sequence; a plurality of sensing rings, each of which comprises a sensing ring electrode and a sensing ring film connected to the sensing ring electrode, the sensing ring film comprising a first sensing plane and a second sensing plane connected alternately, the first sensing plane and the second sensing plane being made of flexible triboelectric materials with different polarities; and a plurality of supporting rings connected to the plurality of sensing rings and the plurality of sensing belts respectively. The application also discloses a preparation method of the dual-mode flexible sensor and a continuum robot. The application can simultaneously realize tactile sensing and strain sensing, is convenient for stable operation in a complex environment of a human intestinal tract, does not interfere with robot movement, has high precision and high sensitivity, is reliable and stable in a long term, and significantly improves the sensing ability and operation performance of the continuum robot.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of continuum robot, and particularly relates to a dual-mode flexible sensor, a preparation method thereof and a continuum robot. BACKGROUND

[0002] After early digestive tract tumor treatment, the 5-year survival rate can be more than 90%, while the 5-year survival rate of middle and late tumors is less than 30%, so early diagnosis and treatment is the key to improve the survival rate. Studies have shown that 80% of colorectal cancer is transformed from intestinal benign polyps, and early detection and removal of polyps through colonoscopy is an effective means and preferred treatment for preventing colorectal cancer.

[0003] At present, the most widely and effective screening method is the colonoscopy that enters the intestinal tract through the patient's anus. The electronic endoscope is widely used in clinical application, and in the operation process, the doctor needs to manually push the slender scope into the intestinal tract. Only a small section at the front end of the endoscope scope can be manually operated to change the bending direction, which serves as the advancement guide of the scope in the intestinal tract. The endoscope scope mainly relies on external force to passively advance in the intestinal tract, which can easily cause great pressure on the intestinal wall and lead to scope accumulation and "knotting" phenomenon. In the conventional examination, since the camera is arranged at the end of the scope, the doctor adjusts the scope posture according to the camera picture, and can only observe the end environment and cannot perceive the contact state between the scope surface and the intestinal tract. The large visual blind area can cause adverse contact, and in severe cases, can cause intestinal perforation, tissue necrosis and massive bleeding, etc., which increases the pain of the patient and even causes life danger. In addition, the traditional endoscope has high requirements for the operation level of the doctor, and the doctor needs to accumulate a large amount of experience to safely and smoothly complete the operation. This increases the examination burden, reduces the examination quality and safety, prolongs the training time and increases the training cost, so that small and medium-sized hospitals cannot provide related examinations, which brings inconvenience to patients. Therefore, the development of an endoscope robot with sensing ability, self-adjusting posture and simple operation is the development trend of treating colorectal cancer.

[0004] In recent years, the application of continuum robots in medical, industrial and service fields has gradually increased, and the sensing technology has also developed, but the existing sensors still have the following defects: (1) single sensing mode, low precision and sensitivity; (2) poor reliability and stability in complex environments; (3) poor biocompatibility, unstable after long-term use; (4) poor consistency of sensor devices and cannot be mass-produced. At the same time, there are the following shortcomings when arranging sensors on the surface of the continuum robot: first, the existing sensor materials cannot fully meet the application requirements of the continuum robot in the human intestinal environment in terms of flexibility and biocompatibility. Second, due to the fine and compact structure of the continuum robot, the existing technology has challenges in arranging large-area flexible sensor arrays. At the same time, the existing sensor array integration method is easy to interfere with the movement of the continuum robot, limiting its effect in actual application. Therefore, the existing technology still needs to be further optimized and improved in terms of the structure design of the sensor array, the circuit layout method and the integration strategy to meet the use requirements of the continuum robot in complex environments. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a dual-mode flexible sensor and a preparation method thereof, and a continuum robot.

[0006] To achieve the above-mentioned purpose, the technical solution provided by an embodiment of the present application is as follows:

[0007] A dual-mode flexible sensor comprises:

[0008] A plurality of sensing strips, each of which comprises a flexible substrate, a strain sensing electrode, an isolation film, a tactile sensing electrode and a sensing strip film connected in sequence, the sensing strip film comprising an encapsulation film, a first sensing convex group and a second sensing convex group arranged alternately on the encapsulation film, the first sensing convex group and the second sensing convex group respectively adopting flexible triboelectric materials with different polarities;

[0009] A plurality of sensing rings, each of which comprises a sensing ring electrode and a sensing ring film connected to the sensing ring electrode, the sensing ring film comprising a first sensing plane and a second sensing plane connected alternately, the first sensing plane and the second sensing plane respectively adopting flexible triboelectric materials with different polarities;

[0010] A plurality of supporting rings are connected to the plurality of sensing rings and the plurality of sensing bands respectively, the plurality of sensing rings are coaxially spaced, the plurality of sensing bands are circumferentially spaced on the outer circumferential side of the plurality of sensing rings, when the polarity of the first sensing convex surface group and the first sensing plane is the same, the first sensing convex surface group and the second sensing plane are oppositely spaced, and the second sensing convex surface group and the first sensing plane are oppositely spaced; when the polarity of the first sensing convex surface group and the second sensing plane is the same, the first sensing convex surface group and the first sensing plane are oppositely spaced, and the second sensing convex surface group and the second sensing plane are oppositely spaced.

[0011] As a further improvement of the present application, one of the first sensing convex surface group and the second sensing convex surface group is a PTFE-Ecoflex sensing convex surface group, and the other is a PA-Ecoflex sensing convex surface group; one of the first sensing plane and the second sensing plane is a PTFE-Ecoflex sensing plane, and the other is a PA-Ecoflex sensing plane.

[0012] As a further improvement of the present application, the first sensing convex surface group includes at least one first sensing half-spherical surface, and the second sensing convex surface group includes at least one second sensing half-spherical surface.

[0013] As a further improvement of the present application, the encapsulating film is a PVA-Ecoflex encapsulating film; and / or

[0014] The strain sensing electrode and the tactile sensing electrode are both hydrogel electrodes; and / or

[0015] The flexible substrate and the isolation film are both made of Ecoflex material; and / or

[0016] The sensing ring electrode is an aluminum electrode.

[0017] As a further improvement of the present application, each sensing ring is connected between the axial surfaces of two supporting rings; and / or

[0018] Each sensing band is connected to the outer circumferential surface of the supporting ring; and / or

[0019] The number of sensing bands and sensing rings is four.

[0020] A preparation method of a bimodal flexible sensor, for preparing the bimodal flexible sensor, the preparation method comprising the following steps:

[0021] (1) preparing a plurality of sensing strips: preparing a sensing strip film, a flexible substrate and an isolation film, forming a strain sensing electrode on the flexible substrate, covering the strain sensing electrode with the isolation film, forming a tactile sensing electrode on the isolation film, and covering the tactile sensing electrode with the sensing strip film;

[0022] (2) preparing a plurality of sensing rings and a plurality of supporting rings, and connecting the plurality of sensing rings with the plurality of supporting rings respectively;

[0023] (3) arranging the plurality of supporting rings with sensing rings in a certain order;

[0024] (4) connecting the plurality of sensing strips in the correct order to the outer circumferential surface of the plurality of supporting rings.

[0025] As a further improvement of the present application, the step (1) comprises:

[0026] (1.0) electro-negatively modifying Ecoflex material, mixing PA, PVA and PTFE powders with Ecoflex prepolymer liquid in a mass ratio of 1:5 respectively, and stirring;

[0027] (1.1) adding a dispersing agent and dispersing to obtain three mixed solutions;

[0028] (1.2) vacuumizing the three mixed solutions, sucking the three mixed solutions, and dropping them respectively on the corresponding positions of the mold;

[0029] (1.3) vacuumizing again and heating;

[0030] (1.4) demolding to obtain a sensing strip film;

[0031] (1.5) using Ecoflex as a prepolymer liquid to heat and prepare a flexible substrate and an isolation film;

[0032] (1.6) performing surface hydrophilic treatment on the flexible substrate;

[0033] (1.7) performing surface hydrogen bond treatment on the flexible substrate, the isolation film and the sensing strip film;

[0034] (1.8) preparing a hydrogel solution: adding SA powder into NaCl solution at room temperature, stirring to make SA fully swell in the NaCl solution, continuing to stir in a constant temperature water bath, preparing a NaCl / SA composite solution, and placing the solution at room temperature; adding AM monomer and stirring; performing ice water bath on the solution; adding crosslinking agent MBAA and light initiator Irgacure 2959, stirring, and obtaining a uniform transparent hydrogel solution after centrifugation;

[0035] (1.9) Inject the hydrogel solution into the groove of the flexible substrate to form a strain sensing electrode, cover the strain sensing electrode with an isolation film, and then inject the hydrogel solution onto the isolation film to form a tactile sensing electrode. Then cover the tactile sensing electrode with a sensing strip film and irradiate it with an ultraviolet lamp with a wavelength of 365nm to obtain a sensing strip with strong adhesion at each interface.

[0036] As a further improvement of the present invention, step (2) includes:

[0037] (2.1) Electronegativity modification of Ecoflex material: PA and PTFE powders were mixed with Ecoflex prepolymer solution at a mass ratio of 1:5 and stirred;

[0038] (2.2) adding a dispersant and dispersing to obtain two mixed solutions;

[0039] (2.3) Vacuum the two mixed solutions, draw the two mixed solutions, and drop them on the corresponding positions of the mold respectively;

[0040] (2.4) Evacuate again and heat;

[0041] (2.5) demolding to obtain the sensing ring film;

[0042] (2.6) Using a 3D printer, prepare a support ring made of soft resin;

[0043] (2.7) Adhere the aluminum electrode to the axial surface of the support ring;

[0044] (2.8) The sensing ring film is pre-stretched and then adhered to the aluminum electrode.

[0045] A continuum robot comprising:

[0046] Robot body;

[0047] At least one of the dual-modal flexible sensors is coated on the robot body.

[0048] As a further improvement of the present invention, the support ring is connected to the robot body.

[0049] The beneficial effects of the present invention are:

[0050] (1) Dual-modal sensing mechanism: The present invention is based on a dual-modal sensing mechanism that is co-coupled with the triboelectric principle and the strain principle. It effectively solves the problem of single sensing mode in the prior art and significantly improves the sensor's sensing capability, enabling it to perform tactile perception and strain perception simultaneously.

[0051] (2) Improve the flexibility and biocompatibility of the sensor: by using high flexibility friction electric tactile sensing composite material and biocompatible flexible ionic hydrogel electrode, the application significantly improves the application performance of the sensor in the complex environment of human intestinal tract, and ensures its long-term stable use on the continuum robot.

[0052] (3) Non-interference integrated mode: design and integrate non-interference full mirror large area sensor array structure, ensure the consistency of the sensor device and the feasibility of large-scale production, can wrap the whole continuum robot, at the same time avoid the interference to the motion of the continuum robot, improve the overall operation performance of the continuum robot.

[0053] (4) High precision and high sensitivity: the sensor developed by the application not only maintains high precision and high sensitivity, but also has the advantages of simple structure and low cost, solves the problem of complex structure and high cost of existing high precision sensor, and expands its popularity in practical application.

[0054] (5) Reliability and long-term stability: by improving the structure design and integration strategy of the sensor, the reliability and long-term stability of the sensor are greatly improved, which ensures its stable work in complex environment, meets the application demand of the continuum robot in different operation environment, and has important application value and popularization prospect. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0056] Figure 1 Structure diagram of the dual-mode flexible sensor of the preferred embodiment of the application;

[0057] Figure 2 Structure diagram of the dual-mode flexible sensor of the preferred embodiment of the application;

[0058] Figure 3 Structure diagram of the sensing belt of the preferred embodiment of the application;

[0059] Figure 4 Structure diagram of the sensing ring of the preferred embodiment of the application;

[0060] Figure 5 Structure diagram of the sensing ring of the preferred embodiment of the application;

[0061] Figure 6The arrangement of the first sensing hemispherical surface and the second sensing hemispherical surface of the sensing belt and the first sensing plane and the second sensing plane of the sensing ring of the preferred embodiment of the present application is shown in the schematic diagram;

[0062] Figure 7 The structure schematic diagram of the continuum robot without the bimodal flexible sensor of the preferred embodiment of the present application is shown in the diagram;

[0063] Figure 8 The structure schematic diagram of the continuum robot with the bimodal flexible sensor of the preferred embodiment of the present application is shown in the diagram;

[0064] In the diagram: 10, bimodal flexible sensor, 1, sensing belt, 11, flexible substrate, 12, strain sensing electrode, 13, isolation film, 14, tactile sensing electrode, 15, sensing belt film, 150, encapsulation film, 151, first sensing convex surface group, 1511, first sensing hemispherical surface, 152, second sensing convex surface group, 1521, second sensing hemispherical surface, 2, sensing ring, 21, sensing ring electrode, 22, sensing ring film, 221, first sensing plane, 222, second sensing plane, 31, first support ring, 311, first notch, 312, first protrusion, 32, second support ring, 321, second notch, 322, second protrusion, 4, continuum robot, 5, robot body, 51, robot joint, 52, working end, 53, nickel-titanium alloy wire. DETAILED DESCRIPTION

[0065] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0066] Embodiment one

[0067] Please refer to Figures 1-6 The embodiments of the present application disclose a bimodal flexible sensor 10, which comprises:

[0068] A plurality of sensing belts 1, each of which comprises a flexible substrate 11, a strain sensing electrode 12, an isolation film 13, a tactile sensing electrode 14 and a sensing belt film 15 connected in sequence, the sensing belt film 15 comprising an encapsulation film 150, a first sensing convex surface group 151 and a second sensing convex surface group 152 arranged alternately on the encapsulation film 150, the first sensing convex surface group 151 and the second sensing convex surface group 152 respectively adopting flexible triboelectric materials with different polarities;

[0069] a plurality of sensing rings 2, each of the plurality of sensing rings 2 comprising a sensing ring electrode 21, a sensing ring film 22 connected to the sensing ring electrode 21, the sensing ring film 22 comprising a first sensing plane 221 and a second sensing plane 222 connected alternately, the first sensing plane 221 and the second sensing plane 222 being made of flexible triboelectric materials with different polarities respectively;

[0070] a plurality of supporting rings connected to the plurality of sensing rings 2 and the plurality of sensing bands 1 respectively, the plurality of sensing rings 2 being arranged coaxially and spaced apart, the plurality of sensing bands 1 being arranged circumferentially and spaced apart on the outer circumferential side of the plurality of sensing rings 2, when the first sensing convex surface group 151 has the same polarity as the first sensing plane 221, the first sensing convex surface group 151 and the second sensing plane 222 are arranged opposite and spaced apart, and the second sensing convex surface group 152 and the first sensing plane 221 are arranged opposite and spaced apart; when the first sensing convex surface group 151 has the same polarity as the second sensing plane 222, the first sensing convex surface group 151 and the first sensing plane 221 are arranged opposite and spaced apart, and the second sensing convex surface group 152 and the second sensing plane 222 are arranged opposite and spaced apart.

[0071] Preferably, one of the first sensing convex surface group 151 and the second sensing convex surface group 152 is a PTFE-Ecoflex sensing convex surface group, and the other is a PA-Ecoflex sensing convex surface group; one of the first sensing plane 221 and the second sensing plane is a PTFE-Ecoflex sensing plane, and the other is a PA-Ecoflex sensing plane.

[0072] In one example, the first sensing convex surface group 151 is a PTFE-Ecoflex sensing convex surface group, and the second sensing convex surface group 152 is a PA-Ecoflex sensing convex surface group. In one example, the first sensing plane 221 is a PTFE-Ecoflex sensing plane, and the second sensing plane 222 is a PA-Ecoflex sensing plane. At this time, the first sensing convex surface group 151 faces the second sensing plane 222, that is, the PTFE-Ecoflex sensing convex surface group faces the PA-Ecoflex sensing plane, and the second sensing convex surface group 152 faces the first sensing plane 221, that is, the PA-Ecoflex sensing convex surface group faces the PA-Ecoflex sensing plane. The PTFE-Ecoflex sensing convex surface group and the PTFE-Ecoflex sensing plane are both made of a mixture of PTFE and Ecoflex, and the PA-Ecoflex sensing convex surface and the PA-Ecoflex sensing plane are both made of a mixture of PA and Ecoflex, which have strong tensile capacity, are convenient for forming a sensor with a large span, and the triboelectric signal generated by the collision of PA and PTFE is strong, the signal characteristics are obvious, and detection is convenient.

[0073] Preferably, the first sensing convex surface group 151 comprises at least one first sensing hemispherical surface 1511, and the second sensing convex surface group 152 comprises at least one second sensing hemispherical surface 1521. The sensing convex surface is in the shape of a hemispherical surface, which increases the resilience and enables the sensing convex surface to quickly return to the original state after colliding with the sensing plane, while preventing the charge from drifting. Specifically, the first sensing hemispherical surface 1511 is a PTFE-Ecoflex sensing hemispherical surface, and the second sensing hemispherical surface 1521 is a PA-Ecoflex sensing hemispherical surface. In one example, the first sensing convex surface group 151 comprises three first sensing hemispherical surfaces 1511 arranged side by side at intervals, and the second sensing convex surface group 152 comprises three second sensing hemispherical surfaces 1521 arranged side by side at intervals. The three first sensing hemispherical surfaces 1511 and the three second sensing hemispherical surfaces 1521 can correspond to the second sensing plane 222 and the first sensing plane 221, respectively, to prevent the charge from drifting and ensure more sensitive sensing.

[0074] Preferably, the encapsulation film is a PVA-Ecoflex encapsulation film, which facilitates better encapsulation of the electrodes and better isolation of the charge between adjacent hemispherical surfaces. Preferably, the strain sensing electrode 12 and the tactile sensing electrode 14 are both hydrogel electrodes, which have good biocompatibility and significantly improve the application performance of the sensor in the complex environment of the human intestinal tract, ensuring long-term stable use of the sensor on the continuum robot. Preferably, the flexible substrate 11 and the isolation film 13 are both made of Ecoflex material, which has strong tensile ability. Preferably, the sensing ring electrode 21 is an aluminum electrode, but it is not limited to an aluminum electrode and can also be a copper electrode, an electrode paper, or an electrode tape.

[0075] In order to realize the reliability and stability of the connection of each component, preferably, each sensing ring 2 is connected between the axial surfaces of two support rings. Preferably, each sensing band 1 is connected to the outer peripheral surface of the support ring. Preferably, the number of sensing bands 1 and sensing rings 2 is four, which facilitates the formation of a large-span sensor. At the same time, the four sensing bands 1 are arranged in the up, down, left, and right directions of the continuum robot, thereby facilitating the collection of movement in four directions and improving the high precision and high sensitivity of the sensor. At the same time, the arrangement of the four sensing rings enables the sensor structure to be more uniform and stable.

[0076] In order to avoid interference with the encapsulation film 150 on the sensing strip 1 when the sensing strip 1 is assembled on the plurality of support rings, the plurality of support rings comprises two first support rings 31 and six second support rings 32, the periphery of the first support ring 31 is provided with four first notches 311, and the first protrusions 312 are formed between adjacent first notches 311, and the two outermost ends of the encapsulation film 150 of the sensing strip 1 are adhered to the outer periphery of the first protrusions 312 of the two first support rings 31, respectively, and the periphery of the second support ring 32 is provided with eight second notches 321, and the second protrusions 322 are formed between adjacent second notches 321, and the middle part of the encapsulation film 150 of the sensing strip 1 is adhered to the second protrusions 322 of the second support ring 32.

[0077] Preferably, transparent adhesive tape (not shown in the figure) is arranged at the positions where the sensing strip 1 contacts the first support ring 31 and the second support ring 32, so as to increase the resilience of the sensing strip 1. Preferably, an anti-static essential oil layer (not shown in the figure) is arranged on the surface of the flexible substrate 11 of the sensing strip 1 and the surface of the encapsulation film 150 of the sensing strip film 15. The arrangement of the anti-static essential oil layer can maximize the prevention of external environmental interference and internal environmental charge crosstalk between different touch sensing points.

[0078] In order to facilitate signal transmission, preferably, each sensing strip 1 is connected with three signal lines, two of which are connected with the strain sensing electrode 12, and the other is connected with the touch sensing electrode 14, and the sensing ring electrode 21 of each sensing ring 2 is connected with a signal line, so that each dual-mode flexible sensor 10 has 16 signal lines. Preferably, the signal line is a 0.05mm shielding line, which can maximize the prevention of various electrical interferences in the subsequent circuit.

[0079] When a certain point of the bimodal flexible sensor 10 collides, the collision force will cause the flexible substrate 11 to deform, thereby causing the first sensing hemispherical surface 1511 and the second sensing plane 222, the second sensing hemispherical surface 1521 and the first sensing plane 221 of the relative positions of the sensing belt film 15 and the sensing ring film 22 to contact, causing the tactile sensing electrode 14 and the sensing ring electrode 21 to output different signals or signal combinations, which can be analyzed by the upper computer through an algorithm to determine the position of the collision. When the bimodal flexible sensor 10 is installed on the continuum robot, it can provide reliable basis and protection for the operation of the continuum robot in a complex environment, improve the sensing ability and operation precision of the robot, and avoid colliding objects to achieve obstacle avoidance behavior. At the same time, the sensing belt 1 in the bimodal flexible sensor 10 will stretch or compress as the posture of the continuum robot changes, thereby causing the corresponding deformation of the strain sensing electrode 12 inside it, which will also stretch or compress. Because the resistance of these strain sensing electrodes 12 increases when stretched and decreases when compressed, the bending angle of the continuum robot can be determined by measuring the resistance change of the strain sensing electrode 12, which provides a basis for subsequent adjustment of the posture of the continuum robot.

[0080] Embodiment Two

[0081] The embodiment of the present application discloses a preparation method of a bimodal flexible sensor, which is used for preparing the bimodal flexible sensor 10 of embodiment one, please refer to Figures 1-6 , the preparation method comprises the following steps:

[0082] (1) preparing a plurality of sensing belts 1: preparing the sensing belt film 15, the flexible substrate 11 and the isolation film 13, forming the strain sensing electrode 12 on the flexible substrate 11, covering the strain sensing electrode 12 with the isolation film 13, forming the tactile sensing electrode 14 on the isolation film 13, and covering the sensing belt film 15 on the tactile sensing electrode 14;

[0083] (2) preparing a plurality of sensing rings 2 and a plurality of support rings, and connecting the plurality of sensing rings 2 with the plurality of support rings respectively;

[0084] (3) arranging the plurality of support rings with the sensing rings 2 in a certain order;

[0085] (4) connecting the plurality of sensing belts 1 in the correct order on the outer circumferential surface of the plurality of support rings.

[0086] Preferably, step (1) comprises:

[0087] (1.0) electro-negative modification of Ecoflex material, mixing PA, PVA and PTFE powders with Ecoflex prepolymer liquid in a mass ratio of 1:5 and stirring;

[0088] (1.1) adding a dispersant and dispersing to obtain three mixed solutions;

[0089] (1.2) vacuumizing the three mixed solutions, sucking the three mixed solutions, and dropping them respectively at corresponding positions of a mold;

[0090] (1.3) vacuumizing again and heating;

[0091] (1.4) demolding to obtain a sensing tape film 15;

[0092] (1.5) heating with Ecoflex as a prepolymer solution to prepare a flexible substrate 11 and an isolation film 13;

[0093] (1.6) performing surface hydrophilic treatment on the flexible substrate 11;

[0094] (1.7) performing surface hydrogen bond treatment on the flexible substrate 11, the isolation film 13, and the sensing tape film 15;

[0095] (1.8) preparing a hydrogel solution: adding SA powder into a NaCl solution at room temperature, stirring to make the SA fully swell in the NaCl solution, continuing to stir in a constant-temperature water bath, obtaining a NaCl / SA composite solution, and placing the solution at room temperature; adding AM monomers and stirring; performing ice-water bath on the solution; adding a crosslinking agent MBAA and a photoinitiator Irgacure 2959, stirring, and obtaining a uniform and transparent hydrogel solution after centrifugation;

[0096] (1.9) injecting the hydrogel solution into a channel of the flexible substrate 11 to form a strain sensing electrode 12, covering the isolation film 13 on the strain sensing electrode 12, injecting the hydrogel solution onto the isolation film 13 to form a tactile sensing electrode 14, covering the sensing tape film 15 on the tactile sensing electrode 14, and irradiating with an ultraviolet lamp with a wavelength of 365 nm to obtain a sensing tape 1 with firmly bonded interfaces.

[0097] Preferably, step (2) comprises:

[0098] (2.1) performing electronegativity modification on Ecoflex material, mixing PA and PTFE powders respectively with Ecoflex prepolymer solution according to a mass ratio of 1:5, and stirring;

[0099] (2.2) adding a dispersant and dispersing to obtain two mixed solutions;

[0100] (2.3) vacuumizing the two mixed solutions, sucking the two mixed solutions, and dropping them respectively at corresponding positions of a mold;

[0101] (2.4) vacuumizing again and heating;

[0102] (2.5) demolding to obtain the sensing ring film 22;

[0103] (2.6) using a 3D printer to prepare a support ring of soft resin material;

[0104] (2.7) adhering an aluminum electrode to the axial surface of the support ring;

[0105] (2.8) adhering the pre-stretched sensing ring film 22 to the aluminum electrode.

[0106] Preferably, it further comprises reinforcing a layer of transparent tape at the position where each sensing strip 1 contacts the support ring; and / or applying anti-static essential oil at the surface of the flexible substrate 11 of the sensing strip 1 and the surface of the encapsulation film 150 of the sensing strip film 15.

[0107] In order to better illustrate the preparation method of the dual-mode flexible sensor of the present application, the preparation method is specifically described as follows.

[0108] S1, preparing a plurality of sensing strips 1, and the specific preparation process of each sensing strip 1 is as follows:

[0109] S101: electro-negative modification of Ecoflex material, mixing PA, PVA and PTFE powders with Ecoflex prepolymer liquid in a mass ratio of 1:5, and stirring for 2 minutes. Among them, PA is polyamide, PTFE is polytetrafluoroethylene, and PVA is polyvinyl alcohol.

[0110] S102: adding 0.5 mL of n-hexane as a dispersant, dispersing in a JY92-IIDN ultrasonic cell crusher at a dispersion power of 15% for 2 minutes, respectively obtaining a first mixed solution containing PA and Ecoflex, a second mixed solution containing PVA and Ecoflex, and a third mixed solution containing PTFE and Ecoflex.

[0111] S103: vacuumizing the first mixed solution, the second mixed solution and the third mixed solution for 5 minutes, and then using a rubber head dropper to suck the first mixed solution, the second mixed solution and the third mixed solution and drop them respectively at the corresponding positions of the first mold.

[0112] S104: vacuumizing again for 2 minutes and heating at a temperature of 80°C for 20 minutes.

[0113] S105: demolding to obtain a sensing strip film.

[0114] S106: using Ecoflex as a prepolymer liquid, heating at a temperature of 80°C for 20 minutes to prepare an Ecoflex flexible substrate and an Ecoflex isolation film.

[0115] S107: Surface hydrophilic treatment of Ecoflex flexible substrate: Place the Ecoflex flexible substrate in an oxygen plasma cleaning machine, with the surface of the Ecoflex flexible substrate having the channel facing upwards, and treat it for 20 minutes at a power of 250W.

[0116] S108: Surface hydrogen bond treatment of Ecoflex flexible substrate, Ecoflex isolation film and sensing tape film: Place the Ecoflex flexible substrate, Ecoflex isolation film and sensing tape film in a benzophenone-ethanol solution, soak for 2 minutes, and then dry with a nitrogen gun after taking them out.

[0117] S109: Preparation of hydrogel solution: At room temperature, add SA powder to NaCl solution, and stir using a magnetic stirrer for 8h at room temperature to allow the SA to swell fully in the NaCl solution; continue stirring in a 50℃ constant temperature water bath for 0.5h to allow the SA to dissolve fully, thereby preparing a transparent, uniform and stable NaCl / SA composite solution, and let the composite solution stand at room temperature overnight; add AM monomer and stir for 2h; perform ice water bath on the composite solution; add crosslinking agent MBAA and photoinitiator Irgacure 2959 and stir for 10min, and then centrifuge to obtain a uniform and transparent hydrogel solution. Wherein, SA is sodium alginate, AM is acrylamide, and MBAA is N,N'-methylene bisacrylamide.

[0118] S110: Inject the hydrogel solution into the channel of the Ecoflex flexible substrate 11 to form a strain sensing electrode 12, cover the isolation film 13 on the strain sensing electrode 12 with tweezers, inject the hydrogel solution onto the isolation film 13 to form a tactile sensing electrode 14, and then cover the sensing tape film 15 on the tactile sensing electrode 14 with tweezers, and irradiate it with an ultraviolet lamp with a wavelength of 365nm for 10 minutes to obtain a sensing tape with firm adhesion at each interface.

[0119] S2, preparation of a plurality of sensing rings 2, each of which is prepared according to the following process:

[0120] S201: Electronegativity modification of Ecoflex material, mix PA and PTFE powders with Ecoflex prepolymer liquid in a mass ratio of 1:5 respectively, and stir for 2 minutes.

[0121] S202: Add 0.5mL of n-hexane as a dispersant, and disperse in a JY92-IIDN ultrasonic cell crusher at a dispersing power of 15% for 2 minutes, to obtain a fourth mixed solution containing PA and Ecoflex and a fifth mixed solution containing PTFE and Ecoflex respectively.

[0122] S203: Vacuumize the fourth mixed solution and the fifth mixed solution, and suck the fourth mixed solution and the fifth mixed solution, and drop them in the corresponding positions of the second mold, respectively.

[0123] S204: Vacuumize again for 2 minutes, and heat at a temperature of 80°C for 20 minutes.

[0124] S205: Demold to obtain the sensing ring film.

[0125] S206: Use a 3D printer to prepare the first support ring 31 and the second support ring 32 of the soft resin material.

[0126] S207: Adhere the aluminum electrode to the axial surface of the first support ring 31 and the second support ring 32.

[0127] S208: After pre-stretching the sensing ring film, adhere it to the aluminum electrode.

[0128] S3, assemble the sensing belt 1 and the sensing ring 2:

[0129] S301: Arrange the four first support rings 31 and the second support rings 32 of the sensing ring 2 in a certain order;

[0130] S302: Use a little glue to adhere the four sensing belts 1 in the correct order to the outer circumferential surface of the first support ring 31 and the second support ring 32.

[0131] S304: Reinforce a layer of transparent tape at the position where the sensing belt 1 contacts the first support ring 31 and the second support ring 32. In this way, the resilience of the sensing belt 1 is increased.

[0132] S305: Apply anti-static essential oil to the surface of the Ecoflex flexible substrate 11 of the sensing belt 1 and the surface of the PVA-Ecoflex packaging film 150 of the sensing belt film 15. The setting of the anti-static essential oil can maximize the prevention of external environmental static interference and internal environmental charge crosstalk between different touch sensing points.

[0133] At this point, the bimodal flexible sensor 10 is prepared. In this process, each sensing belt 1 has three signal lines, two of which are inserted into the strain sensing electrode 12, and the other is inserted into the touch sensing electrode 14. The sensing ring electrode 21 of each sensing ring 2 adheres to a signal line, so that each bimodal flexible sensor 10 has 16 signal lines. The preferred signal line is a 0.05mm shielding line, which can maximize the various electrical disturbances in the subsequent circuit.

[0134] Example Three

[0135] Please refer to Figures 1-8A continuum robot 4, comprising: a robot body 5; at least one bimodal flexible sensor 10 of embodiment one, the bimodal flexible sensor 10 being wrapped on the robot body 5. The robot body 5 comprises a plurality of robot joints 51 connected into a continuum robot structure by nitinol wires 53, and a working end 52 located at the end connected to the robot joints 51 by nitinol wires 53. The plurality of robot joints 51 are connected with a plurality of driving leads, each of which is controlled by an independent motor, so as to adjust the bending of the robot joints 51, in the process, the nitinol wires 53 are compressed or bent. The structure of the robot body 5 and the technology of driving the movement of the robot joints 51 adopt the general technology in the field, which will not be described here.

[0136] Preferably, one of the bimodal flexible sensors 10 is wrapped outside the working end 52 and twelve robot joints 51, and the other bimodal flexible sensors 10 are wrapped outside every thirteen robot joints 51.

[0137] In order to improve the stability of the bimodal flexible sensor 10 wrapped on the robot body 5, preferably, the plurality of robot joints 51 and the working end 52 are connected with a plurality of support rings. Specifically, the first support ring 31 and the second support ring 32 are bonded to the corresponding working end 52 and robot joint 51 by 502 glue.

[0138] The bimodal flexible sensor 10 is connected with a signal acquisition circuit, and then connected to an upper computer. When a certain point of the continuum robot 4 collides, the collision force will cause the flexible substrate 11 of the bimodal flexible sensor 10 to deform, thereby causing the first sensing hemispherical surface 1511 and the second sensing plane 222 of the sensing ring film 22, and the second sensing hemispherical surface 1521 and the first sensing plane 221 to contact, resulting in the tactile sensing electrode 14 and the sensing ring electrode 21 outputting different signals or signal combinations. Through algorithm analysis by the upper computer, the position of the collision can be determined, and through the driving circuit to adjust the stretching length of the nitinol wire 53, the continuum robot 4 is bent to avoid the collided object, realizing the obstacle avoidance behavior. When the robot joint 51 of the continuum robot 4 is bent, the bimodal flexible sensor 10 wrapped thereon will be bent, and the sensing belt 1 in the bimodal flexible sensor 10 will be stretched or compressed as the robot posture changes, thereby causing the strain sensing electrode 12 inside to deform accordingly, and also be stretched or compressed. Since the resistance of these strain sensing electrodes 12 increases when stretched and decreases when compressed, the bending angle of the robot joint 51 of the continuum robot 4 can be determined by measuring the resistance change of the strain sensing electrode 12, which provides a basis for subsequent adjustment of the driving lead to adjust the posture of the continuum robot 4.

[0139] It will be obvious to a person skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments and can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims to the identity of the reference signs therein.

[0140] Furthermore, it should be understood that although the description is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A dual-mode flexible sensor, characterized in that: include: A plurality of sensing strips, each of which includes a flexible substrate, a strain sensing electrode, an isolation film, a tactile sensing electrode, and a sensing strip film connected in sequence, wherein the sensing strip film includes an encapsulation film, and a first sensing convex surface group and a second sensing convex surface group alternately arranged on the encapsulation film, wherein the first sensing convex surface group and the second sensing convex surface group are respectively made of flexible triboelectric materials with different polarities; A plurality of sensing rings, each of the sensing rings comprising a sensing ring electrode and a sensing ring film connected to the sensing ring electrode, the sensing ring film comprising a first sensing plane and a second sensing plane alternately connected, the first sensing plane and the second sensing plane respectively using flexible triboelectric materials with different polarities; A plurality of supporting rings are respectively connected to the plurality of sensing rings and the plurality of sensing bands, the plurality of sensing rings are coaxially spaced, and the plurality of sensing bands are circumferentially spaced on the outer circumference of the plurality of sensing rings. When the polarity of the first sensing convex surface group is the same as that of the first sensing plane, the first sensing convex surface group is relatively spaced from the second sensing plane, and the second sensing convex surface group is relatively spaced from the first sensing plane; when the polarity of the first sensing convex surface group is the same as that of the second sensing plane, the first sensing convex surface group is relatively spaced from the first sensing plane, and the second sensing convex surface group is relatively spaced from the second sensing plane.

2. The dual-mode flexible sensor according to claim 1, characterized in that: One of the first sensing convex surface group and the second sensing convex surface group is a PTFE-Ecoflex sensing convex surface group, and the other is a PA-Ecoflex sensing convex surface group; one of the first sensing plane and the second sensing plane is a PTFE-Ecoflex sensing plane, and the other is a PA-Ecoflex sensing plane.

3. The dual-mode flexible sensor according to claim 2, characterized in that: The first perceptual convex surface group includes at least one first perceptual hemispherical surface, and the second perceptual convex surface group includes at least one second perceptual hemispherical surface.

4. The dual-mode flexible sensor according to claim 1, characterized in that: The packaging film is a PVA-Ecoflex packaging film; and / or The strain sensing electrodes and the tactile sensing electrodes are both hydrogel electrodes; and / or The flexible substrate and the isolation film are both made of Ecoflex material; and / or The sensing ring electrode is an aluminum electrode.

5. The dual-mode flexible sensor according to claim 1, characterized in that: Each of the sensing rings is connected between the axial surfaces of the two support rings; and / or Each of the sensing bands is connected to the outer circumference of the support ring; and / or The number of the sensing bands and the number of the sensing rings are both four.

6. A method for preparing a dual-mode flexible sensor, characterized in that: For preparing the dual-modal flexible sensor according to any one of claims 1 to 5, the preparation method comprises the following steps: (1) Preparing a plurality of sensing strips: preparing a sensing strip film, a flexible substrate, and an isolation film, forming a strain sensing electrode on the flexible substrate, covering the strain sensing electrode with the isolation film, forming a tactile sensing electrode on the isolation film, and covering the tactile sensing electrode with the sensing strip film; (2) preparing a plurality of sensing rings and a plurality of supporting rings, and connecting the plurality of sensing rings to the plurality of supporting rings respectively; (3) arranging the plurality of support rings that have been equipped with the sensing ring in a certain order; (4) Connect the plurality of sensing bands to the outer circumferences of the plurality of support rings in the correct order.

7. The method for preparing a dual-mode flexible sensor according to claim 6, wherein: The step (1) comprises: (1.0) Electronegativity modification of Ecoflex material: PA, PVA and PTFE powders were mixed with Ecoflex prepolymer solution in a mass ratio of 1:5 and stirred; (1.1) adding a dispersant and dispersing to obtain three mixed solutions; (1.2) Vacuum the three mixed solutions, draw the three mixed solutions, and drop them on the corresponding positions of the mold respectively; (1.3) Evacuate again and heat; (1.4) demoulding to obtain a sensing tape film; (1.5) Using Ecoflex as prepolymer solution, heating to prepare flexible substrate and isolation film; (1.6) Performing surface hydrophilic treatment on the flexible substrate; (1.7) Performing surface hydrogen bonding treatment on the flexible substrate, isolation film, and sensing strip film; (1.8) Preparation of hydrogel solution: SA powder was added to a NaCl solution at room temperature and stirred to allow the SA to fully swell in the NaCl solution. Stirring was continued in a constant temperature water bath to prepare a NaCl / SA composite solution, which was then allowed to stand at room temperature. AM monomer was added and stirred. The solution was placed in an ice-water bath. The crosslinker MBAA and the photoinitiator Irgacure 2959 were added and stirred. After centrifugation, a uniform and transparent hydrogel solution was obtained. (1.9) Inject the hydrogel solution into the groove of the flexible substrate to form a strain sensing electrode, cover the strain sensing electrode with an isolation film, and then inject the hydrogel solution onto the isolation film to form a tactile sensing electrode. Then cover the tactile sensing electrode with a sensing strip film and irradiate it with an ultraviolet lamp with a wavelength of 365nm to obtain a sensing strip with strong adhesion at each interface.

8. The method for preparing a dual-mode flexible sensor according to claim 6, wherein: The step (2) comprises: (2.1) Electronegativity modification of Ecoflex material: PA and PTFE powders were mixed with Ecoflex prepolymer solution at a mass ratio of 1:5 and stirred; (2.2) adding a dispersant and dispersing to obtain two mixed solutions; (2.3) Vacuum the two mixed solutions, draw the two mixed solutions, and drop them on the corresponding positions of the mold respectively; (2.4) Evacuate again and heat; (2.5) demolding to obtain the sensing ring film; (2.6) Using a 3D printer, prepare a support ring made of soft resin; (2.7) Adhere the aluminum electrode to the axial surface of the support ring; (2.8) The sensing ring film is pre-stretched and then adhered to the aluminum electrode.

9. A continuum robot, characterized in that: include: Robot body; At least one dual-modal flexible sensor according to any one of claims 1 to 5, wherein the dual-modal flexible sensor is wrapped around the robot body.

10. The continuum robot according to claim 9, characterized in that: The supporting ring is connected to the robot body.

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