Preparation method and application of high-resolution ion skin
By combining the structure of a hard salt layer and a gel layer, the preparation process was simplified and a high-resolution ion skin sensor was prepared, which solved the problem that dexterous hands have difficulty in accurately identifying the material and texture of objects, and achieved stronger perception capabilities of dexterous hands.
Patent Information
- Application Number
- CN202510967191.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-14
- Publication Date
- 2025-09-12
AI Technical Summary
The electronic skin and ionic skin on existing dexterous hands are difficult to accurately identify the material and texture of objects, the preparation process is complex, and it is difficult to achieve mass production.
A combined structure of a hard salt layer and a gel layer is adopted. By laminating, winding and soaking the pre-cured gel layer and the hard salt layer, a high-resolution ion skin with hard salt protrusions is prepared, which is combined with flexible electrodes to form a sensor.
The preparation process has been simplified, the preparation efficiency of high-resolution ionic skin has been improved, the ability to recognize fine textures and materials has been achieved, and the dexterous hand has been given more powerful grasping and perception capabilities.
Smart Images
Figure CN120620776A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of flexible sensors, and more specifically to a preparation method and application of high-resolution ionic skin. Background Art
[0002] With the rapid development of the robotics industry, the market for humanoid robots has gradually expanded. To give humanoid robots stronger external perception capabilities, the industry has developed dexterous hands. Robots equipped with dexterous hands can detect whether an object has been grasped and its general shape by observing changes in electrical signals when grasping it. This application of dexterous hands has enriched the robot's ability to acquire external information. Currently, the core component of the sensor used by dexterous hands to perceive external information is electronic skin. When grasping an object, the electronic skin deforms, changing its resistance and thus the output electrical signal. By analyzing this electrical signal, external information can be received. Ionic skin can also change its ion conductivity when deformed, and can also be used as the core sensor of dexterous hands. Ionic skin generally has better stability and strain sensing range than electronic skin, and may replace most electronic skins in the future and be widely used.
[0003] However, the electronic skin and ionic skin on dexterous hands can only sense simple mechanical and temperature changes, and it is difficult to finely identify the material and texture of objects. This limits the application of dexterous hands in application scenarios with higher perception requirements. In order to improve the resolution ability of ionic skin, it is necessary to design a fingerprint-like structure with different soft and hardness on the surface of the ionic skin. However, the synthesis of such a fingerprint-like structure is very complicated. For example, the article (Adv. Mater., 2023, 35, 2300593) requires stretching the pre-cured precursor to a specific elongation and placing it on an Ecoflex substrate. Then, a salt-containing agar gel is placed in the center of the pre-cured precursor and left to stand for a long time in a high humidity environment to obtain a fingerprint-like ionic skin with a Liesegang ring. The preparation process is extremely complicated, the product size is severely limited, and it is difficult to achieve mass production. How to use a simple process to enable electronic skin or ionic skin to have fine material and texture recognition is still a difficult problem that needs to be overcome vigorously.
[0004] Therefore, it is necessary to provide a high-resolution ionic skin preparation method to solve the above problems. Summary of the Invention
[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a high-resolution ionic skin preparation method and application to solve the problems existing in the above-mentioned background technology.
[0006] The present invention provides the following technical solutions: a method for preparing high-resolution ionic skin and its application, wherein the high-resolution ionic skin comprises a hard salt layer and a gel layer, wherein the hard salt layer comprises water, a polymer, a hard salt and a water-soluble salt, and the gel layer comprises water, a polymer and a water-soluble salt;
[0007] Preferably, in the hard salt layer, the water content is 45-65wt%, the polymer content is 15-30wt%, the hard salt content is 2-10wt%, and the water-soluble salt content is 5-20wt%. In the gel layer, the water content is 60-85wt%, the polymer content is 10-30wt%, and the water-soluble salt content is 5-20wt%.
[0008] Preferably, the polymer is prepared by polymerization of a monomer and an initiator. The monomer is one or more of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-methylenebisacrylamide, and cinnamamide. The initiator is one or more of potassium persulfate, ammonium persulfate, and sodium persulfate.
[0009] Preferably, the hard salt is one or more of calcium hydrogen phosphate, lead iodide, lead fluoride, cobalt hydroxide, cobalt phosphate, magnesium hydroxide, and silver dichromate.
[0010] Preferably, the hardness salt is formed by reacting a cationic salt and an anionic salt. The cationic salt is one or more of calcium chloride, lead nitrate, cobalt chloride, magnesium chloride, and silver nitrate. The anionic salt is one or more of sodium hydrogen phosphate, sodium iodide, sodium fluoride, sodium hydroxide, sodium phosphate, sodium dichromate, potassium hydrogen phosphate, potassium iodide, potassium fluoride, potassium hydroxide, potassium phosphate, and potassium dichromate.
[0011] Preferably, the water-soluble salt is one or more of sodium chloride, potassium chloride, sodium sulfate, and potassium sulfate.
[0012] Preferably, the method for preparing high-resolution ionic skin comprises the following steps:
[0013] S1. Preparation of pre-cured gel layer: Mix monomers and water in proportion, stir for 30-60 minutes, then add initiator and water-soluble salt, stir for 30-60 minutes in an ice bath, apply the mixed solution, and cure at 60°C for 0.5-1 hour to obtain a pre-cured gel layer with a thickness of 0.1-2 mm.
[0014] S2. Preparation of pre-cured hard salt layer: Mix the monomer, water, and anionic salt in proportion, stir for 30-60 minutes, then add the initiator and water-soluble salt, stir for 30-60 minutes in an ice bath, apply the mixed solution, and cure at 60°C for 0.5-1 hour to obtain a pre-cured hard salt layer. The thickness of the pre-cured hard salt layer is 0.1-0.5 mm.
[0015] S3. Preparation of pre-cured high-resolution ionic skin: The pre-cured gel layer and the pre-cured hard salt layer are laminated together by rolling, rolled into a roll, and then cut in the normal direction to obtain the pre-cured ionic skin; the pre-cured ionic skin is placed in a 1M cationic salt solution, soaked for 40-90 minutes, and then taken out to obtain the pre-cured high-resolution ionic skin with hard salt protrusions.
[0016] S4. Preparation of high-resolution ion skin: The pre-cured high-resolution ion skin was placed at 60°C and 60-90% RH for 1-2 hours to obtain a high-resolution ion skin with hard salt protrusions.
[0017] Preferably, the high-resolution ion skin is used in a flexible sensor. The high-resolution ion skin is soaked in an encapsulation resin solution, taken out, naturally leveled and dried, and a layer of flexible electrodes is printed on the surface by screen printing to obtain a high-resolution ion skin sensor, which can be used in devices such as dexterous hands that require material and texture perception.
[0018] Technical effects and advantages of the present invention:
[0019] The present invention significantly simplifies the preparation process and greatly improves the preparation efficiency of high-resolution ion skin by designing a hard salt layer preparation strategy. By controlling the thickness of the pre-cured layer and the winding size, high-resolution ion skin of different sizes can be customized. Through the preparation process design, a ring structure that imitates a finger fingerprint is synthesized in the flexible ion skin. The modulus-differentiated composite structure in this high-resolution ion skin gives it unique tactile sensing performance. Based on the triboelectric effect, the high-resolution ion skin can maintain normal stress sensing ability while having fine texture recognition and material recognition capabilities. This high-resolution ion skin-based application in robotic dexterous hands can give the dexterous hands more powerful grasping perception capabilities and open up new application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a side view of the high-resolution ionic skin sample of the present invention.
[0021] Figure 2 This is a schematic diagram of the high-resolution ionic skin sample surface of the present invention.
[0022] Figure 3 The signal changes output by the high-resolution ionic skin sensor obtained in Example 1 when grasping different objects.
[0023] The accompanying drawings are marked as follows: 1. Ionic skin gel; 2. Hard salt. DETAILED DESCRIPTION
[0024] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. In addition, the forms of the various structures described in the following embodiments are merely examples. The high-resolution ionic skin preparation method and application involved in the present invention are not limited to the various structures described in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Specific embodiment 1
[0026] S1. Preparation of pre-cured gel layer:
[0027] Acrylamide, N,N-dimethylacrylamide and water were mixed in proportion and stirred for 60 minutes. Potassium persulfate and sodium chloride were then added and stirred for 60 minutes in an ice bath. The mixed solution was coated and cured at 60°C for 0.5 hours to obtain a pre-cured gel layer with a thickness of 0.2 mm.
[0028] S2. Preparation of pre-cured hard salt layer:
[0029] Acrylamide, N,N-dimethylacrylamide, water and sodium dichromate were mixed in proportion and stirred for 60 minutes. Potassium persulfate and sodium chloride were then added and stirred for 60 minutes in an ice bath. The mixed solution was applied and cured at 60°C for 0.5 hours to obtain a pre-cured hard salt layer with a thickness of 0.2 mm.
[0030] S3. Preparation of pre-cured high-resolution ion skin:
[0031] The pre-cured gel layer and the pre-cured hard salt layer are laminated by roller pressing, rolled into a roll, and cut in the normal direction to obtain a pre-cured ionic skin; the pre-cured ionic skin is placed in a 1M silver nitrate aqueous solution, soaked for 60 minutes, and then taken out to obtain a pre-cured high-resolution ionic skin with hard salt protrusions.
[0032] S4. Preparation of high-resolution ionic skin:
[0033] The pre-cured high-resolution ion skin was placed at 60°C and 65% RH for 1 hour to obtain a high-resolution ion skin with hard salt protrusions. Figure 2 As shown in Figure 2, the gel layer contains 75% water, 12% polymer, and 13% water-soluble salt. The hard salt layer contains 57% water, 20% polymer, 8% hard salt, and 15% water-soluble salt.
[0034] Performance testing:
[0035] The prepared high-resolution ion skin was soaked in a packaging resin solution and then taken out, naturally leveled and dried. A layer of flexible electrodes was printed on the surface by screen printing to obtain a high-resolution ion skin sensor. The sensor was attached to the surface of a dexterous finger, and different objects were grasped to detect the output signal, such as Figure 3 As shown, the sensor can output different electrical signals according to the shape and texture of the grasped object. By analyzing the electrical signals, the object's material and texture can be identified. Specific embodiment 2
[0037] S1. Preparation of pre-cured gel layer:
[0038] Acrylamide, methacrylamide and water were mixed in proportion and stirred for 60 minutes. Sodium persulfate and potassium chloride were then added and stirred for 60 minutes in an ice bath. The mixed solution was coated and cured at 60°C for 0.5 hours to obtain a pre-cured gel layer with a thickness of 1.2 mm.
[0039] S2. Preparation of pre-cured hard salt layer:
[0040] Acrylamide, methacrylamide, water and sodium phosphate were mixed in proportion and stirred for 60 minutes. Then sodium persulfate and potassium chloride were added and stirred for 60 minutes in an ice bath. The mixed solution was coated and cured at 60°C for 0.5 hours to obtain a pre-cured hard salt layer with a thickness of 0.5 mm.
[0041] S3. Preparation of pre-cured high-resolution ion skin:
[0042] The pre-cured gel layer and the pre-cured hard salt layer are laminated by roller pressing, rolled into a roll, and cut in the normal direction to obtain a pre-cured ionic skin; the pre-cured ionic skin is placed in a 1M cobalt chloride aqueous solution, soaked for 60 minutes, and then taken out to obtain a pre-cured high-resolution ionic skin with hard salt protrusions.
[0043] S4. Preparation of high-resolution ionic skin:
[0044] The pre-cured high-resolution ion skin was placed at 60°C and 90% RH for 2 hours to produce a high-resolution ion skin with hard salt protrusions. The gel layer contained 80% water, 10% polymer, and 10% water-soluble salt. The hard salt layer contained 63% water, 17% polymer, 8% hard salt, and 12% water-soluble salt.
[0045] Performance testing:
[0046] The prepared high-resolution ion skin is soaked in an encapsulating resin solution, taken out, naturally leveled and dried, and a layer of flexible electrodes is screen-printed on the surface to obtain a high-resolution ion skin sensor. The sensor is attached to the surface of a dexterous finger, and different objects are grasped to detect the output signal. The sensor can output different electrical signals according to the shape and texture of the grasped object. The material and texture of the object can be identified by analyzing the electrical signal.
[0047] Comparative Example 1:
[0048] S1. Preparation of pre-cured gel layer:
[0049] Acrylamide, N,N-dimethylacrylamide and water were mixed in proportion and stirred for 60 minutes. Potassium persulfate and sodium chloride were then added and stirred for 60 minutes in an ice bath. The mixed solution was coated and cured at 60°C for 0.5 hours to obtain a pre-cured gel layer with a thickness of 0.2 mm.
[0050] S2. Preparation of pre-cured hard salt layer:
[0051] Acrylamide, N,N-dimethylacrylamide, water and sodium dichromate were mixed in proportion and stirred for 60 minutes. Potassium persulfate and sodium chloride were then added and stirred for 60 minutes in an ice bath. The mixed solution was applied and cured at 60°C for 0.5 hours to obtain a pre-cured hard salt layer with a thickness of 2 mm.
[0052] S3. Preparation of pre-cured high-resolution ion skin:
[0053] The pre-cured gel layer and the pre-cured hard salt layer are laminated by roller pressing, rolled into a roll, and cut in the normal direction to obtain a pre-cured ionic skin; the pre-cured ionic skin is placed in a 1M silver nitrate aqueous solution, soaked for 60 minutes, and then taken out to obtain a pre-cured high-resolution ionic skin with hard salt protrusions.
[0054] S4. Preparation of high-resolution ionic skin:
[0055] The pre-cured high-resolution ion skin was placed at 60°C and 65% RH for 1 hour to obtain a high-resolution ion skin with hard salt protrusions. Figure 2 As shown in Figure 2, the gel layer contains 75% water, 12% polymer, and 13% water-soluble salt. The hard salt layer contains 57% water, 20% polymer, 8% hard salt, and 15% water-soluble salt.
[0056] Performance testing:
[0057] The resulting high-resolution ion skin was immersed in an encapsulating resin solution, removed, and naturally leveled and dried. A layer of flexible electrodes was screen-printed on the surface to create a high-resolution ion skin sensor. The sensor was then attached to the surface of a dexterous finger, and the sensor was used to grasp various objects and detect the output signal. Compared to Example 1, the hard salt layer was too thick, resulting in a weak sensor signal and inability to identify the object's material and texture.
[0058] Comparative Example 2:
[0059] S1. Gel layer preparation:
[0060] Acrylamide, N,N-dimethylacrylamide, water, and sodium dichromate were mixed in proportion and stirred for 60 minutes. Potassium persulfate and sodium chloride were then added and stirred in an ice bath for 60 minutes. The mixture was poured into a mold and cured at 60°C for 3 hours to obtain a pre-cured ionic skin gel. Directly making the pre-cured ionic skin into a sensor, due to the lack of a hard salt layer, it was unable to identify the material and texture of different objects when grasping different objects.
[0061] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense, and may refer to mechanical or electrical connections, internal communication between two components, or direct connection. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute positions of the objects being described change, the relative positional relationships may also change.
[0062] Secondly: The drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention. Other structures may refer to conventional designs. The same embodiment and different embodiments of the present invention may be combined with each other without conflict.
[0063] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A high-resolution ionic skin, characterized by: The high-resolution ionic skin includes a hard salt layer and a gel layer. The hard salt layer comprises water, polymer, hard salt and water-soluble salt, and the gel layer comprises water, polymer and water-soluble salt.
2. The high-resolution ionic skin according to claim 1, characterized in that: The hard salt layer has a water content of 45-65 wt%, a polymer content of 15-30 wt%, a hard salt content of 2-10 wt%, and a water-soluble salt content of 5-20 wt%. The gel layer has a water content of 60-85 wt%, a polymer content of 10-30 wt%, and a water-soluble salt content of 5-20 wt%.
3. The high-resolution ionic skin according to claim 1, characterized in that: The polymer is prepared by polymerization of a monomer and an initiator. The monomer is one or more of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-methylenebisacrylamide, and cinnamamide. The initiator is one or more of potassium persulfate, ammonium persulfate, and sodium persulfate.
4. The high-resolution ionic skin according to claim 1, characterized in that: The hard salt is one or more of calcium hydrogen phosphate, lead iodide, lead fluoride, cobalt hydroxide, cobalt phosphate, magnesium hydroxide, and silver dichromate.
5. The high-resolution ionic skin according to claim 4, characterized in that: The hardness salt is formed by the reaction of a cationic salt and an anionic salt. The cationic salt is one or more of calcium chloride, lead nitrate, cobalt chloride, magnesium chloride, and silver nitrate. The anionic salt is one or more of sodium hydrogen phosphate, sodium iodide, sodium fluoride, sodium hydroxide, sodium phosphate, sodium dichromate, potassium hydrogen phosphate, potassium iodide, potassium fluoride, potassium hydroxide, potassium phosphate, and potassium dichromate.
6. The high-resolution ionic skin according to claim 1, characterized in that: The water-soluble salt is one or more of sodium chloride, potassium chloride, sodium sulfate and potassium sulfate.
7. A method for preparing a high-resolution ion skin, based on the high-resolution ion skin according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Preparation of pre-cured gel layer: Mix monomers and water in proportion, stir for 30-60 minutes, then add initiator and water-soluble salt, stir for 30-60 minutes in an ice bath, apply the mixed solution, and cure at 60°C for 0.5-1 hour to obtain a pre-cured gel layer with a thickness of 0.1-2 mm. S2. Preparation of pre-cured hard salt layer: Mix the monomer, water, and anionic salt in proportion, stir for 30-60 minutes, then add the initiator and water-soluble salt, stir for 30-60 minutes in an ice bath, apply the mixed solution, and cure at 60°C for 0.5-1 hour to obtain a pre-cured hard salt layer. The thickness of the pre-cured hard salt layer is 0.1-0.5 mm. S3. Preparation of pre-cured high-resolution ionic skin: The pre-cured gel layer and the pre-cured hard salt layer are laminated together by rolling, rolled into a roll, and then cut in the normal direction to obtain the pre-cured ionic skin; the pre-cured ionic skin is placed in a 1M cationic salt solution, soaked for 40-90 minutes, and then taken out to obtain the pre-cured high-resolution ionic skin with hard salt protrusions. S4. Preparation of high-resolution ion skin: The pre-cured high-resolution ion skin was placed at 60°C and 60-90% RH for 1-2 hours to obtain a high-resolution ion skin with hard salt protrusions.
8. Application of the high-resolution ionic skin obtained by the method according to claim 7 in a flexible sensor, characterized in that: The high-resolution ion skin is soaked in an encapsulation resin solution, taken out, naturally leveled and dried, and a layer of flexible electrodes is screen-printed on the surface to obtain a high-resolution ion skin sensor, which can be used in devices such as dexterous hands that require material and texture perception.