A full-flexible tactile and haptic dual-mode bionic electronic skin for dexterous manipulation of a robot hand

Abstract

The present application relates to a kind of full flexible approach sense and touch dual-mode bionic electronic skin for mechanical hand dexterous operation, comprising: approach sense sensing unit layer, touch sensing unit layer, polymer spacing layer and polymer encapsulation layer;The approach sense sensing unit layer is used to convert the distance and material information of approaching object into electrical signal based on maxwell displacement current;The touch sensing unit layer is used to detect the pressure information after approaching object contact based on off-electric type electric capacity;The polymer spacing layer is arranged between the approach sense sensing unit layer and touch sensing unit layer, for isolating the approach sense sensing unit layer and touch sensing unit layer;The polymer encapsulation layer is arranged below the touch sensing unit layer, for encapsulating the approach sense sensing unit layer, touch sensing unit layer.The present application can be widely applied in sensing technology field.

Description

Technical Field

[0001] This invention relates to a fully flexible, bimodal bionic electronic skin for dexterous operation of robotic arms, which combines proximity and tactile sensations and belongs to the field of sensing technology. Background Technology

[0002] Powerful perception capabilities are crucial for robotic arms to achieve human-like dexterity. Currently, robots primarily rely on various sensors to perceive changes in the external environment. Electro-bionic skin is the most important perception method besides the robot's vision system. Proximity perception and tactile perception, as complementary functions, enable the recognition of the position, shape, and material of approaching objects, as well as the perception of pressure upon contact. This is significant for the pre-deceleration drive during dexterity maneuvers, the rapid response to different grasping strategies for different materials and shapes, and ultimately, the safe and efficient interaction with the surrounding environment.

[0003] Currently, proximity sensors used in robots are mainly based on principles such as infrared light, ultrasound, capacitance, and magnetometry. These are non-flexible and typically large in size, making them difficult to apply to the delicate fingertips where size and flexibility are critical. Furthermore, infrared-based proximity sensors are susceptible to interference from object color and ambient light; magnetometry-based proximity sensors are limited by the materials used to detect approaching objects; ultrasound-based proximity sensors struggle to detect proximity information at sub-centimeter distances; and capacitance-based proximity sensors struggle to achieve both fast response time and long sensing distance. Current tactile sensors used in robots also struggle to maintain good linearity across a wide pressure range. Moreover, the integration and fabrication of fully flexible proximity and tactile dual-modal sensors also present certain challenges. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a fully flexible, proximity-and-touch dual-modal bionic electronic skin for dexterous robotic hand operation. This electronic skin is fully flexible, has a simple fabrication process, and is easy to array design. The proximity sensing unit can achieve fast response time and material recognition, while the tactile sensing unit can maintain good linearity over a wide pressure range.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A fully flexible, bimodal bionic electronic skin for dexterous manipulation of robotic hands, comprising: Proximity sensing unit layer, tactile sensing unit layer, polymer spacer layer, and polymer encapsulation layer; The proximity sensing unit layer is used to convert the distance and material information of the approaching object into electrical signals based on Maxwell displacement current; The tactile sensing unit layer is used to detect pressure information after contact with an approaching object based on ionized capacitance; The polymer spacer layer is disposed between the proximity sensing unit layer and the tactile sensing unit layer to isolate the proximity sensing unit layer and the tactile sensing unit layer. The polymer encapsulation layer is disposed below the tactile sensing unit layer and is used to encapsulate the proximity sensing unit layer and the tactile sensing unit layer.

[0006] Furthermore, the proximity sensor unit includes an electrostatic induction layer and an ion gel electrode placed horizontally from top to bottom; The electrostatic induction layer is used to detect the approach of charged objects based on the electrostatic induction effect; The ion gel electrode serves as the back electrode of the electrostatic induction layer, used to transmit charge migration caused by the proximity of a charged object, and connects to the test lines of the test unit.

[0007] Furthermore, the electrostatic induction layer is made of silicone doped with silica nanoparticles, and a multi-ring fingerprint microstructure is provided on the electrostatic induction layer.

[0008] Furthermore, the electrostatic induction layer is fabricated by uniformly incorporating silica into a silica gel solution using a planetary mixer, and then drying the solution in a mold to obtain silica gel doped with silica nanoparticles as the electrostatic induction layer.

[0009] Furthermore, the tactile sensing unit includes an ionized capacitor upper electrode layer, an ion gel dielectric layer, and an ionized capacitor lower electrode layer; The ion gel dielectric layer is laid between and in close contact with the upper electrode layer and the lower electrode layer of the ionized capacitor, and the ionized capacitance value is determined by the area of ​​the ion-electron interface formed after the upper electrode layer and the lower electrode layer of the ionized capacitor come into contact with the ion gel dielectric layer.

[0010] Furthermore, a plurality of tactile sensing units are disposed on the ion gel dielectric layer, and each of the tactile sensing units is arranged in an array according to the structural characteristics of the fingertips of dexterous fingers.

[0011] Furthermore, each of the tactile sensing units adopts a hierarchical microstructure, which includes several first ion condensation hemispheres arranged in a ring array, and the radius of each layer of first ion condensation hemispheres increases sequentially from the inside to the outside. Each of the first ion condensation hemispheres has a second ion condensation hemisphere arranged in a ring array, and the radii of the second ion condensation hemispheres are all the same.

[0012] Furthermore, the center of the tactile sensing unit is a first ion condensation hemisphere with a radius of 100 μm, the second layer is a ring array of five second ion condensation hemispheres with a radius of 200 μm, and the third layer is a ring array of ten first ion condensation hemispheres with a radius of 300 μm.

[0013] Furthermore, the radius of the second ion-condensed hemisphere is 25 μm.

[0014] This invention, by adopting the above technical solutions, has the following advantages: This invention proposes a fully flexible, dual-modal bionic electronic skin for dexterous manipulation of robotic hands, incorporating both proximity and tactile senses. This electronic skin is fully flexible, simple to fabricate, and easy to array. The proximity sensing unit can achieve rapid response time and material recognition, while the tactile sensing unit can maintain good linearity over a wide pressure range. It is easily integrated with dexterous hands without affecting their structural performance or restricting their normal movement. By integrating it into the fingertips of dexterous hands, it enables shape and material recognition during dexterous grasping of three-dimensional objects. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of a fully flexible, dual-modal bionic electronic skin structure for dexterous operation of a robotic hand, provided in an embodiment of the present invention. Figure 2 The response time of the proximity sensor unit based on Maxwell displacement current provided in the embodiments of the present invention; Figure 3 The response characteristics of the proximity sensor unit based on Maxwell displacement current provided in the embodiments of the present invention for objects approaching with different materials; Figure 4 The proximity distance response characteristics of the Maxwell displacement current-based proximity sensor unit provided in this embodiment of the invention for a known material object; Figure 5 This is a schematic diagram of an ion gel dielectric layer structure with hierarchical microstructure provided in an embodiment of the present invention; Figure 6 The pressure sensing linearity curve of the tactile sensing unit based on ionized capacitor provided in the embodiment of the present invention; The markings in the attached diagram are as follows: 1. Proximity sensor unit based on Maxwell displacement current; 2. Tactile sensing unit based on ionized capacitance; 3. Electrostatic sensing layer doped with silica nanoparticles; 4. Ion gel electrode; 5. Polymer spacer layer; 6. Upper electrode of ionized capacitance; 7. Ion gel dielectric layer with hierarchical microstructure; 8. Lower electrode of ionized capacitance; 9. Polymer encapsulation layer. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0017] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0018] In some embodiments of the present invention, a fully flexible, bimodal bionic electronic skin for dexterous manipulation of robotic hands is provided, comprising a proximity sensing unit based on Maxwell displacement current and a tactile sensing unit based on ionized capacitance. This bimodal bionic electronic skin is fully flexible, simple to fabricate, and easy to array. The proximity sensing unit achieves fast response time and material recognition, while the tactile sensing unit maintains good linearity over a wide pressure range. By integrating it into dexterous fingertips, it enables shape and material recognition during dexterous grasping of three-dimensional objects.

[0019] Example 1 like Figure 1As shown, this invention provides a fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic arm, comprising: a proximity sensing unit layer 1, a tactile sensing unit layer 2, a polymer spacer layer 5, and a polymer encapsulation layer 9 arranged sequentially from top to bottom. The proximity sensing unit layer 1 converts the distance and material information of the approaching object into an electrical signal based on Maxwell displacement current; the tactile sensing unit layer 2 detects the pressure information after contact with the approaching object based on ionized capacitance; the polymer spacer layer 5 is disposed between the proximity sensing unit layer 1 and the tactile sensing unit layer 2 to isolate them; the polymer encapsulation layer 9 is disposed below the tactile sensing unit layer 2 to encapsulate the proximity sensing unit layer 1 and the tactile sensing unit layer 2, preventing water loss from affecting sensor performance.

[0020] Furthermore, the proximity sensor unit 1 includes an electrostatic induction layer 3 and an ion gel electrode 4, which are horizontally placed from top to bottom. The electrostatic induction layer 3 is used to sense the approach of a charged object based on the electrostatic induction effect; the ion gel electrode 4 serves as the back electrode of the electrostatic induction layer 3, and is used to transmit the charge migration caused by the approach of the charged object, and is connected to the test lines of the test unit.

[0021] like Figure 2 As shown, in this embodiment, the response time of the proximity sensing unit 1 can reach 100μs.

[0022] like Figure 3 As shown, since different objects have different electrical characteristics, the proximity sensing unit generates different electrical signals when different objects approach, which can be used for non-contact material identification.

[0023] like Figure 4 As shown, for a nearby object of known material, the proximity sensing unit can achieve distance sensing.

[0024] Furthermore, the electrostatic induction layer 3 uses silicone doped with silica nanoparticles as the electrostatic induction layer, and multiple ring-shaped fingerprint microstructures are disposed on this electrostatic induction layer. The spacing and number of rings of each fingerprint microstructure are determined according to actual needs.

[0025] In this embodiment, the electrostatic induction layer is prepared by uniformly incorporating silica into a silica gel solution using a planetary mixer and then drying it in a mold to obtain silica gel doped with silica nanoparticles as the electrostatic induction layer, thereby enhancing the sensing capability of the electrostatic induction layer as a proximity sensing unit.

[0026] Furthermore, the tactile sensing unit 2 includes, from top to bottom, an ion-gel upper electrode layer 6, an ion-gel dielectric layer 7, and an ion-gel lower electrode layer 8. The ion-gel dielectric layer 7 is deposited between and in close contact with the ion-gel upper electrode layer 6 and the ion-gel lower electrode layer 8, such that the ion-gel capacitance value is primarily determined by the area of ​​the ion-electron interface formed after the ion-gel upper electrode layer 6 and the ion-gel lower electrode layer 8 come into contact with the ion-gel dielectric layer 7.

[0027] Furthermore, several tactile sensing units are disposed on the ion gel dielectric layer 7, and each tactile sensing unit is arranged in an array according to the structural characteristics of the fingertip of a dexterous finger.

[0028] Furthermore, such as Figure 5 As shown, each tactile sensing unit adopts a hierarchical microstructure, which includes several first ion condensation hemispheres arranged in a ring array, and the radius of each first ion condensation hemisphere increases sequentially from the inside to the outside; each first ion condensation hemisphere is equipped with a second ion condensation hemisphere arranged in a ring array, and the radii of the second ion condensation hemispheres are all the same.

[0029] In fact, the specific number and radius of the first ion-condensed hemisphere and the second ion-gel hemisphere can be modified according to actual needs, so that when the ion-gel dielectric layer 7 is compressed under pressure, there will always be new hemispherical microstructures that can make new contact with the upper electrode to form a new electric double layer.

[0030] Preferably, in this embodiment, the center of each tactile sensing unit is a single ion-condensed hemisphere with a radius of 100 μm; the second layer consists of five ion-condensed hemispheres with a radius of 200 μm arranged in a ring array; and the third layer consists of ten ion-condensed hemispheres with a radius of 300 μm arranged in a ring array. Each of the aforementioned ion-condensed hemispheres has ion-condensed hemispheres with a radius of 25 μm arranged on its cross-section in a ring array.

[0031] As the pressure on the ionized capacitor continues to increase, new ion-electron interfaces are continuously formed between the upper electrode layer 6 and the ionized gel dielectric layer 7, which has a hierarchical microstructure and contains ion-condensed hemispheres with different height gradients. The capacitance value can vary from pF to μF, spanning five orders of magnitude. Therefore, the tactile sensing unit in this scheme maintains good linearity over a wide pressure range. Figure 6 As shown.

[0032] In summary, the fully flexible, dual-modal bionic electronic skin for dexterous robotic hand operation proposed in this invention solves the problems of rapid response time and material recognition when objects approach, as well as maintaining good linearity of the tactile sensing unit over a wide pressure range. By integrating it into the fingertips of dexterous hands, it enables the recognition of three-dimensional object shapes and materials during dexterous grasping without affecting the structural performance of the dexterous hand or restricting its normal movement.

[0033] This invention is not only applicable to integration into dexterous fingertips for dexterous grasping, but also applicable to proximity and tactile dual-modal information monitoring in robotic arms, upper limb prostheses, and lower limb prostheses.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A fully flexible, bimodal bionic electronic skin for dexterous manipulation of robotic hands, characterized in that, include: Proximity sensing unit layer, tactile sensing unit layer, polymer spacer layer, and polymer encapsulation layer; The proximity sensing unit layer is used to convert the distance and material information of the approaching object into electrical signals based on Maxwell displacement current; The tactile sensing unit layer is used to detect pressure information after contact with an approaching object based on ionized capacitance; The polymer spacer layer is disposed between the proximity sensing unit layer and the tactile sensing unit layer to isolate the proximity sensing unit layer and the tactile sensing unit layer. The polymer encapsulation layer is disposed below the tactile sensing unit layer and is used to encapsulate the proximity sensing unit layer and the tactile sensing unit layer. The proximity sensing unit layer includes an electrostatic induction layer and an ion gel electrode placed horizontally from top to bottom; the electrostatic induction layer is used to sense the approach of a charged object based on the electrostatic induction effect; the ion gel electrode serves as the back electrode of the electrostatic induction layer, used to transmit the charge migration caused by the approach of a charged object, and connects to the test lines of the test unit. The electrostatic induction layer is made of silicone doped with silica nanoparticles, and a multi-ring fingerprint microstructure is provided on the electrostatic induction layer.

2. The fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic hand as described in claim 1, characterized in that, The electrostatic induction layer is prepared by uniformly incorporating silica into a silica gel solution using a planetary mixer and then drying it in a mold to obtain silica gel containing silica nanoparticles as the electrostatic induction layer.

3. The fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic hand as described in claim 1, characterized in that, The tactile sensing unit includes an ionized capacitor upper electrode layer, an ion gel dielectric layer, and an ionized capacitor lower electrode layer. The ion gel dielectric layer is laid between and in close contact with the upper electrode layer and the lower electrode layer of the ionized capacitor, and the ionized capacitance value is determined by the area of ​​the ion-electron interface formed after the upper electrode layer and the lower electrode layer of the ionized capacitor come into contact with the ion gel dielectric layer.

4. The fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic hand as described in claim 3, characterized in that, The ion gel dielectric layer is provided with a number of tactile sensing units, and each of the tactile sensing units is arranged in an array according to the structural characteristics of the fingertips of dexterous fingers.

5. The fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic hand as described in claim 4, characterized in that, Each of the tactile sensing units adopts a hierarchical microstructure, which includes several first ion condensation hemispheres arranged in a ring array, and the radius of each layer of first ion condensation hemispheres increases sequentially from the inside to the outside. Each of the first ion condensation hemispheres has a second ion condensation hemisphere arranged in a ring array, and the radii of the second ion condensation hemispheres are all the same.

6. The fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic hand as described in claim 5, characterized in that, The center of the tactile sensing unit is a first ion condensation hemisphere with a radius of 100 μm, the second layer is a ring array of five second ion condensation hemispheres with a radius of 200 μm, and the third layer is a ring array of ten first ion condensation hemispheres with a radius of 300 μm.

7. The fully flexible, dual-modal bionic electronic skin for dexterous operation of a robotic hand as described in claim 5, characterized in that, The radius of the second ion-condensed hemisphere is 25 μm.

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