An actuator based on a flexible sensor and a method of manufacturing the same

Abstract

The embodiment of the application discloses an actuator based on a flexible sensor and a manufacturing method thereof, and is characterized in that the actuator comprises a finger framework and at least one flexible sensor arranged in the finger framework, wherein the flexible sensor comprises a resistance wire and two connecting components, the resistance wire is integrated in the inside of the finger framework, and the two connecting components are used for connecting the resistance wire and a wire to monitor resistance value change of the resistance wire in real time; the resistance wire comprises conductive nanoparticles and a substrate, and the conductive nanoparticles are uniformly distributed in the substrate. By monitoring the resistance value change of the resistance wire, the state of the actuator can be monitored in real time, the resistance value of the resistance wire cannot be affected by an external environment, the sensing process is stable and reliable, the flexible sensor is not easy to be damaged, and the practicality is high.

Description

Technical Field

[0001] This application relates to the field of flexible robotic arm technology, and in particular to an actuator based on a flexible sensor and a method for manufacturing the same. Background Technology

[0002] The application of flexible actuators in industrial production is gradually increasing, among which flexible fingers are a common type of actuator. Consequently, the need for real-time monitoring of the bending and grasping states of flexible fingers is becoming increasingly urgent. Since flexible fingers are composed of soft materials such as silicone, traditional sensors can interfere with their bending movements; therefore, flexible sensors are typically used for sensing.

[0003] Existing flexible sensors mainly fall into four categories: First, resistive flexible sensors rely on conductive textile filaments or conductive particle liquids for sensing. The conductive textile filaments lack elasticity and are easily damaged when the flexible finger extends, while the conductive particle liquid is prone to leakage. Second, capacitive flexible sensors use conductive silicone materials as electrodes, improving the compatibility between the electrode material and the flexible finger. However, the electrodes easily form new capacitances with external conductors, interfering with the sensing results. Third, machine vision sensors mainly involve setting multiple marker points on the internal surface of the sensor and using a camera to identify changes in the position of these marker points to infer the deformation of the flexible finger. However, this method is costly and difficult to implement. Fourth, piezoresistive flexible sensors consist of elastic resistors filled with conductive nanoparticles and based on flexible materials such as silicone. When the flexible finger is driven, the elastic resistor extends synchronously with the finger, and the bending of the finger is sensed by monitoring the resistance value. However, the elastic resistors manufactured using existing technologies have poor consistency, and the terminal connections are not secure.

[0004] It is evident that existing flexible sensors cannot bend or stretch with flexible fingers, are too expensive, have poor applicability, are easily affected by external environmental interference, and have unstable sensing performance. Summary of the Invention

[0005] This application provides an actuator based on a flexible sensor and a method for manufacturing the same. The actuator has low manufacturing cost, can guarantee various deformations of the actuator, has stable sensing capability and strong anti-interference capability.

[0006] In a first aspect, embodiments of this application provide an actuator based on a flexible sensor, the actuator comprising: a finger structure and at least one flexible sensor disposed within the finger structure, wherein,

[0007] The flexible sensor includes a resistance wire and two connecting components. The resistance wire is integrated inside the finger structure, and the two connecting components are used to connect the resistance wire to a wire to monitor the resistance change of the resistance wire in real time.

[0008] The resistance wire comprises conductive nanoparticles and a substrate, wherein the conductive nanoparticles are uniformly distributed in the substrate.

[0009] In one alternative design, the finger architecture is a soft architecture, and the material of the finger architecture includes silicone.

[0010] In an alternative design, the resistance wire is integrated within the finger structure, including:

[0011] The resistance wire is laid flat on the fingertip portion of the finger structure; or,

[0012] The resistance wire is embedded in the sides of the fingertip and finger frame.

[0013] In an alternative design, each of the two connecting components includes: a hollow rivet and two perforated copper plates.

[0014] In one alternative design, the portion of the resistance wire connected to the connecting component has a hole structure, the hollow rivet passes through the hole structure, both ends of the hollow rivet are connected to a perforated copper sheet, and the wire is welded to one end of the hollow rivet.

[0015] In one alternative design, the diameter of the perforated copper sheet is larger than the diameter of the hole structure, and the diameter of the hollow rivet is larger than the diameter of the hole structure, so that the hollow rivet is fixed in the hole structure.

[0016] In one alternative design, the conductive nanoparticles are made of at least one of the following materials: metal powder, carbon nanotubes, and graphene.

[0017] In one alternative design, the substrate is made of silicone material, and the resistance wire deforms as the finger structure deforms.

[0018] Secondly, embodiments of this application provide a method for manufacturing an actuator based on a flexible sensor, the method comprising:

[0019] Dilute the liquid silica gel with a diluent;

[0020] Conductive nanoparticles are uniformly mixed with diluted liquid silica gel;

[0021] A resistor sheet is obtained by pressing the mixed liquid silicone onto a rigid sheet and then baking it to cure it.

[0022] The resistor sheet is cut into a predetermined shape to obtain the resistance wire;

[0023] By providing connecting components at both ends of the resistance wire and connecting them to wires, a flexible sensor is obtained.

[0024] The flexible sensor is embedded in a flexible material and solidified according to a preset model to obtain the actuator.

[0025] This application provides an actuator based on a flexible sensor. The actuator includes a finger structure and at least one flexible sensor disposed within the finger structure. The flexible sensor includes a resistance wire and two connecting components. The resistance wire is integrated within the finger structure, and the two connecting components connect the resistance wire to a wire to monitor changes in the resistance value of the resistance wire in real time. The resistance wire includes conductive nanoparticles and a substrate, with the conductive nanoparticles uniformly distributed in the substrate. Therefore, the actuator based on a flexible sensor provided in this application integrates a resistance wire into the finger structure, enabling real-time monitoring of the actuator's bending state. The flexible sensor deforms accordingly with the bending and elongation of the actuator, exhibiting strong compatibility and durability. Furthermore, monitoring the actuator's bending state through changes in resistance value is less affected by external environmental factors, has strong anti-interference capabilities, and provides a highly stable sensing process. Attached Figure Description

[0026] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A three-view drawing of an actuator based on a flexible sensor is provided for an embodiment of this application;

[0028] Figure 2 A second type of actuator based on a flexible sensor provided in this application embodiment;

[0029] Figure 3 A schematic diagram of a resistance wire provided in an embodiment of this application;

[0030] Figure 4 A schematic diagram of a connecting component provided in an embodiment of this application;

[0031] Figure 5 This is a flowchart illustrating a method for manufacturing an actuator based on a flexible sensor, as provided in an embodiment of this application.

[0032] Figures 1 to 4 The components indicated by the numbers are: 1. Finger frame, 2. Resistance wire, 3. Hole structure, 4. Connecting component, 5. Hollow rivet, 6. Perforated copper sheet, 7. Wire. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings.

[0034] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that although the terms first, second, etc., may be used in the following embodiments to describe a class of objects, the objects are not limited to these terms. These terms are only used to distinguish specific objects of that class of objects. For example, the terms first, second, etc., may be used in the following embodiments to describe connecting parts, but connecting parts are not limited to these terms. These terms are only used to distinguish different connecting parts. The same applies to other classes of objects that may be described using the terms first, second, etc. in the following embodiments, and will not be repeated here.

[0035] This application provides an actuator based on a flexible sensor and a method for manufacturing the same. The actuator can be monitored in real time, and the sensing process is stable and has strong anti-interference capabilities.

[0036] The following describes an actuator based on a flexible sensor, which relates to the embodiments of this application, through several implementation methods.

[0037] like Figure 1 As shown, Figure 1 A three-view diagram of an actuator based on a flexible sensor is shown. The actuator includes a finger structure 1 and at least one flexible sensor disposed within the finger structure 1.

[0038] The flexible sensor includes a resistance wire 2 and two connecting parts 4. The resistance wire 2 is integrated inside the finger structure 1, and the two connecting parts 4 are used to connect the resistance wire 2 to the wire 7 to monitor the resistance change of the resistance wire 2 in real time.

[0039] The resistance wire 2 comprises conductive nanoparticles and a substrate, wherein the conductive nanoparticles are uniformly distributed in the substrate.

[0040] In this embodiment, the resistance wire 2 of the flexible sensor is partially integrated into the fingertip of the finger structure 1. The connecting component 4 of the flexible sensor is located outside the finger structure 1. The connecting component 4 is used to connect the resistance wire 2 and the wire 7, so that after the resistance wire 2 is embedded in the insulating material of the finger structure 1, the resistance change of the resistance wire 2 can be monitored in real time. When the actuator bends, the resistance wire 2 will also elongate accordingly, causing the resistance to rise slightly. The bending state of the actuator can be determined based on the monitored resistance change. When the actuator grasps an object, the overall bending trend of the actuator is restricted by the object, so that the fingertip of the finger structure 1 is subjected to a force opposite to the bending direction, thereby causing the actuator to elongate as a whole. The elongation rate at this time is much greater than the elongation rate when the actuator is unloaded. Therefore, the resistance change of the resistance wire 2 is greater, which can be used to determine that the actuator is in a grasping state.

[0041] like Figure 1 In the illustrated embodiment, the resistance of the flexible finger is approximately 40 kΩ when it is in a straight state; when bent under no-load conditions with a 100 kPa drive, the resistance rises to approximately 43 kΩ; and when bent under load conditions with a 100 kPa drive, i.e., when grasping an object, the resistance rises to approximately 48 kΩ. It is evident that the actuator based on the flexible sensor provided in this application can determine the bending or elongation state of the actuator by the change in the resistance of the resistance wire 2. Of course, in other embodiments, the basic resistance value of the resistance wire varies depending on its formulation, thickness, and length; this application does not impose any limitations on this.

[0042] As can be seen, this application provides an actuator based on a flexible sensor. By embedding a flexible sensor inside the finger structure 1, the actuator's activity state can be monitored in real time without affecting its bending movement. Furthermore, the flexible sensor can deform accordingly with the actuator's movement, exhibiting strong compatibility and avoiding problems such as breakage, leakage, or wear, thus demonstrating high practicality. In addition, the actuator's activity state is monitored by tracking changes in the resistance of the resistance wire 2; the sensing process is highly stable and unaffected by external environmental factors.

[0043] In some alternative implementations, the finger architecture 1 is a soft architecture, and the material of the finger architecture 1 includes silicone.

[0044] In this embodiment, the material of the finger structure 1 includes, but is not limited to, silicone; it can be any flexible material, and this application embodiment does not impose any limitations on it. The shape of the finger structure 1 should be designed according to the requirements of the actuator. The embodiment shown in this application is only one example, and the external structure of the finger structure 1 is not limited.

[0045] In some alternative implementations, the resistance wire 2 is integrated inside the finger structure 1, including:

[0046] The resistance wire 2 is laid flat on the fingertip portion of the finger structure 1; or,

[0047] The resistance wire 2 is embedded on the sides of the finger pad and fingertip of the finger frame 1.

[0048] In this embodiment, such as Figure 1 As shown, the resistance wire 2 is set on the fingertip of the finger structure 1. The fingertip area is large, so multiple resistance wires 2 can be set. Therefore, the total resistance value of the resistance wires 2 changes more during monitoring, making the monitoring more accurate. In addition, setting multiple resistance wires 2 on the fingertip can improve the consistency of the resistance wires 2 and effectively reduce the influence of small air bubbles in the silicone on the resistance value.

[0049] like Figure 2 As shown, another method of integrating the resistance wire 2 is demonstrated. Figure 2 In the embodiments described, the resistance wire 2 is integrated on the side of the fingertip and the side of the finger structure 1, without occupying a large area of ​​the fingertip portion of the finger structure 1. Therefore, for actuators with special requirements, the shape of the finger structure 1 can be customized, and grooves or protrusions can be added to the fingertip portion to grasp different objects without hindering the structural design of the actuator due to the addition of the resistance wire 2. This application only shows the above two integration methods of the resistance wire 2. Of course, the resistance wire 2 can also be integrated in any other arbitrary shape at any position in the mobile phone structure, and this application does not impose any restrictions on this.

[0050] In some alternative implementations, each of the two connecting components 4 includes: a hollow rivet 5 and two perforated copper sheets 6.

[0051] In some optional embodiments, the portion of the resistance wire 2 connected to the connecting component 4 is provided with a hole structure 3, the hollow rivet 5 passes through the hole structure 3, both ends of the hollow rivet 5 are respectively connected to the perforated copper sheet 6, and the wire 7 is welded to one end of the hollow rivet 5.

[0052] In some optional embodiments, the diameter of the perforated copper sheet 6 is larger than the diameter of the hole structure 3, and both ends of the hollow rivet 5 are fixedly connected to the perforated copper sheet 6, so that the hollow rivet 5 is fixed in the hole structure 3.

[0053] In this embodiment, such as Figure 3 and Figure 4 As shown, there is a hole-type structure 3 at each end of the resistance wire 2 so that the connecting component 4 can connect the resistance wire 2 and the wire 7. Figure 3 The first and second ends of the resistance wire 2 shown each have a terminal area. The width of the terminal area is larger than the width of the resistance wire 2 so that the connecting component 4 can be stably connected. Figure 4The diagram shows a cross-sectional view of one of the installed connecting components 4, as shown below. Figure 4 As shown, a perforated copper sheet 6 is respectively provided on the upper and lower end faces of the terminal area. The diameter of the perforated copper sheet 6 can be the same as or different from the diameter of the hole structure 3. The overall diameter of the perforated copper sheet 6 is larger than the diameter of the hole structure 3 to prevent the hollow rivet 5 from falling off after fixing. The hollow rivet 5 passes through the perforated copper sheet 6, the hole structure 3 and the perforated copper sheet 6 in sequence to fix the two perforated copper sheets 6 in the terminal area. Then, a wire 7 is welded to the part where one of the perforated copper sheets 6 connects to the hollow rivet 5 to form a reliable terminal. Based on this, the wire 7 is stably and firmly connected to the resistance wire 2 through the connecting component 4. In this way, even if the resistance wire 2 is integrated into an insulator such as silicone, the resistance change of the resistance wire 2 can still be monitored through the wire 7. The welding ensures a stable connection between the wire 7 and the connecting component 4, preventing monitoring interruptions and instability, and enabling stable sensing.

[0054] In some alternative embodiments, the conductive nanoparticles include: metal powder, carbon nanotubes, and graphene.

[0055] In this embodiment, the conductive nanoparticles include, but are not limited to, those described above, and may also be other nanoparticles with conductive properties.

[0056] In some alternative embodiments, the substrate is a silicone material, and the resistance wire 2 deforms as the finger structure 1 deforms.

[0057] In this embodiment, the matrix material supporting the conductive nanoparticles is silicone, but other materials can also be used; this application does not limit this. When the silicone material is in a liquid state, the conductive nanoparticles are mixed evenly with the liquid silicone, and then solidification and shaping are performed to obtain the resistance wire 2. The resistance wire 2 obtained by the above method has good elasticity. Since both the matrix material and the finger structure 1 material are flexible materials, when the resistance wire 2 is embedded in the finger structure 1, the resistance wire 2 can bend with the bending of the finger structure 1 and lengthen with the elongation of the finger structure 1, without the resistance wire 2 breaking or the filler leaking, making it very stable and reliable in use.

[0058] correspond Figures 1 to 4 The present application also provides a method for fabricating an actuator based on a flexible sensor, as shown in the example actuator. Figure 5 As shown, the method includes:

[0059] S501, use a diluent to dilute liquid silica gel;

[0060] S502, uniformly mix conductive nanoparticles with diluted liquid silica gel;

[0061] S503 is a resistor sheet made by pressing a mixture of liquid silicone onto a rigid sheet and then baking it to cure.

[0062] S504, Cut the resistor sheet according to the preset shape to obtain the resistance wire 2;

[0063] S505, connecting components 4 are provided at both ends of the resistance wire 2 and connected to the wire 7 to obtain a flexible sensor;

[0064] S506, The flexible sensor is embedded into a flexible material and solidified according to a preset model to obtain the actuator.

[0065] In this embodiment, since conductive nanoparticles such as metal powder, carbon nanotubes, and graphene are difficult to mix evenly with silicone directly, a diluent is needed to dilute the liquid silicone. Commonly used diluents include white spirit and dimethyl silicone oil. The diluted liquid silicone can be thoroughly mixed with the conductive nanoparticles, and then the mixed liquid silicone is cured and shaped. If the liquid silicone with added diluent is cured using traditional methods, it will be difficult to cure completely. Therefore, this application uses a smooth and flat rigid sheet to press the liquid silicone. The rigid sheet can be acrylic sheet, aluminum sheet, steel sheet, etc. Thickness limiting sheets are fixed around the four sides or four corners of two rigid sheets, and baked at 90 degrees Celsius for curing. After baking for about 2 hours, the nearly fully cured resistor sheet is taken out and baked at 90 degrees Celsius for another 4 to 8 hours until the resistor sheet is completely cured and shaped, resulting in a resistor sheet with uniform thickness, smooth surface, and uniform internal nanoparticle mixing. The use of rigid sheet material for pressing is to make the resistor sheet uniform in thickness. Of course, the pressing method is not limited to the thickness-limited sheet of this application. Rollers can also be used in conjunction with plastic film to press the mixed liquid silicone. This application does not limit this method.

[0066] After obtaining the resistive sheet, it is cut using a custom-shaped die to obtain a resistance wire 2 of a preset shape. The resistance wire 2 is not limited to the rectangular structure of this application; it can also be any structure such as a thin strip or an arc, as long as it meets the structural requirements of the finger structure 1. This application does not impose any restrictions on this. Then, connecting components 4 are installed at both ends of the resistance wire 2, and wires 7 are welded to them, so that the wires 7 and the connecting components 4 are firmly connected to the resistance wire 2, which increases the stability of the sensing and obtains a flexible sensor.

[0067] Finally, the flexible sensor is integrated into the flexible material, which is the finger structure 1 of the actuator, and is solidified and shaped according to the preset shape of the finger structure 1 to obtain the actuator.

[0068] In summary, the actuator based on a flexible sensor provided in this application can determine the activity state of the actuator by monitoring the resistance change of the resistance wire 2, thereby determining whether it is unloaded or gripping. In addition, the flexible sensor of this application can deform accordingly with the bending and elongation of the actuator, making it less prone to damage and highly practical. The resistance change of the resistance wire 2 is only affected by the bending state of the actuator and is not affected by the external environment. Therefore, the sensing process is very stable and reliable. The resistance wire 2 is connected to the wire 7 through a special terminal, making the connection more secure and increasing the efficiency of use.

[0069] Although alternative embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make further changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0070] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this invention.

Claims

1. An actuator based on a flexible sensor, characterized in that, The actuator includes: a finger structure and at least one flexible sensor disposed within the finger structure, wherein, The flexible sensor includes a resistance wire and two connecting components. The resistance wire is integrated inside the finger structure, and the two connecting components are used to connect the resistance wire to a wire to monitor the resistance change of the resistance wire in real time. The resistance wire comprises conductive nanoparticles and a substrate, wherein the conductive nanoparticles are uniformly distributed in the substrate; The resistance wire is integrated inside the finger structure, including: the resistance wire is embedded in the side of the finger pad and fingertip of the finger structure, and the elongation rate of the actuator when bending to grasp an object is greater than the elongation rate of the actuator when bending without load. Each of the two connecting components includes: a hollow rivet and two perforated copper sheets; The part of the resistance wire that connects to the connecting component is provided with a hole structure. The hollow rivet passes through the hole structure. Both ends of the hollow rivet are respectively connected to the copper sheet with holes. The wire is welded to one end of the hollow rivet. The diameter of the perforated copper sheet is larger than the diameter of the hole structure, and the diameter of the hollow rivet is larger than the diameter of the hole structure, so that the hollow rivet is fixed in the hole structure; The first and second ends of the resistance wire each have a terminal area, and the width of the terminal area is larger than the width of the resistance wire; the hollow rivet passes through the perforated copper sheet, the hole structure and the perforated copper sheet in sequence to fix the two perforated copper sheets in the terminal area. The manufacturing process of the resistance wire includes the following steps: diluted liquid silicone and conductive nanoparticles are thoroughly mixed and uniformly. Then, the mixed liquid silicone is cured and shaped. Specifically, the mixed liquid silicone is pressed with a rigid plate and baked at 90 degrees Celsius for 2 hours. After baking, the nearly fully cured resistance sheet is taken out and baked at 90 degrees Celsius for another 4 to 8 hours until the resistance sheet is completely cured and shaped, resulting in a resistance sheet with uniform thickness, smooth surface and uniform internal nanoparticle mixing.

2. The actuator based on a flexible sensor as described in claim 1, characterized in that, The finger structure is a soft structure, and the material of the finger structure includes silicone.

3. The actuator based on a flexible sensor as described in claim 1, characterized in that, The conductive nanoparticles are made of at least one of the following materials: metal powder, carbon nanotubes, and graphene.

4. The actuator based on a flexible sensor as described in claim 1, characterized in that, The substrate is made of silicone material, and the resistance wire deforms as the finger structure deforms.

5. A method for manufacturing an actuator based on a flexible sensor as described in any one of claims 1-4, characterized in that, The method includes: Dilute the liquid silica gel with a diluent; Conductive nanoparticles are uniformly mixed with diluted liquid silica gel; A resistor sheet is obtained by pressing the mixed liquid silicone onto a rigid sheet and then baking it to cure it. The resistor sheet is cut into a predetermined shape to obtain the resistance wire; By providing connecting components at both ends of the resistance wire and connecting them to wires, a flexible sensor is obtained. The flexible sensor is embedded in a flexible material and solidified according to a preset model to obtain the actuator.

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