Multi-dimensional force measuring device and preparation method

Abstract

The present invention discloses a multi-dimensional force measurement device, comprising a force sensing body and a force sensor. The contact element of the force sensing body can contact the structure to be measured. The contact element adopts a spherical force contact surface. At least two groups of force sensors are arranged on the mounting surfaces of the mounting element in different directions. The mounting element is connected to the contact element. The force contact surface contacts the structure to be measured. The contact element is subjected to force and transmits the force to the mounting element. The force sensor on the mounting element can detect torque information. The force sensors on different mounting surfaces of the mounting element constitute independent measurement units. Each measurement unit is responsible for force measurement in one direction, which effectively enhances the signal decoupling effect and improves the energy conversion efficiency. The force sensor of the present invention adopts a potassium sodium niobate lead-free piezoelectric nanowire-based sensor, which significantly improves the conversion efficiency of mechanical energy and electrical energy and improves the measurement sensitivity of the multi-dimensional force measurement device. The present invention also provides a preparation method of the above-mentioned multi-dimensional force measurement device.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring sensors, and in particular to a multi-dimensional force measuring device and a preparation method thereof. Background Art

[0002] A multi-dimensional force sensor is a sensing element that can simultaneously detect force or torque information in at least two directions within three-dimensional space. As a key component in the intelligentization of equipment and tools, multi-dimensional force sensors have broad application prospects in areas such as vehicle-mounted weighing, robotics, human motion data, biomedicine, intelligent equipment, and aerospace. With the recent research and development of robotic perception systems, the demand for multi-dimensional force sensors in robots' legs, shoulders, feet, wrists, and even fingertips has become increasingly widespread and diverse. These sensors are often integrated with other sensors to collect real-time environmental information about various actuators.

[0003] Although multi-dimensional force sensors have broad application prospects, in practical applications, they often face challenges such as complex signal decoupling, difficult structural design and manufacturing, and insufficient anti-interference ability. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-dimensional force measurement device and a preparation method thereof, so as to solve the problems existing in the above-mentioned related technologies, enhance the signal decoupling effect of the multi-dimensional force measurement device, and improve the measurement sensitivity of the device.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a multi-dimensional force measuring device, comprising:

[0007] A force sensing body, the force sensing body comprising a contact element and a mounting element, the contact element having a force contact surface capable of contacting the structure to be measured, the force contact surface being a spherical surface, the mounting element being connected to the contact element and being located on a side of the contact element away from the force contact surface;

[0008] A force sensor, wherein the force sensor is a lead-free piezoelectric nanowire-based sensor made of potassium sodium niobate. The force sensors are provided in at least two groups and are arranged on mounting surfaces in different directions of the mounting element. The force sensor can detect and output torque information transmitted from the contact element to the mounting element.

[0009] Preferably, the contact element is a spherical structure.

[0010] Preferably, the contact element is connected to the mounting element by means of a connecting shaft.

[0011] Preferably, the connecting shaft is a quadrangular prism structure, and the connecting shaft is coaxially arranged with the contact element and the mounting element.

[0012] Preferably, the mounting element is a cubic structure, and the multiple groups of force sensors are arranged on different sides of the mounting element.

[0013] Preferably, the mounting element is a cube structure, one side surface of the mounting element is connected to the contact element, and the other side surfaces of the mounting element are provided with the force sensors.

[0014] Preferably, the mounting element is covered with a shell, the shell is an open structure, the contact element extends from the opening of the shell, and the force sensor is located in the shell.

[0015] Preferably, the housing has a wire threading hole, and the wire of the force sensor extends out from the housing through the wire threading hole.

[0016] Preferably, the force sensor includes a substrate, a potassium sodium niobate piezoelectric layer and an encapsulation layer. The potassium sodium niobate piezoelectric layer is arranged on the substrate, and the potassium sodium niobate piezoelectric layer is made of potassium sodium niobate nanowires. Electrodes are provided on both working surfaces of the potassium sodium niobate piezoelectric layer, and the electrodes can be connected to wires. The encapsulation layer is coated on the outside of the substrate, the potassium sodium niobate piezoelectric layer and the electrodes.

[0017] The present invention also provides a method for preparing the multi-dimensional force measuring device, comprising the following steps:

[0018] preparing a substrate for growing potassium sodium niobate nanowires, evaporating electrodes and connecting wires, and packaging to obtain the force sensor;

[0019] The force sensing body is prepared by 3D printing, and the force sensor is arranged on the mounting element.

[0020] Compared with the related art, the present invention has achieved the following technical effects: the multi-dimensional force measurement device of the present invention includes a force sensing body and a force sensor, the force sensing body includes a contact element and a mounting element, the contact element has a force contact surface that can contact the structure to be measured, the force contact surface is a spherical surface, the mounting element is connected to the contact element, and the mounting element is located on the side of the contact element away from the force contact surface; the force sensor is a potassium sodium niobate lead-free piezoelectric nanowire-based sensor, the number of force sensors is at least two groups, the force sensors are arranged on the mounting surfaces of the mounting element in different directions, and the force sensor can detect the torque information transmitted from the contact element to the mounting element and output it.

[0021] In the multi-dimensional force measurement device of the present invention, the contact element of the force sensing body can contact the structure to be measured, the contact element adopts a spherical force contact surface, at least two groups of force sensors are arranged on the mounting surfaces of the mounting element in different directions, the mounting element is connected to the contact element, the force contact surface contacts the structure to be measured, the contact element is subjected to force and transmits the force to the mounting element, the force sensor on the mounting element can detect torque information, the force sensors on different mounting surfaces of the mounting element constitute independent measurement units, each measurement unit is responsible for force measurement in one direction, thereby effectively enhancing the signal decoupling effect and improving the energy conversion efficiency; in addition, the force sensor of the present invention adopts a potassium sodium niobate lead-free piezoelectric nanowire-based sensor, which significantly improves the conversion efficiency of mechanical energy and electrical energy, and improves the measurement sensitivity of the multi-dimensional force measurement device.

[0022] The present invention also provides a method for preparing a multi-dimensional force measuring device, so as to prepare the multi-dimensional force measuring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic structural diagram of a multi-dimensional force measurement device disclosed in an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the disassembled structure of the multi-dimensional force measurement device disclosed in an embodiment of the present invention;

[0026] Figure 3 A schematic structural diagram of a force sensor of a multi-dimensional force measurement device disclosed in an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of KNN nanowire synthesis in the method for preparing the multi-dimensional force measurement device disclosed in an embodiment of the present invention;

[0028] Figure 5 Schematic diagram of the preparation of a KNN nanowire-based piezoelectric sensor according to the method for preparing a multi-dimensional force measurement device disclosed in an embodiment of the present invention.

[0029] In the figure: 1. Force sensing body; 2. Force sensor; 3. Contact element; 4. Mounting element; 5. Connecting shaft; 6. Housing; 7. Threading hole; 8. Wire. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The purpose of the present invention is to provide a multi-dimensional force measurement device and a preparation method thereof, so as to solve the problems existing in the above-mentioned related technologies, enhance the signal decoupling effect of the multi-dimensional force measurement device, and improve the measurement sensitivity of the device.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] This embodiment provides a multi-dimensional force measurement device, please refer to Figure 1-Figure 5 , including a force sensing body 1 and a force sensor 2, the force sensing body 1 includes a contact element 3 and a mounting element 4, the contact element 3 has a force contact surface that can contact the structure to be measured, and the force contact surface is a spherical surface, the mounting element 4 is connected to the contact element 3, and the mounting element 4 is located on the side of the contact element 3 away from the force contact surface; the force sensor 2 is a potassium sodium niobate lead-free piezoelectric nanowire-based sensor, the number of force sensors 2 is at least two groups, the force sensors 2 are arranged on the mounting surfaces of the mounting element 4 in different directions, and the force sensor 2 can detect the torque information transmitted from the contact element 3 to the mounting element 4 and output it.

[0035] In the multi-dimensional force measurement device of the present invention, the contact element 3 of the force sensing body 1 can contact the structure to be measured, the contact element 3 adopts a spherical force contact surface, at least two groups of force sensors 2 are arranged on the mounting surfaces of the mounting element 4 in different directions, the mounting element 4 is connected to the contact element 3, the force contact surface is in contact with the structure to be measured, the contact element 3 is subjected to force and transmits the force to the mounting element 4, the force sensor 2 on the mounting element 4 can detect torque information, the force sensors 2 on different mounting surfaces of the mounting element 4 constitute independent measurement units, each measurement unit is responsible for force measurement in one direction, thereby effectively enhancing the signal decoupling effect and improving the energy conversion efficiency; in addition, the force sensor 2 of the present invention adopts a potassium sodium niobate lead-free piezoelectric nanowire-based sensor, the high voltage electrical constant and good flexibility of the potassium sodium niobate nanowire improve the sensitivity of force perception in each direction, significantly improve the conversion efficiency of mechanical energy and electrical energy, thereby effectively enhancing the detection sensitivity and accuracy of the multi-dimensional force measurement device.

[0036] Contact element 3 is spherical, ensuring a spherical force contact surface. When the force contact surface contacts the structure to be measured, it can transmit forces in all directions to mounting element 4, enabling decoupling of torque and pressure information in all directions. In practical applications, the structure of contact element 3 can be adjusted to suit different measurement conditions and specific measurement requirements, for example, by configuring contact element 3 to have a hemispherical structure.

[0037] Specifically, the contact element 3 is connected to the mounting element 4 by means of a connecting shaft 5, and the connecting shaft 5 is provided to transmit the force exerted on the contact element 3, thereby preventing the mounting element 4 from affecting the contact between the contact element 3 and the structure to be measured. At the same time, sufficient installation space is provided for the force sensor 2, thereby preventing the contact element 3 and the structure to be measured from affecting the installation and fixation of the force sensor 2, thereby ensuring the structural stability and working reliability of the force sensing body 1.

[0038] In this embodiment, the connecting shaft 5 is a quadrangular prism structure, and the connecting shaft 5 is coaxial with the contact element 3 and the mounting element 4 to ensure smooth and accurate force transmission. In practical applications, the connecting shaft 5 can also adopt a cylindrical structure.

[0039] It should also be noted that the mounting element 4 is a cubic structure, the side surfaces of the mounting element 4 form mounting surfaces, and the multiple groups of force sensors 2 are arranged on different side surfaces of the mounting element 4 .

[0040] In this specific embodiment, mounting element 4 is a cube-shaped structure. One side of mounting element 4 is connected to contact element 3, and force sensors 2 are installed on the other sides of mounting element 4 to measure torque information in different directions. Furthermore, mounting element 4 is configured as a cube, and force sensor 1 forms an integrated "sphere-axis-cube" structure, achieving precise distribution of forces in different directions and enabling decoupling of torque and pressure information in each direction, thereby enabling independent detection of forces from multiple directions. This structure also avoids coupling issues between signals, improving the sensor's detection stability and directional identification capabilities. In actual applications, the structure of mounting element 4 can be adjusted according to specific installation requirements, for example, using other multi-faceted cube structures.

[0041] More specifically, the mounting element 4 is provided with a housing 6, which is an open structure. The contact element 3 extends from the opening of the housing 6, and the force sensor 2 is located within the housing 6. The housing 6 provides stable support for the force sensing body 1 and the force sensor 2. The shape of the housing 6 can be selected to match the shape of the mounting element 4, and the specifications of the housing 6 can be adjusted according to the specifications of the mounting element 4 and the force sensor 2.

[0042] In practical applications, a threading hole 7 may be provided on the housing 6 , and a wire 8 of the force sensor 2 extends out of the housing 6 through the threading hole 7 , so as to facilitate information transmission of the force sensor 2 .

[0043] Furthermore, it should be noted that the force sensor 2 includes a substrate, a potassium sodium niobate piezoelectric layer, and an encapsulation layer. The potassium sodium niobate piezoelectric layer is disposed on the substrate and is made of potassium sodium niobate nanowires. Electrodes are disposed on both working surfaces of the potassium sodium niobate piezoelectric layer, and the electrodes are connected to a conductor 8. The encapsulation layer is coated on the substrate, the potassium sodium niobate piezoelectric layer, and the exterior of the electrodes. The lead-free potassium sodium niobate piezoelectric nanowire-based sensor of the present invention utilizes the dual polarization characteristics of piezoelectric and flexoelectric effects of KNN (potassium sodium niobate) nanowires to significantly improve the conversion efficiency between mechanical energy and electrical energy. Compared to traditional materials, the lead-free potassium sodium niobate piezoelectric nanowire-based sensor can more sensitively convert tiny forces into electrical signals, thereby improving the overall detection accuracy and sensitivity of the force sensor 2.

[0044] Example 2

[0045] This embodiment provides a method for preparing a multi-dimensional force measurement device, to prepare the multi-dimensional force measurement device of embodiment 1, specifically comprising the following steps:

[0046] A substrate for growing potassium sodium niobate nanowires is prepared, and electrodes are evaporated and connected with wires 8, and then packaged to obtain a force sensor 2;

[0047] The force sensing body 1 is prepared by 3D printing, and the force sensor 2 is set on the mounting element 4.

[0048] The multi-dimensional force measuring device prepared by the preparation method of the present invention improves the sensitivity of the detection signal and realizes effective signal decoupling.

[0049] Example 3

[0050] This embodiment provides a method for preparing a multi-dimensional force measurement device, which mainly includes the following three parts:

[0051] The first part involves the synthesis of KNN nanowires: The polytetrafluoroethylene (PTFE) reactor liner and magnetic stirrer are cleaned and dried in an ultrasonic cleaner. The magnetic stirrer is then placed inside the liner. Next, 20.279g of KOH and 3.2g of NaOH are placed into the PTFE liner, along with deionized water. The mixture is stirred on a magnetic stirrer to form a mixture. Stir for 15 minutes. Once the heat has been largely released, 1g of Nb2O5 is added to the mixture and stirred for 1 hour, resulting in a milky white suspension.

[0052] The stirring magnet was removed from the milky white suspension, and the Nb:STO substrate was placed on a custom Teflon stand and lowered into the solution in the reactor liner, maintaining the substrate surface approximately 15 mm from the bottom. Deionized water was then added to fill the liner to 80% of its volume. The liner was then placed in a steel reactor shell and sealed. After the reactor was placed in a 200°C oven for 24 hours, it was removed and allowed to cool to room temperature. The Nb:STO substrate was then removed from the reactor liner, rinsed with deionized water, and dried in a 60°C drying oven for 60 minutes, resulting in a substrate with potassium sodium niobate nanowires grown on one side.

[0053] The second part involves the synthesis of a KNN nanowire-based piezoelectric sensor. Using a pipette, 3 μL of a 2 wt% PMMA (polymethyl methacrylate) solution is dropped onto the substrate surface where the potassium sodium niobate nanowires are grown. A uniform coating is then applied using a glue spreader and dried on a heating platform. A layer of gold electrodes is then deposited on both the upper and lower surfaces of the substrate (at a chamber pressure of 1 × 10 Pa for 60 seconds). Wire 8 is then bonded to the gold electrodes using silver paste, resulting in a packaged pressure device. The packaged pressure device is then encapsulated and cured using a solution prepared by mixing PDMS (polydimethylsiloxane) and a curing agent in a ratio of 10:1 and stirring for 20 minutes. Finally, the device is trimmed into a sandwich-structured piezoelectric sensor.

[0054] The third part is the design of a multi-dimensional force sensor device: 3D printing technology is used to print a multi-dimensional pressure sensor device structure, which is mainly composed of a shell 6 and a force sensing body 1. The force sensing body 1 is designed as an integrated "ball-axis-cube" structure, and the above-mentioned piezoelectric sensors (force sensors 2) are arranged on different faces of the cube of the force sensing body 1. Since the upper sphere (contact element 3) is connected to the lower end cube frame (mounting element 4) through the connecting shaft 5, when the sphere (contact element 3) is subjected to force, its force will be transmitted to the frame (mounting element 4). The piezoelectric sensor (force sensor 2) on the frame (mounting element 4) can detect the torque information, thereby accurately distributing the force from different directions and ensuring that the force sensor 2 can receive independent signals in different directions; the shell 6 is the support and protection part of the force sensor 2.

[0055] The multi-dimensional force measurement device of the present invention combines the unique properties of KNN piezoelectric nanomaterials and the structural advantages of the integrated "ball-axis-cube" structure. It utilizes the dual polarization characteristics of the piezoelectric and flexoelectric effects of KNN nanowires to significantly improve the conversion efficiency between mechanical energy and electrical energy. The "ball-axis-cube" combination achieves precise distribution of forces in different directions, making it possible to decouple torque and pressure information in each direction, thereby enabling independent detection of forces from multiple directions. At the same time, this structure avoids the coupling problem between signals and improves the detection stability and direction recognition ability of the device.

[0056] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A multi-dimensional force measuring device, characterized in that: include: A force sensing body, the force sensing body comprising a contact element and a mounting element, the contact element having a force contact surface capable of contacting the structure to be measured, the force contact surface being a spherical surface, the mounting element being connected to the contact element and being located on a side of the contact element away from the force contact surface; force sensors, each of which is a lead-free potassium sodium niobate piezoelectric nanowire-based sensor. There are at least two groups of force sensors, each of which is disposed on mounting surfaces of the mounting element in different directions. The force sensors are capable of detecting and outputting torque information transmitted from the contact element to the mounting element. The contact element is connected to the mounting element by a connecting shaft; The mounting element is a cube structure, one side of the mounting element is connected to the contact element, and the other sides of the mounting element are provided with the force sensor; The mounting element is covered with a shell, the shell is an open structure, the contact element extends from the opening of the shell, and the force sensor is located in the shell.

2. The multi-dimensional force measurement device according to claim 1, characterized in that: The contact element is a spherical structure.

3. The multi-dimensional force measurement device according to claim 1, characterized in that: The connecting shaft is a quadrangular prism structure, and the connecting shaft is coaxially arranged with the contact element and the mounting element.

4. The multi-dimensional force measurement device according to claim 1, characterized in that: The shell has a wire threading hole, and the wire of the force sensor extends out from the shell through the wire threading hole.

5. The multi-dimensional force measurement device according to any one of claims 1 to 4, characterized in that: The force sensor includes a substrate, a potassium sodium niobate piezoelectric layer, and an encapsulation layer. The potassium sodium niobate piezoelectric layer is arranged on the substrate and is made of potassium sodium niobate nanowires. Electrodes are arranged on both working surfaces of the potassium sodium niobate piezoelectric layer, and the electrodes can be connected to the wires. The encapsulation layer is coated on the outside of the substrate, the potassium sodium niobate piezoelectric layer, and the electrodes.

6. A method for preparing a multi-dimensional force measuring device according to any one of claims 1 to 5, characterized in that: The steps include: preparing a substrate for growing potassium sodium niobate nanowires, evaporating electrodes and connecting wires, and packaging to obtain the force sensor; The force sensing body is prepared by 3D printing, and the force sensor is arranged on the mounting element.

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