Multi-dimensional force measuring device and preparation method

Abstract

The invention discloses a multi-dimensional force measuring device, which comprises a force sensing body and force sensors, a contact element of the force sensing body can be in contact with a to-be-measured structure, the contact element adopts a spherical force contact surface, at least two groups of force sensors are arranged on mounting surfaces in different directions of a mounting element, and the mounting element is connected with the contact element. The force contact surface is in contact with a to-be-measured structure, the contact element is stressed and transmits force to the installation element, the force sensors on the installation element can detect torque information, the force sensors on different installation surfaces of the installation element form independent measurement units, each measurement unit is responsible for force measurement in one direction, the signal decoupling effect is effectively enhanced, and the measurement precision is improved. The energy conversion efficiency is improved; the force sensor adopts a potassium-sodium niobate leadless piezoelectric nanowire-based sensor, so that the conversion efficiency of mechanical energy and electric energy is remarkably improved, and the measurement sensitivity of the multi-dimensional force measurement device is improved. The invention further provides a preparation method of the multi-dimensional force measuring 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 no less than two directions in three-dimensional space. As one of the key components for intelligent equipment and tools, multi-dimensional force sensors have broad application prospects in vehicle weighing, robotics, human motion data, biomedicine, intelligent equipment, and aerospace. In recent years, with the research and development of robot perception systems, the demand for multi-dimensional force sensors in the legs, shoulders, feet, wrists, and even fingertips of robots has become increasingly widespread and diverse, and is usually integrated with other sensors to collect real-time environmental information of 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 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 measurement 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 the mounting element 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 potassium sodium niobate piezoelectric nanowire-based sensor, the number of the 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.

[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 a plurality of groups of force sensors are arranged on different sides of the mounting element.

[0013] Preferably, the mounting element is a cubic 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 out from the opening of the shell, and the force sensor is located in the shell.

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

[0016] Preferably, the force sensor includes a substrate, a potassium sodium niobate piezoelectric layer and a packaging layer, the potassium sodium niobate piezoelectric layer is arranged on the substrate, the potassium sodium niobate piezoelectric layer is made of potassium sodium niobate nanowires, electrodes are arranged on both working surfaces of the potassium sodium niobate piezoelectric layer, the electrodes can be connected to the wires, and the packaging 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 above-mentioned multi-dimensional force measurement device, comprising the following steps:

[0018] A substrate for growing potassium sodium niobate nanowires is prepared, and electrodes are evaporated and connected with wires, and the force sensor is obtained after packaging;

[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 is in contact with 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, and 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 drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

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

[0027] Figure 4 A schematic diagram of KNN nanowire synthesis in the method for preparing a 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 be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work 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 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] Embodiment 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, 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, and 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 piezoelectric constant and good flexibility of the potassium sodium niobate nanowire improve the sensitivity of force perception in each direction, and 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] The contact element 3 is a spherical structure to ensure that the force contact surface is a spherical surface. When the force contact surface contacts the structure to be measured, it can transmit forces in various directions to the mounting element 4, making it possible to decouple the torque and pressure information in various directions. In practical applications, the structure of the contact element 3 can also be adjusted according to different measurement conditions and specific measurement requirements, for example, the contact element 3 can be set to a hemispherical structure.

[0037] Specifically, the contact element 3 is connected to the mounting element 4 by means of the connecting shaft 5. The connecting shaft 5 is provided to transmit the force exerted on the contact element 3 to prevent the mounting element 4 from affecting the contact between the contact element 3 and the structure to be measured. Meanwhile, sufficient installation space is provided for the force sensor 2 to prevent 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 specific embodiment, the connecting shaft 5 is a quadrangular prism structure, and the connecting shaft 5 is coaxially arranged with the contact element 3 and the mounting element 4 to ensure smooth and accurate transmission of force. 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, the mounting element 4 is a cubic structure, one side of the mounting element 4 is connected to the contact element 3, and the other sides of the mounting element 4 are provided with force sensors 2 to measure torque information in different directions. At the same time, the mounting element 4 is set to a cubic structure, and the force sensing body 1 forms an integrated structure of "sphere-axis-cube", which realizes the precise distribution of forces in different directions, making it possible to decouple the torque and pressure information in each direction, so that forces from multiple directions can be detected independently, and this structure avoids the coupling problem between signals, and improves the detection stability and direction recognition ability of the sensor. In practical applications, the structure of the mounting element 4 can also be adjusted according to specific installation requirements, such as using other multi-faceted cube structures.

[0041] More specifically, the mounting element 4 is provided with a housing 6, the housing 6 is an open structure, the contact element 3 extends from the opening of the housing 6, the force sensor 2 is located in the housing 6, and the housing 6 provides a 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 is also necessary to explain that the force sensor 2 includes a substrate, a potassium sodium niobate piezoelectric layer and a packaging layer, the potassium sodium niobate piezoelectric layer is arranged on the substrate, the potassium sodium niobate piezoelectric layer is made of potassium sodium niobate nanowires, electrodes are arranged on both working surfaces of the potassium sodium niobate piezoelectric layer, the electrodes can be connected to the wire 8, and the packaging layer is coated on the substrate, the potassium sodium niobate piezoelectric layer and the outside of the electrode. The potassium sodium niobate lead-free piezoelectric nanowire-based sensor of the present invention utilizes the dual polarization characteristics of the piezoelectric and flexoelectric effects of KNN (potassium sodium niobate) nanowires to significantly improve the conversion efficiency between mechanical energy and electrical energy. Compared with traditional materials, the potassium sodium niobate lead-free 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] Embodiment 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 a force sensor 2 is obtained after packaging;

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

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

[0049] Embodiment 3

[0050] This embodiment provides a method for preparing a multi-dimensional force measurement device to prepare the multi-dimensional force measurement device of Embodiment 1, which mainly includes the following three parts:

[0051] The first part is the synthesis of KNN nanowires: put the polytetrafluoroethylene reactor liner and the stirring magnet into an ultrasonic cleaner, clean and dry them, and put the stirring magnet into the liner. Then, put 20.279g of KOH and 3.2g of NaOH into the polytetrafluoroethylene liner, add deionized water, and stir on a magnetic stirrer to obtain a mixed solution. Stir for 15 minutes, wait until the heat is basically released, then weigh 1g of Nb2O5 and add it to the mixed solution and stir for 1 hour to obtain a milky white suspension.

[0052] Take out the stirring magnet from the milky white suspension, then place the Nb:STO substrate on a special polytetrafluoroethylene bracket and put it into the solution of the reactor liner, keeping the substrate surface about 15mm away from the bottom of the liner. Then add deionized water to 80% of the volume of the liner, place the liner in the steel reactor shell and seal it well. After the reactor is placed in a 200℃ oven for 24h, take out the reactor, cool it naturally to room temperature, take out the Nb:STO substrate from the reactor liner and rinse the surface with deionized water, then put it in a 60℃ drying oven for 60min to obtain a substrate with one side grown with potassium sodium niobate nanowires.

[0053] The second part is the synthesis of the preparation of KNN nanowire-based piezoelectric sensor: 3uL of 2wt% PMMA (polymethyl methacrylate) solution is sucked with a pipette and dropped on the surface of the substrate where the potassium sodium niobate nanowires are grown, and it is evenly rotated with a glue spreader and placed on a heating table for drying, and then a layer of gold electrode is evaporated on the upper and lower surfaces of the substrate (the pressure in the evaporation chamber is 1×10Pa, and the evaporation time is 60s), and the wire 8 is bonded to the gold electrode with silver paste to obtain the pressure device to be packaged. Then, the pressure device to be packaged is packaged and cured with a solution of PDMS (polydimethylsiloxane) and curing agent mixed and stirred for 20 minutes in a ratio of 10:1, and finally trimmed into a piezoelectric sensor with a sandwich structure.

[0054] The third part is the design of multi-dimensional force sensor device: the multi-dimensional pressure sensor device structure is printed by 3D printing technology, and its structure is mainly composed of a shell 6 and a force sensing body 1. The structure of the force sensing body 1 is designed as an integrated structure of "ball-axis-cube", and the above-mentioned piezoelectric sensor (force sensor 2) is 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 (installation 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 (installation element 4), and the piezoelectric sensor (force sensor 2) on the frame (installation 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, and 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; through the "ball-axis-cube" combination, the precise distribution of forces in different directions is achieved, making it possible to decouple the torque and pressure information in each direction, thereby being able to independently detect 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 used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A multi-dimensional force measurement 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 the mounting element being located on a side of the contact element away from the force contact surface; A force sensor, wherein the force sensor is a lead-free potassium sodium niobate piezoelectric nanowire-based sensor, the number of the 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.

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 contact element is connected to the mounting element by means of a connecting shaft.

4. The multi-dimensional force measurement device according to claim 3, 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.

5. The multi-dimensional force measurement device according to claim 1, characterized in that: The installation element is a cubic structure, and a plurality of groups of force sensors are arranged on different sides of the installation element.

6. The multi-dimensional force measurement device according to claim 5, characterized in that: The mounting element is a cubic structure, one side surface of the mounting element is connected to the contact element, and the other side surfaces of the mounting element are all provided with the force sensors.

7. The multi-dimensional force measurement device according to claim 6, characterized in that: The mounting element is provided with a shell outside, the shell is an open structure, the contact element extends out from the opening of the shell, and the force sensor is located in the shell.

8. The multi-dimensional force measurement device according to claim 7, characterized in that: The shell has a threading hole, and the wire of the force sensor extends out from the shell through the threading hole.

9. The multi-dimensional force measurement device according to any one of claims 1 to 8, characterized in that: The force sensor includes a substrate, a potassium sodium niobate piezoelectric layer and a packaging 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 arranged on both working surfaces of the potassium sodium niobate piezoelectric layer, and the electrodes can be connected to the wires. The packaging layer is coated on the substrate, the potassium sodium niobate piezoelectric layer and the outside of the electrodes.

10. A method for preparing a multi-dimensional force measurement device according to any one of claims 1 to 9, characterized in that: The steps include: A substrate for growing potassium sodium niobate nanowires is prepared, and electrodes are evaporated and connected with wires, and the force sensor is obtained after packaging; The force sensing body is prepared by 3D printing, and the force sensor is arranged on the mounting element.

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