Flexible three-dimensional pressure sensing equipment

Abstract

A flexible three-dimensional pressure sensing device disclosed by the present invention comprises a force sensitive part, three-dimensional conduction parts and electrodes, the force sensitive part is composed of a whole piece of flexible conductive material, the flexible conductive material has piezoresistive characteristics, a plurality of three-dimensional conduction parts are distributed on the surface of the force sensitive part, and the three-dimensional conduction parts are used for conducting pressure to the force sensitive part. The pressure comprises normal pressure and shear pressure, a plurality of electrodes are arranged on the periphery of the force sensitive part, and the electrodes are used for leading out resistance distribution data of the force sensitive part through wires; and the rear-end circuit equipment calculates the three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensing equipment at each moment according to the resistance distribution data. On the basis, the flexible three-dimensional pressure sensing equipment can improve the three-dimensional sensing capability, simplify the equipment structure, reduce the manufacturing difficulty and cost, improve the flexibility of the equipment and expand the application scene of the equipment.

Description

Technical Field

[0001] The embodiments of the present invention relate to, but are not limited to, the field of pressure sensing technology, and in particular to a flexible three-dimensional pressure sensing device. Background Art

[0002] With the booming development of emerging technology fields such as the Internet of Things, the metaverse, smart homes and furniture, humanoid and flexible robots, the demand for pressure measurement technology for human-computer interaction interfaces is becoming more and more urgent. These industries expect the device interface to accurately capture the pressure changes of the user or environmental interface to achieve a more natural, safe and intelligent interactive experience. For example, if a humanoid robot can have electronic skin, that is, a tactile function similar to human skin, it will greatly enhance its ability to interact with the environment and humans. Existing flexible tactile sensors, such as linear piezoresistive or array tactile sensors, have problems such as complex manufacturing process, high cost, and single sensing function. At the same time, these sensors often cannot achieve multi-dimensional pressure detection when detecting touch position, force intensity and shape, which limits their scope of application.

[0003] Traditional pressure monitoring technology, which uses a pressure sensor matrix for measurement, has significant limitations. Each sensor unit needs to be connected by an independent wire, resulting in a large number of wires in the sensor matrix, which not only increases the complexity of the device and increases the cost, but also affects the flexibility, stretchability and adhesion of the device to complex surfaces. When each sensor unit in the pressure sensor matrix is ​​upgraded to a three-dimensional pressure sensor, the number of wires per sensor increases from two to six or more, further exacerbating the complexity and cost of the device, and greatly limiting the flexibility and application scenarios of the device. Summary of the invention

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0005] The embodiment of the present invention provides a flexible three-dimensional pressure sensing device with a simple structure, fully flexible material, only electrodes and wires need to be arranged around the periphery, no wires are required inside, and the device has good fit to curved surfaces. This can improve the three-dimensional perception capability, simplify the device structure, reduce the difficulty and cost of manufacturing, improve the flexibility of the device, and expand the application scenarios of the device.

[0006] A first aspect of an embodiment of the present invention provides a flexible three-dimensional pressure sensing device, comprising: a force-sensitive component, a three-dimensional conductive component and an electrode, wherein the force-sensitive component is composed of a whole piece of flexible conductive material, and the flexible conductive material has a piezoresistive property. A plurality of three-dimensional conductive components are distributed on the surface of the force-sensitive component, and the three-dimensional conductive components are used to transmit pressure to the force-sensitive component, causing a corresponding change in the resistance characteristic of the force-sensitive component, and the pressure includes normal pressure and shear pressure. A plurality of electrodes are arranged around the force-sensitive component, and the electrodes are used to lead out the resistance distribution data of the force-sensitive component through wires, so that the back-end circuit device calculates the three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensing device at each moment based on the resistance distribution data.

[0007] In some embodiments, the force-sensitive component is a solid planar structure, or a network structure with holes.

[0008] In some embodiments, the force-sensitive component is made of a conductive composite material, or liquid metal, or a conductor or semiconductor material rich in conductive ions, or a conductive fiber assembly with piezoresistive properties, or an elastomer and fiber assembly containing an intrinsic conductive polymer.

[0009] In some embodiments, the stereoscopic conductive component has a three-dimensional protruding structure, and a plurality of the stereoscopic conductive components are evenly or unevenly distributed on the surface of the force-sensitive component, and each of the stereoscopic conductive components is tightly combined with the force-sensitive component.

[0010] In some embodiments, the electrode is made of a coating or plating of a good conductor, or a micron-nanostructured material, or a carbon-based conductive material, or an intrinsic conductive polymer, or a liquid metal, or a conductive fiber material, and a plurality of the electrodes are evenly or unevenly arranged around the force-sensitive component.

[0011] In some embodiments, the elastic modulus of the material of the three-dimensional conductive component is greater than or equal to the elastic modulus of the material of the force sensitive component.

[0012] In some embodiments, a chemical bond is generated at an interface between the stereoconductive component and the force sensitive component.

[0013] In some embodiments, when the three-dimensional conductive component and the force-sensitive component use the same material, a sheet-like elastic conductive material with a three-dimensional raised structure is formed by template injection molding or mold printing, and the electrodes and the wires are printed at designated positions around the force-sensitive component.

[0014] In some embodiments, when the three-dimensional conductive component and the force-sensitive component are made of different materials, the force-sensitive component is first cut or processed into a desired size and shape, and then the three-dimensional conductive component is fixed to the surface of the force-sensitive component.

[0015] In some embodiments, the fixing method includes: using a dispensing machine to dispense conductive material to the position where the three-dimensional conductive component is set to form the three-dimensional conductive component, or using three-dimensional printing technology to prepare the three-dimensional conductive component on the surface of the force-sensitive component, or applying each unit of the additional mechanical conduction part to the corresponding position on the surface of the force-sensitive component through textile and garment processing.

[0016] In some embodiments, the surface of the three-dimensional conductive component is partially or completely covered with a packaging layer, and the packaging material of the packaging layer is a flexible polymer elastomer with a low elastic modulus.

[0017] A flexible three-dimensional pressure sensing device provided by an embodiment of the present invention includes: a force-sensitive component, a three-dimensional conductive component and an electrode. The force-sensitive component is composed of a whole piece of flexible conductive material, and the flexible conductive material has a piezoresistive property. A plurality of three-dimensional conductive components are distributed on the surface of the force-sensitive component. The three-dimensional conductive component is used to transmit pressure to the force-sensitive component, causing the resistance characteristic of the force-sensitive component to change accordingly. The pressure includes normal pressure and shear pressure. A plurality of electrodes are arranged around the force-sensitive component. The electrodes are used to lead out the resistance distribution data of the force-sensitive component through a wire, so that the back-end circuit device calculates the three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensing device at each moment according to the resistance distribution data. The embodiment of the present invention uses a flexible conductive material to form a force-sensitive component. The flexible conductive material has a piezoresistive property, that is, the resistance changes when it is squeezed or stretched. Therefore, the flexible conductive material can construct plane data of resistance distribution. A plurality of three-dimensional conductive components are distributed on the surface of the flexible conductive material. The three-dimensional conductive component can transmit pressure to the force-sensitive component and ensure that both normal pressure and shear pressure can be transmitted. A plurality of electrodes are arranged around the flexible conductive material, and the electrodes are used to connect the wire to lead out the signal. The resistance distribution data inside the flexible conductive material can be read in real time by the method of impedance scanning imaging. The three-dimensional pressure distribution of each position of the plane formed by all three-dimensional conductive components can be obtained according to the resistance distribution data, thereby realizing a flexible three-dimensional pressure sensing device with no electrodes or only partial electrodes inside, fully flexible, based on impedance scanning imaging, and multi-point simultaneous detection, and its function is equivalent to a three-dimensional pressure sensor matrix. Based on this, the flexible three-dimensional pressure sensing device of the present invention has the advantages of simple structure, fully flexible material, only electrodes and wires need to be arranged around, no wires can be inside, and good fit for curved surface shapes. It can improve three-dimensional perception ability, simplify equipment structure, reduce manufacturing difficulty and cost, improve equipment flexibility, and expand the application scenarios of equipment.

[0018] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0020] Figure 1A A schematic diagram of a top view of a flexible three-dimensional pressure sensing device provided in one embodiment of the present invention;

[0021] Figure 1B for Figure 1A A schematic diagram of the cross-sectional structure along the dotted line in the top view;

[0022] Figure 2 A schematic diagram of a cross-sectional structure of a flexible three-dimensional pressure sensing device after packaging provided by another embodiment of the present invention;

[0023] Figure 3A A schematic diagram of a top view of a flexible three-dimensional pressure sensing device provided by another embodiment of the present invention;

[0024] Figure 3B for Figure 3A A schematic diagram of the cross-sectional structure along the dotted line in the top view;

[0025] Figure 4 A schematic diagram of the cross-sectional structure of a flexible three-dimensional pressure sensing device after packaging provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] It should be understood that in the description of the embodiments of the present invention, the meaning of multiple (or multiple) is more than two, greater than, less than, and exceeding are understood to exclude the number itself, and above, below, and within are understood to include the number itself. If there is a description of "first", "second", etc., it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0028] With the booming development of emerging technology fields such as the Internet of Things, the metaverse, smart homes and furniture, humanoid and flexible robots, the demand for pressure measurement technology for human-computer interaction interfaces is becoming more and more urgent. These industries expect the device interface to accurately capture the pressure changes of the user or environmental interface to achieve a more natural, safe and intelligent interactive experience. For example, if a humanoid robot can have electronic skin, that is, a tactile function similar to human skin, it will greatly enhance its ability to interact with the environment and humans. Existing flexible tactile sensors, such as linear piezoresistive or array tactile sensors, have problems such as complex manufacturing process, high cost, and single sensing function. At the same time, these sensors often cannot achieve multi-dimensional pressure detection when detecting touch position, force intensity and shape, which limits their scope of application.

[0029] Traditional pressure monitoring technology, which uses a pressure sensor matrix for measurement, has significant limitations. Each sensor unit needs to be connected by an independent wire, resulting in a large number of wires in the sensor matrix, which not only increases the complexity of the device and increases the cost, but also affects the flexibility, stretchability and adhesion of the device to complex surfaces. When each sensor unit in the pressure sensor matrix is ​​upgraded to a three-dimensional pressure sensor, the number of wires per sensor increases from two to six or more, further exacerbating the complexity and cost of the device, and greatly limiting the flexibility and application scenarios of the device.

[0030] In order to solve the above technical problems, an embodiment of the present invention provides a flexible three-dimensional pressure sensing device, including: a force-sensitive component, a three-dimensional conductive component and an electrode. The force-sensitive component is composed of a whole piece of flexible conductive material, and the flexible conductive material has a piezoresistive property. A plurality of three-dimensional conductive components are distributed on the surface of the force-sensitive component. The three-dimensional conductive component is used to transmit pressure to the force-sensitive component, causing the resistance characteristic of the force-sensitive component to change accordingly. The pressure includes normal pressure and shear pressure. A plurality of electrodes are arranged around the force-sensitive component. The electrodes are used to lead out the resistance distribution data of the force-sensitive component through a wire, so that the back-end circuit device calculates the three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensing device at each moment according to the resistance distribution data. The embodiment of the present invention uses a flexible conductive material to form a force-sensitive component. The flexible conductive material has a piezoresistive property, that is, the resistance changes when it is squeezed or stretched. Therefore, the flexible conductive material can construct plane data of resistance distribution. A plurality of three-dimensional conductive components are distributed on the surface of the flexible conductive material. The three-dimensional conductive component can transmit pressure to the force-sensitive component and ensure that both normal pressure and shear pressure can be transmitted. A plurality of electrodes are arranged around the flexible conductive material, and the electrodes are used to connect the wire to lead out the signal. The resistance distribution data inside the flexible conductive material can be read in real time by the method of impedance scanning imaging. The three-dimensional pressure distribution of each position of the plane formed by all three-dimensional conductive components can be obtained according to the resistance distribution data, thereby realizing a flexible three-dimensional pressure sensing device with no electrodes or only partial electrodes inside, fully flexible, based on impedance scanning imaging, and multi-point simultaneous detection, and its function is equivalent to a three-dimensional pressure sensor matrix. Based on this, the flexible three-dimensional pressure sensing device of the present invention has the advantages of simple structure, fully flexible material, only electrodes and wires need to be arranged around, no wires can be inside, and good fit for curved surface shapes. It can improve three-dimensional perception ability, simplify equipment structure, reduce manufacturing difficulty and cost, improve equipment flexibility, and expand the application scenarios of equipment.

[0031] The flexible three-dimensional pressure sensing device of the present invention is composed of three parts, including: a force-sensitive component, a three-dimensional conductive component and an electrode.

[0032] It is understandable that the force-sensitive component is composed of a whole piece of flexible conductive material, which is usually a solid plane layer structure, or a network structure, that is, a part of it contains holes. The flexible conductive material can produce a change in resistance at the corresponding position when it is compressed, that is, it has a pressure-sensitive property, or a piezoresistive property; or it may not be a piezoresistive material in the conventional sense, but as long as the resistance at the compressed position changes regularly when it is compressed.

[0033] It can be understood that the three-dimensional conduction component transmits the three-dimensional pressure to the force-sensitive component, causing a characteristic corresponding change in the resistance of the force-sensitive component; electrodes are arranged around the overall device, and the resistance distribution of the force-sensitive component can be monitored in real time by impedance imaging, thereby inferring the three-dimensional pressure distribution information of each position on the device surface at each moment.

[0034] It can be understood that the three-dimensional conduction component is a series of three-dimensional structures, which can be a three-dimensional raised structure in the shape of a semi-sphere, a cube, a pyramid, a triangular cone, or an artistic shape. The three-dimensional raised structure can be regarded as a three-dimensional raised unit. Each three-dimensional raised unit of the three-dimensional conduction component is uniformly or non-uniformly distributed on the surface of the force-sensitive part. Since the three-dimensional conduction component and the force-sensitive component are tightly combined, each three-dimensional unit of the three-dimensional conduction component can effectively transmit the normal pressure and shear force borne by the unit to the force-sensitive component.

[0035] It can be understood that the electrodes can be evenly arranged around the entire device, the electrodes can be equally spaced, and the density of the electrodes can be adjusted according to the requirements of resolution and accuracy at different positions; in addition to arranging the electrodes around, the electrodes can also be selectively arranged at different positions under the force-sensitive material, thereby greatly improving the position accuracy and pressure accuracy of the sensor measurement.

[0036] It is understandable that the force-sensitive component preferably uses a conductive composite material. In order to enhance the piezoresistive properties, the resistance of the conductive material is preferably in the semiconductor range; typical examples include piezoresistive rubber, graphene silicone composite materials, carbon nanotube polyurethane composite materials, etc.; the material of the force-sensitive component can also be a conductor or semiconductor material with a certain fluidity such as gallium-indium alloy or a liquid rich in conductive ions; the material of the force-sensitive component can also be a conductive fiber assembly with piezoresistive properties, such as a pure cotton knitted fabric with graphene and carbon nanotubes attached to the surface, or a spandex warp knitted mesh completely coated with a carbon black polyurethane composite prepared by screen printing; in addition, the material of the force-sensitive component can also be an elastomer containing an intrinsically conductive polymer, such as a composite film of polypyrrole and polyurethane. Finally, as long as it is an elastic, continuously conductive sheet-like mesoporous or sheet-like solid material, and at the same time satisfies the requirement that the resistance at the compressed position changes regularly when under pressure, it meets the use requirements of the force-sensitive component of the embodiment of the present invention.

[0037] It can be understood that the material of the three-dimensional conduction component can be exactly the same as that of the force-sensitive component, or it can be another conductor material, semiconductor material, or insulating material; the three-dimensional conduction component is usually a solid structure, and in order to achieve effective pressure conduction, the material elastic modulus of the three-dimensional conduction component is preferably greater than or equal to the material elastic modulus of the force-sensitive part; in addition, the three-dimensional conduction component needs to be tightly combined with the force-sensitive component, and it is preferred to generate a chemical bond between the interfaces of the two, such as generating polymer cross-links, etc., so as to ensure the long-term stability and robustness of the device structure.

[0038] It is understandable that the material of the electrode part can be a coating, plating or micron-nanostructured material of a good conductor such as gold, silver, copper, etc. (such as silver nanowire / silicone composite material, such as silver powder particle / epoxy resin composite material), or a carbon-based conductive material (such as carbon fiber, etc.), or an intrinsic conductive polymer (such as poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, etc.) or liquid metal (such as gallium-indium alloy, etc.), or a conductive fiber material.

[0039] It can be understood that when the materials of the three-dimensional conductive component and the force-sensitive component are the same, template injection molding or mold printing and other methods can be used to form a sheet of elastic conductive material with a three-dimensional conductive structural unit, and then the electrode material is printed uniformly or non-uniformly at the designated electrode position around the device (such as screen printing, chemical evaporation, physical evaporation, magnetron sputtering, etc.), or the conductive electrode material is pasted (such as applying silver paste resin, etc.), or embroidery wire (such as silver-coated nylon yarn), or sewing conductive sewing thread, etc.; finally, the device is connected to the back-end circuit equipment through the electrode connection wire.

[0040] It can be understood that when the three-dimensional conduction component and the force-sensitive component are made of different materials, the force-sensitive component is first cut or processed into the required size and shape, and then the conduction part is fixed on the surface of the force-sensitive component. A dispensing machine can be used to dispense the conduction material to the position of the three-dimensional raised unit to form a three-dimensional conduction component. The three-dimensional conduction component can also be prepared on the surface of the force-sensitive part using three-dimensional printing technology. The additional mechanical conduction part can also be applied to the corresponding position on the surface of the force-sensitive component through textile and garment processing, such as sewing buttons (using buttons as force conduction parts) or other small accessories.

[0041] It can be understood that the surface of the three-dimensional conduction component can be partially or fully covered with a packaging layer. The packaging material of the packaging layer is preferably a flexible polymer elastomer with a low elastic modulus, so as to ensure that the pressure of each part can produce stress concentration near the conduction unit, ensuring that the pressure can reach the three-dimensional conduction component from the surface. The three-dimensional conduction component can accurately and repeatably transmit the three-dimensional pressure to the corresponding position of the force-sensitive component.

[0042] It is understandable that since the force-sensitive component is the base of the entire device, when the force-sensitive component has good elasticity in three directions, the device can not only realize three-dimensional pressure dynamic monitoring in the original plane state, but also better fit various three-dimensional shapes (such as spherical shape, fitting to the part of the humanoid robot that imitates the human head). During the fitting process, part of the device is stretched. After calibration, the fitted device can also provide multi-point three-dimensional force real-time monitoring.

[0043] It can be understood that the pressure-sensitive characteristics of the force-sensitive component partially determine the sensitivity of the device in three-dimensional pressure detection. When other conditions remain unchanged, the more obvious the piezoresistive characteristics of the force-sensitive material, the higher the sensitivity of the device; the size and stiffness of the three-dimensional conduction component also partially determine the measurement range and sensitivity of the device in three-dimensional pressure detection. When other conditions remain unchanged, the greater the stiffness at the same size, the more obvious the stress concentration on the force-sensitive component, resulting in higher sensitivity, while possibly reducing the force measurement range; similarly, three-dimensional conduction components of different shapes and sizes will also cause different stress concentration effects, resulting in different three-dimensional force measurement sensitivities and mechanical measurement ranges; in addition, the number, distribution and density of the three-dimensional protruding units of the three-dimensional conduction component also partially determine the number of measurable points, measurable point distribution and measurement density of three-dimensional force measurement.

[0044] It is understandable that, under the premise of the same back-end circuit equipment and algorithm, the distribution, position and number of electrodes dominantly determine the error size and accuracy of the measurable pressure position, and also affect the accuracy of pressure measurement. For example, when the number of electrodes is greater, the finer the resistance distribution that can be obtained when using electrical impedance imaging analysis, the higher the accuracy of normal pressure measurement, the smaller the error of position identification, and the higher the accuracy of shear force measurement. When the electrodes are not only distributed around, but can also be arranged evenly or unevenly on the back of the force-sensitive component, the resistance acquisition accuracy of electrical impedance imaging analysis can be further improved, thereby improving the position accuracy and pressure accuracy of the device's three-dimensional pressure detection.

[0045] Based on this, the flexible three-dimensional pressure sensing device of the present invention is mainly composed of elastic materials, and is divided into three parts according to function: force-sensitive components, three-dimensional conductive components and electrodes. A whole piece of flexible conductive material is used to form the force-sensitive component, and the flexible conductive material has piezoresistive characteristics, that is, the resistance changes when it is squeezed or stretched. Therefore, the flexible conductive material can construct plane data of resistance distribution. Distributed three-dimensional conductive components formed by the same material or heterogeneous materials are distributed on the surface of the flexible conductive material. The three-dimensional conductive components can transmit pressure to the force-sensitive component to ensure that both normal pressure and shear pressure can be transmitted. A plurality of electrodes are arranged around the flexible conductive material, and the electrodes are used to connect the wires to lead out signals. The resistance data inside the flexible conductive material is read in real time by the method of electrical impedance scanning imaging. According to the resistance distribution data, the three-dimensional pressure distribution of each position of the plane formed by all the protruding structures can be obtained, thereby realizing a three-dimensional pressure touch sensing device with no electrodes or only partial electrodes inside, full flexibility, based on electrical impedance scanning imaging, and multi-point simultaneous detection, that is, the function is equivalent to a three-dimensional pressure sensor matrix.

[0046] In summary, the embodiments of the present invention provide a three-dimensional pressure sensing device with a simple structure, fully flexible material, only electrodes and wires need to be arranged around the periphery, no wires may be inside, and good fit for curved surfaces, which has the following advantages:

[0047] (1) A fully flexible pressure sensing device with a three-dimensional raised structure. In addition to being able to measure pressure in the Z direction, that is, the normal direction, the device can also measure the force in the XY plane, that is, the shear force in the horizontal direction, and has obvious advantages in three-dimensional force perception.

[0048] (2) Real-time multi-point touch control is achieved in the entire touch area, ensuring that the touch control of each raised point is three-dimensional pressure, rather than the three-dimensional pressure of a single point.

[0049] (3) Electrical impedance scanning technology can be used to minimize the number of electrodes and wires inside the touch area.

[0050] (4) The device has a simple structure, low cost, and is easy to process, while having excellent stability and robustness. In particular, compared with the prior art, the present invention greatly simplifies the device structure and improves stability and durability.

[0051] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0052] Embodiment 1

[0053] See also Figure 1A and Figure 1BThis embodiment provides a flexible three-dimensional pressure sensing device, which includes three parts: a force-sensitive component 1, a three-dimensional conductive component 2, and an electrode 3. The force-sensitive component 1 is a layer of silicone rubber filled with graphene and carbon nanotubes. Due to the presence of the filling particles, the force-sensitive component 1 has a piezoresistive effect; the three-dimensional conductive component 2 is a hemispherical three-dimensional protrusion structure made of pure silicone material, which can be prepared on the surface of the force-sensitive component 1 by a dispensing machine or 3D printing; Figure 1A and Figure 1B Only one protrusion structure matrix is ​​shown to constitute the three-dimensional conductive component 2, and the number of protrusion structures can also be adjusted according to needs; since both the force-sensitive component 1 and the three-dimensional conductive component 2 contain silicone rubber components, they can be tightly connected to each other; since the three-dimensional conductive component 2 is an elastic three-dimensional structure rather than a planar structure, it can not only effectively transmit normal pressure, but also effectively transmit tangential pressure. In addition, since the three-dimensional conductive component 2 is made of silicone, it can play an insulating role, that is, it can prevent the external conductor (such as the human body) from making direct electrical contact with the force-sensitive component 1, causing adverse effects such as noise or reducing the accuracy of the device. The electrode 3 is a composite material of silver nanowires and silicone, which can be formed by applying an ethanol dispersion of silver nanowires and then applying a certain amount of silicone after the ethanol evaporates. The electrode 3 also contains silicone rubber components, so it can also produce effective bonding with the force-sensitive component 1. At the same time, the silver nanowires in the electrode 3 can also produce effective electrical connection with the force-sensitive component 1.

[0054] Since the force-sensitive component 1 has a piezoresistive characteristic, that is, the resistance changes when it is under pressure, the force-sensitive component 1 can provide the resistance distribution data of the entire device coverage area. The three-dimensional conductive component 2 preferably has a larger elastic modulus than the force-sensitive component 1, so as to effectively transmit the normal pressure and the tangential pressure to the force-sensitive component 1, causing the corresponding resistance change. When external pressure or tangential force is applied to any one or more protrusion structures of the three-dimensional conductive component 2, the planar resistance distribution characteristics of the specific force-sensitive component 1 will be caused. At this time, by applying current to the peripheral electrodes in turn and measuring the voltage distribution of other electrodes, the resistance distribution of the force-sensitive component 1 is read in real time by using the method of impedance scanning imaging. Then, based on these resistance distribution data, the three-dimensional pressure distribution of each position in the plane of the device can be inferred, that is, the distribution data of the pressure and shear force borne by the three-dimensional conductive component 2. Thereby realizing a three-dimensional pressure sensing device with no internal electrodes or only partial electrodes, full flexibility, based on impedance scanning imaging, and multi-point simultaneous detection.

[0055] The device only arranges electrodes around the periphery, which effectively reduces the huge number of wires required by the traditional three-dimensional pressure sensor matrix. At the same time, if an overall stretchable flexible device is to be made on the basis of the traditional three-dimensional pressure sensor matrix, stretchable wire technology is also required. Then, this embodiment 1 can also avoid the need for stretchable wire technology, so it is highly practical. In addition, embodiment 1 can realize real-time monitoring of three-dimensional pressure at multiple points in the plane, which has significant advantages over inductive or capacitive pressure touch panels that can only identify the position of fingers. At the same time, compared with the single normal pressure measurement function of electrical impedance scanning imaging, it can provide shear force distribution at multiple points, so it is innovative.

[0056] See also Figure 2 In this embodiment, an optional encapsulation layer 4 can be added on the basis of the above device, that is, silicone is poured on the entire device surface to make the device surface flat. Preferably, the elastic modulus of the silicone used in the encapsulation layer 4 is lower than the elastic modulus of the three-dimensional conductive component 2, so as to ensure that the normal pressure and lateral shear force at each position on the device surface after encapsulation can be effectively transmitted to the corresponding protruding position of the three-dimensional conductive component 2.

[0057] Embodiment 2

[0058] See also Figure 3A and Figure 3B This embodiment provides a flexible three-dimensional pressure sensing device, which includes three parts: a force-sensitive component 1, a three-dimensional conductive component 2, and an electrode 3. Different from the first embodiment, the force-sensitive component 1 and the three-dimensional conductive component 2 of this embodiment are made of the same material, so they can be prepared in one step, simplifying the preparation process. The preferred material and processing method are to prepare a polyurethane and graphene composite material by injection molding. Figure 2 The structure shown in FIG. 1 is a flat plate with nine hemispherical protrusions, and the flat plate and the protrusions are an integrated structure. The conductive adhesive of silver powder / epoxy resin is coated on the Figure 2 As shown in the electrode positions, there are electrodes 3 not only around the circumference, but also below and inside the force-sensitive portion.

[0059] In this way, the three-dimensional conductive component 2 itself is also conductive and has a certain piezoresistive effect, so the force-sensitive component 1 and the three-dimensional conductive component 2 as a whole constitute a piezoresistive composite material body. When the raised part is subjected to pressure and shear force, the magnitude and direction of the force will be in a one-to-one correspondence with the resistance distribution of the entire piezoresistive material composite. In this way, through the method of electrical impedance scanning imaging, the resistance distribution can be measured in real time, thereby inferring the force magnitude and direction at each position on the surface of the device. A three-dimensional pressure sensing device with only partial electrodes inside, full flexibility, based on electrical impedance scanning imaging, and multi-point simultaneous detection is realized.

[0060] See also Figure 4 In this embodiment, an optional encapsulation layer 4 can be added on the basis of the above-mentioned device, that is, a polyurethane encapsulation layer is cast on the entire device surface to make the surface of the device flat. The elastic modulus of the silicone used in the encapsulation layer 4 is preferably lower than the elastic modulus of the three-dimensional conductive component 2, so as to ensure that the normal pressure and lateral shear force at each position on the surface of the device after encapsulation can be effectively transmitted to the corresponding raised position of the three-dimensional conductive component 2. Since the encapsulation layer 4 is made of insulating material, it can play the role of insulating the device, preventing the human body from contacting the piezoresistive composite material and causing electric shock, noise, and reduced accuracy.

[0061] Embodiment 3

[0062] See also Figure 1A and Figure 1B The top view portion of the present embodiment provides a flexible three-dimensional pressure sensing device of a textile structure. The force-sensitive component 1 is composed of elastic fabric, the main component of which is polyurethane filament yarn mixed with carbon black nanoparticles. Since the polyurethane filaments are a loose porous structure after forming a textile structure, they may or may not be electrically connected to each other, that is, the effective conductive contact area of ​​the fabric will change with the pressure, so there can be an overall piezoresistive effect; at the same time, when the pressure increases to a certain extent, the effective conductive contact area inside the fabric is basically stable, and the polyurethane / carbon black composite material itself is compressed, and there will be further piezoresistive effect. Therefore, this embodiment uses a textile structure with a piezoresistive effect, which can realize the measurement of small pressure, medium pressure and large pressure. Buttons are sewn on the surface of the fabric, that is, the force-sensitive component 1 as a three-dimensional force conduction component 2. The button can play the role of pressure and shear force conduction. In order to enhance the force conduction effect, the sewing points of the button can be preferably increased from 2 to multiple sewing points. Optionally, the button can also be attached to the elastic fabric of the force-sensitive component 1 by hot melt adhesive or other adhesive bonding methods. Finally, silver-plated nylon yarn is sewn around each electrode position of the conductive fabric of the force-sensitive component 1 as electrode 3 to connect the signal.

[0063] Since the third embodiment of the present invention is a three-dimensional pressure sensing device made entirely of textile and clothing materials, the device has various characteristics of textile and clothing products, including softness, porousness, breathability, washability, dryability, surface conformability, etc. Therefore, the device can be easily integrated into smart clothing or robot clothing or even household textiles to achieve a variety of multi-point three-dimensional pressure detection functions. In addition, since the textile-type force-sensitive component 1 can have a piezoresistive effect for small pressure, medium pressure and large pressure, the sensing device can be used in multi-point three-dimensional pressure touch, multi-point collision pressure detection, and even real-time measurement of medium and low-speed impact pressure size and pressure direction. It has practical value.

[0064] In addition, three-dimensional weaving, three-dimensional knitting, and three-dimensional braiding methods can be used to prepare the force-sensitive component 1 and the three-dimensional conductive component 2 at one time, so as to achieve better integrated preparation of the equipment and the integrity of the pressure sensing device structure.

[0065] In addition, the distribution of the electrodes 3 does not have to be uniform, and the distribution density of the electrodes can be adjusted according to the distribution density of the pressure sensing units and the different accuracy requirements for pressure sensing information at different parts.

[0066] Embodiment 4

[0067] See also Figure 1A and Figure 1B , this embodiment provides a fully flexible multi-point three-dimensional pressure sensing device. Different from the first embodiment, the force-sensitive component 1 of this embodiment is composed of a conductive hydrogel (such as a hydrogel rich in NaCl), and can also be composed of other conductive liquids rich in conductive ions (such as sodium ions, potassium ions, etc.) encapsulated in a silicone plate (silicone is used as a container for liquid) or liquid metal (such as gallium-indium alloy). Since these materials have good fluidity (liquid metal, etc.) or very small elastic modulus (such as conductive hydrogel), they can be very sensitive to very small pressures. When a three-dimensional conductive component 2 is arranged externally (preferably a hydrogel protrusion structure or a silicone protrusion structure of the same type that does not contain conductive materials), real-time measurement of weak three-dimensional pressure can be achieved, and the magnitude and direction of the pressure at each force point can be given.

[0068] Embodiment 5

[0069] The above embodiments all show solid structures, and non-solid materials can also be used. Figure 1A and Figure 1B , Example 5 shows a force-sensitive component 1 composed of an open-pored sponge layer, wherein multi-arm carbon nanotubes are deposited inside the sponge layer, so that the sponge layer has a piezoresistive effect; and a hemispherical three-dimensional structure formed by foaming is also provided on the surface of the sponge layer as a three-dimensional conductive component 2, see Figure 1B finally, electrodes 3 are arranged around the sponge, and after connecting the wires, real-time measurement of multi-point three-dimensional micro pressure of the planar structure of the electrical impedance scanning method can be achieved.

[0070] In addition, in addition to filling carbon-based conductive nanoparticles with foamed sponge technology, 3D printing and other methods can also be used to prepare piezoresistive material electrical impedance scanning three-dimensional pressure sensing devices with three-dimensional force conduction structures.

[0071] Based on this, compared with the prior art, the flexible three-dimensional pressure sensing device of the present invention has at least the following beneficial effects:

[0072] (1) Three-dimensional force: The present invention can realize multifunctional detection of the touch position, the magnitude and direction of the pressure at each touch position, and the overall shape of the touch pressure, greatly improving the sensor's perception ability. In particular, the perception of three-dimensional force can provide richer information than the perception of pure normal pressure.

[0073] (2) Simple structure and process: Compared with the pressure sensor matrix, the present invention adopts an integrated structure, which does not require the design of complex internal microstructures and wiring, reducing the difficulty and cost of production.

[0074] (3) Flexible and stretchable: The sensor material is low-cost and flexible. Without the use of stretchable wires, it has natural flexibility and stretchability. It can be easily covered on the surface of various irregular three-dimensional objects for all-round tactile coverage and perception, which improves the applicability and practicality of the sensor.

[0075] (4) Textile properties: When the flexible three-dimensional force sensing device is made of textile materials, it also has various advantages of textiles and clothing products, including skin-friendly, comfortable, breathable, porous, thin, machine washable, dryable, etc., so it can be perfectly combined with various textiles and clothing products.

[0076] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above-mentioned implementation mode. Technical personnel familiar with the field can also make various equivalent deformations or substitutions under the shared conditions without violating the spirit of the present invention. These equivalent deformations or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A flexible three-dimensional pressure sensing device, characterized in that: include: A force-sensitive component, a three-dimensional conductive component and an electrode, wherein the force-sensitive component is composed of a whole piece of flexible conductive material, the flexible conductive material has piezoresistive properties, a plurality of three-dimensional conductive components are distributed on the surface of the force-sensitive component, the three-dimensional conductive components are used to transmit pressure to the force-sensitive component, causing a corresponding change in the resistance characteristic of the force-sensitive component, the pressure includes normal pressure and shear pressure, a plurality of electrodes are arranged around the force-sensitive component, the electrodes are used to lead out the resistance distribution data of the force-sensitive component through wires, so that the back-end circuit equipment calculates the three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensing device at each moment based on the resistance distribution data.

2. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: The force-sensitive component is a solid planar structure, or a network structure with holes.

3. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: The force-sensitive component is made of a conductive composite material, or liquid metal, or a conductor or semiconductor material rich in conductive ions, or a conductive fiber assembly with piezoresistive properties, or an elastomer and fiber assembly containing an intrinsic conductive polymer.

4. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: The stereo conductive component has a three-dimensional convex structure, and a plurality of the stereo conductive components are evenly or unevenly distributed on the surface of the force sensitive component, and each of the stereo conductive components is tightly combined with the force sensitive component.

5. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: The electrodes are made of a coating or plating of a good conductor, or a micron-nanostructured material, or a carbon-based conductive material, or an intrinsic conductive polymer, or a liquid metal, or a conductive fiber material. Multiple electrodes are evenly or unevenly arranged around the force-sensitive component.

6. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: The material elastic modulus of the three-dimensional conductive component is greater than or equal to the material elastic modulus of the force sensitive component.

7. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: When the three-dimensional conductive component and the force-sensitive component are made of the same material, a sheet of elastic conductive material having a three-dimensional raised structure is formed by template injection molding or mold embossing, and the electrodes and the wires are printed at designated positions around the force-sensitive component.

8. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: When the three-dimensional conductive component and the force-sensitive component are made of different materials, the force-sensitive component is firstly cut or processed into a required size and shape, and then the three-dimensional conductive component is fixed on the surface of the force-sensitive component.

9. The flexible three-dimensional pressure sensing device according to claim 8, characterized in that: The fixing method includes: using a dispensing machine to dispense conductive material to the position where the three-dimensional conductive component is set to form the three-dimensional conductive component, or using three-dimensional printing technology to prepare the three-dimensional conductive component on the surface of the force-sensitive component, or applying each unit of the additional mechanical conductive part to the corresponding position on the surface of the force-sensitive component through textile and garment processing.

10. The flexible three-dimensional pressure sensing device according to claim 1, characterized in that: The surface of the three-dimensional conductive component is partially or completely covered with a packaging layer, and the packaging material of the packaging layer is a flexible polymer elastomer with a low elastic modulus.

Images