Flexible three-dimensional pressure sensing equipment

Abstract

The utility model discloses a flexible three-dimensional pressure sensing device, which comprises a force-sensitive part, three-dimensional conduction parts and electrodes, the force-sensitive part is made 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, the three-dimensional conduction parts are used for conducting pressure to the force-sensitive part, and the electrodes are arranged on 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 enlarge the application scene of the equipment.

Description

TECHNICAL FIELD

[0001] The embodiment of the utility model relates to but is not limited to the technical field of pressure sensing, in particular to a flexible three-dimensional pressure sensing device. BACKGROUND

[0002] In the current booming development of emerging technology fields such as the Internet of Things, the meta universe, smart home and furniture, humanoid and flexible robots, the demand for pressure measurement technology of human-computer interaction interface is increasingly urgent. These industries expect the device interface to accurately capture the pressure changes of the user or the environment interface to achieve a more natural, safe and intelligent interaction experience. For example, if a humanoid robot has electronic skin, i.e., a tactile function similar to human skin, it will greatly improve its interaction ability 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, limiting their application range.

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

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

[0005] The embodiment of the utility model provides a flexible three-dimensional pressure sensing device which has simple structure, full flexible material, only needs to arrange electrodes and wires on the periphery, can have no any wire inside, and has good adhesion to curved surface shape, so as to improve three-dimensional sensing ability, simplify device structure, reduce manufacturing difficulty and cost, improve flexibility of device, and expand applicable scenarios of device.

[0006] The utility model discloses a first aspect of embodiment provides a kind of flexible three-dimensional pressure sensing equipment, comprising: force sensing component, three-dimensional conducting component and electrode, the force sensing component is made of a whole piece of flexible conductive material, the flexible conductive material has piezoresistive characteristic, the surface of the force sensing component is distributed with multiple three-dimensional conducting components, the three-dimensional conducting component is used to conduct pressure to the force sensing component, causes the resistance characteristic of the force sensing component corresponding change, the pressure includes normal pressure and shear pressure, the periphery of the force sensing component is arranged with multiple electrode, the electrode is used to lead out the resistance distribution data of the force sensing component by wire, so that back-end circuit equipment is calculated according to the resistance distribution data and obtains the three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensing equipment at each time.

[0007] In some embodiments, the force sensing component is a solid plane structure, or a network structure with holes.

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

[0009] In some embodiments, the three-dimensional conducting component has a three-dimensional convex structure, and multiple three-dimensional conducting components are uniformly or non-uniformly distributed on the surface of the force sensing component, and each three-dimensional conducting component is tightly combined with the force sensing component.

[0010] In some embodiments, the electrode uses a coating or plating layer of a good conductor, or is a micron-nano structure material, or is a carbon-based conductive material, or is an intrinsic conductive polymer, or is liquid metal, or is a conductive fiber material, and multiple electrodes are uniformly or non-uniformly arranged around the force sensing component.

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

[0012] In some embodiments, a chemical bond is generated between the three-dimensional conducting component and the force sensing component.

[0013] In some embodiments, when the materials used by the three-dimensional conducting component and the force sensing component are the same, a template injection molding or mold stamping method is used to form a sheet-shaped elastic conductive material with a three-dimensional convex structure, and the electrode and the wire are printed at the specified position around the force sensing component.

[0014] In some embodiments, when the materials of the stereoscopic conductive component and the force sensing component are different, the force sensing component is first cut or processed to the required size and shape, and then the stereoscopic conductive component is fixed on the surface of the force sensing component.

[0015] In some embodiments, the fixing method includes dispensing conductive material to the position where the stereoscopic conductive component is arranged to form the stereoscopic conductive component by using a dispensing machine, or using a three-dimensional printing technology to prepare the stereoscopic conductive component on the surface of the force sensing component, or applying each unit of the additional mechanical conductive part to the corresponding position on the surface of the force sensing component by means of textile garment processing.

[0016] In some embodiments, the surface of the stereoscopic conductive component is partially or fully covered with an encapsulation layer, and the encapsulation material of the encapsulation layer is a flexible high polymer elastomer with a low elastic modulus.

[0017] The utility model discloses a kind of flexible three-dimensional pressure sensing equipment, comprising: force-sensitive component, three-dimensional conducting component and electrode, force-sensitive component is made of a whole piece of flexible conductive material, flexible conductive material has piezoresistive characteristic, the surface of force-sensitive component is distributed with multiple three-dimensional conducting components, three-dimensional conducting component is used to conduct pressure to force-sensitive component, cause the corresponding change of resistance characteristic of force-sensitive component, pressure includes normal pressure and shear pressure, the periphery of force-sensitive component is arranged with multiple electrodes, electrode is used to lead out the resistance distribution data of force-sensitive component by wire, so that the three-dimensional pressure distribution information of flexible three-dimensional pressure sensing equipment surface every position at every time is calculated according to resistance distribution data by rear-end circuit equipment.The utility model embodiment adopts flexible conductive material to constitute force-sensitive component, this flexible conductive material has piezoresistive characteristic, that is, resistance changes when being extruded, being stretched.Therefore, the flexible conductive material can construct the plane data of resistance distribution.The surface of flexible conductive material is distributed with multiple three-dimensional conducting components, and three-dimensional conducting component can conduct pressure to force-sensitive component, and ensure that normal pressure and shear pressure can be transmitted.The periphery of flexible conductive material is arranged with multiple electrodes, and electrode is used to connect wire to lead out signal.Electrical impedance scanning imaging method can be used to read the resistance distribution data inside flexible conductive material in real time, and the three-dimensional pressure distribution of each position of the plane formed by all three-dimensional conducting components can be known according to resistance distribution data, so that flexible three-dimensional pressure sensing equipment of internal electrodeless or only having partial electrode, full flexible, based on electrical impedance scanning imaging, multiple point simultaneous detection is realized, and its function is equivalent to three-dimensional pressure sensor matrix.Based on this, the flexible three-dimensional pressure sensing equipment of the utility model has the advantages of simple structure, full flexible material, only need to arrange electrode and wire on periphery, internal can be without any wire, and good adhesion to curved surface shape, which can improve three-dimensional perception ability, simplify equipment structure, reduce manufacturing difficulty and cost, improve the flexibility of equipment, and expand the applicable scenarios of equipment.

[0018] Other features and advantages of the present application will be set forth in the following description of the application, and in part will become apparent to those skilled in the art upon examination of the following specification or can be learned by practice of the application. The objects and other advantages of the application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

[0020] Figure 1A A top view structural schematic diagram of flexible three-dimensional pressure sensing equipment provided by an embodiment of the utility model is provided;

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

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

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

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

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

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to 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 intended to limit the present invention.

[0027] It should be understood that in the description of the embodiments of the present invention, "multiple" (or multiple) means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, and "above," "below," and "within" are understood to include the number itself. The use of "first," "second," and the like in the description is solely for the purpose of distinguishing technical features and is not to be construed 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 increasingly urgent. These industries expect device interfaces to accurately capture pressure changes in the user or environmental interface to achieve a more natural, safe, and intelligent interactive experience. For example, if humanoid robots can have electronic skin, that is, tactile functions similar to human skin, it will greatly enhance their 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 processes, high costs, and single sensing functions. At the same time, these sensors are often unable to achieve multi-dimensional pressure detection when detecting touch position, force intensity, and shape, which limits their scope of application.

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

[0030] To solve the above technical problems, the utility model embodiment provides a kind of flexible three-dimensional pressure sensing equipment, comprising: force-sensitive component, three-dimensional transmission component and electrode, force-sensitive component is made of a whole piece of flexible conductive material, flexible conductive material has piezoresistive characteristic, the surface of force-sensitive component is distributed with multiple three-dimensional transmission components, three-dimensional transmission component is used to conduct pressure to force-sensitive component, causes the corresponding change of the resistance characteristic of force-sensitive component, pressure includes normal pressure and shear pressure, the periphery of force-sensitive component is arranged with multiple electrodes, electrode is used to lead out the resistance distribution data of force-sensitive component by wire, so that the three-dimensional pressure distribution information of each position on the surface of flexible three-dimensional pressure sensing equipment at each time is calculated according to resistance distribution data by rear-end circuit equipment.The utility model embodiment adopts flexible conductive material to constitute force-sensitive component, which has piezoresistive characteristic, that is, resistance changes when being extruded or stretched.Therefore, the flexible conductive material can construct plane data of resistance distribution.There are multiple three-dimensional transmission components on the surface of flexible conductive material, and three-dimensional transmission component can conduct pressure to force-sensitive component and ensure that normal pressure and shear pressure can be transmitted.There are multiple electrodes around the flexible conductive material, and electrode is used to connect wire to lead out signal.Electrical impedance scanning imaging method can be used to read resistance distribution data inside flexible conductive material in real time, and three-dimensional pressure distribution of each position of the plane formed by all three-dimensional transmission components can be obtained according to resistance distribution data, so as to realize flexible three-dimensional pressure sensing equipment with no electrode or only partial electrode inside, full flexibility, based on electrical impedance scanning imaging and multiple-point simultaneous detection, which is equivalent to three-dimensional pressure sensor matrix.Based on this, the flexible three-dimensional pressure sensing equipment of the utility model has the advantages of simple structure, full flexible material, only need to arrange electrodes and wires around, can have no any wire inside, and has good conformability to curved surface shape, which can improve three-dimensional perception ability, simplify device structure, reduce manufacturing difficulty and cost, improve flexibility of the device and expand applicable scenarios of the device.

[0031] The flexible three-dimensional pressure sensing equipment of the utility model is composed of three parts, including: force-sensitive component, three-dimensional transmission component and electrode.

[0032] It can be understood that the force sensing component is composed of a whole piece of flexible conductive material, which is usually a solid planar layer structure, and can also be a network structure, i.e., partially containing holes. The flexible conductive material can generate a corresponding change in resistance at the position under pressure, i.e., has a piezoresistive property, or can not be a conventional piezoresistive material, but as long as the resistance at the position under pressure changes regularly under pressure.

[0033] It can be understood that the three-dimensional conductive component transmits three-dimensional pressure to the force sensing component, causing a characteristic corresponding change in the resistance of the force sensing component; electrodes are arranged around the entire device, and the resistance distribution of the force sensing component can be monitored in real time by the method of electrical impedance imaging, so as to calculate the three-dimensional pressure distribution information at each position on the surface of the device at each moment.

[0034] It can be understood that the three-dimensional conductive component is a series of three-dimensional structures, which can be semi-spherical, cubic, pyramidal, triangular pyramid, or artistic shape three-dimensional convex structures. The three-dimensional convex structure can be regarded as a three-dimensional convex unit, and each three-dimensional unit of the three-dimensional conductive component is uniformly or non-uniformly distributed on the surface of the force sensing component. Since the three-dimensional conductive component and the force sensing component are closely combined together, each three-dimensional unit of the three-dimensional conductive component can effectively transmit the normal pressure and shear force borne by the unit to the force sensing component.

[0035] It can be understood that the electrodes can be uniformly arranged around the entire device, and the electrodes can be arranged at equal intervals, or 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 entire device, the electrodes can also be selectively arranged at different positions below the force sensing material, so as to greatly improve the position accuracy and pressure accuracy of the sensor measurement.

[0036] It can be understood that the force sensing component preferably adopts a conductive composite material, and the resistance of the conductive material is preferably in the range of a semiconductor in order to enhance the piezoresistive property. Typical examples include pressure-sensitive rubber, graphene silicone composite material, carbon nanotube polyurethane composite material, etc. The material of the force sensing component can also be a gallium-indium alloy or a liquid rich in conductive ions, etc. The material of the force sensing component can also be a conductive fiber assembly with piezoresistive property, such as pure cotton knitted fabric with graphene and carbon nanotube attached to the surface, or a nylon warp net completely coated with carbon black polyurethane composite material prepared by screen printing. In addition, the material of the force sensing component can also be an elastomer containing an intrinsic conductive polymer, such as a composite film of polypyrrole and polyurethane. Finally, as long as the material is a flexible continuous conductive sheet with holes or a solid sheet material, and the resistance at the position under pressure changes regularly under pressure, it meets the use requirements of the force sensing component of the embodiment of the present application.

[0037] It can be understood that the material of the stereoscopic conduction component can be completely the same as that of the force-sensitive component, or can be another conductor material, semiconductor material, or insulating material; the stereoscopic conduction component is usually a solid structure, and in order to realize effective conduction of pressure, the elastic modulus of the material of the stereoscopic conduction component is preferably greater than or equal to the elastic modulus of the material of the force-sensitive component; in addition, the stereoscopic conduction component needs to be closely combined with the force-sensitive component, and preferably a chemical bond is generated between the interfaces of the two, such as polymer crosslinking and the like, so as to ensure the long-term stability and robustness of the device structure.

[0038] It can be understood that the material of the electrode part can be a coating, plating or micron / nano structure material of a good conductor such as gold, silver, copper and the like (such as a silver nanowire / silica gel composite material, a silver powder particle / epoxy resin composite material), or a carbon-based conductive material (such as carbon fiber and the like), or an intrinsically conductive polymer (such as poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and the like) or a liquid metal (such as a gallium-indium alloy and the like), or a conductive fiber material.

[0039] It can be understood that when the materials of the stereoscopic conduction component and the force-sensitive component are the same, a template injection molding or mold stamping method can be used to form a sheet-shaped elastic conductive material with a stereoscopic conduction structure unit, and then electrode materials are printed (such as screen printing, chemical evaporation, physical evaporation, magnetron sputtering and the like) or conductive electrode materials are pasted (such as silver paste resin and the like) or conductive wires are embroidered (such as silver-plated nylon yarn) or conductive sewing threads are sewn at specified electrode positions on the periphery of the device uniformly or non-uniformly; finally, the device is connected to the back-end circuit device through the electrode connecting wires.

[0040] It can be understood that when the materials of the stereoscopic conduction component and the force-sensitive component are different, the force-sensitive component is first cut or processed to the required size and shape, and then the conduction part is fixed on the surface of the force-sensitive component; the conduction material can be glued to the positions of the set stereoscopic three-dimensional protruding units by using a glue dispenser to form a stereoscopic conduction component, or a three-dimensional printing technology can be used to prepare a stereoscopic conduction component on the surface of the force-sensitive part, or an additional mechanical conduction part can be applied to the corresponding position on the surface of the force-sensitive component by means of textile and garment processing, such as sewing a button (the button is used as a force conduction part) or other small accessories and the like.

[0041] It can be understood that the surface of the stereoscopic conducting component can be partially or fully covered with an encapsulating layer, and the encapsulating material of the encapsulating layer is preferably a flexible high polymer elastomer with a low elastic modulus, so as to ensure that stress concentration can be generated near the conducting unit for each part, and the pressure can reach the stereoscopic conducting component from the surface, and the stereoscopic conducting component can accurately and repeatedly conduct three-dimensional pressure to the corresponding position of the force sensing component.

[0042] It can be understood that, since the force sensing component is the base of the entire device, when the force sensing component has good elasticity in three directions, the device can not only realize dynamic monitoring of three-dimensional pressure in the original planar state, but also can be well fitted to various three-dimensional shapes (such as spherical shapes, fitted to the part of the human-shaped robot head top), and during the fitting process, the device is stretched, and after the fitting device is calibrated, it can also provide real-time monitoring of multi-point three-dimensional force.

[0043] It can be understood that the pressure-sensitive characteristics of the force sensing component determine the sensitivity of the device in three-dimensional pressure detection, and when other conditions are unchanged, the more obvious the piezoresistive characteristics of the force sensing material, the higher the sensitivity of the device; the size and stiffness of the stereoscopic conducting component also partially determine the measurement range and sensitivity of the device in three-dimensional pressure detection, and when other conditions are unchanged, the greater the stiffness under the same size, the more obvious the stress concentration formed by the force sensing component, thereby causing higher sensitivity, while possibly reducing the force measurement range; similarly, different shapes and sizes of the stereoscopic conducting component will also cause different stress concentration effects, thereby resulting in different three-dimensional force measurement sensitivity and mechanical measurement range; in addition, the number, distribution and density of the stereoscopic three-dimensional protruding units of the stereoscopic conducting component also partially determine the number of measurable points, the distribution of measurable points and the measurement density of three-dimensional force measurement.

[0044] It can be understood that, under the premise of the same backend circuit device 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 precision of pressure measurement, for example, when the number of electrodes is greater, the resistance distribution that can be obtained when using electrical impedance imaging analysis is more accurate, and then the accuracy of normal force measurement is higher, the error of position identification is smaller, and at the same time, the accuracy of shear force measurement is also higher. When the electrodes are arranged uniformly or non-uniformly on the back of the force sensing component in addition to being distributed on the periphery, the resistance collection accuracy of electrical impedance imaging analysis can be further improved, thereby improving the position accuracy and pressure accuracy of three-dimensional pressure detection of the device.

[0045] Based on this, the flexible three-dimensional pressure sensing device of the utility model mainly consists of elastic material, and is divided into three parts according to function: force sensing part, three-dimensional conducting part and electrode. The force sensing part is made of a whole piece of flexible conductive material, and the flexible conductive material has piezoresistive characteristic, that is, the resistance changes when being extruded or stretched. Therefore, the flexible conductive material can construct planar data of resistance distribution. The three-dimensional conducting part formed by the same material or different materials is distributed on the surface of the flexible conductive material, and the three-dimensional conducting part can conduct pressure to the force sensing part, ensuring that 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 wires to lead out signals. The resistance data inside the flexible conductive material are read in real time by using the method of electrical impedance scanning imaging, and the three-dimensional pressure distribution of each position of the plane formed by all protruding structures can be obtained according to the resistance distribution data, so that the three-dimensional pressure touch sensing device with internal no electrode or only partial electrode, full flexibility, based on electrical impedance scanning imaging and multi-point simultaneous detection is realized, that is, the function is equivalent to three-dimensional pressure sensor matrix.

[0046] In summary, the utility model embodiment provides a three-dimensional pressure sensing device which has simple structure, full flexible material, only needs to arrange electrodes and wires around, can have no any wire inside, has good adhesion to curved surface shape, and has the following advantages:

[0047] (1) The full flexible pressure sensing device with three-dimensional protruding structure can measure pressure in Z direction, that is, normal direction, and can also measure force in XY plane, that is, shear force in horizontal direction, and has obvious three-dimensional force sensing advantage.

[0048] (2) Multi-point real-time touch is realized in the whole touch area, and the touch of each protruding point is three-dimensional pressure, instead of three-dimensional pressure of a single point.

[0049] (3) The resistance impedance scanning technology can be used to reduce the electrodes and wires inside the touch area to the maximum extent.

[0050] (4) The device has simple structure, low cost, is easy to process, and has excellent stability and robustness. Compared with the prior art, the utility model greatly simplifies the device structure, improves the stability and durability.

[0051] The utility model embodiment will be further described below with reference to the drawings.

[0052] Embodiment one

[0053] Please refer to Figure 1A and Figure 1BThe embodiment provides a flexible three-dimensional pressure sensing device, which comprises three parts, a force sensing part 1, a three-dimensional conducting part 2 and an electrode 3. The force sensing part 1 is a layer of silicone rubber filled with graphene and carbon nanotubes. Due to the existence of the filling particles, the force sensing part 1 has a piezoresistive effect. The three-dimensional conducting part 2 is a hemispherical three-dimensional protruding structure made of pure silicone rubber and can be prepared on the surface of the force sensing part 1 by means of a point glue machine or 3D printing. Figure 1A and Figure 1B Only one protruding structure matrix is shown to form the three-dimensional conducting part 2, and the number of protruding structures can be adjusted according to requirements. Since the force sensing part 1 and the three-dimensional conducting part 2 both contain silicone rubber components, they can be closely connected to each other. Since the three-dimensional conducting part 2 is an elastic three-dimensional structure rather than a planar structure, it can effectively transmit not only the normal pressure but also the tangential pressure. In addition, since the three-dimensional conducting part 2 is made of silicone rubber, it can play an insulating role, that is, it can avoid the direct electrical contact of the force sensing part 1 with external conductors (such as the human body), thereby causing noise or reducing the accuracy of the device and other adverse effects. The electrode 3 is a composite material of silver nanowires and silicone rubber, which can be formed by applying a silver nanowire ethanol dispersion and then applying a certain amount of silicone rubber after ethanol evaporation. The electrode 3 also contains a silicone rubber component, so it can also be effectively bonded to the force sensing part 1. At the same time, the silver nanowires in the electrode 3 can also be effectively electrically connected to the force sensing part 1.

[0054] Since the force sensing part 1 has a piezoresistive property, that is, the resistance changes when it is pressed, the force sensing part 1 can provide resistance distribution data of the entire area covered by the device. The three-dimensional conducting part 2 preferably has a greater elastic modulus than the force sensing part 1, so as to effectively conduct the normal pressure and the tangential pressure to the force sensing part 1, causing a corresponding resistance change. When external pressure or tangential force is applied to any one or more protruding structures of the three-dimensional conducting part 2, the planar resistance distribution characteristics of the specific force sensing part 1 will be caused. At this time, by sequentially applying current to the circumferential electrodes and measuring the voltage distribution of the other electrodes, the resistance distribution of the force sensing part 1 is read in real time by using the method of electrical impedance scanning imaging. Then, according to the resistance distribution data, the three-dimensional pressure distribution of each position in the plane of the device, that is, the distribution data of the pressure and shear force borne by the three-dimensional conducting part 2, can be deduced. Thus, a three-dimensional pressure sensing device with internal no electrode or only partial electrode, full flexibility, based on electrical impedance scanning imaging, multi-point simultaneous detection is realized.

[0055] The device only arranges electrodes on the periphery, effectively reducing the large number of wires required by the conventional three-dimensional pressure sensor matrix. At the same time, if a whole-stretchable flexible device is to be made on the basis of the conventional three-dimensional pressure sensor matrix, additional stretchable wire technology is required, but the embodiment 1 can also avoid the need for stretchable wire technology, thus having high practicality. In addition, embodiment 1 can realize real-time monitoring of the three-dimensional pressure of multiple points in the plane, which has a significant advantage compared to the inductive or capacitive pressure touch panel which can only identify the position of the finger, and can provide shear force distribution of multiple points compared to the single normal pressure measurement function of the electrical impedance scanning imaging, thus having innovation.

[0056] Referring to Figure 2 The embodiment can also add an optional encapsulation layer 4 on the basis of the above-mentioned device, that is, pouring silica gel on the entire device surface to make the surface of the device flat. Preferably, the elastic modulus of the silica gel used in the encapsulation layer 4 is lower than the elastic modulus of the three-dimensional conductive component 2, so that the normal pressure and transverse shear force of each position of the surface of the device after encapsulation can be effectively transmitted to the corresponding protruding position of the three-dimensional conductive component 2.

[0057] Embodiment two

[0058] Referring to Figure 3A and Figure 3B The embodiment provides a flexible three-dimensional pressure sensing device, which comprises three parts, a force sensing component 1, a three-dimensional conductive component 2, and an electrode 3. Unlike embodiment one, the force sensing component 1 and the three-dimensional conductive component 2 of the 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 is to prepare a polyurethane and graphene composite material by injection molding into the structure shown in Figure 2 , that is, a flat plate with nine semicircular spherical protrusions, the flat plate and the protrusions are integrated. The silver powder / epoxy resin conductive adhesive is coated on the electrode position shown in Figure 2 , so that there are electrodes 3 not only on the periphery, but also on the inner side below the force sensing part.

[0059] In this way, the three-dimensional conductive component 2 itself is also conductive and has a certain piezoresistive effect, so the force sensing component 1 and the three-dimensional conductive component 2 form a piezoresistive composite material body as a whole. When the protruding part is subjected to pressure and shear force, the size and direction of the force will have a one-to-one correspondence with the resistance distribution of the entire piezoresistive material composite. In this way, by the method of electrical impedance scanning imaging, the resistance distribution can be measured in real time, so as to deduce the force size and force direction of each position on the surface of the device. Realize a three-dimensional pressure sensing device with internal partial electrodes, full flexibility, based on electrical impedance scanning imaging, multiple point simultaneous detection.

[0060] Referring to Figure 4 , the embodiment can also be based on the above-mentioned device, and an optional encapsulation layer 4 is added, that is, a polyurethane encapsulation layer is prepared on the surface of the entire device, so that the surface of the device becomes flat. The elastic modulus of the silica gel used in the encapsulation layer 4 is preferably lower than the elastic modulus of the three-dimensional conductive component 2, so that the normal pressure and the transverse shear force of each position of the surface of the device after encapsulation can be effectively transmitted to the corresponding protruding position of the three-dimensional conductive component 2. Since the encapsulation layer 4 is an insulating material, it can play a role in device insulation, preventing human contact with the piezoresistive composite material body from causing electric shock, noise, and reduced accuracy.

[0061] Embodiment Three

[0062] Referring to Figure 1A and Figure 1B , the embodiment provides a flexible three-dimensional pressure sensing device with a textile structure. The force sensing component 1 is composed of an elastic cloth, and the main component of the cloth is polyurethane filament yarn mixed with carbon black nanoparticles. Since the polyurethane filament has a loose and porous structure after forming a textile structure, it may or may not have electrical connection between each other, that is, the effective conductive contact area of the fabric will change with pressure, so that the overall piezoresistive effect can be achieved. 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, which will have a further piezoresistive effect. Therefore, the textile structure with piezoresistive effect used in this embodiment 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 sensing component 1, as the force three-dimensional conductive component 2. The buttons can play the role of pressure and shear force conduction. In order to enhance the effect of force conduction, the number of sewing points of the buttons can be increased from 2 to multiple. Optionally, the buttons can also be attached to the elastic cloth of the force sensing component 1 by hot melt adhesive or other adhesive. Finally, silver-plated nylon yarn is sewn on the four electrode positions of the conductive fabric of the force sensing component 1 as the electrode 3, and the signal can be connected out.

[0063] Since the three-dimensional pressure sensing device of the third embodiment is made of textile and clothing materials, it has the characteristics of textile and clothing products, including softness, porosity, air permeability, washability, dryability, and surface conformability. 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 sensing component 1 can have a piezoresistive effect on small, medium, and large pressures, the sensing device has practical value in multi-point three-dimensional pressure touch, multi-point collision pressure detection, and even real-time measurement of low-speed impact pressure size and direction.

[0064] In addition, three-dimensional weaving, three-dimensional knitting, and three-dimensional braiding methods can be used to prepare the force sensing component 1 and the three-dimensional conducting component 2 in one step, achieving better integrated preparation of the device and structural integration of the pressure sensing device.

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

[0066] Embodiment Four

[0067] Please refer to Figure 1A and Figure 1B , the present embodiment provides a full-flexible multi-point three-dimensional pressure sensing device. Unlike the first embodiment, the force sensing component 1 of the present embodiment is composed of conductive hydrogel (such as NaCl-rich hydrogel), or other conductive liquids (such as sodium ions, potassium ions, etc.) encapsulated in a silica gel flat plate (silica gel is used as a container for the liquid) or liquid metal (such as gallium-indium alloy). Because 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, and when the three-dimensional conducting component 2 (preferably the same type of hydrogel protrusion structure without conductive material or silica gel protrusion structure) is externally arranged, real-time measurement of weak three-dimensional pressure can be achieved, and the size and direction of the force at each point can be given.

[0068] Embodiment Five

[0069] The above embodiments give solid structures, in addition to non-solid materials. Please refer to Figure 1A and Figure 1B , embodiment five gives a force sensing component 1 composed of an open-cell sponge sheet layer, with multi-walled carbon nanotubes deposited inside the sponge sheet layer, so that the sponge sheet layer has a piezoresistive effect; the surface of the sponge sheet layer also has a half-sphere three-dimensional structure formed by foaming as a three-dimensional conducting component 2, as shown inFigure 1B The cross-section part of the sponge is filled with carbon-based conductive nanoparticles; finally, the electrodes 3 are arranged around the sponge, and after connecting the lead wires, the real-time measurement of the multi-point three-dimensional micro-pressure of the planar structure of the electrical impedance scanning method can be realized.

[0070] In addition, besides filling the sponge with carbon-based conductive nanoparticles, the piezoresistive material electrical impedance scanning three-dimensional pressure sensing device with a three-dimensional force conduction structure can also be prepared by 3D printing and the like.

[0071] Therefore, compared with the prior art, the flexible three-dimensional pressure sensing device has at least the following beneficial effects:

[0072] (1) Three-dimensional force: the flexible three-dimensional pressure sensing device can realize multifunctional detection of the touched position, the size and direction of the pressure of each touched position, and the overall shape of the touch pressure, and greatly improves the sensing ability of the sensor.

[0073] (2) Simple structure and process: compared with the pressure sensor matrix, the flexible three-dimensional pressure sensing device adopts an integrated structure, does not need to design a complex internal microstructure and wiring, and reduces the manufacturing difficulty and cost.

[0074] (3) Flexible and stretchable: the sensor material has low cost and flexibility, and has natural flexibility and stretchability without using stretchable lead wires.

[0075] (4) Textile properties: when the flexible three-dimensional force sensing device is composed of textile materials, it also has various advantages of textile and clothing products, including skin-friendly, comfortable, breathable, porous, light, machine washable, dryable, etc.

[0076] The above is a specific description of the preferred embodiment of the present application, but the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A flexible three-dimensional pressure sensing device, characterized by, The application relates to a flexible three-dimensional pressure sensor device, which comprises a force-sensitive component, a three-dimensional conducting component and an electrode, the force-sensitive component is composed of a whole piece of flexible conductive material, the flexible conductive material has a piezoresistive characteristic, a plurality of three-dimensional conducting components are distributed on the surface of the force-sensitive component, the three-dimensional conducting components are used for conducting pressure to the force-sensitive component, causing corresponding changes 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 for leading out the resistance distribution data of the force-sensitive component through wires, so that a back-end circuit device calculates three-dimensional pressure distribution information of each position on the surface of the flexible three-dimensional pressure sensor device at each moment according to the resistance distribution data. The force-sensitive component is a solid plane structure or a network structure with holes.

2. The flexible three-dimensional pressure sensing device of claim 1, wherein, The force-sensitive component adopts conductive composite material, or is liquid metal, or is a conductor or semiconductor material rich in conductive ions, or is a conductive fiber assembly with a piezoresistive characteristic, or is an elastomer containing an intrinsic conductive polymer and a fiber assembly.

3. The flexible three-dimensional pressure sensing device of claim 1, wherein, The three-dimensional conducting component has a three-dimensional convex structure, and a plurality of three-dimensional conducting components are uniformly or non-uniformly distributed on the surface of the force-sensitive component, and each three-dimensional conducting component is tightly combined with the force-sensitive component.

4. The flexible three-dimensional pressure sensing device of claim 1, wherein, The electrode adopts a coating or plating layer of a good conductor, or is a micron-nano structure material, or is a carbon-based conductive material, or is an intrinsic conductive polymer, or is liquid metal, or is a conductive fiber material, and a plurality of electrodes are uniformly or non-uniformly arranged around the force-sensitive component.

5. The flexible three-dimensional pressure sensing device of claim 1, wherein, The elastic modulus of the material of the three-dimensional conducting component is greater than or equal to the elastic modulus of the material of the force-sensitive component.

6. The flexible three-dimensional pressure sensing device of claim 1, wherein, When the materials of the three-dimensional conducting component and the force-sensitive component are the same, a sheet-shaped elastic conductive material with a three-dimensional convex structure is formed by adopting a template injection molding or mold stamping method, and the electrode and the wire are printed at the specified position around the force-sensitive component.

7. The flexible three-dimensional pressure sensing device of claim 1, wherein, The surface of the three-dimensional conducting component is partially or fully covered with an encapsulation layer, and the encapsulation material of the encapsulation layer adopts a flexible polymer elastomer with low elastic modulus.

8. The flexible three-dimensional pressure sensing device of claim 1, wherein, ​

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