CN113720503B - Large-area-array high-sensitivity flexible elastic pressure sensor and preparation method thereof - Google Patents
Large-area-array high-sensitivity flexible elastic pressure sensor and preparation method thereof Download PDFInfo
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/02—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning
Abstract
The invention discloses a large-area array high-sensitivity flexible elastic pressure sensor and a preparation method thereof, wherein the pressure sensor comprises a composite layer, and the composite layer comprises a substrate, a transition layer, a spacing layer, an electrode layer and a force-sensitive layer; the force sensitive layer comprises a conformal graphene film and a micro-nano multi-level coating; the conformal graphene film is formed by spraying graphene microchip slurry on a substrate and an electrode layer for the first time; the micro-nano multi-stage coating is formed by spraying low-conductivity composite slurry on the conformal graphene film for the second time. The preparation method comprises the steps of printing a transition layer on a substrate, printing an electrode layer on the transition layer, preparing a spacer layer, spraying graphene microchip slurry on the substrate and the electrode layer to obtain a conformal graphene film, and finally spraying low-conductivity composite slurry on the film to form the micro-nano multi-level coating. The invention has the advantages of improving the sensitivity of the sensor, increasing the area of the array, being beneficial to the microminiaturization of array devices and ensuring that the sensor has good flexibility and stretchability.
Description
Technical Field
The invention relates to the technical field of flexible pressure sensing, in particular to a large-area-array high-sensitivity flexible elastic pressure sensor and a preparation method thereof.
Background
The flexible pressure sensor is widely applied to the fields of intelligent manufacturing, intelligent medical treatment, educational service and the like. The rapid development of the related art has created an urgent need for sensing technology for high performance flexible pressure sensors. The high-precision flexible mechanical sensing technology represented by robot touch sensing, robot safety protection, wearable human health detection and automobile intelligent sensing is actively developed, has huge market prospect, and becomes an important mark for measuring the comprehensive strength and international competitiveness of a country. However, our country relies heavily on importation in terms of high-end flexible pressure sensing array devices, which is listed as one of the "neck-clamping" technologies that restrict our industrial development.
In the technical field of flexible pressure sensing, parameters such as sensitivity, large-area array, flexible elasticity modularization and the like of a sensor are taken as key indexes to form consensus. However, compared to mechanoreceptors distributed in large amounts on human skin, electronic skin has far less than the human tactile perception level in terms of high sensitivity, large area array tactile perception, and soft elastic modularity. The root point is: the high sensitivity of a cell device is often difficult to transfer to a large area array device, subject to materials and fabrication processes; the micro-integration of the array device on the flexible substrate is limited, and the indexes such as the array scale and the area are required to be improved.
Patent CN201910128787.2 discloses a flexible conductive composite film for a sensor, a preparation method thereof and a flexible sensor, wherein the preparation method is to coat graphene dispersion liquid and carbon nanotube dispersion liquid on an organic silica gel mold with a convex point array respectively to obtain conductive silica gel molds, and relatively press-fit two sides of the conductive silica gel molds with the convex point array, so that the coated graphene dispersion liquid and carbon nanotube dispersion liquid are positioned between the two organic silica gel molds, and the flexible conductive composite film is prepared. The sensor of the invention has high sensitivity and is easy to prepare, but has the defects of insufficient array area and insufficient stretchability and flexibility.
Disclosure of Invention
Aiming at the technical problems that the large area array, high sensitivity and flexibility of the flexible pressure sensor at the current stage are difficult to achieve, the invention provides a large area array high-sensitivity flexible pressure sensor and a preparation method thereof.
The technical scheme of the invention is as follows:
the utility model provides a big area array high sensitivity gentle elasticity pressure sensor, it includes two composite layers, and two composite layer structures are the same and counterpoint laminating, wherein:
the composite layer comprises a substrate, a transition layer, a spacing layer, an electrode layer and a force sensitive layer; the electrode layer is a metal electrode, preferably a silver electrode; the force sensitive layer comprises a conformal graphene film and a micro-nano multi-level coating; the conformal graphene film is formed by spraying graphene microchip slurry on a substrate and an electrode layer for the first time; the micro-nano multi-stage coating is formed by spraying low-conductivity composite slurry on the conformal graphene film for the second time; the transition layer and the spacer layer are arranged on the substrate, the electrode layer is arranged on the transition layer, and the force sensitive layer is arranged on the substrate and the electrode layer.
Further, the graphene microchip is conformally coated on the electrode layer and the substrate through the first spraying of the graphene microchip slurry to form a conformal graphene film, the conformal graphene film is coated with the second spraying of the low-conductivity composite slurry to induce the rheological forming of micro-nano conductive particles on the surface of the conformal graphene film, and a three-dimensional conductive network on the surface of the fiber and a self-compensating structure coupled with force and electricity are constructed. The self-compensating structure generates self-compensating deformation when being pressed, the multi-stage self-compensating structure can effectively lift the contact area and compressibility of the force-sensitive layer, and the device has the characteristic of wide range and high sensitivity, so that the micro-nano multi-stage self-compensating structure is constructed and further assembled into an upper micro-nano interlocking force-sensitive interface and a lower micro-nano interlocking force-sensitive interface, and the range and sensitivity of the sensor can be effectively lifted.
Further, the solid content of graphene microplates in the graphene microplate slurry is 0.1-12%wt, and the thickness of the conformal graphene film is 0.5-5 μm. The particle diameter of the graphene microchip is 1-20 mu m, and the number of layers of the graphene microchip is 1-10，The surface resistance of the conformal graphene film is 100k omega-200 k omega.
Further, the composite paste with low conductivity includes a carbon nanotube composite paste or a carbon black paste. The solid content of the carbon nano tube in the carbon nano tube composite slurry is 0.5-5%wt, the carbon nano tube composite slurry comprises carbon nano tube slurry, or carbon nano tube and carbon black composite slurry, or carbon nano tube, carbon black and graphene composite slurry, and the micro-nano multi-level coating thickness is 30-100 mu m，The surface resistance of the micro-nano multi-stage coating is 200kΩ -1mΩ. .
Further, the spraying process is one or a combination of air spraying, ultrasonic spraying and electrostatic spraying.
Furthermore, in order to improve the measuring range and the sensitivity of the sensor and avoid the short circuit of the upper electrode and the lower electrode under the action of pressure, the force-sensitive layer also comprises a high-resistance coating, and the high-resistance coating is formed by spraying high-resistance composite slurry on the micro-nano multi-stage coating for the third time. The high-resistance composite slurry comprises carbon nano tubes and/or carbon black, the thickness of the high-resistance coating is 1-5 mu M, and the surface resistance is 500kΩ -2MΩ; and the force-sensitive conductive coating formed by the first spraying, the second spraying and the third spraying is constructed into a resistance gradient force-sensitive layer.
Further, the substrate is made of a soft elastic material, preferably artificial leather fabric or natural leather or silicone rubber or polyurethane. The transition layer is a printed serpentine polyurethane transition layer. The electrode layer is a snake-shaped fractal structure stretchable array metal electrode, and the thickness of the electrode layer is 5-8 mu m, preferably a snake-shaped silver paste electrode layer. The serpentine configuration enables the sensor to have better stretchability in use.
The force-sensitive layer is an arrayed gradient force-sensitive layer, and the force-sensitive layer comprises force-sensitive units. In the area of the force sensitive unit, the area of the electrode is 2% -10%.
The spacer layer is an annular insulating spacer layer, and the annular shape and the size are consistent with those of a hollowed-out mask used in the first, second and third spraying processes, namely, the force sensitive unit area is exposed. The spacer layer is made of polyurethane, epoxy resin or silicone rubber, the thickness of the spacer layer is 10-20 mu m, and the spacer layer is higher than the electrode layer and lower than the Yu Limin layer.
Further, the graphene microchip composite slurry is dispersed by means of ultrasonic oscillation and the like before spraying, the cross-sectional area ratio of the ejector pin opening of the spray gun is regulated and controlled to be 0.2-0.5 when the graphene microchip composite slurry is sprayed, the spraying air pressure is regulated to be 0.45-0.6MPa, so that large fog cones and highly uniform atomized liquid drops are obtained, a conformal graphene film is obtained on the electrode layer, and aggregation of graphene microchip is avoided.
When the low-conductivity composite slurry and the high-resistance composite slurry are sprayed, the cross-sectional area ratio of the opening of the ejector pin of the spray gun is regulated and controlled to be less than or equal to 0.15, and the pressure of spraying air is regulated and controlled to be less than or equal to 0.5MPa, so that a convolution liquid drop is formed, and a micro-nano multi-stage stacking structure is formed on the surface of the conformal graphene.
Furthermore, the leather is artificial leather fabric or natural leather, and the leather substrate can enable the prepared sensor to have good flexibility and stretchability, and meanwhile, the sensor cannot cause damage such as infection to human skin wearing the sensor.
Furthermore, the electrodes on the silver paste electrode layer are arranged in parallel, so that the electrodes are not easy to break when in use, and the silver paste electrode layer has good stretchability.
Further, the force sensitive units on the sensor form an array, and the array can be periodically arranged or non-periodically arranged in any multi-unit mode, so that the force sensitive unit sensor has designability and tailorability. The array scale is m n, where m is 1,2,3 … 128, n is 1,2,3 … 128, and m n > 4.
The invention also provides a preparation method of the large-area array high-sensitivity flexible elastic pressure sensor, which comprises the following steps:
respectively processing the two leathers;
preparing transition layers on two pieces of leather, preferably preparing a serpentine polyurethane transition layer by a screen printing technology;
preparing an electrode layer on the transition layer, preferably preparing a serpentine metal array reading electrode layer on the serpentine polyurethane transition layer by screen printing;
preparing an annular insulating spacer layer on a substrate;
preparing graphene microchip slurry, low-conductivity composite slurry and high-resistance composite slurry;
spraying graphene microchip slurry on a substrate and an array reading electrode layer for the first time to obtain a conformal graphene film, then drying, processing a precise mask for large-area arrayed spraying by using a laser cutting machine before the first spraying, and then spraying the graphene microchip slurry in a mask alignment mode;
spraying low-conductivity composite slurry on the conformal graphene film for the second time to form a micro-nano multi-stage coating, then drying, processing a precise mask for large-area array spraying by using a laser cutting machine before the preferred second spraying, and then spraying the low-conductivity composite slurry on the mask in an alignment mode to obtain two micro-nano multi-stage force sensitive layers with the same structure;
and (3) aligning, laminating and packaging two micro-nano multi-level force sensitive layers with the same structure by a flexible film aligning and laminating technology, so as to prepare the interlocked large-area array sensor.
The nitrogen low-temperature plasma is used for treating two pieces of leather, so that the film forming uniformity of the water-based force-sensitive slurry and the silver slurry can be improved.
The snake-shaped structure can enable the sensor to keep good stretchability in the use process, meanwhile, compared with PVC foaming materials, polyurethane has better stability, chemical resistance, rebound resilience and mechanical property, has smaller compression deformability, and is suitable for being used as a material of a transition layer in the sensor.
Further, the proportion of graphene microplates and the ultrasonic spraying process are regulated and controlled, so that uniform conformal film formation of graphene on the fiber surface is realized; regulating the particle dispersibility of the slurry and the size of the liquid drops subjected to ultrasonic atomization, inducing the rheological formation of micro-nano conductive particles on the surface of the conformal graphene, and constructing a three-dimensional conductive network on the surface of the fiber and a self-compensating structure of force-electricity coupling. The three-dimensional conductive network and the self-compensating structure on the fiber surface can generate self-compensating deformation when being pressed, and the measuring range and the sensitivity of the sensor can be effectively improved.
The preparation method of the multi-stage structure is regulated and controlled, and the adhesive force of the force-sensitive film is improved; the area resistance range of the film is regulated and controlled, and the sensitivity and the measuring range of the interlocking device are improved.
The method comprises the steps of dispersing graphene microchip composite slurry by means of ultrasonic oscillation and the like before first spraying, regulating and controlling the cross-sectional area of an ejector pin opening of a spray gun to be 0.2-0.5 in the first spraying, regulating the spraying air pressure to be 0.45-0.6MPa, so as to obtain a large fog cone and highly uniform atomized liquid drops, and obtaining a conformal graphene film on an electrode layer to avoid agglomeration of graphene microchip. When the low-conductivity composite slurry and the high-resistance composite slurry are sprayed, the cross-sectional area ratio of the opening of the ejector pin of the spray gun is regulated and controlled to be less than or equal to 0.15, and the pressure of spraying air is regulated and controlled to be less than or equal to 0.5MPa, so that a convolution liquid drop is formed, and a micro-nano multi-stage stacking structure is formed on the surface of the conformal graphene.
Further, the spraying process is one or a combination of air spraying, ultrasonic spraying and electrostatic spraying.
Further, the high-resistance composite slurry is sprayed on the micro-nano multi-coating for the third time to form a high-resistance coating, then the high-resistance coating is dried, and a precise mask for large-area array spraying is processed by a laser cutting machine before the third spraying, and then the high-resistance composite slurry is sprayed on the mask in an aligned mode.
Furthermore, the hollowed mask alignment spraying technology is adopted in the first, second and third spraying processes. When the hollowed-out mask is prepared, the laser cutting machine or the stamping cutting machine is utilized to prepare the arrayed hollowed-out holes on the single-sided adhesive tape or the double-sided adhesive tape or the PET film with the silica gel adhesive, and the size and the interval of the hollowed-out holes are consistent with those of the designed force-sensitive units.
The pressure imaging system prepared by using the large-area-array flexible and elastic pressure sensor comprises a sensor, a row selector, a flexible adapter plate, a microprocessor, a wireless transmission module and a user interface, wherein the wireless transmission module is preferably a Bluetooth transmission module.
The interlocked piezoresistive sensor array adopts a row-column acquisition circuit, and the adjacent unit devices have the signal crosstalk problem, so that a zero potential scanning method is adopted, voltages are sequentially applied to each row through a row selector, and the voltages of the other rows are zero, thereby greatly reducing the row-column signal crosstalk and improving the data reading speed.
The flexible adapter plate is connected with the sensor and the microprocessor and is responsible for communication between the sensor and the microprocessor, control signals of the microprocessor are transmitted to the sensor, information acquired by the sensor is transmitted to the microprocessor, and the flexible adapter plate can ensure that the system keeps good flexibility when in use and cannot break.
The microprocessor controls the whole system and can perform A/D conversion and noise reduction on signals output by the sensor.
The microprocessor processes the signals transmitted by the sensor and transmits the signals to the user interface through the wireless transmission module, and the user interface can display the distribution imaging of the touch pressure in real time aiming at different application scenes.
The invention has the advantages that:
the flexible and elastic substrate such as the artificial leather fabric substrate, the natural leather substrate, the silicon rubber or the polyurethane can keep certain flexibility and stretchability when the sensor is used, and meanwhile, the damage such as infection and the like can not be caused in the process of contacting with human skin. The secondary or multiple spraying technology is beneficial to microminiaturization of array devices on the flexible and elastic substrate, can enlarge the area of a sensor array, and simultaneously constructs a self-compensating structure, and the self-compensating structure generates self-compensating deformation when being pressed, so that the measuring range and the sensitivity of the sensor can be effectively improved. The sensor prepared by the preparation process provided by the invention has the advantages of high sensitivity, tiny integration of array devices, convenience, large array area and good flexible stretch performance.
Drawings
FIG. 1 is a composite layer structure diagram of one embodiment of a large area array high sensitivity flexible pressure sensor of the present invention.
FIG. 2 is a graph showing the effect of a composite layer of one embodiment of a large area array high sensitivity flexible pressure sensor according to the present invention.
FIG. 3 is a flow chart of a process for preparing a large-area array high-sensitivity flexible pressure sensor.
Fig. 4 is a graph of array circuit signal crosstalk analysis.
Fig. 5 is a schematic diagram of a zero potential scan method of an array circuit.
FIG. 6 is a schematic diagram of a low noise array acquisition circuit for a large area array high sensitivity flexible pressure sensor and a pressure imaging system according to an embodiment.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
The examples are presented for better illustration of the invention, but the invention is not limited to the examples. Those skilled in the art will appreciate that various modifications and adaptations of the embodiments described above are possible in light of the above teachings and are intended to be within the scope of the invention.
Example 1
Referring to fig. 1, a composite layer structure diagram of a large area array high-sensitivity flexible elastic pressure sensor is shown. Specifically, the large area array high-sensitivity flexible elastic pressure sensor of the present embodiment includes a first force-sensitive composite layer and a second force-sensitive composite layer.
In this embodiment, the first force-sensitive composite layer and the second force-sensitive composite layer have the same structure and are aligned and attached, wherein the composite layer includes a substrate, a transition layer, a spacer layer, an electrode layer and a force-sensitive layer, and the electrode layer is a silver electrode.
The force sensitive layer comprises a conformal graphene film, a micro-nano multi-stage coating and a high-resistance coating. The conformal graphene film is formed by spraying graphene microchip slurry on the substrate and the electrode layer for the first time, and the micro-nano multi-stage coating is formed by spraying composite slurry with low conductivity on the conformal graphene film for the second time. The transition layer and the spacer layer are arranged on the substrate, the electrode layer is arranged on the transition layer, and the force sensitive layer is arranged on the substrate and the electrode layer.
Preferably, the solid content of graphene microplates in the graphene microplate slurry is 12% wt, and the thickness of the conformal graphene film is 5 μm. The particle size of the graphene microchip is 20 mu m, the number of layers of the graphene microchip is 10, and the surface resistance is 100k omega.
Preferably, the composite slurry with low conductivity is carbon nanotube slurry, the solid content of the carbon nanotubes in the carbon nanotube slurry is 5% wt, the thickness of the formed micro-nano multi-stage coating is 100 mu m, and the surface resistance is 500k omega.
Preferably, the high-resistance coating is formed by spraying the high-resistance composite slurry on the micro-nano multi-stage coating for the third time. The high-resistance composite slurry comprises carbon nanotubes, the thickness of the high-resistance coating is 5 mu M, and the surface resistance is 2MΩ.
Preferably, the substrate is made of artificial leather fabric, and the artificial leather fabric has low cost, good flexibility and stretchability, and can not cause damage such as infection to human skin in the use process of the sensor.
Preferably, the electrode layer and the transition layer are respectively a snake-shaped silver paste electrode and a snake-shaped polyurethane, the electrodes on the electrode layer are arranged in parallel, and the thickness of the electrode layer is 5 mu m. The serpentine structure can enable the tensile property of the sensor to be stronger, and meanwhile, compared with PVC foaming materials, polyurethane has better stability, chemical resistance, rebound resilience and mechanical property, has smaller compression deformability, and is very suitable for being used as the material of the sensor transition layer.
Preferably, the force sensitive layer is an arrayed gradient force sensitive layer, and the force sensitive layer comprises force sensitive units. In the area of the force sensitive unit, the area of the electrode is 2% -10%.
Preferably, the spacer layer is an annular insulating spacer layer, and the annular shape and size are consistent with the size of a hollowed-out mask used in the first, second and third spraying processes, namely, the force sensitive unit area is exposed. The spacer layer is made of polyurethane, epoxy resin or silicone rubber, the thickness of the spacer layer is 10-20 mu m, and the spacer layer is higher than the electrode layer and lower than the Yu Limin layer.
Preferably, the graphene microchip slurry is dispersed in an ultrasonic oscillation mode before the first spraying; the cross-sectional area ratio of the ejection needle opening of the ejection gun is regulated and controlled to be 0.5 when the ejection gun is sprayed for the first time, the air pressure of the ejection gun is regulated and controlled to be 0.6MPa, so that large fog cones and highly uniform atomized liquid drops are obtained, a conformal graphene film is obtained on an electrode layer, and agglomeration of graphene micro-plates is avoided. When the low-conductivity composite slurry and the high-resistance composite slurry are sprayed, the cross-sectional area ratio of the opening of the ejector pin of the spray gun is regulated to be 0.15, and the spraying air pressure is regulated to be 0.5MPa, so that a convolution liquid drop is formed, and a micro-nano multi-stage stacking structure is formed on the surface of the conformal graphene.
Preferably, the force sensing elements on the sensor form an array, the array being periodically arranged, the array being 128 x 128 in size.
The sensor in the embodiment has good flexibility and stretchability and high sensitivity, and is convenient for micro integration of array devices.
Example 2
In order to more clearly illustrate the structure and the preparation method of the large-area array high-sensitivity flexible elastic pressure sensor of the present invention, the following description is made in detail with reference to fig. 2 and 3. Referring to fig. 3, a process flow chart of preparing a large-area array high-sensitivity flexible sensor according to the invention specifically includes the steps of:
s11, respectively processing the two leathers. In the embodiment, the nitrogen low-temperature plasma is used for treating two pieces of artificial leather fabrics, so that the film forming uniformity of the water-based force-sensitive sizing agent and the silver paste can be improved.
S12, preparing a transition layer and an electrode layer on two pieces of leather through a screen printing technology. In the embodiment, the transition layer is made of snake-shaped polyurethane, the electrode layer is made of snake-shaped silver paste electrode, and the snake-shaped structure enables the sensor to have good stretchability in use.
S13, machining the precise mask for large-area array spraying by using a laser cutting machine. In this embodiment, the mask is a porous structure and each hole is above a serpentine electrode.
And S14, dispersing the graphene microchip slurry in an ultrasonic oscillation mode.
And S15, spraying graphene microchip slurry on the electrode layer through mask ultrasonic alignment spraying, so as to realize a uniform conformal graphene film on the fiber surface, regulating and controlling the cross-sectional area of an opening of a thimble of a spray gun to be 0.5 during spraying, and regulating the spraying air pressure to be 0.6MPa, thereby obtaining a large fog cone and highly uniform atomized liquid drops, and avoiding aggregation of graphene microchip.
S16, spraying carbon nano tube slurry on the conformal graphene film through mask ultrasonic alignment spraying, regulating the cross-sectional area ratio of the ejector pin opening of the spray gun to be 0.15 during spraying, regulating the spraying air pressure to be 0.5MPa so as to form a convolution liquid drop, and forming a micro-nano secondary stacking structure on the surface of the conformal graphene film, so that a first force-sensitive composite layer and a second force-sensitive composite layer with the same structure are obtained.
S17, based on a flexible film alignment lamination technology, aligning and laminating the first force-sensitive composite layer and the second force-sensitive composite layer, packaging and laminating the interlocked large-area array device are achieved, and reliable binding of the reading circuit electrode is achieved by adopting the flexible adapter plate.
FIG. 2 is an effect diagram of a large area array high sensitivity flexible elastic pressure sensor composite layer prepared according to the preparation method of the embodiment, wherein a plurality of force sensitive units are arranged on the composite layer, and the structures are connected through a snake-shaped electrode.
Example 3
In this embodiment, the large area array flexible elastic pressure sensor obtained by the preparation method of the present invention is matched with a pressure imaging system made of other modules, and in order to more clearly illustrate the working principle and the constitution of the system, the following details are described with reference to fig. 4, 5 and 6.
Fig. 4 is a signal crosstalk analysis chart of an array circuit, and as shown in the chart, adjacent unit devices have a signal crosstalk problem. FIG. 5 is a schematic diagram of a zero potential scanning method of an array circuit, wherein voltages are sequentially applied to each row through a row selector, and voltages of the other rows are zero, so that row-column signal crosstalk is greatly reduced, and the data reading speed is improved.
Fig. 6 is a schematic diagram of a low noise array acquisition circuit of a large area array high sensitivity flexible elastic pressure sensor and a pressure imaging system according to the present embodiment, where an interlocking piezoresistive sensor array is shown in the figure, and a row-column acquisition circuit is adopted, and signal crosstalk problem exists in adjacent unit devices, and the present embodiment adopts a zero potential scanning method shown in fig. 5, and voltage is applied to each row in sequence through a row selector, and voltages of the other rows are zero, so that row-column signal crosstalk is greatly reduced, and data reading speed is improved. As shown in fig. 6, the present embodiment further develops an array sensor signal acquisition and conditioning circuit module, which includes a flexible adapter board, a microprocessor, a wireless transmission module and a user interface.
The flexible adapter plate is in charge of communication between the sensor and the microprocessor, control signals of the microprocessor are transmitted to the sensor, information acquired by the sensor is transmitted to the microprocessor, and the flexible adapter plate can ensure that the system keeps good flexibility when in use and cannot break.
The microprocessor controls the whole system and can perform A/D conversion and noise reduction on signals output by the sensor.
The microprocessor processes the signals transmitted by the sensor and transmits the signals to the user interface through the wireless transmission module, and the user interface can display the distribution imaging of the touch pressure in real time aiming at different application scenes.
Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered by the scope of the claims of the present invention.
Claims (5)
1. The utility model provides a big area array high sensitivity gentle elasticity pressure sensor which characterized in that includes the composite layer:
the composite layer comprises a substrate, a transition layer, a spacing layer, an electrode layer and a force sensitive layer; the force sensitive layer comprises a conformal graphene film and a micro-nano multistage coating; the conformal graphene film is formed by spraying graphene microchip slurry on the substrate and the electrode layer for the first time; the micro-nano multi-stage coating is formed by spraying low-conductivity composite slurry on the conformal graphene film for the second time; the transition layer and the spacer layer are arranged on the substrate, the electrode layer is arranged on the transition layer, and the force sensitive layer is arranged on the substrate and the electrode layer;
the solid content of graphene microplates in the graphene microplate slurry is 0.1-12%wt, and the thickness of the conformal graphene film is 0.5-5 mu m; the particle size of the graphene microchip is 1-20 mu m, the number of layers of the graphene microchip is 1-10, and the surface resistance of the conformal graphene film is 100 omega-200 kΩ;
the low-conductivity composite slurry comprises carbon nano tube composite slurry or carbon black slurry, wherein the solid content of the carbon nano tubes in the carbon nano tube composite slurry is 0.5-5%wt; the carbon nano tube composite sizing agent comprises carbon nano tube sizing agent, or carbon nano tube and carbon black composite sizing agent, or carbon nano tube, carbon black and graphene composite sizing agent; the thickness of the micro-nano multi-stage coating structure is 30-100 mu M, and the surface resistance of the micro-nano multi-stage coating is 200k omega-1M omega;
the force-sensitive layer further comprises a high-resistance coating, wherein the high-resistance coating is formed by spraying high-resistance composite slurry on the micro-nano multi-stage coating for the third time, the high-resistance composite slurry comprises carbon nano tubes and/or carbon black, the thickness of the high-resistance coating is 1-5 mu M, and the surface resistance is 500k omega-2M omega;
the substrate is made of a soft elastic material; the spacer layer is an annular insulating spacer layer, the spacer layer is made of polyurethane, epoxy resin or silicone rubber, the thickness of the spacer layer is 10-20 mu m, and the spacer layer is higher than the electrode layer and lower than the force sensitive layer; the force-sensitive layer is an arrayed gradient force-sensitive layer, the force-sensitive layer comprises a force-sensitive unit, and the area of an electrode in the area of the force-sensitive unit is 2% -10%; the transition layer is serpentine polyurethane; the electrode layer is a snake-shaped fractal structure stretchable array metal electrode, and the thickness of the electrode layer is 5-8 mu m.
2. The large area array high sensitivity flexible pressure sensor of claim 1, wherein: the graphene microchip slurry is dispersed by utilizing an ultrasonic oscillation mode before spraying.
3. The large area array high sensitivity flexible pressure sensor of claim 1, wherein: regulating the cross-sectional area ratio of the ejector pin opening of the spray gun to be 0.2-0.5 when spraying the graphene microchip slurry, and regulating the spraying air pressure to be 0.45-0.6MPa; when the low-conductivity composite slurry and the high-resistance composite slurry are sprayed, the cross-sectional area ratio of the opening of the ejector pin of the spray gun is regulated and controlled to be less than or equal to 0.15, and the spraying air pressure is regulated to be less than or equal to 0.5MPa.
4. A method of manufacturing a large area array highly sensitive flexible pressure sensor as claimed in any one of claims 1 to 3, characterized in that the method comprises the steps of:
(1) Preparing a transition layer on the substrate;
(2) Preparing an array readout electrode layer on the transition layer;
(3) Preparing an annular insulating spacer layer on the substrate;
(4) Spraying graphene microchip slurry on the substrate and the array reading electrode layer for the first time to obtain a conformal graphene film, and then drying;
(5) Spraying low-conductivity composite slurry on the conformal graphene film for the second time to form a micro-nano multi-stage coating structure, and then drying to obtain an arrayed gradient force-sensitive composite layer;
(6) Flexibly packaging the arrayed gradient force-sensitive composite layer;
dispersing graphene microchip slurry before the first spraying; spraying high-resistance composite slurry on the micro-nano multi-stage coating structure for the third time to form a high-resistance coating, and then drying; the spraying process is respectively regulated and controlled during the first spraying, the second spraying and the third spraying; and performing the first, second and third spraying by using the hollowed-out mask alignment.
5. A pressure imaging system prepared using the sensor of any of claims 1-3, wherein the pressure imaging system comprises a sensor, a line selector, a flexible patch panel, a microprocessor, a wireless transmission module, and a user interface, wherein:
the row selector enables voltages to be sequentially applied to each row of the row-column acquisition circuit, and the rest voltages are zero; the flexible adapter plate is connected with the sensor and the microprocessor; the microprocessor controls the whole system, converts and reduces the signal output by the sensor; the wireless transmission module transmits signals between the microprocessor and the user interface; the user interface displays pressure distribution imaging in real time.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20120009678A (en) * | 2010-07-20 | 2012-02-02 | 한국표준과학연구원 | Elastic tactile sensor and method of fabricating thereof |
| KR20140074478A (en) * | 2012-12-10 | 2014-06-18 | 한국기계연구원 | Highly Sensitive Tactile Sensor using Interlocking of Conducting nano or micro pillars |
| CN104897316A (en) * | 2015-06-16 | 2015-09-09 | 青岛大学 | Capacitive ultrathin flexible stress sensor and producing method thereof |
| CN106441645A (en) * | 2016-09-29 | 2017-02-22 | 中国科学院重庆绿色智能技术研究院 | Graphene pressure sensor array system and preparation method thereof |
| CN109855782A (en) * | 2019-02-21 | 2019-06-07 | 电子科技大学 | Sensor compliant conductive composite membrane and preparation method thereof and flexible sensor |
| CN110095211A (en) * | 2019-05-24 | 2019-08-06 | 清华大学深圳研究生院 | A kind of stretchable tactile sensor array and preparation method thereof |
| CN110108394A (en) * | 2019-05-20 | 2019-08-09 | 中国科学院重庆绿色智能技术研究院 | Large area array separate type pressure sensor and preparation method thereof, waterborne conductive slurry and preparation method thereof |
| CN110333010A (en) * | 2019-04-10 | 2019-10-15 | 绍兴文理学院元培学院 | A kind of interdigitation large area flexible sensor array and preparation method thereof |
| CN111562038A (en) * | 2020-06-16 | 2020-08-21 | 厦门大学 | Flexible capacitive pressure sensor and flexible capacitive pressure array sensor |
| CN111739933A (en) * | 2020-06-23 | 2020-10-02 | 中国科学院上海微系统与信息技术研究所 | Floating flexible device and preparation method thereof |
| CN112097631A (en) * | 2020-08-24 | 2020-12-18 | 哈尔滨工业大学（深圳） | Composite conductive material, strain sensor and preparation method thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8187795B2 (en) * | 2008-12-09 | 2012-05-29 | The Board Of Trustees Of The University Of Illinois | Patterning methods for stretchable structures |
| FR3038710B1 (en) * | 2015-07-10 | 2021-05-28 | Cpc Tech | SENSOR WITH A PHYSICAL CHARACTERISTIC, PREFERABLY INCLUDING A MULTI-LAYER STRUCTURE |
-
2021
- 2021-08-18 CN CN202110957606.4A patent/CN113720503B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20120009678A (en) * | 2010-07-20 | 2012-02-02 | 한국표준과학연구원 | Elastic tactile sensor and method of fabricating thereof |
| KR20140074478A (en) * | 2012-12-10 | 2014-06-18 | 한국기계연구원 | Highly Sensitive Tactile Sensor using Interlocking of Conducting nano or micro pillars |
| CN104897316A (en) * | 2015-06-16 | 2015-09-09 | 青岛大学 | Capacitive ultrathin flexible stress sensor and producing method thereof |
| CN106441645A (en) * | 2016-09-29 | 2017-02-22 | 中国科学院重庆绿色智能技术研究院 | Graphene pressure sensor array system and preparation method thereof |
| CN109855782A (en) * | 2019-02-21 | 2019-06-07 | 电子科技大学 | Sensor compliant conductive composite membrane and preparation method thereof and flexible sensor |
| CN110333010A (en) * | 2019-04-10 | 2019-10-15 | 绍兴文理学院元培学院 | A kind of interdigitation large area flexible sensor array and preparation method thereof |
| CN110108394A (en) * | 2019-05-20 | 2019-08-09 | 中国科学院重庆绿色智能技术研究院 | Large area array separate type pressure sensor and preparation method thereof, waterborne conductive slurry and preparation method thereof |
| CN110095211A (en) * | 2019-05-24 | 2019-08-06 | 清华大学深圳研究生院 | A kind of stretchable tactile sensor array and preparation method thereof |
| CN111562038A (en) * | 2020-06-16 | 2020-08-21 | 厦门大学 | Flexible capacitive pressure sensor and flexible capacitive pressure array sensor |
| CN111739933A (en) * | 2020-06-23 | 2020-10-02 | 中国科学院上海微系统与信息技术研究所 | Floating flexible device and preparation method thereof |
| CN112097631A (en) * | 2020-08-24 | 2020-12-18 | 哈尔滨工业大学（深圳） | Composite conductive material, strain sensor and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| Jinyoung Myoung."Multi-Layered Flexible Pressure Sensors with Tunable Sensitivity and Linearity".《Department of Chemical Engineering Graduate School of UNIST，Master's Thesis》.2019,1-79. * |
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