WO2018039939A1

WO2018039939A1 - Capacitive pressure sensor and fabrication method thereof

Info

Publication number: WO2018039939A1
Application number: PCT/CN2016/097407
Authority: WO
Inventors: 张波; 张旻; 张臣雄
Original assignee: 华为技术有限公司
Priority date: 2016-08-30
Filing date: 2016-08-30
Publication date: 2018-03-08
Also published as: CN108291845A

Abstract

A capacitive pressure sensor, comprising: a first flexible substrate (101), a first graphene electrode plate (102), an insulation dielectric layer (103), a second graphene electrode plate (104) and a second flexible substrate (105), wherein the insulation dielectric layer (103) is for separating and holding the first graphene electrode plate (102) and the second graphene electrode plate (104) at predetermined intervals; and the first graphene electrode plate (102) and the second graphene electrode plate (104) respectively comprise at least one series of graphene electrodes, wherein the at least one series of graphene electrodes of the first graphene electrode plate (102) and the at least one series of graphene electrodes of the second graphene electrode plate (104) are cross-arranged, and also each capacitance among the multiple capacitances in the capacitive pressure sensor comprises a pair of oppositely facing graphene electrodes located at the intersection of the first graphene electrode plate (102) and the second graphene electrode plate (104). Also provided is a manufacturing method for the capacitive pressure sensor.

Description

Capacitive pressure sensor and preparation method thereof

Technical field

This invention relates to the field of electrical engineering and, more particularly, to capacitive pressure sensors and methods of making same.

Background technique

After entering the 21st century, the development of mobile terminals is very rapid, and the use of smart phones has spread all over the world. Because the smart phone has excellent operating system, free to install all kinds of software, full-screen full touch screen operation sense, it completely ended the previous keyboard phone. With the rapid development of modern electronic technology, the requirements for full touch screen operation are getting higher and higher. In addition to the requirements of fast, sensitive and accurate, users can feedback and interact, especially the pressure on the user's touch screen operation. Inductive feedback has new needs and challenges.

The current touch screen pressure sensing technology is mainly based on the traditional four-angle capacitive pressure sensor method, and the pressure sensing precision is low.

Summary of the invention

Embodiments of the present invention provide a capacitive pressure sensor and a method for fabricating the same, which can provide high pressure sensing accuracy.

In a first aspect, a capacitive pressure sensor is provided, the capacitive pressure sensor comprising:

a first flexible substrate (101), a first graphene electrode plate (102), an insulating dielectric layer (103), a second graphene electrode plate (104), and a second flexible substrate (105), wherein

The insulating dielectric layer (103) is used for isolating the first graphene electrode plate (102) and the second graphene electrode plate (104) and maintaining a predetermined interval;

The first graphene electrode plate (102) and the second graphene electrode plate (104) respectively include at least one diode-connected graphene electrode, and at least one diode-connected graphene electrode of the first graphene electrode plate (102) a graphene electrode serially connected to at least one of the second graphene electrode plates (104), and each of the plurality of capacitors of the capacitive pressure sensor includes the first graphene electrode plate (102) and the A pair of opposed facing graphene electrodes at intersections in the second graphene electrode plate (104).

In the embodiment of the present invention, the first graphene electrode plate and the second graphene electrode plate are arranged by arranging at least one of the graphene electrodes of the first graphene electrode plate and at least one of the graphene electrodes of the second graphene electrode plate. Each pair of graphene electrodes for forming a capacitance is located at an intersection position, so that the capacitive pressure sensor can be quickly positioned to the conductive electrodes of the first graphene electrode plate and the second graphene electrode plate according to the position of the touch, thereby improving use The pressure sensing accuracy of the touch screen of the capacitive pressure sensor of the embodiment of the invention.

With reference to the first aspect, in a first possible implementation, the specific implementation is: the insulating dielectric layer (103) is hollowed out in a designated area, and the designated area includes any pair of facing facing graphene electrodes in the insulating dielectric layer. The area faced in (103).

In the present embodiment, the pressure sensing accuracy of the touch panel using the capacitive pressure sensor of the embodiment of the present invention can be further improved by hollowing out the facing region of the graphene electrode facing each other in the insulating dielectric layer.

In combination with the first aspect and the foregoing implementation manner, in a second possible implementation manner of the first aspect, the first graphene electrode plate (102) is located in the first flexible substrate (101). One side of the insulating dielectric layer (103), the second graphene electrode plate (104) is located on a side of the second flexible substrate (105) facing the insulating dielectric layer (103); or, the first graphene electrode a plate (102) is located on a side of the first flexible substrate (101) facing away from the insulating dielectric layer (103), and the second graphene electrode plate (104) is located in the second flexible substrate (105) One side of the insulating dielectric layer (103).

In combination with the first aspect and the foregoing implementation manner, in a third possible implementation manner of the first aspect, the first graphene electrode plate (102) includes an M-channel series of graphene electrodes, each of which includes N graphene electrodes; the second graphene electrode plate (104) comprises N parallel-connected graphene electrodes, each of which comprises M graphene electrodes; wherein M and N are positive integers, and at least one of M and N Greater than 1.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation of the first aspect, the specific implementation is: M and N are equal.

In combination with the first aspect and the foregoing implementation manner, in a fifth possible implementation manner of the first aspect, any one of the first graphene electrode plates (102) connected in series with the graphene electrode and the second graphene electrode plate The angle at which any of the tandem graphene electrodes intersect in (104) includes any value between 0 and 180 degrees.

With reference to the first aspect and the foregoing implementation manner, in a sixth possible implementation manner of the first aspect, the first flexible substrate (101) and/or the second flexible substrate (105) are Transparent flexible substrate.

With reference to the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the transparent flexible substrate comprises: a polyethylene terephthalate PET film, and a poly An imide PI film or a polystyrene PS film.

In combination with the first aspect and the foregoing implementation manner, in an eighth possible implementation manner of the first aspect, each of the first graphene electrode plate (102) and the second graphene electrode plate (104) are connected in series Adjacent graphene electrodes in the graphene electrode are connected by graphene leads.

In an implementation manner, the adjacent graphene electrodes are connected in series by a graphene lead, which can be formed at one time when preparing the graphene electrode plate, which is advantageous for the rapid realization of the preparation process.

In conjunction with the eighth possible implementation of the first aspect, in a ninth possible implementation manner of the first aspect, the first graphene electrode plate (102) and the second graphene electrode plate ( Each of the graphene electrodes connected in series in 104) is electrically connected by a conductive electrode including a graphene electrode, a metal electrode or an indium tin oxide ITO electrode.

With reference to the first aspect and the foregoing implementation manner, in the tenth possible implementation manner of the first aspect, the specific implementation is that the thickness of the capacitive pressure sensor is less than or equal to 0.2 mm.

In combination with the first aspect and the foregoing implementation manner, in an eleventh possible implementation manner of the first aspect, the first graphene electrode plate (102) and the second graphene electrode plate (104) are specifically implemented. The size of each of the graphene electrodes is between 1 mm x 1 mm and 5 mm x 5 mm.

In a second aspect, a method for preparing a capacitive pressure sensor is provided, the method comprising: transferring a first graphene film to a first flexible substrate, etching at least one series of graphene electrodes and connecting the graphite in series One end of the olefin electrode is formed with a conductive electrode to form a first electrode plate; the second graphene film is transferred to the second flexible substrate, at least one series of graphene electrodes are etched and fabricated at one end of each series of graphene electrodes a conductive electrode is formed to form a second electrode plate, wherein the second electrode plate and the first electrode plate are aligned in a predetermined arrangement, at least one of the first electrode plates is connected in series with the graphene electrode and the second electrode plate At least one series of graphene electrodes are arranged in a cross arrangement, and each pair of facing facing graphene electrodes is located at an intersection of the first electrode plate and the second electrode plate; preparing an insulating dielectric layer; the first electrode plate, The insulating dielectric layer and the second electrode plate are bonded to form a capacitive pressure sensor, wherein the first electrode plate and the second electrode plate are in accordance with the predetermined Arranged in columns aligned.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the preparing the dielectric layer is specifically: preparing the third substrate according to the position of the graphene electrode of the first electrode plate or the second electrode plate a grid-like photoresist trench having a grid size substantially equal to a graphene electrode size; a dielectric layer is spin-coated on the grid-like photoresist trench and cured Demolding, an insulating dielectric layer that replicates the lattice structure of the grid-like photoresist trench is obtained.

In conjunction with the first possible implementation of the second aspect, in a second possible implementation of the second aspect, the first electrode plate, the dielectric dielectric layer, and the second electrode plate are bonded to form a capacitive The pressure sensor is specifically implemented by: activating the insulating dielectric layer, and aligning and bonding each grid of the first surface of the insulating dielectric layer with a corresponding graphene electrode in the first electrode plate, Each grid of the second side of the insulating dielectric layer is aligned and bonded to a corresponding graphene electrode in the second electrode plate to form a capacitive pressure sensor.

In conjunction with the second possible implementation of the second aspect, in a third possible implementation of the second aspect, each of the first side of the insulating dielectric layer and each of the first electrode plates Aligning and bonding the graphene electrodes, aligning and bonding each grid of the second side of the insulating dielectric layer with each graphene electrode in the second electrode plate is realized as:

Directing a first side of the insulating dielectric layer toward a side of the first electrode plate where the graphene electrode is located, and each grid of the first side of the insulating dielectric layer and the corresponding graphene in the first electrode plate The electrodes are aligned and bonded;

The second surface of the insulating dielectric layer faces the side of the second electrode plate where the graphene electrode is located, and each grid of the second surface of the insulating dielectric layer and the corresponding graphene in the second electrode plate The electrodes are aligned and bonded.

In conjunction with the second possible implementation of the second aspect, in a fourth possible implementation of the second aspect, each of the first side of the insulating dielectric layer and each of the first electrode plates Aligning and bonding the graphene electrodes, aligning and bonding each grid of the second side of the insulating dielectric layer with each graphene electrode in the second electrode plate is realized as:

Directing a first side of the insulating dielectric layer toward a side of the first electrode plate where the graphene electrode is absent, and each grid of the first side of the insulating dielectric layer and the corresponding graphite in the first electrode plate The olefin electrode is aligned and bonded;

The second surface of the insulating dielectric layer faces a side of the second electrode plate where the graphene electrode is absent, and each mesh of the second surface of the insulating dielectric layer and the corresponding graphite in the second electrode plate The olefin electrodes are aligned and bonded.

Based on the above solution, the capacitive pressure sensor of the embodiment of the present invention and the preparation method thereof are obtained by cross-arranging at least one graphene electrode of the first graphene electrode plate and at least one graphene electrode of the second graphene electrode plate to make the first Each pair of graphene electrodes for forming a capacitance in a graphene electrode plate and a second graphene electrode plate is located at an intersection position, so that the capacitive pressure sensor can be quickly positioned to the first graphene electrode plate according to the position of the touch The conductive electrode of the two graphene electrode plates can improve the pressure sensing accuracy of the touch panel using the capacitive pressure sensor of the embodiment of the present invention.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative work.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional structural view showing a capacitive pressure sensor according to an embodiment of the present invention.

2 is a three-dimensional perspective view of a capacitive pressure sensor and a graphene electrode according to an embodiment of the present invention.

Figure 3 is a schematic illustration of two graphene electrode plates constituting a capacitor in accordance with one embodiment of the present invention.

4 is a schematic view of two graphene electrode plates constituting a capacitor according to another embodiment of the present invention.

Fig. 5 is a flow chart showing a method of preparing a capacitive pressure sensor according to an embodiment of the present invention.

6 is a schematic view showing a method of preparing a capacitive pressure sensor according to an embodiment of the present invention.

Figure 7 is a schematic illustration of an insulating dielectric layer of a grid structure in accordance with one embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In the prior art, the touch screen pressure sensing technology is mainly based on the traditional four-corner capacitive pressure sensor method, and the pressure sensing precision is low.

Graphene is composed of a single layer of carbon atoms and has many characteristics not found in three-dimensional materials. For example, its carrier mobility, thermal conductivity and Young's modulus are very large, and it is also flexible and transparent. The embodiment of the invention utilizes the flexible and transparent conductive properties of graphene, and according to this characteristic, a corresponding special structural design is carried out.

1 is a schematic cross-sectional view of a capacitive pressure sensor 100 in accordance with one embodiment of the present invention. As shown in FIG. 1, the capacitive pressure sensor 100 can include:

It should be understood that a pair of facing graphene electrodes at the intersection positions of the first graphene electrode plate (102) and the second graphene electrode plate (104) are located on the first graphene electrode plate ( 102) A pair of graphene electrodes at the intersection of the graphene electrode in series and the graphene electrode in series in the second graphene electrode plate (104).

For ease of understanding, it may be assumed that the first graphene electrode plate (102) and the second graphene electrode plate (104) are overlapped together, at this time, the first graphene electrode plate (102) and the second graphene electrode plate (104). Any one of the pair of facing facing graphene electrodes is located in the first graphene electrode plate (102) in a first series of graphene electrodes and a second graphene electrode plate (104) in a second series of graphene electrodes An intersecting position, each pair of facing graphene electrodes comprising a first graphene electrode of the first series connected graphene electrode and a second graphene electrode of the second tandem graphene electrode at the intersecting position electrode.

It should be understood that, in the embodiment of the present invention, each capacitance of the capacitive pressure sensor includes a pair of facing graphene electrodes of the first graphene electrode plate (102) and the second graphene electrode plate (104).

Of course, it should be understood that there may be unpaired graphene electrodes in the first graphene electrode plate (102) and the second graphene electrode plate (104), and these unpaired graphene electrodes are not used to constitute the The capacitance of the capacitive pressure sensor, or the effect of these unpaired graphene electrodes on the capacitance of the capacitive pressure sensor, is much less than the formation of a paired graphene electrode, negligible.

Optionally, as an embodiment, the insulating dielectric layer (103) is hollowed out in a designated region including a region of any pair of facing facing graphene electrodes facing in the insulating dielectric layer (103).

2 is a three-dimensional perspective view of a capacitive pressure sensor and a graphene electrode according to an embodiment of the present invention. In Fig. 2, the left side shows a capacitive pressure sensor, and one small unit of the capacitive pressure sensor is represented by a three-dimensional perspective view on the right side, wherein 201 denotes a graphene electrode, 202 denotes a flexible substrate, and 203 denotes an insulating dielectric layer. As shown in FIG. 2, the regions of the upper and lower electrode plates 201 facing each other in the insulating dielectric layer 203 are hollowed out.

In the embodiment of the present invention, the pressure sensing accuracy of the touch panel using the capacitive pressure sensor of the embodiment of the present invention can be further improved by hollowing out the facing region of the graphene electrode facing each other in the insulating dielectric layer.

Optionally, as an embodiment, the first graphene electrode plate (102) is located on a side of the first flexible substrate (101) facing away from the insulating dielectric layer (103), and the second graphene electrode plate (104) is located. A side of the second flexible substrate (105) facing away from the insulating dielectric layer (103).

In the embodiment of the present invention, by preparing the graphene electrode plate on one side of the flexible substrate facing away from the insulating dielectric layer, the user can touch the graphene electrode more closely, thereby improving the use of the capacitive pressure sensor of the embodiment of the present invention. The response speed of the touch screen.

Optionally, as an embodiment, the first graphene electrode plate (102) is located on one side of the first flexible substrate (101) facing the insulating dielectric layer (103), and the second graphene electrode plate (104) is located at the first One side of the second flexible substrate (105) facing the insulating dielectric layer (103).

In the embodiment of the present invention, the graphene electrode plate is prepared on one side of the flexible substrate facing the insulating medium layer, so that the user does not directly touch the graphene electrode, thereby slowing the wear rate of the graphene electrode and improving the capacitive pressure sensor. The service life.

Optionally, the first flexible substrate (101) and/or the second flexible substrate (105) are transparent flexible substrates. When the graphene electrode plate is prepared on one side of the flexible substrate facing the insulating medium layer, the position of the graphene electrode can be clearly seen by using the transparent flexible substrate, which is advantageous for further improving the use of the capacitive pressure sensor of the embodiment of the present invention. The pressure sensing accuracy of the touch screen.

Optionally, the first graphene electrode plate (102) comprises M-channel series of graphene electrodes, each of which comprises N graphene electrodes; and the second graphene electrode plate (104) comprises N-way series of graphene electrodes, each The road includes M graphene electrodes; wherein M and N are positive integers, and at least one of M and N is greater than 1.

Figure 3 is a schematic illustration of two graphene electrode plates constituting a capacitor in accordance with one embodiment of the present invention. In Fig. 3, 310 and 320 denote graphene electrode plates, 311 denotes a conductive electrode, and 312 denotes a graphene electrode. As shown in FIG. 3, the graphene electrode plate 310 includes three parallel-connected graphene electrodes each including four graphene electrodes; the graphene electrode plate 320 includes four parallel-connected graphene electrodes each including three graphenes. electrode. Wherein, when the graphene electrode plate 310 and the graphene electrode plate 320 overlap according to the current position, the graphene electrodes in the two graphene electrode plates are in one-to-one correspondence, and the corresponding graphene electrodes are located in the all-way of the graphene electrode plate 310. The position where the tandem graphene electrode intersects the one-way graphene electrode of the graphene electrode plate 320.

Further, M and N are equal.

4 is a schematic view of two graphene electrode plates constituting a capacitor according to another embodiment of the present invention. In Fig. 4, 410 and 420 denote graphene electrode plates, 411 denotes a conductive electrode, and 412 denotes a graphene electrode. As shown in FIG. 4, the graphene electrode plate 410 includes four diode-connected graphene electrodes each including four graphene electrodes; the graphene electrode plate 420 includes four parallel-connected graphene electrodes, each of which includes four graphenes. electrode.

Optionally, an angle at which any one of the first graphene electrode plates (102) intersects with the graphene electrode of any one of the second graphene electrode plates (104) is between 0 degrees and 180 degrees. Any value.

Optionally, the transparent flexible substrate comprises a polyethylene terephthalate PET film, a polyimide PI film or a polystyrene PS film or the like.

Optionally, adjacent graphene electrodes of each of the graphene electrodes connected in series in the first graphene electrode plate (102) and the second graphene electrode plate (104) are connected by graphene leads.

In the embodiment of the present invention, the adjacent graphene electrodes are connected in series through the graphene lead, which can be formed once in the preparation of the graphene electrode plate, which is advantageous for the rapid realization of the preparation process.

Optionally, each of the first graphene electrode plate (102) and the second graphene electrode plate (104) are connected in series by a conductive electrode including a graphene electrode, a metal electrode or an oxidation. Indium tin oxide (ITO) electrode. Specifically, as shown in FIG. 3, each of the serially connected graphene electrodes is electrically connected by the conductive electrode 311; as shown in FIG. 4, each of the serially connected graphene electrodes is electrically connected by the conductive electrode 411.

Optionally, the capacitive pressure sensor has a thickness less than or equal to 0.2 mm. In the embodiment of the present invention, the thickness of the capacitive pressure sensor is less than or equal to 0.2 mm, which is only a preferred solution. Of course, the case where the thickness of the capacitive pressure sensor is greater than 0.2 mm is not excluded.

Optionally, each of the first graphene electrode plate (102) and the second graphene electrode plate (104) has a size between 1 mm x 1 mm and 5 mm x 5 mm. The size of the graphene electrode between 1 mm x 1 mm and 5 mm x 5 mm is only a preferred solution, and the case where the graphene electrode is less than 1 mm x 1 mm or larger than 5 mm x 5 mm is not excluded.

The embodiment of the invention further provides a method for preparing the capacitive pressure sensor 100 of the embodiment shown in FIG. 5 is a flow chart of a method of fabricating a capacitive pressure sensor 100 in accordance with one embodiment of the present invention. The method of Figure 5 includes:

510. Prepare a first electrode plate.

Specifically, the first graphene film may be transferred to the first flexible substrate, at least one series of graphene electrodes are etched, and a conductive electrode is formed at one end of each of the series connected graphene electrodes to form a first electrode plate.

In order to facilitate understanding of the preparation scheme of the embodiment of the present invention, it will be described with reference to FIG. 6. 6 is a schematic view showing a method of preparing a capacitive pressure sensor according to an embodiment of the present invention.

It should be understood that graphene growth can be performed by any method known in the art, such as chemical vapor deposition (CVD) to produce a graphene film or the like. Preferably, the graphene film has a self-transmittance of greater than 80%.

The flexible transparent substrate can be any polymeric material having a light transmission greater than 80%, such as PET, polymethyl methacrylate (PMMA) material, while the transparent substrate material has a thickness of no greater than 50 microns (μm). The transfer method may adopt a transfer method such as a wet method or a dry method, which is not limited in the embodiment of the present invention.

It is first necessary to transfer graphene to a flexible substrate. Preferably, the flexible substrate may be a transparent flexible substrate such as a polyethylene terephthalate (PET) film, a polyimide (PI) film or a polystyrene (PS) film. Wait.

Take PET film as an example. As shown in step 1 "graphene transfer" in Fig. 6, in a nickel substrate on which graphene is grown, a polymethyl Methacrylate (PMMA) film or a polydimethylsiloxane is sequentially used. Polydimethylsiloxane (PDMS) film was sprayed on the side where graphene was grown, then the graphene was removed from the nickel substrate, and the PET film was sprayed, and then the PMMA film and the PDMS film were removed to transfer the graphene to the PET film. The specific implementation of the transfer of the graphene to the flexible substrate can be referred to the prior art, and the embodiments of the present invention are not described herein.

After the graphene transfer is completed, at least one series of graphene electrodes can be etched on the graphene film and a conductive electrode can be fabricated at one end of each series of graphene electrodes.

Specifically, it can be shown as step 2 "graphene electrode and metal electrode preparation" in FIG.

The photoresist is spin-coated on the graphene film transferred to the transparent flexible substrate, and then the electrode shape is formed on the graphene film by photolithography and oxygen plasma etching, and the electrode size is 1 mm×1 mm to 5 mm×5 mm, and then A second photolithography is performed on the obtained graphene electrode, and a gold or silver electrode is formed on the edge of the graphene electrode by photolithography and evaporation to sequentially extract the signal of the graphene electrode.

520, preparing a second electrode plate.

Specifically, the second graphene film may be transferred to the second flexible substrate, at least one series of graphene electrodes are etched, and a conductive electrode is formed at one end of each of the serially connected graphene electrodes to form a second electrode plate.

The preparation process of the second electrode plate can refer to the preparation process of step 510, except that the pattern of the etched graphene electrode may be different.

Wherein, when the second electrode plate and the first electrode plate are aligned and arranged in a predetermined arrangement, at least one of the graphene electrodes connected in series with the first electrode plate and at least one of the graphene electrodes connected in series with the second electrode plate are arranged in a cross arrangement And each pair of facing facing graphene electrodes is located at an intersection position in the first electrode plate and the second electrode plate.

Specifically, if the second electrode plate and the first electrode plate overlap at a predetermined angle, any one of the first electrode plate and the second electrode plate facing the facing graphene electrode is located in the first electrode plate and is connected in a first series. a graphene electrode and a second electrode plate in the second electrode plate intersecting the second series of graphene electrodes, each pair of facing graphene electrodes including the first series of graphene electrodes at the intersection of the first graphene electrode And a second graphene electrode at the intersection of the second series of graphene electrodes. At this time, the intersection position is the aforementioned intersection position.

In particular, when the graphene electrodes of the first electrode plate and the second electrode plate both comprise an M-way series connection The graphene electrode, and each of the serially connected graphene electrodes including M graphene electrodes, the first electrode plate may be the same as the second electrode plate.

530. Prepare an insulating dielectric layer.

Specifically, the insulating dielectric layer can be prepared by a thick glue process on the silicon wafer, baked for a period of time, and then solidified and then demolded to obtain an insulating dielectric layer.

Further, a grid-like photoresist trench may be prepared on the third substrate according to the position of the graphene electrode of the first electrode plate or the second electrode plate, and the mesh size in the groove of the grid-shaped photoresist is A graphene electrode is approximately equal in size; an insulating dielectric layer is spin-coated on the grid-like photoresist trench and cured to obtain a dielectric layer that replicates the lattice structure of the grid-like photoresist trench.

Step 3 of Figure 6 shows a method of preparing a PDMS cavity. The PDMS cavity is an insulating dielectric layer of an embodiment of the invention.

Specifically, for example, a grid-like photoresist trench having a depth of 10-100 micrometers and a width of 50-200 micrometers can be prepared on a silicon wafer by a thick glue process, the mesh size is equivalent to the above-described graphene electrode size, and then in the light. The 10 mm thick dimethylsiloxane PDMS was spin-coated on the engraved groove structure, and baked at 80 ° C for 2 hours to form a PDMS film having a lattice structure reproduced as shown in FIG. 7 .

540. Align the insulating dielectric layer, the first electrode plate and the second electrode plate, and bond and package.

Specifically, the first electrode plate, the insulating dielectric layer and the second electrode plate may be bonded and packaged into a capacitive pressure sensor, wherein the first electrode plate and the second electrode plate are aligned and aligned according to the predetermined arrangement.

Step 4 of Figure 6 shows the bonding and packaging method.

In a specific bonding and encapsulation method, an insulating dielectric layer such as a PDMS film may be activated in an oxygen plasma etching machine for 60 s, and then aligned with the first electrode plate prepared in step 510 on the alignment stage. Then, the first electrode plate with the PDMS film is activated and treated in an oxygen plasma etching machine for 60 s, and then aligned and bonded to the first electrode plate prepared in step 520 on the alignment stage, and then packaged into a capacitor type. Pressure Sensor.

Of course, it should be understood that there may be differences in the methods of bonding and encapsulation methods, depending on the preparation equipment. For example, in the case of the preparation device support, an insulating dielectric layer such as a PDMS film may be simultaneously bonded to the first electrode plate and the second electrode plate at the same time, packaged into a capacitive pressure sensor, and the like.

It should be understood that, in various embodiments of the present invention, the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be The implementation process of the embodiments of the present invention constitutes any limitation.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. The medium to store the program code.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A capacitive pressure sensor, comprising:

a first flexible substrate (101), a first graphene electrode plate (102), an insulating dielectric layer (103), a second graphene electrode plate (104), and a second flexible substrate (105), wherein

The insulating dielectric layer (103) is for isolating the first graphene electrode plate (102) and the second graphene electrode plate (104) and maintaining a predetermined interval;

The first graphene electrode plate (102) and the second graphene electrode plate (104) respectively include at least one diode-connected graphene electrode, and at least one of the first graphene electrode plates (102) is connected in series At least one of the graphene electrodes in series with the graphene electrode and the second graphene electrode plate (104) are arranged in a cross arrangement, and each of the plurality of capacitors of the capacitive pressure sensor includes the first graphene electrode A pair of opposing facing graphene electrodes at the intersections in the plate (102) and the second graphene electrode plate (104).
The capacitive pressure sensor of claim 1 wherein:

The insulating dielectric layer (103) is hollowed out at a designated area including a region of any pair of facing facing graphene electrodes facing in the insulating dielectric layer (103).
The capacitive pressure sensor according to claim 1 or 2, wherein

The first graphene electrode plate (102) is located on one side of the first flexible substrate (101) facing the insulating dielectric layer (103), and the second graphene electrode plate (104) is located at the first a side of the second flexible substrate (105) facing the insulating dielectric layer (103); or

The first graphene electrode plate (102) is located on a side of the first flexible substrate (101) facing away from the insulating dielectric layer (103), and the second graphene electrode plate (104) is located at the side A side of the second flexible substrate (105) facing away from the insulating dielectric layer (103).
The capacitive pressure sensor according to any one of claims 1 to 3, wherein

The first graphene electrode plate (102) includes an M-channel series of graphene electrodes, each of which includes N graphene electrodes;

The second graphene electrode plate (104) includes N channels of graphene electrodes, each of which includes M graphene electrodes;

Where M and N are positive integers, and at least one of M and N is greater than 1.
A capacitive pressure sensor according to any one of claims 1 to 3, wherein M and N are equal.
The capacitive pressure sensor according to any one of claims 1 to 5, wherein

An angle at which any one of the first graphene electrode plates (102) is connected in series with the graphene electrode of any one of the second graphene electrode plates (104) is between 0 degrees and 180 degrees. Any value.
The capacitive pressure sensor according to any one of claims 1 to 6, wherein

The first flexible substrate (101) and/or the second flexible substrate (105) are transparent flexible substrates.
A capacitive pressure sensor according to claim 7, wherein said transparent flexible substrate comprises a polyethylene terephthalate PET film, a polyimide PI film or a polystyrene PS film.
The capacitive pressure sensor according to any one of claims 1 to 8, wherein

Adjacent graphene electrodes of each of the graphene electrodes connected in series in the first graphene electrode plate (102) and the second graphene electrode plate (104) are connected by a graphene wire.
The capacitive pressure sensor of claim 9 wherein:

The graphene electrode connected in series in each of the first graphene electrode plate (102) and the second graphene electrode plate (104) is electrically connected by a conductive electrode including a graphene electrode, a metal electrode or Indium tin oxide ITO electrode.
The capacitive pressure sensor according to any one of claims 1 to 10, wherein the capacitive pressure sensor has a thickness of less than or equal to 0.2 mm.
The capacitive pressure sensor according to any one of claims 1 to 11, wherein each of the first graphene electrode plate (102) and the second graphene electrode plate (104) has a graphene electrode The size ranges from 1 mm x 1 mm to 5 mm x 5 mm.
A method for preparing a capacitive pressure sensor, comprising:

Transferring the first graphene film to the first flexible substrate, etching at least one series of graphene electrodes, and forming a conductive electrode at one end of each of the series connected graphene electrodes to form a first electrode plate;

Transferring the second graphene film to the second flexible substrate, etching at least one series of graphene electrodes, and forming a conductive electrode at one end of each of the series connected graphene electrodes to form a second electrode plate, wherein the first electrode plate When the two electrode plates are aligned with the first electrode plate in a predetermined arrangement, at least one of the graphene electrodes connected in series with the first electrode plate and at least one diode-connected graphene electrode of the second electrode plate are arranged in a cross arrangement. And each pair of facing facing graphene electrodes is located at an intersection of the first electrode plate and the second electrode plate;

Preparing an insulating dielectric layer;

Bonding the first electrode plate, the insulating dielectric layer and the second electrode plate to form a capacitive pressure sensor, wherein the first electrode plate and the second electrode plate are arranged according to the predetermined arrangement Alignment.
The method of claim 13 wherein said preparing an insulating dielectric layer comprises:

Forming a grid-like photoresist trench on the third substrate according to a position of the graphene electrode of the first electrode plate or the second electrode plate, and a mesh size in the groove of the grid-like photoresist A graphene electrode is approximately equal in size;

An insulating dielectric layer is spin-coated on the grid-like photoresist trench and cured to obtain a dielectric layer that replicates the mesh structure of the grid-like photoresist trench.
The method according to claim 14, wherein the bonding the first electrode plate, the insulating dielectric layer and the second electrode plate to form a capacitive pressure sensor comprises:

Performing an activation treatment on the insulating dielectric layer, and aligning and bonding each grid of the first side of the insulating dielectric layer with a corresponding graphene electrode in the first electrode plate to insulate the insulating layer Each grid of the second side of the dielectric layer is aligned and bonded to a corresponding graphene electrode in the second electrode plate to form a capacitive pressure sensor.
The method of claim 15 wherein:

Aligning and bonding each grid of the first side of the insulating dielectric layer with each of the graphene electrodes of the first electrode plate, each of the second sides of the insulating dielectric layer Aligning and bonding the grid with each of the graphene electrodes in the second electrode plate comprises:

Directing a first side of the insulating dielectric layer toward a side where the graphene electrode is located in the first electrode plate, and each mesh of the first side of the insulating dielectric layer and the first electrode plate Corresponding graphene electrodes are aligned and bonded;

Orienting a second side of the insulating dielectric layer toward a side where the graphene electrode is located in the second electrode plate, and each mesh of the second side of the insulating dielectric layer and the second electrode plate The corresponding graphene electrodes are aligned and bonded.
The method of claim 15 wherein:

Aligning and bonding each grid of the first side of the insulating dielectric layer with each of the graphene electrodes of the first electrode plate, each of the second sides of the insulating dielectric layer Aligning and bonding the grid with each of the graphene electrodes in the second electrode plate comprises:

Directing a first side of the insulating dielectric layer toward a side where the graphene electrode is absent in the first electrode plate, and each mesh of the first side of the insulating dielectric layer and the first electrode plate Corresponding graphene electrodes are aligned and bonded;

Orienting a second side of the insulating dielectric layer toward a side where the graphene electrode is absent in the second electrode plate, and each mesh of the second side of the insulating dielectric layer and the second electrode plate The corresponding graphene electrodes are aligned and bonded.