Graphene composite sensor integrating pressure and acceleration

Abstract

The invention discloses a pressure and acceleration integrated graphene composite sensor, which relates to the technical field of sensors, and comprises at least one composite unit, and the composite unit comprises a pressure sensor and an acceleration sensor; the pressure sensor comprises a pressure support frame, a central cross beam and a plurality of first graphene piezoresistors; the first graphene piezoresistors are respectively arranged at the joints of the tail ends of the central cross beams and the pressure support frame; the acceleration sensor comprises an acceleration supporting frame, a central island, a plurality of connecting beams, a plurality of second graphene piezoresistors and a plurality of mass blocks; a plurality of side holes are formed in the central island, and sensitive blocks are fixedly arranged in the middles of the side holes; the second graphene piezoresistor is fixedly arranged on the sensitive block; and each first graphene piezoresistor and each second graphene piezoresistor are respectively connected with two composite electrodes. Pressure and acceleration can be measured at the same time, and the measurement accuracy can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a graphene composite sensor integrating pressure and acceleration. Background Art

[0002] In modern artillery system testing, projectile firing subjects the barrel to extreme conditions of high temperature, high pressure, and high velocity. Especially during the high-pressure acceleration phase within the barrel and the muzzle exit, the significant acceleration can cause variations in the sensor's frequency response. These variations can induce zero-point shift, leading to inconsistencies between the integral of the acceleration curve and the projectile velocity measured before impact, and between the integral of the velocity curve and the penetration depth, resulting in significant errors in pressure measurements.

[0003] However, in actual measurements, errors will occur in the pressure test of the pressure sensor in a high acceleration measurement environment. The reason is that in this measurement environment, the pressure detection unit will be affected by both acceleration and pressure factors at the same time, and its pressure measurement data does not eliminate the influence of acceleration on it, which is also a problem faced by traditional pressure sensors (such as piezoelectric types). Moreover, due to the current lack of composite sensors that can simultaneously measure pressure and acceleration, the acceleration and pressure are measured separately. Even if a single pressure signal is obtained by decoupling the pressure signal from the obtained acceleration signal, the consistency cannot be guaranteed due to the limitation of the separate pressure and acceleration measurement environment, so the error of the final pressure data is still a big problem. Summary of the Invention

[0004] The purpose of the present invention is to provide a graphene composite sensor integrating pressure and acceleration to solve the problems existing in the above-mentioned prior art, which can measure pressure and acceleration simultaneously and improve measurement accuracy.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a graphene composite sensor integrating pressure and acceleration, comprising at least one composite unit, wherein the composite unit comprises a pressure sensor and an acceleration sensor; the pressure sensor comprises a pressure support frame, a central cross beam and a plurality of first graphene piezoelectric resistors; the central cross beam is arranged in the middle of the pressure support frame, and each end face of the central cross beam is fixedly connected to the corresponding inner side wall of the pressure support frame; the thickness of the central cross beam is less than the thickness of the pressure support frame; each first graphene piezoelectric resistor is respectively arranged at the connection between the end of the central cross beam and the pressure support frame; the acceleration sensor comprises an acceleration support frame, a central island, a plurality of connecting beams, a plurality of second graphene piezoelectric resistors and a plurality of mass blocks; the central island is located in the middle of the acceleration support frame, and the central island The circumferential direction is fixedly connected to the acceleration support frame through each of the connecting beams; the thickness of the central island and each of the connecting beams is less than the thickness of the acceleration support frame; a plurality of side holes are opened on the central island, and the side holes are opposite to the connecting beams one by one, and the extended length of the side holes is consistent with the extended length of the connecting beams, and a sensitive block is fixedly arranged in the middle of the side hole; the second graphene piezoresistor corresponds to the sensitive block one by one, and the second graphene piezoresistor is fixedly arranged on the sensitive block; the second graphene piezoresistor is located on the front end face of the central island, and each of the mass blocks is fixedly arranged on the back side of the central island; the pressure support frame and the acceleration support frame are fixed side by side, and each of the first graphene piezoresistors and each of the second graphene piezoresistors is respectively connected to two composite electrodes.

[0007] Preferably, the pressure support frame and the acceleration support frame are both square frames, and the number of the connecting beams, the side holes and the mass blocks are all four.

[0008] Preferably, in the thickness direction, one side of the central cross beam is flush with the front face of the pressure support frame; the central island has the same thickness as the connecting beam, and the thickness of the central island is less than the thickness of the acceleration support frame, and in the thickness direction, one side of the central island is flush with the front face of the acceleration support frame.

[0009] Preferably, a diaphragm is also included, and the front sides of the pressure support frame and the acceleration support frame are both provided with metal sealing convex rings; each of the first graphene piezoresistors and each of the second graphene piezoresistors are located on the inner side of the corresponding metal sealing convex rings; a bonding bump is fixedly provided in the middle of the central cross beam, the diaphragm seal covers each of the metal sealing convex rings, and the bonding bump is bonded to the diaphragm at the end face away from the central cross beam.

[0010] Preferably, the pressure sensor is further provided with a temperature compensation element, and the external circuits of the pressure sensor and the acceleration sensor share the temperature compensation element, and the temperature compensation element is used for temperature compensation of the pressure sensor and the acceleration sensor.

[0011] Preferably, back side sealing convex rings are fixedly provided on the back sides of the pressure support frame and the acceleration support frame.

[0012] Preferably, both sides of the connection between the end of the central cross beam and the pressure support frame are chamfered.

[0013] Preferably, the central island is a square block, and each side of the square block is fixedly connected to the acceleration support frame via one of the connecting beams.

[0014] Preferably, the four corners of the central island are chamfered.

[0015] Preferably, the number of the composite units is two, and the two composite units are fixedly arranged side by side.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The graphene composite sensor integrating pressure and acceleration provided by the present invention can realize simultaneous measurement of pressure and acceleration by integrating a pressure sensor and an acceleration sensor and utilizing the piezoresistive properties of graphene. The acceleration sensor is only affected by acceleration, and the acceleration signal can be directly obtained through the acceleration sensor. The acceleration signal detected by the acceleration sensor can be decoupled from the pressure signal detected by the pressure sensor to finally obtain a single pressure signal, making the detection more accurate. The integrated design can reduce the number of devices in weapon testing, thereby simplifying the design and space occupancy of the test system device. It can also reduce the problems caused by the traditional connection of multiple sensors, thereby providing more accurate data and more stable reliability for weapon testing. For the pressure sensor, the thickness of the central cross beam is less than the pressure support frame, forming a "flexible beam + rigid frame" structure. When external pressure is transmitted to the pressure sensor, the central cross beam is preferentially bent and deformed, while the support frame remains rigid, ensuring that stress is concentrated on the end of the cross beam and the frame. The first graphene piezoresistor is set at the connection between the end of the central cross beam and the frame (stress concentration area), where the strain is the largest, and the graphene produces a significant resistance change due to the piezoresistive effect. For the acceleration sensor, the central island is flexibly connected to the acceleration support frame through a connecting beam, and the mass block is fixed on the back of the central island. When the sensor is subjected to acceleration, the mass block drives the central island to move due to inertia, causing the connecting beam to undergo tensile or compressive deformation. The side holes correspond to the connecting beams one by one and have the same extension length, so that the strain of the connecting beam is transmitted to the sensitive block through the side holes. The second graphene piezoresistor is fixed on the sensitive block and only senses the deformation caused by acceleration. Finally, the internal signal is converted into an electrical signal output through the composite electrode. The excellent conductivity, flexibility, thermal conductivity, carrier mobility and mechanical strength of graphene make the resistance change caused by strain easier to capture. The first and second graphene piezoresistors are connected to the external Wheatstone bridge through independent composite electrodes, and the pressure and acceleration signals are output through two independent circuits respectively to avoid signal crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the overall structure of the graphene composite sensor integrating pressure and acceleration provided by the present invention when it is a composite unit;

[0020] Figure 2 for Figure 1Schematic diagram of the overall structure after removing the diaphragm;

[0021] Figure 3 for Figure 1 a side cross-sectional view of the structure;

[0022] Figure 4 This is a schematic diagram of the overall structure of the pressure sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0023] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure of the structure at the first cutting plane;

[0024] Figure 6 for Figure 4 A schematic diagram of the cross-sectional structure of the structure at a second cross-sectional plane (perpendicular to the first cross-sectional plane);

[0025] Figure 7 This is a schematic structural diagram of the pressure support frame and central cross beam of the pressure sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0026] Figure 8 This is a schematic structural diagram of the pressure support frame of the pressure sensor and the first graphene piezoresistors distributed on the central cross beam in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0027] Figure 9 A schematic diagram of the U-shaped structure of the graphene piezoresistor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0028] Figure 10 A schematic diagram of the distribution of composite electrodes of a pressure sensor in a graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0029] Figure 11 This is a schematic diagram of the overall structure of the acceleration sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0030] Figure 12 for Figure 11 A schematic diagram of the cross-sectional structure of the structure at the third cutting plane;

[0031] Figure 13 for Figure 11 A schematic diagram of the cross-sectional structure of the structure at the fourth cutting plane (perpendicular to the third cutting plane);

[0032] Figure 14 This is a schematic structural diagram of the acceleration support frame, connecting beam and central island of the acceleration sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0033] Figure 15 This is a schematic diagram of the arrangement structure of the second graphene piezoresistor on the acceleration sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0034] Figure 16 This is a schematic structural diagram of the back side of the central island of the acceleration sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0035] Figure 17 A schematic diagram of the distribution of composite electrodes of an acceleration sensor in a graphene composite sensor integrating pressure and acceleration provided by the present invention;

[0036] Figure 18 This is a schematic diagram of the overall structure of the four corners of the central island of the acceleration sensor in the graphene composite sensor integrating pressure and acceleration provided by the present invention after being chamfered;

[0037] Figure 19 This is a schematic structural diagram of two composite units in the graphene composite sensor integrating pressure and acceleration provided by the present invention.

[0038] In the picture:

[0039] 10-diaphragm; 11-inner sealing convex ring; 12-outer sealing convex ring; 13-bonding convex point; 14-pressure back side sealing convex ring; 15-acceleration back side sealing convex ring; 16-acceleration front side sealing convex ring;

[0040] 20-pressure sensor; 21-pressure support frame; 22-center cross beam; 23-first graphene piezoresistor; 24-temperature compensation element; 25-temperature compensation composite electrode;

[0041] 30 - acceleration sensor; 31 - acceleration support frame; 32 - center island; 321 - side hole; 322 - sensitive block; 33 - connecting beam; 34 - second graphene piezoresistor; 35 - mass block;

[0042] 40-Combination electrode. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] The purpose of the present invention is to provide a graphene composite sensor that integrates pressure and acceleration to solve the problems existing in the prior art, capable of measuring pressure and acceleration simultaneously and improving measurement accuracy.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Example 1

[0047] This embodiment provides a graphene composite sensor integrating pressure and acceleration, such as Figures 1 to 19 As shown, it includes at least one composite unit, and the composite unit includes a pressure sensor 20 and an acceleration sensor 30; the pressure sensor 20 includes a pressure support frame 21, a central cross beam 22 and a plurality of first graphene piezoresistors 23; the central cross beam 22 is arranged in the middle of the pressure support frame 21, and each end face of the central cross beam 22 is fixedly connected to the corresponding inner wall of the pressure support frame 21; the thickness of the central cross beam 22 is less than the thickness of the pressure support frame 21; each first graphene piezoresistor 23 is respectively arranged at the connection between the end of the central cross beam 22 and the pressure support frame 21; the acceleration sensor 30 includes an acceleration support frame 31, a central island 32, a plurality of connecting beams 33, a plurality of second graphene piezoresistors 34 and a plurality of mass blocks 35; the central island 32 is located in the middle of the acceleration support frame 31, and the circumference of the central island 32 is connected by each connecting beam 3 3 is fixedly connected to the acceleration support frame 31; the thickness of the central island 32 and each connecting beam 33 is less than the thickness of the acceleration support frame 31; a plurality of side holes 321 are opened on the central island 32, and the side holes 321 are opposite to the connecting beams 33 one by one, and the extended length of the side holes 321 is consistent with the extended length of the connecting beam 33, and a sensitive block 322 is fixedly installed in the middle of the side hole 321; the second graphene piezoresistors 34 correspond to the sensitive blocks 322 one by one, and the second graphene piezoresistors 34 are fixedly installed on the sensitive blocks 322; the second graphene piezoresistors 34 are located on the front end surface of the central island 32, and each mass block 35 is fixedly installed on the back side of the central island 32; the pressure support frame 21 and the acceleration support frame 31 are fixed together side by side, and each first graphene piezoresistors 23 and each second graphene piezoresistors 34 are respectively connected to two composite electrodes 40.

[0048] By integrating the pressure sensor 20 and the acceleration sensor 30 and utilizing the piezoresistive properties of graphene, simultaneous measurement of pressure and acceleration can be achieved. The acceleration sensor 30 is only affected by acceleration, and the acceleration signal can be directly obtained through the acceleration sensor 30. The acceleration signal detected by the acceleration sensor 30 can be decoupled from the pressure signal detected by the pressure sensor 20, and finally a single pressure signal can be obtained, making the detection more accurate; and the integrated design can reduce the number of devices in weapon testing, thereby simplifying the design and space occupancy of the test system device; and can reduce the problems caused by the traditional connection of multiple sensors, thereby providing more accurate data and more stable reliability for weapon testing; for the pressure sensor 20, the thickness of the central cross beam 22 is less than the pressure support frame 21, forming a "flexible beam + rigid frame" structure. When external pressure is transmitted to the pressure sensor 20, the central cross beam 22 first bends and deforms, while the support frame remains rigid, ensuring that stress is concentrated at the connection between the end of the cross beam and the frame. The first graphene piezoresistor 23 is arranged on the central cross beam The connection between the end of 22 and the frame (stress concentration area) has the largest strain here, and the graphene produces a significant resistance change due to the piezoresistive effect; for the acceleration sensor 30, the center island 32 is flexibly connected to the acceleration support frame 31 through the connecting beam 33, and the mass block 35 is fixed on the back side of the center island 32. When the sensor is subjected to acceleration, the mass block 35 drives the center island 32 to move due to the inertial force, causing the connecting beam 33 to undergo tensile or compressive deformation. The side holes 321 correspond to the connecting beam 33 one by one, and the extended lengths are consistent, so that the strain of the connecting beam 33 is transmitted through the side holes. The signal is transmitted through the hole 321 to the sensitive block 322. The second graphene piezoresistor 34 is fixed on the sensitive block 322 and only senses the deformation caused by acceleration. Finally, the internal signal is converted into an electrical signal output through the composite electrode 40. The excellent conductivity, flexibility, thermal conductivity, carrier mobility and mechanical strength of graphene make the resistance change caused by strain easier to capture. The first and second graphene piezoresistors 34 are connected to the external Wheatstone bridge through independent composite electrodes 40. The pressure and acceleration signals are output through two independent circuits respectively to avoid signal crosstalk.

[0049] Specifically, the pressure sensor 20 and acceleration sensor 30 designed in conjunction with the above structure have high G-value and high overload characteristics, ensuring that they can maintain good accuracy and stability for a long time, minimizing damage caused by high temperature, high pressure, high impact and other environments during weapon testing, and greatly improving the sensor's vibration and impact resistance.

[0050] The following is a description of the overall structure of the graphene composite sensor that integrates pressure and acceleration:

[0051] Among the optional solutions of this embodiment, it is more preferred that Figure 19As shown, there are two composite units, which are fixedly arranged side by side.

[0052] Specifically, the array design allows the externally applied load to act more evenly on the composite sensor, thereby improving the stability, impact resistance and vibration resistance of the sensor.

[0053] Among them, other related settings for composite units are as follows:

[0054] Specifically, such as Figure 2 As shown, taking a single-layer U-shaped graphene piezoresistive film as an example, when the diaphragm 10 is subjected to an external load, it will exert pressure on the pressure sensor 20, causing the central cross beam 22 to be stressed and strained, and then the strain is converted into a resistance change through the sensitive element, and the resistance change is converted into an electrical signal output through the Wheatstone bridge; the diaphragm 10 can play a supporting and protective role for the acceleration sensor 30.

[0055] Specifically, all composite electrodes 40 are externally connected via a Wheatstone bridge. A Wheatstone bridge is a circuit for measuring resistance. Its operating principle is based on Kirchhoff's voltage law. The bridge consists of four resistors arranged in a diamond configuration, with one pair of opposing resistors connected to a power supply and the other pair of opposing resistors connected to a galvanometer. This is an existing sensor technology and will not be described in detail here.

[0056] Among the optional solutions of this embodiment, it is more preferred that Figures 1 to 10 As shown, pressure sensor 20 is also provided with a temperature compensation element 24. This element is shared by the external circuits of pressure sensor 20 and accelerometer 30 and is used to compensate for the temperature of pressure sensor 20 and accelerometer 30. This element can effectively offset resistance changes caused by temperature variations, further improving the measurement accuracy of the composite sensor.

[0057] Specifically, temperature changes may cause changes in the resistance of graphene, thereby causing pressure measurement errors. Therefore, the same sensitive element as the pressure sensor 20 is used as the temperature compensation element 24 (two temperature compensation composite electrodes 40 are connected to the temperature compensation element 24) to eliminate the error caused by temperature, thereby improving the accuracy of the pressure sensor 20.

[0058] Among the optional solutions of this embodiment, it is more preferred that Figures 1 to 10As shown, it also includes a diaphragm 10, and the front of the pressure support frame 21 and the acceleration support frame 31 are both provided with metal sealing convex rings; each first graphene piezoresistor 23 and each second graphene piezoresistor 34 are located on the inner side of the corresponding metal sealing convex ring; a bonding bump 13 is fixedly provided in the middle of the central cross beam 22, and the diaphragm 10 is sealed and covered on each metal sealing convex ring, and the bonding bump 13 is bonded to the diaphragm 10 away from the end face of the central cross beam 22.

[0059] Specifically, when the diaphragm 10 is subjected to an external load, it applies a load to the pressure sensor 20 and protects both the pressure sensor 20 and the acceleration sensor 30 ; a membrane-beam composite structure is formed by the diaphragm 10 and the central cross beam 22 to achieve a large stroke.

[0060] Specifically, the front metal sealing ring of the pressure support frame 21 includes an inner sealing ring 11 and an outer sealing ring 12. The inner sealing ring 11 encloses the four first graphene piezoresistors 23, while the outer sealing ring 12 encloses the sensitive element of the temperature compensation element 24. This seal ensures that the measuring portion of the pressure sensor 20 is sealed. For the acceleration support frame 31, the front metal sealing ring is the acceleration front sealing ring 16.

[0061] Among the optional solutions of this embodiment, it is more preferred that Figures 1 to 18 As shown, backside sealing convex rings are fixedly provided on the back sides of the pressure support frame 21 and the acceleration support frame 31. The pressure backside sealing convex ring 14 is provided on the back side of the pressure support frame 21, and the acceleration backside sealing convex ring 15 is provided on the back side of the acceleration support frame 31.

[0062] Specifically, the front metal sealing convex ring and the north back sealing convex ring realize sealing protection for the pressure support frame 21 and the acceleration support frame 31 from top to bottom.

[0063] Specifically, the material of the diaphragm 10 is consistent with the material of the substrate (ie, the material of the pressure support frame 21 and the acceleration support frame 31 ).

[0064] Specifically, each graphene varistor film is covered with a protective film made of materials such as SiNx, Al2O3, and BN. Al2O3 has a high melting point and excellent thermal conductivity, allowing the sensor to withstand transient high temperatures during weapons testing without failure. It also offers excellent electrical insulation properties, helping to reduce electrical interference generated when multiple test devices are used simultaneously and protecting the sensor's electrical signal output. References to this material elsewhere in this article will not be repeated.

[0065] The following are the relevant settings of the pressure sensor 20 and the acceleration sensor 30:

[0066] Specifically, the pressure sensor 20 has a bilaterally symmetrical structure, and the acceleration sensor 30 has a centrally symmetrical structure.

[0067] Among the optional solutions of this embodiment, it is more preferred that Figures 1 to 10 As shown, the pressure support frame 21 and the acceleration support frame 31 are both square frames, and the number of connecting beams 33, side holes 321 and mass blocks 35 are all 4 (the ends of the four side holes 321 are connected in the middle of the central island 32 to form a cross-shaped hole, and the sensitive block 322 separates the corresponding side hole 321 into two left and right parts).

[0068] Among the optional solutions of this embodiment, it is more preferred that Figures 1 to 10 As shown, in the thickness direction, one side of the center cross beam 22 is flush with the front of the pressure support frame 21; the center island 32 has the same thickness as the connecting beam 33, and the thickness of the center island 32 is less than the thickness of the acceleration support frame 31. In the thickness direction, one side of the center island 32 is flush with the front of the acceleration support frame 31.

[0069] Specifically, the first graphene piezoresistor 23 on the pressure sensor 20 and the second graphene piezoresistor 34 on the acceleration sensor 30 can both use the same graphene piezoresistor; its shape can be U-shaped, turn-shaped (a ring-shaped structure formed by wrapping and winding), etc.; the number of layers can be single-layer, double-layer or multi-layer.

[0070] Specifically, a single-layer U-shaped graphene varistor film was chosen because it transfers more completely and cleanly during the process than a multi-layer one. Multi-layer graphene varistor films are prone to cracking or uneven layers during transfer, and their surface integrity and cleanliness are key factors affecting their electrical performance.

[0071] Specifically, the pressure support frame 21 and the acceleration support frame 31 are formed as one piece, which is a substrate. The optional material of the substrate can be Si, SiC or Al2O3, etc.

[0072] Specifically, the optional material of the composite electrode 40 may be Au, Pt, Ni, or the like.

[0073] First, the relevant structural setting of the pressure sensor 20 is described as follows:

[0074] Among the optional solutions of this embodiment, it is more preferred that Figures 1 to 10 As shown, both sides of the connection between the end of the central cross beam 22 and the pressure support frame 21 are chamfered.

[0075] Specifically, when the pressure sensor 20 is subjected to an external load, the resistance of the single-layer U-shaped graphene piezoresistive film changes, and the physical signal is converted into an electrical signal for output through the corresponding two composite electrodes 40 .

[0076] Second, the relevant structural configuration of the acceleration sensor 30 is described as follows:

[0077] Among the optional solutions of this embodiment, it is more preferred that Figure 1 、 Figure 2 and Figures 11 to 19 As shown, the central island 32 is a square block, and each side of the square block is fixedly connected to the acceleration support frame 31 through a connecting beam 33.

[0078] Specifically, by disposing the four mass blocks 35 , the stiffness of the acceleration sensor 30 can be increased, its natural frequency can be raised, and nonlinear errors can be reduced.

[0079] Specifically, a double-layer graphene varistor can be used as a sensitive element and placed on the sensitive block 322. The double-layer setting can provide better stability under high overload conditions and is suitable for more stringent weapon measurement environments.

[0080] Among the optional solutions of this embodiment, it is more preferred that Figure 18 As shown, all four corners of the center island 32 are chamfered. With the optimized structural design, the sensitivity is improved, which can further enhance the performance of the acceleration sensor 30 and is particularly suitable for accurate measurement under high overload conditions.

[0081] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A graphene composite sensor integrating pressure and acceleration, characterized by: comprising at least one composite unit, wherein the composite unit comprises a pressure sensor and an acceleration sensor; The pressure sensor includes a pressure support frame, a central cross beam, and a plurality of first graphene piezoelectric resistors; the central cross beam is arranged in the middle of the pressure support frame, and each end surface of the central cross beam is fixedly connected to the corresponding inner side wall of the pressure support frame; the thickness of the central cross beam is less than the thickness of the pressure support frame; each first graphene piezoelectric resistor is respectively arranged at the connection between the end of the central cross beam and the pressure support frame; The acceleration sensor includes an acceleration support frame, a central island, a plurality of connecting beams, a plurality of second graphene piezoresistors and a plurality of mass blocks; the central island is located in the middle of the acceleration support frame, and the circumference of the central island is fixedly connected to the acceleration support frame through the connecting beams; the thickness of the central island and the connecting beams are both less than the thickness of the acceleration support frame; a plurality of side holes are opened on the central island, the side holes are opposite to the connecting beams one by one, and the extended length of the side holes is consistent with the extended length of the connecting beams, and a sensitive block is fixedly arranged in the middle of the side hole; the second graphene piezoresistors correspond to the sensitive blocks one by one, and the second graphene piezoresistors are fixedly arranged on the sensitive blocks; the second graphene piezoresistors are located on the front end face of the central island, and the mass blocks are fixedly arranged on the back side of the central island; The pressure support frame and the acceleration support frame are fixed side by side, and each of the first graphene piezoresistors and each of the second graphene piezoresistors are respectively connected to two composite electrodes.

2. The graphene composite sensor integrating pressure and acceleration according to claim 1, characterized in that: The pressure support frame and the acceleration support frame are both square frames, and the number of the connecting beams, the side holes and the mass blocks are all four.

3. The graphene composite sensor integrating pressure and acceleration according to claim 2, characterized in that: In the thickness direction, one side of the central cross beam is flush with the front face of the pressure support frame; the central island has the same thickness as the connecting beam, and the thickness of the central island is less than the thickness of the acceleration support frame. In the thickness direction, one side of the central island is flush with the front face of the acceleration support frame.

4. The graphene composite sensor integrating pressure and acceleration according to claim 3, characterized in that: It also includes a diaphragm, and the front of the pressure support frame and the acceleration support frame are both provided with metal sealing convex rings; each of the first graphene piezoresistors and each of the second graphene piezoresistors are located on the inner side of the corresponding metal sealing convex rings; a bonding bump is fixedly provided in the middle of the central cross beam, and the diaphragm seal covers each of the metal sealing convex rings, and the bonding bump is bonded to the diaphragm at the end face away from the central cross beam.

5. The graphene composite sensor integrating pressure and acceleration according to claim 2, characterized in that: The pressure sensor is further provided with a temperature compensation element, which is shared by the external circuits of the pressure sensor and the acceleration sensor and is used for temperature compensation of the pressure sensor and the acceleration sensor.

6. The graphene composite sensor integrating pressure and acceleration according to claim 2, characterized in that: Back side sealing convex rings are fixedly provided on the back sides of the pressure support frame and the acceleration support frame.

7. The graphene composite sensor integrating pressure and acceleration according to claim 2, characterized in that: Both sides of the connection between the end of the central cross beam and the pressure support frame are chamfered.

8. The graphene composite sensor integrating pressure and acceleration according to claim 2, characterized in that: The central island is a square block, and each side of the square block is fixedly connected to the acceleration support frame through one of the connecting beams.

9. The graphene composite sensor integrating pressure and acceleration according to claim 8, characterized in that: The four corners of the central island are all chamfered.

10. The graphene composite sensor integrating pressure and acceleration according to claim 8, characterized in that: The number of the composite units is two, and the two composite units are fixedly arranged side by side.

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