Flexible bionic piezoelectric cilia sensor array for detecting flow velocity, flow direction and air pressure

Abstract

The invention discloses a flexible piezoelectric cilia sensor array for detecting flow velocity, flow direction and air pressure, which belongs to the field of bionic airflow sensing and comprises an air bag cilia sensor array, a piezoelectric film sensor array, a signal processing module, an airflow signal output end, a comprehensive signal output end and a wire. The air bag cilium sensor array is composed of air flow sensing units and comprises a base, a supporting piece, a film air bag, an annular electrode and piezoelectric cilia. The piezoelectric film sensor array comprises a common ground layer, a sensing layer, a positive electrode layer and an isolation protection layer from top to bottom; and the signal processing module comprises a comprehensive signal receiving end, an airflow signal receiving end and an external equipment connecting end. The air bag cilium sensor array and the piezoelectric film sensor array sense air flow and air pressure signals in real time and input the signals into the signal processing module, electric signals output by the connecting end of external equipment are analyzed, and multi-dimensional, real-time and high-sensitivity detection of the flow speed, the flow direction and the air pressure is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of biomimetic air flow sensing, and particularly relates to a flexible biomimetic piezoelectric cilia sensor array for detecting flow rate, flow direction, and air pressure. Background Art

[0002] Air flow detection is an essential part in fields such as meteorological monitoring, aerospace, environmental monitoring, medical health, etc. Traditional air flow sensors are limited to single quantity measurement, have low sensitivity, and relatively large volume and structural stiffness. The present invention designs a flexible biomimetic piezoelectric cilia sensor array for simultaneously detecting flow rate, flow direction, and air pressure. In order to achieve simultaneous measurement of the three key parameters of air flow detection, namely flow rate, flow direction, and air pressure, the present invention proposes a detection method based on a sealed cavity structure and mechanical principles. To improve the sensitivity of the sensor, the present invention incorporates a thin-film airbag with uniformly distributed pressure-sensitive elements and a biomimetic piezoelectric cilia structure, and improves the sensitivity through multi-dimensional signal monitoring. All substrates and isolation layers of the present invention except for the sensitive elements are made of flexible PE, reducing the structural volume and stiffness. Summary of the Invention

[0003] The purpose of the present invention is to design an air flow sensor for simultaneously detecting flow rate, flow direction, and air pressure, aiming to solve the technical problems of existing air flow sensors being limited to single quantity measurement, having low sensitivity, and large volume and structural stiffness.

[0004] To achieve the above purpose, the present invention designs a flexible biomimetic piezoelectric cilia sensor array for detecting flow rate, flow direction, and air pressure, which includes an airbag cilia sensor array, a piezoelectric film sensor array, a signal processing module, an air flow signal output terminal, a comprehensive signal output terminal, and a wire. The airbag cilia sensor array is located at the top layer of the flexible piezoelectric cilia sensor array, and its external interface is the air flow signal output terminal. The piezoelectric film sensor array is located directly below the airbag cilia sensor array and shares a common ground layer with the airbag cilia sensor array, and its external interface is the comprehensive signal output terminal. The signal processing module is connected to the air flow signal output terminal and the comprehensive signal output terminal through wires.

[0005] Preferably, the airbag cilia sensor array includes 10*10 air flow sensing units distributed in a matrix form. The air flow unit includes a base, a support member, a thin-film airbag, a ring electrode, and piezoelectric cilia.

[0006] Preferably, a slot is opened on the outer periphery of the base for fixedly connecting the thin-film airbag. The material of the base is flexible PE. The inner surface of the base is connected to the bottom surface of the support member, and a through hole coaxial with the thin-film airbag is opened at the top of the support member for connecting the ring electrode.

[0007] Preferably, the outer diameter of the annular electrode is the same as the diameter of the through hole. The bottom of the annular electrode is fixedly connected to a support member, and the top is slightly higher than the thin film airbag. The inner diameter of the annular electrode is equal to the diameter of the piezoelectric cilia. The piezoelectric cilia are hermetically welded to the annular electrode using cold welding technology. The base, support member, thin film airbag, annular electrode, and piezoelectric cilia form a sealed air cavity.

[0008] Preferably, the material of the thin film airbag is PE, and 4 piezoresistive sensing elements are adhesively bonded to the outer periphery at intervals of 90°. The electrodes of the piezoresistive elements are fabricated by magnetron sputtering. The negative electrode of the piezoresistive sensing element is connected to the annular electrode, and a common ground wire is led out to connect to the integrated signal output terminal. The positive electrode is located at the bottom of the thin film airbag and is connected to the air flow signal output terminal.

[0009] Preferably, the integrated signal output terminal has a total of 3 interfaces, which are composed of a ground terminal and a pneumatic signal output terminal. The pneumatic signal output terminal is directly below the ground terminal. The ground terminal is the external interface of the common ground layer. The number of interfaces of both the ground terminal and the pneumatic signal output terminal is 3, and the upper and lower interfaces are coaxial. This is for convenient integrated assembly. In actual use, the number of ground interfaces is 2, and the number of pneumatic signal output interfaces is 1.

[0010] Preferably, the common ground layer is the common layer of the airbag cilia sensor array and the piezoelectric thin film sensor array, and the ground wires of the annular electrodes and the piezoelectric thin film sensor array arranged in a 10*10 matrix form are led out.

[0011] Preferably, the piezoelectric thin film sensor array is located directly below the common ground layer and includes, from top to bottom, a common ground layer, a sensing layer, a positive electrode layer, and an isolation and protection layer. The sensing layer is composed of 10*10 bump-type piezoresistive sensing units, and each piezoresistive sensing unit is directly below an air flow sensing unit.

[0012] Preferably, the pneumatic signal output terminal of the positive electrode layer is connected to the signal processing module through a wire. The material of the isolation and protection layer is flexible PE material to protect the piezoelectric thin film sensor array.

[0013] Preferably, the external interfaces of the signal processing module include 3 integrated signal receiving terminals, 4 air flow signal receiving terminals, 1 port connected to the positive pole of an external display device, and 1 port connected to the ground pole of an external display device.

[0014] The beneficial effects of the present invention compared with existing air flow sensors:

[0015] (1) The present invention proposes a flexible bionic piezoelectric cilia sensor array combining an airbag cilia sensor array and a piezoelectric thin film sensor array. Based on a sealed cavity structure and mechanical principles, it can simultaneously measure the flow rate, flow direction, and air pressure in real time.

[0016] (2) The present invention creatively introduces a thin-film airbag with uniformly distributed peripheral pressure-sensitive elements and a bionic piezoelectric cilia structure, which improves the sensor sensitivity through multi-dimensional signal monitoring.

[0017] (3) The base, thin-film airbag, and isolation protection layer material of the present invention are flexible PE, which have the characteristics of good flexibility, chemical corrosion resistance, and light weight, greatly reducing the structural volume and stiffness, facilitating the installation of the sensor, and achieving miniaturization and lightweight. Description of the Drawings

[0018] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the specific embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0019] Figure 1 is a schematic structural diagram of a flexible bionic piezoelectric cilia sensor array for detecting flow rate, flow direction, and air pressure provided by the present invention;

[0020] Figure 2 is a cross-sectional view of the air flow sensing unit provided by the present invention;

[0021] Figure 3 is a top view of the thin-film airbag provided by the present invention;

[0022] Figure 4 is a schematic structural diagram of the piezoelectric thin-film sensor array provided by the present invention;

[0023] Figure 5 is a schematic structural diagram of the signal processing module provided by the present invention.

[0024] Figure 6 is an information processing process diagram of the signal processing module provided by the present invention.

[0025] In the figures: 1. Airbag cilia sensor array; 2. Piezoelectric thin-film sensor array; 3. Signal processing module; 4. Air flow signal output terminal; 5. Comprehensive signal output terminal; 6. Wire; 7. Base; 8. Support; 9. Thin-film airbag; 10. Ring electrode; 11. Piezoelectric cilia; 12. Pressure-sensitive sensing element; 13. Negative electrode of the pressure-sensitive sensing element; 14. Positive electrode of the pressure-sensitive sensing element; 15. Ground terminal; 16. Air pressure signal output terminal; 17. Common ground layer; 18. Sensing layer; 19. Positive electrode layer; 20. Isolation protection layer; 21. Comprehensive signal receiving terminal; 22. Air flow signal receiving terminal; 23. Positive terminal port for connecting external equipment; 24. Ground terminal port for connecting external equipment. Detailed Embodiments

[0026] The present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be emphasized that the following description is merely exemplary and not intended to limit the scope of the present invention and its applications.

[0027] This example discloses a flexible bionic piezoelectric cilia sensor array for detecting flow velocity, flow direction, and air pressure.

[0028] As Figure 1 shown, the present invention includes an airbag cilia sensor array 1, a piezoelectric thin film sensor array 2, a signal processing module 3, an air flow signal output terminal 4, a comprehensive signal output terminal 5, and a wire 6. The airbag cilia sensor array 1 is located at the uppermost layer of the flexible piezoelectric cilia sensor array, and its external interface is the air flow signal output terminal 4. The piezoelectric thin film sensor array 2 is located directly below the airbag cilia sensor array 1 and is fixedly connected to the airbag cilia sensor array 1, and leads out the comprehensive signal output terminal 5. The signal processing module 3 is connected to the air flow signal output terminal 4 and the air pressure signal output terminal 5 through the wire 6.

[0029] In the present invention, the module for real-time measurement of wind direction and wind speed is the airbag cilia sensor array 1. As Figure 2 shown, the airbag cilia sensing unit includes a base 7, a support member 8, a thin film airbag 9, a circular electrode 10, and a piezoelectric cilium 11. The material of the base 7 is flexible PE. The outer peripheral slot of the base 7 fixedly clamps the thin film airbag 9. The support member 8 is completely covered by the thin film airbag 9. The lower surface of the support member 8 is connected to the inner surface of the base 7. Through holes with a diameter equal to the outer diameter of the circular electrode 10 are opened at the top of the support member 8 and the thin film airbag 9 for connecting the circular electrode 10. The inner diameter of the circular electrode 10 is equal to the diameter of the piezoelectric cilium 11. The piezoelectric cilium 11 is fixedly connected to the bottom of the circular electrode 10 by cold welding technology. In a windless environment, the piezoelectric cilium 11 is coaxial with the base 7, the support member 8, the thin film airbag 9, and the circular electrode 10, and does not exert pressure on the thin film airbag 9. The base 7, the support member 8, the thin film airbag 9, the circular electrode 10, and the piezoelectric cilium 11 form a sealed air cavity, and the sealed air cavity structure will undergo a large deformation under a weak external signal. As Figure 3 shown, the thin film airbag 9 includes 4 uniformly distributed pressure-sensitive sensing elements 12 fixedly connected to the outer surface. The material of the thin film airbag 9 is flexible PE. The negative electrode 13 is connected to the circular electrode 10 to lead out the common ground electrode. The positive electrode 14 is connected to the air flow signal output terminal 4 at the bottom of the thin film airbag 9. Changes in the external wind speed and wind direction cause the piezoelectric cilium 11 to generate a position offset. The piezoelectric cilium 11 exerts an uneven pressure on the thin film airbag 9, resulting in an asymmetric deformation of the thin film airbag 9. The conductive length, width, area, etc. of the pressure-sensitive sensing elements 12 on the surface of the thin film airbag 9 in different directions change, thereby realizing multi-directional and highly sensitive real-time detection of wind direction and wind speed. The air flow signal output terminal 4 is connected to the air flow signal receiving terminal 22 of the signal processing module 3 through the wire 6. As Figure 5as shown

[0030] In the present invention, the sensing module for real-time detecting air pressure is an interacting airbag cilia sensor array 1 and a piezoelectric film sensor array 2, as Figure 4 shown. The piezoelectric film sensor array 2 includes a common ground layer 17, a sensing layer 18, a positive electrode layer 19, and an isolation protection layer 20 from top to bottom. The common ground layer 17 composites the ground electrode of the piezoelectric film sensor array 2 and the ground electrode led out from the annular electrode 10 in the airbag cilia sensor array 1. The sensing layer 18 is composed of 10×10 bump-type pressure-sensitive sensing units located directly below the air flow sensing units. The external interface of the positive electrode layer 19 is the air pressure signal output terminal 16, which is connected to the signal processing module 3 through a wire 6. The isolation protection layer 20 isolates and protects the piezoelectric film sensor array. When the external environmental air pressure changes, the gas volume in the sealed air cavity structure expands or contracts, resulting in a change in the positive pressure of the support member 8 on the inner surface of the base 7. The pressure change on the inner surface of the base 7 causes different degrees of deformation of the sensing layer 18 of the bump-type pressure-sensitive sensing unit directly below, resulting in a change in the resistance value of the bump-type pressure-sensitive sensing unit, thereby realizing real-time air pressure detection. The comprehensive signal output terminal 5 of the piezoelectric film sensor array 2 is connected to the comprehensive signal receiving terminal 21 of the signal processing module 3 through a wire 6, as Figure 5 shown

[0031] as Figure 5 shown. In the present invention, the module for receiving real-time air flow and air pressure signals, preliminarily processing and transmitting the signals is the signal processing module 3, which includes 3 comprehensive signal receiving terminals 21, 4 air flow signal receiving terminals 22, 1 port 23 for connecting the positive electrode of an external display device, and 1 port 24 for connecting the ground electrode of an external display device. As Figure 6 shown, the signal processing module 3 amplifies weak voltage signals through a built-in small signal amplification circuit, filters out circuit background noise through a filtering circuit, modulates the electrical signals with interference removed in terms of current or voltage, and finally transmits them to an external device in real time through the port 23 for connecting the positive electrode of an external display device and the port 24 for connecting the ground electrode of an external display device through an A / D digital-to-analog conversion circuit, realizing synchronous real-time detection of wind speed, wind direction, and air pressure.

[0032] This specific implementation manner is only an explanation of the present invention and does not limit the present invention. After reading this specification thoroughly, those skilled in the art can make modifications without creative contributions to this implementation manner as needed, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A flexible piezoelectric ciliary sensor array for detecting flow velocity, flow direction and air pressure, characterized in that , comprising an airbag ciliary sensor array (1), a piezoelectric film sensor array (2), a signal processing module (3), an airflow signal output terminal (4), an integrated signal output terminal (5), and a wire (6). The airbag ciliary sensor array (1) is located at the top layer of the flexible piezoelectric ciliary sensor array, leading to the airflow signal output terminal (4); the piezoelectric film sensor array (2) is located directly below the airbag ciliary sensor array (1), leading to the integrated signal output terminal (5); and the signal processing module (3) is connected to the airflow signal output terminal (4) and the integrated signal output terminal (5) via a wire (6).

2. The airbag ciliary sensor array according to claim 1, characterized in that: The invention comprises 10*10 airflow sensing units distributed in a matrix, wherein the airflow sensing unit comprises a base (7), a support member (8), a thin film airbag (9), an annular electrode (10), and piezoelectric hairs (11). The base (7) is made of a flexible PE material, and the inner surface is connected to the bottom of the support member (8). The support member (8) is completely covered by the thin film airbag (9). The bottom of the thin film airbag (9) is clamped in the outer peripheral groove of the base (7). The top of the thin film airbag (9) and the support member (8) are opened to bond the annular electrode (10). The inner diameter of the annular electrode (10) is equal to the diameter of the piezoelectric hairs (11). The piezoelectric hairs (11) are welded to the annular electrode (10) by cold welding technology. The base (7), the support member (8), the thin film airbag (9), the annular electrode (10), and the piezoelectric hairs (11) form a closed air cavity.

3. The film airbag according to claim 2, characterized in that: The material of the film airbag is flexible PE, and four fixed pressure-sensitive sensing elements (12) are evenly distributed on the periphery. The negative electrode (13) of the pressure-sensitive element (12) is connected to the annular electrode (10) and a ground wire is drawn out to connect to the integrated signal output terminal (5). The positive electrode (14) is located at the bottom of the film airbag and is connected to the airflow signal output terminal (4).

4. The integrated signal output terminal according to claim 3, characterized in that: The signal output terminal comprises a ground terminal (15) and an air pressure signal output terminal (16). The ground terminal (15) is an external interface of a common ground layer (17). The ground terminal (15) and the air pressure signal output terminal (16) have the same number of interfaces for ease of assembly.

5. The common ground layer according to claim 4, characterized in that: The common ground layer is a common layer of the airbag ciliary sensor array (1) and the piezoelectric film sensor array (2), and connects the ground wire of the annular electrode (10) and the piezoelectric film sensor array (2).

6. The piezoelectric film sensor array according to claim 5, characterized in that: The invention comprises a common ground layer (17), a sensing layer (18), a positive electrode layer (19), and an isolation protection layer (20). The sensing layer (18) is composed of 10*10 convex point pressure-sensitive sensing units, and the pressure-sensitive sensing units are located directly below the airflow sensing units. The air pressure signal output end (16) of the external interface of the positive electrode layer (19) is connected to the signal processing module (3) through a wire (6), and the isolation protection layer (20) isolates and protects the piezoelectric film sensor array.

7. The signal processing module according to claim 6, characterized in that: It comprises three integrated signal receiving terminals (21), four airflow signal receiving terminals (22), one port (23) connected to the positive pole of an external display device, and one port (24) connected to the ground pole of an external display device.

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