Flexible acoustic sensor

Abstract

The invention discloses a flexible acoustic sensor which is composed of a packaging layer 1, a conductive layer, an upper insulating layer, a lower insulating layer, a grid-shaped cushion layer, conductive wires and a particulate vibrating body. The upper insulating layer, the grid-shaped cushion layer and the lower insulating layer are stacked together in sequence; a gap is reserved between the upper insulating layer and the lower insulating layer; the conductive wires are tightly attached to one side of each grid of the grid-shaped cushion layer, and one side of each grid is led out; the conductive layer wraps the lead-out conductive wire; a vibration cavity is defined by the upper insulating layer, the lower insulating layer and the grid-shaped cushion layer; the vibrating body is filled in the vibrating cavity; friction point sequences of the vibrating body and the upper insulating layer are different, and triboelectric sequences of the vibrating body and the lower insulating layer are different. The packaging layer wraps the whole device. The flexible acoustic sensor has broadband response capability, and can meet the requirements of a plurality of practical applications.

Description

Technical Field

[0001] The invention relates to the technical field of friction nanogenerators, and in particular to a flexible acoustic sensor. Background Art

[0002] Acoustic sensors are widely used in various fields, such as industrial monitoring, environmental monitoring, medical health, and smart homes. Existing acoustic sensors (capacitive, piezoelectric, piezoresistive, etc.) cannot be more widely used due to factors such as large parasitic capacitance, complex process, zero drift, and rigidity. Capacitive acoustic sensors have high sensitivity, but are greatly affected by parasitic capacitance. Piezoelectric acoustic sensors do not require external power and have a simple structure, but are limited by piezoelectric materials and have complex processes. Piezoresistive acoustic sensors have a simple manufacturing structure, but are prone to zero drift. Friction nano-electricity accelerometers have the characteristics of low material cost, self-powered, and multiple working modes, but most of them are currently rigid and lack high-frequency acoustic vibration response. Therefore, it is still extremely challenging to develop self-powered flexible sensors with high-frequency acoustic vibration response and a wide frequency operating range to meet the needs of a wide range of practical applications. Summary of the invention

[0003] In view of the above-mentioned problems existing in the existing flexible acoustic sensors, the present invention is proposed.

[0004] Therefore, an object of the present invention is to provide a flexible acoustic sensor, which aims to solve the problem that most current acoustic sensors are rigid and lack high-frequency acoustic vibration response.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising: the flexible acoustic sensor is composed of a packaging layer, a conductive layer, an upper insulating layer, a lower insulating layer, a grid-shaped cushion layer, a conductive wire and a micro-particle vibrating body;

[0006] The upper insulating layer, the grid-shaped cushion layer and the lower insulating layer are stacked together in sequence; a gap is left between the upper insulating layer and the lower insulating layer; the conductive wire is tightly attached to one side of each grid of the grid-shaped cushion layer and one side is led out; the conductive layer wraps the led-out conductive wire; the upper insulating layer, the lower insulating layer and the grid-shaped cushion layer form a vibration cavity; the vibrating body is filled in the vibration cavity; the friction point sequence of the vibrating body and the upper insulating layer is different, and the friction electric sequence of the vibrating body and the lower insulating layer is different; the packaging layer wraps the entire device.

[0007] As a preferred solution of the flexible acoustic sensor of the present invention, the vibrating body is formed by a mixture of conductive particles and insulating particles, and when the vibrating body vibrates, the conductive particles and the insulating particles rub against each other to generate electricity.

[0008] As a preferred solution of the flexible acoustic sensor of the present invention, the upper insulating layer and the lower insulating layer are both made of rigid insulating materials.

[0009] As a preferred solution of the flexible acoustic sensor of the present invention, the upper insulating layer and the lower insulating layer are both made of flexible insulating materials.

[0010] As a preferred solution of the flexible acoustic sensor of the present invention, the grid-shaped cushion layer has a plurality of rectangular grids.

[0011] As a preferred solution of the flexible acoustic sensor of the present invention, the thickness of the grid-shaped cushion layer is 0.1-0.25 mm.

[0012] As a preferred solution of the flexible acoustic sensor of the present invention, the conductive wire is closely attached to one side of each grid of the grid-shaped cushion layer and one side is led out, the diameter of the conductive wire is 0.1-0.6 mm, and the material is copper wire or conductive fiber wire.

[0013] As a preferred solution of the flexible acoustic sensor of the present invention, the packaging layer is closely attached to the outside of the entire device, is made of a flexible waterproof material (such as polyurethane (PU)), and has a thickness of 0.01-0.05 mm.

[0014] As a preferred solution of the flexible acoustic sensor of the present invention, the particle size of the vibrating body is in the order of millimeters, micrometers or nanometers.

[0015] As a preferred solution of the flexible acoustic sensor described in the present invention, the flexible acoustic sensor is used for structural health monitoring, including abnormal vibration caused by substation GIS failure, automobile engine monitoring, rail break detection, geological exploration and pipeline leakage monitoring.

[0016] The beneficial effect of the present invention is that a new acoustic sensing method is proposed, the sensor structure is simple, easy to manufacture, and can be self-powered; and, tests show that the vibration frequency response range of the sensor can reach 3-10kHz. Through the multi-layer structure design (packaging layer, conductive layer, upper insulating layer, lower insulating layer, grid-like pad layer, conductive wire and micro-particle vibrating body), the flexible acoustic sensor achieves high sensitivity and stability, ensuring reliability and long-term stable operation in different environments. By designing the vibrating body to be a mixture of conductive particles and insulating particles, and generating friction electrification during vibration, the sensor can detect weak vibration signals with high sensitivity, and is particularly suitable for low signal-to-noise ratio environments. The upper insulating layer and the lower insulating layer are made of rigid insulating materials, which improves the structural stability and mechanical strength of the sensor and is suitable for harsh environments. The use of flexible insulating materials enhances the flexibility and adaptability of the sensor, enabling it to better fit irregular surfaces and expand its application range. The design and thickness control (0.1-0.25mm) of the grid-like pad layer ensure uniform force and high sensitivity while reducing weight. The design of the conductive wire optimizes the transmission of electrical signals and improves the efficiency and reliability of signal transmission. The encapsulation layer made of flexible waterproof material provides waterproof and dustproof protection and enhances environmental adaptability. The particle size control of the vibrating body (millimeter, micron or nanometer scale) expands the frequency response range and is suitable for multi-band monitoring. Ultimately, the flexible acoustic sensor has shown broad application prospects and significant performance advantages in many fields such as structural health monitoring, substation GIS fault monitoring, automobile engine monitoring, rail break detection, geological exploration and pipeline leakage monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing 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 creative work. Among them:

[0018] Figure 1 Schematic diagram of the overall structure of the flexible acoustic sensor of the present invention;

[0019] Figure 2 This is a physical picture of the acoustic sensing of the flexible acoustic sensor of the present invention;

[0020] Figure 3 It is a spectrum analysis diagram of the flexible acoustic sensor of the present invention;

[0021] Figure 4 This is a stability test diagram of the flexible acoustic sensor of the present invention. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0025] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0026] Example 1

[0027] Reference Figure 1-Figure 4 , as the first embodiment of the present invention, a flexible acoustic sensor is provided, and the device includes.

[0028] An acoustic sensor, the innovation of which is that: the acoustic sensor is composed of a packaging layer 1, a conductive layer 2, an upper insulating layer 3, a lower insulating layer 4, a grid-shaped cushion layer 5, a conductive wire 6 and a microparticle-shaped vibrating body 7;

[0029] The upper insulating layer 3, the grid-shaped cushion layer 5 and the lower insulating layer 4 are stacked together in sequence; a gap is left between the upper insulating layer 3 and the lower insulating layer 4; in specific implementation, the number of grids of the grid-shaped cushion layer 5 can be 2-6 grids, and the material can be silicone material or plastic material, and the material thickness is 0.1-0.25mm;

[0030] The conductive wire 6 is closely attached to one side of each grid of the grid-shaped cushion layer and one side is led out; in specific implementation, the diameter of the conductive wire can be 0.1-0.6mm, and the material can be conductive wire such as copper wire or conductive fiber wire;

[0031] The conductive layer 2 wraps the lead-out conductive wire 6. In a specific implementation, the thickness of the conductive layer is 0.05-0.2 mm, and the material can be a conductive material such as copper foil or aluminum foil;

[0032] The encapsulation layer 1 wraps the entire device. In a specific implementation, the encapsulation layer is a flexible material, such as a waterproof material such as polyurethane (PU), and the material thickness is 0.01-0.05mm;

[0033] The upper insulating layer 3, the lower insulating layer 4 and the grid-shaped cushion layer 5 form a vibration cavity. The vibration body 7 is filled in the vibration cavity; the particle size of a single particle in the vibration body 7 is in the order of millimeters, micrometers or nanometers; the multi-layer composite structure composed of the packaging layer, the conductive layer, the upper insulating layer, the lower insulating layer and the grid-shaped cushion layer not only enhances the overall mechanical strength and durability of the sensor, but also optimizes the internal electrical connection and signal transmission path, ensuring the stability and reliability of long-term use.

[0034] The friction point sequences of the vibrating body 7 and the upper insulating layer 3 are different, and the friction electric sequences of the vibrating body 7 and the lower insulating layer 4 are different.

[0035] Furthermore, the vibrating body 6 is made of a mixture of conductive particles and insulating particles; the conductive particles are processed from a single or multiple conductive materials; the insulating particles are processed from a single or multiple insulating materials. In specific implementation, the insulating particles can be made of plastic (such as PET, PTFE, etc.) or insulating ceramics (such as zirconia, etc.), and the conductive particles can be made of metal (copper, silver, iron, etc.) or carbon; in specific implementation, the ratio of insulating particles to conductive particles can be different (such as 2:3, 2:4, 3:5, etc.); by mixing conductive particles and insulating particles in a specific ratio and filling them in the vibration cavity, the triboelectric effect between different materials is used to improve the sensitivity and response speed of the sensor to weak vibration signals, so that vibration information can be accurately captured even in a low signal-to-noise ratio environment.

[0036] Furthermore, the upper insulating material 3 and the lower insulating material 4 are both made of flexible insulating materials, such as PET, PTFE or PDMS, etc. The encapsulation layer, the upper insulating layer and the lower insulating layer made of flexible materials (such as polyurethane, PET, PTFE or PDMS, etc.) ensure the flexibility and good adhesion of the sensor, so that it can adapt to different surface shapes, especially playing an important role in pipeline leakage monitoring and wearable devices.

[0037] In specific implementation, the present invention can be used for structural health monitoring (such as abnormal vibration caused by substation GIS failure, automobile engine monitoring, rail fracture detection, geological exploration, pipeline leakage monitoring, etc.). When the upper and lower insulating layers or the upper and lower surface layers are made of flexible insulating materials, the sensor can better fit the surface of various pipelines to monitor pipeline leakage, and can also be set on a bracelet as a wearable device to sense vibrations such as voice. Thanks to the above technological innovations, the flexible acoustic sensor has shown unique advantages in many fields, including but not limited to structural health monitoring, automobile engine status monitoring, geological disaster warning, and medical health monitoring, especially in application scenarios requiring high sensitivity and high reliability.

[0038] In summary, the present invention effectively solves the problems of hard limitations and insufficient sensitivity of traditional acoustic sensors through a series of innovative designs and technical means, significantly improves the application scope and performance level of the sensors, and demonstrates excellent performance and wide adaptability in practical applications.

[0039] Example 2

[0040] Reference Figure 1 - Figure 4 , which is the second embodiment of the present invention, provides a flexible acoustic sensor. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0041] In order to verify the performance of the flexible acoustic sensor in pipeline leakage monitoring, this embodiment selected two types of pipelines as test objects, namely standard steel pipelines and PVC plastic pipelines. During the experiment, a flexible acoustic sensor was first prepared according to the requirements of the invention. Specifically, a 0.15mm thick silicone material was selected as the grid-shaped cushion layer, and the size of each grid was 2mm x 2mm, ensuring good elastic recovery ability. The conductive wire uses a copper wire with a diameter of 0.3mm, which fits tightly to the edge of the grid-shaped cushion layer and is led out from one side to ensure good conductivity. The upper and lower insulating layers are both made of 0.02mm thick PDMS material, which not only provides sufficient insulation protection, but also maintains the overall softness. The vibrator is a mixture of conductive particles (copper powder) and insulating particles (PET particles) in a ratio of 3:2, with a particle size of about 100μm, which is filled in the vibration cavity between the upper and lower insulating layers. Finally, a 0.03mm thick polyurethane material is used as the encapsulation layer to fully wrap the entire sensor to ensure its waterproof performance.

[0042] Before the experiment, the sensor was fixed on the outer wall of two sections of pipes, each of which was 1 meter long and 10 cm in diameter. In order to simulate the actual leakage situation, small holes with a diameter of 2 mm were made at different positions of the pipe to release a certain amount of gas or liquid. The sensor was connected to the data acquisition system through a wire to monitor the pressure changes and vibration inside and outside the pipe in real time. For comparative analysis, a traditional rigid acoustic sensor was also set up as a control group. During the experiment, data was recorded every 1 minute and monitored for 1 hour to evaluate the response time and sensitivity of the sensor.

[0043] Table 1 Experimental data table

[0044]

[0045] Through the comparative analysis of the above experimental data, it can be clearly seen that the flexible acoustic sensor of the present invention has significant advantages in many aspects:

[0046] The response times of the flexible acoustic sensors were 15ms and 18ms, respectively, much lower than the 35ms of the control group. This means that in practical applications, flexible sensors can detect pipeline leaks more quickly and issue alarms in a timely manner, helping to reduce losses and improve safety.

[0047] The sensitivity of the flexible acoustic sensor reached 85dB and 82dB, while the control group was only 70dB. The higher sensitivity enables the flexible sensor to capture weak leakage signals more accurately and maintain high detection accuracy even in noisy environments.

[0048] The maximum detection distance of the flexible acoustic sensor is 0.5m and 0.4m, which is much higher than the 0.2m of the control group. This shows that the flexible sensor has stronger long-distance detection capability and is suitable for monitoring long-distance pipelines.

[0049] The false alarm rate of the flexible acoustic sensor was only 0.2% and 0.3%, much lower than the 2.0% of the control group. The low false alarm rate means that the sensor is more reliable in practical applications and reduces unnecessary maintenance and inspection costs.

[0050] The service life of the flexible acoustic sensors is 365 days, while that of the control group is only 180 days. The longer service life not only reduces the replacement frequency, but also reduces maintenance costs and improves economic benefits.

[0051] Although the materials and manufacturing process of the flexible acoustic sensor are more complicated, its cost is 120 yuan per piece, which is lower than the 150 yuan per piece of the control group. This is mainly due to the large-scale production of flexible materials and low-cost manufacturing technology.

[0052] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to several modifications still falling within the scope of the appended claims.

[0053] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0054] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A flexible acoustic sensor, characterized in that: The flexible acoustic sensor is composed of a packaging layer, a conductive layer, an upper insulating layer, a lower insulating layer, a grid-shaped cushion layer, a conductive wire and a micro-particle vibrating body; The upper insulating layer, the grid-shaped cushion layer and the lower insulating layer are stacked together in sequence; a gap is left between the upper insulating layer and the lower insulating layer; the conductive wire is tightly attached to one side of each grid of the grid-shaped cushion layer and one side is led out; the conductive layer wraps the led-out conductive wire; the upper insulating layer, the lower insulating layer and the grid-shaped cushion layer form a vibration cavity; the vibrating body is filled in the vibration cavity; the friction point sequence of the vibrating body and the upper insulating layer is different, and the friction electric sequence of the vibrating body and the lower insulating layer is different; the packaging layer wraps the entire device.

2. The flexible acoustic sensor according to claim 1, characterized in that: The vibrating body is formed by mixing conductive particles and insulating particles, and when the vibrating body vibrates, the conductive particles and the insulating particles rub against each other to generate electricity.

3. The flexible acoustic sensor according to claim 2, characterized in that: The upper insulating layer and the lower insulating layer are both made of rigid insulating material.

4. The flexible acoustic sensor according to claim 3, characterized in that: The upper insulating layer and the lower insulating layer are both made of flexible insulating material.

5. The flexible acoustic sensor according to claim 1, characterized in that: The grid-shaped cushion layer has a plurality of rectangular grids.

6. The flexible acoustic sensor according to claim 5, characterized in that: The thickness of the grid-shaped cushion layer is 0.1-0.25 mm.

7. The flexible acoustic sensor according to claim 6, characterized in that: The conductive wire is closely attached to one side of each grid of the grid-shaped cushion layer and one side is led out. The diameter of the conductive wire is 0.1-0.6 mm and the material is copper wire or conductive fiber wire.

8. The flexible acoustic sensor according to claim 7, characterized in that: The encapsulation layer is closely attached to the outside of the entire device, is made of a flexible waterproof material, and has a thickness of 0.01-0.05 mm.

9. The flexible acoustic sensor according to claim 8, characterized in that: The particle size of the vibrating body is in the order of millimeters, micrometers or nanometers.

10. The flexible acoustic sensor according to claim 9, characterized in that: The flexible acoustic sensor is used for structural health monitoring, including abnormal vibrations caused by substation GIS failures, automobile engine monitoring, rail break detection, geological exploration, and pipeline leakage monitoring.

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