A silicon oil encapsulated evaporation resistant flexible ultrasonic array hydrophone

Abstract

The utility model discloses a kind of evaporative-resistant flexible ultrasonic array hydrophone based on silicone oil packaging, belong to underwater acoustic detection technical field.The hydrophone includes P(VDF-TrFE) ultrasonic flexible array, copper electrode, hydrogel layer, acoustic backing layer, sealed shell and silicone oil filling layer.The sealed shell and acoustic backing layer form airtight cavity, and the silicone oil filled in cavity completely immerges hydrogel layer, ultrasonic flexible array and copper electrode.The utility model utilizes the excellent moisturizing performance of silicone oil, effectively prevents hydrogel moisture evaporation and copper electrode oxidation corrosion, ensures the long-term stability and reliability of hydrophone performance.

Description

Technical Field

[0001] This utility model relates to the field of underwater acoustic detection and ultrasonic sensor technology, specifically to a flexible ultrasonic array hydrophone that can work stably for a long time and prevent the evaporation of internal functional media. Background Technology

[0002] P(VDF-TrFE) piezoelectric copolymers are ideal materials for fabricating flexible hydrophones and arrays due to their flexibility and excellent piezoelectric properties. In the design and application of such hydrophones, to achieve optimal acoustic coupling and impedance matching, hydrogels or a layer of water are often used as coupling media in the transducer's acoustic wave action region. Copper electrodes, due to their excellent conductivity, are widely used to connect P(VDF-TrFE) piezoelectric materials to extract electrical signals, while the acoustic backing layer is used to absorb back-radiated acoustic energy and suppress noise interference.

[0003] However, hydrogels or aqueous media suffer from gradual moisture evaporation during long-term use, especially in environments that are not completely sealed or subject to temperature fluctuations. Moisture evaporation causes the hydrogel to dry and shrink, altering the acoustic characteristics of the device (such as acoustic impedance and sound velocity). This ultimately leads to performance degradation phenomena such as hydrophone receiver sensitivity drift and center frequency shift, and in severe cases, may cause the sound wave transmission path to fail, rendering the device completely inoperable. Simultaneously, copper electrodes are also at risk of oxidation and electrochemical corrosion in humid environments. Current technologies primarily focus on waterproofing the external environment, lacking long-term stable protection solutions for the internal working medium and electrodes. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a flexible ultrasonic array hydrophone that can effectively prevent the evaporation of the internal aqueous medium, protect the electrodes, and ensure long-term stable performance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] An evaporation-resistant flexible ultrasonic array hydrophone based on silicone oil encapsulation includes a P(VDF-TrFE) ultrasonic flexible array, copper electrodes, a hydrogel layer, an acoustic backing layer, a sealing shell, and a silicone oil filling layer. The copper electrodes are disposed on the upper and lower surfaces of the P(VDF-TrFE) ultrasonic flexible array. The hydrogel layer covers the P(VDF-TrFE) ultrasonic flexible array and the copper electrodes facing the sound source. The acoustic backing layer is disposed on the side of the P(VDF-TrFE) ultrasonic flexible array facing away from the sound source. The sealing shell and the acoustic backing layer together form a sealed cavity, encapsulating the P(VDF-TrFE) ultrasonic flexible array, copper electrodes, and hydrogel layer within it. The silicone oil filling layer fills the sealed cavity and completely immerses the hydrogel layer, the P(VDF-TrFE) ultrasonic flexible array, and the copper electrodes.

[0007] The beneficial effects of this utility model are:

[0008] 1. By utilizing the excellent hydrophobicity and extremely low saturated vapor pressure of silicone oil, an impenetrable physical barrier is formed around the core functional area of ​​the device, fundamentally blocking the evaporation of water from the hydrogel to the external environment. This allows the acoustic performance of the hydrophone (such as sensitivity and frequency response) to remain highly stable during long-term use, solving the problem of performance degradation caused by the drying of the medium.

[0009] 2. The silicone oil filling layer effectively moisturizes the surface while completely isolating it from moisture and oxygen in the external environment, providing an inert and dry microenvironment for the internal copper electrodes. This greatly inhibits the oxidation and electrochemical corrosion process of the copper electrodes, significantly extending their service life and improving the reliability of signal transmission.

[0010] 3. This invention is not a simple physical encapsulation. The acoustic backing layer is designed to absorb unwanted back-facing sound waves, reducing noise levels. Simultaneously, the selected silicone oil possesses excellent acoustic properties, with moderate sound velocity and density, and an acoustic impedance between that of the hydrogel and the encapsulation shell, providing a good acoustic transition and ensuring efficient transmission of sound waves from the outside to the sensing unit, minimizing insertion loss.

[0011] 4. The entire packaging solution has a compact structure, with interlayer bonding and potting processes, making it easy to implement and mass-produce. This structure gives the hydrophone good flexibility, allowing it to perfectly fit the complex curved surfaces of underwater vehicles and other equipment, achieving conformal installation and minimizing interference with the flow field. Attached Figure Description

[0012] Figure 1 is a cross-sectional structural diagram of a specific embodiment of the present invention;

[0013] Figure 2 is a three-dimensional structural schematic diagram of this utility model;

[0014] Marker explanation:

[0015] 1: P(VDF-TrFE) Flexible Ultrasonic Array

[0016] 2: Copper electrode

[0017] 3: Hydrogel layer

[0018] 4: Acoustic backing layer

[0019] 5: Sealed outer casing

[0020] 6: Silicone oil filler layer

[0021] 7: Island Bridge Structure Detailed Implementation

[0022] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0023] This embodiment provides an evaporation-resistant flexible ultrasonic array hydrophone based on silicone oil encapsulation, which includes a P(VDF-TrFE) flexible ultrasonic array, copper electrodes, a hydrogel layer, an acoustic backing layer, a sealing shell, and a silicone oil filling layer.

[0024] The P(VDF-TrFE) ultrasonic flexible array has a thickness of 0.8 mm and is formed by laser cutting. Copper electrodes are fabricated on the upper and lower surfaces of the array using photolithography and vacuum deposition processes, with an electrode thickness of 5 μm. A hydrogel layer with a thickness of 1.5 mm covers the acoustic wave incident side of the array. The acoustic backing layer is made of silicone doped with 40% tungsten powder (800 mesh particle size) and has a thickness of 2 mm. The sealing shell is injection molded from silicone and together with the backing layer forms a sealed cavity.

[0025] During fabrication, each component was first ultrasonically cleaned and dried. Then, the acoustic backing layer, the P(VDF-TrFE) array and electrodes, and the hydrogel layer were sequentially aligned and bonded. Silicone was used to bond the sealing shell to the periphery of the backing layer, forming a sealed cavity with a pre-drilled oil injection hole. Medical-grade silicone oil with a kinematic viscosity of 50 cSt was injected under a vacuum of -0.1 MPa, ensuring complete immersion of the internal components without any air bubbles. Finally, the oil injection hole was sealed.

[0026] The prepared hydrophone was subjected to performance testing, and the results showed that its center frequency was 100kHz and its receiving sensitivity was -205dB (reference value 1V / μPa). After 30 days of continuous operation testing, the sensitivity drift was less than 0.5dB, and no visible oxidation corrosion was observed on the copper electrode, verifying the excellent long-term stability and reliability of this invention.

[0027] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A flexible ultrasonic array hydrophone based on silicone oil encapsulation, comprising: P(VDF-TrFE) ultrasonic flexible array (1) is used as the core sensing unit; Copper electrodes (2) are disposed on the upper and lower surfaces of the P(VDF-TrFE) ultrasonic flexible array (1) for signal extraction; A hydrogel layer (3) covers the P(VDF-TrFE) ultrasonic flexible array (1) and its copper electrode (2) facing the sound source. An acoustic backing layer (4) is disposed on the side of the P(VDF-TrFE) ultrasonic flexible array (1) facing away from the sound source; The sealed outer shell (5) together with the acoustic backing layer (4) forms a closed cavity, which encapsulates the P(VDF-TrFE) ultrasonic flexible array (1), copper electrode (2) and hydrogel layer (3). Its features include: a silicone oil filling layer (6) filling the sealed cavity and completely immersing the hydrogel layer (3), the P(VDF-TrFE) ultrasonic flexible array (1) and the copper electrode (2).

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