阅读说明：本技术 一种自供电可视化声音传感器 (Self-powered visual sound sensor ) 是由 汪尧进 潘韩 吴瀚舟 蔡园园 聂长文 于 2021-07-05 设计创作，主要内容包括：本发明公开了一种自供电可视化声音传感器,涉及智能传感器领域,该传感器主要包括柔性衬底、压电薄膜层和电致发光薄膜层,基于声场-压电-电致发光多物理场耦合效应实现,可高效地将声音信号转化为电致发光薄膜层上的光信号变化,通过电致发光薄膜层的光信号亮度直观反应出环境中声音的强弱,实现声音可视化,从而可以实现智能人机交互模式,压电薄膜层直接受声波驱动产生振动,其本征振动响应可灵敏感知宽频域的声音信号,相比于动圈式声音传感器对中、高频率的声音信号仍有灵敏的探测性能,无需外部电源驱动、功耗低、工艺简单、读取信息方式简便,是一种更为智能的人机交互方案,适合当前物联网智能时代的使用需求。(The invention discloses a self-powered visual sound sensor, which relates to the field of intelligent sensors, mainly comprises a flexible substrate, a piezoelectric film layer and an electroluminescent film layer, is realized based on sound field-piezoelectric-electroluminescent multi-physical field coupling effect, can efficiently convert sound signals into light signal changes on the electroluminescent film layer, intuitively reflects the intensity of sound in the environment through the light signal brightness of the electroluminescent film layer, realizes sound visualization, thereby realizing an intelligent man-machine interaction mode, the piezoelectric film layer is directly driven by sound waves to generate vibration, the intrinsic vibration response can sensitively sense sound signals in a wide frequency domain, compared with a moving coil type sound sensor, the sound sensor still has sensitive detection performance on sound signals with middle and high frequencies, does not need an external power supply to drive, has low power consumption, simple process and simple and convenient information reading mode, the method is a more intelligent human-computer interaction scheme and is suitable for the use requirements of the current intelligent era of the Internet of things.)

1. A self-powered visual sound sensor is characterized by comprising a flexible substrate, a first transparent electrode layer, a piezoelectric film layer, a second transparent electrode layer, an electroluminescent film layer and a third transparent electrode layer which are sequentially stacked from bottom to top, wherein the transparent electrode layers on two sides of the electroluminescent film layer are respectively connected with the transparent electrode layers on two sides of the piezoelectric film layer through conductive silver adhesive to form a through circuit;

the piezoelectric film layer in the self-powered visual sound sensor is driven by sound waves to generate vibration and generate an electric signal corresponding to a sound wave signal through a piezoelectric effect, the electric signal generated by the piezoelectric film layer is transmitted to the electroluminescent film layer through an electrifying loop, and the electroluminescent film layer performs an optoelectronic reaction under the action of the electric signal to generate a luminous response with brightness corresponding to the sound wave signal.

2. The self-powered visual acoustic sensor of claim 1, wherein the piezoelectric material used for the piezoelectric film layer has a piezoelectric coefficient d₃₃≥25pC/N。

3. The self-powered visual acoustic sensor of claim 1, wherein the piezoelectric material used in the piezoelectric film layer is polyvinylidene fluoride copolymer or lead zirconate titanate.

4. The self-powered visual acoustic sensor of claim 1, wherein the flexible substrate is made of any one of polyethylene terephthalate, polydimethylsiloxane, imide plastic, polyethylene film, and mica.

5. Self-powered visual acoustic sensor according to claim 1, characterised in that the thickness of the flexible substrate is 0.2-0.4 mm.

6. The self-powered visual acoustic sensor of claim 1, wherein the electroluminescent film layer is made from at least one of zinc sulfide, manganese-doped zinc sulfide, copper-doped zinc sulfide, chlorine-doped zinc sulfide, and strontium-doped zinc sulfide.

7. A self-powered visual acoustic sensor according to any of claims 1 to 6, wherein each transparent electrode layer is adapted with a mass ratio In₂O₃:SnO₂9:1 transparent indium tin oxide.

Technical Field

The invention relates to the field of intelligent sensors, in particular to a self-powered visual sound sensor.

Background

The advanced sensor technology is one of the key problems of the application of the Internet of things, and plays an important role in the development of the novel Internet of things industry. In order to evaluate the human-computer interaction experience of the internet of things equipment and the user, the intelligence level of various sensors is an extremely important index. The sound sensor is one of the most common sensors in life, and is widely applied to the fields of environmental noise detection, military target detection, safety early warning and the like.

At present, a sound sensor is mainly based on a piezoresistive microphone, a capacitive microphone and a moving coil microphone, and a wire is driven to cut a magnetic line of force to generate current through the corresponding resistance and capacitance change of a device under the influence of sound waves or due to the vibration of sound, so that the aim of sound sensing is fulfilled. Non-patent document 1 (ding C, Gao P, Lan L, etc.. ultrasensive and high ply linear transducer with a Timbre-Recognition Based on Vertical gradient [ J ] Advanced Functional Materials,2019,29(51):1907151.) discloses a Stretchable stress sensor with capability of recognizing Timbre prepared from Vertical Graphene and polydimethylsiloxane, which is divided into small pieces due to high-density cracks in the Vertical Graphene, so that the entire sensor responds to sound over a wide frequency range. However, the above-mentioned voice sensor based on the piezoresistive and capacitive principles requires a separate external power supply, and thus has a large power consumption, whereas the moving coil voice sensor is insensitive to the response to the voice signals of medium and high frequencies due to its mechanical structural limitation. To overcome this disadvantage, people have recently made triboelectric acoustic sensors by using the design of the triboelectric effect. Non-patent document 2(Fan X, Chen J, Yang J, etc.. ultrarate, Rollable, Paper-Based Triboelectric Energy Harvesting and Self-Powered Sound Recording [ J ] ACS Nano,2015,9(4): 4236-.

Therefore, various defects of various conventional sound sensors exist, and signal reading terminals of all the sound sensors are always limited to pointers, displays and the like, so that external frequency components are required, and the miniaturization and high integration degree of the sound sensors are greatly limited. Therefore, the traditional sound sensor is difficult to meet new requirements brought by the development of the internet of things due to the limitations of the traditional sound sensor in intellectualization, miniaturization and integration. The characteristics of ultra-low power consumption and large frequency response range of the sound sensor are considered, and the mode of reading sound information by a user is optimized, so that the key problem to be solved urgently by the current intelligent sound sensor is solved.

Disclosure of Invention

The inventor provides a self-powered visual sound sensor aiming at the problems and the technical requirements, and the technical scheme of the invention is as follows:

a self-powered visual sound sensor comprises a flexible substrate, a first transparent electrode layer, a piezoelectric film layer, a second transparent electrode layer, an electroluminescent film layer and a third transparent electrode layer which are sequentially stacked from bottom to top, wherein the transparent electrode layers on two sides of the electroluminescent film layer are respectively connected with the transparent electrode layers on two sides of the piezoelectric film layer through conductive silver adhesive to form a power-on loop;

the piezoelectric film layer in the self-powered visual sound sensor is driven by sound waves to generate vibration and generate an electric signal corresponding to a sound wave signal through a piezoelectric effect, the electric signal generated by the piezoelectric film layer is transmitted to the electroluminescent film layer through the power-on loop, and the electroluminescent film layer performs an electro-optical reaction under the action of the electric signal to generate a luminous response with brightness corresponding to the sound wave signal.

The further technical proposal is that the piezoelectric filmPiezoelectric coefficient d of piezoelectric material used for the layer₃₃≥25pC/N。

The further technical scheme is that the piezoelectric material adopted by the piezoelectric film layer is polyvinylidene fluoride copolymer or lead zirconate titanate.

The further technical scheme is that the flexible substrate is made of any one of polyethylene terephthalate, polydimethylsiloxane, imide plastics, polyethylene film and mica.

The further technical proposal is that the thickness of the flexible substrate is 0.2-0.4 mm.

The electroluminescent film layer is made of at least one of zinc sulfide, manganese-doped zinc sulfide, copper-doped zinc sulfide, chlorine-doped zinc sulfide and strontium-doped zinc sulfide.

The further technical proposal is that each transparent electrode layer adopts In with mass ratio₂O₃:SnO₂9:1 transparent indium tin oxide.

The beneficial technical effects of the invention are as follows:

the application discloses a self-powered visual sound sensor, which is realized based on a sound field-piezoelectric-electroluminescence multi-physical field coupling effect, can efficiently convert sound signals into optical signal changes on an electroluminescence film layer, visually reflects the intensity of sound in the environment through the brightness of the optical signals of the electroluminescence film layer, realizes sound visualization, and further can realize an intelligent man-machine interaction mode. The sensor does not need to be driven by an external power supply, has low power consumption compared with the conventional common piezoresistive and capacitive sound sensors, is particularly suitable for working environments which need long-term work and are difficult to provide power or replace batteries, can realize noise index detection in various environments, and is suitable for the background of the current intelligent era of the Internet of things.

The sensor has a simple structure, and simultaneously, the sensor volume is further reduced and the integration level is improved due to the adoption of a layer-by-layer sputtering film forming process, and meanwhile, the damage threat caused by separation between device function layers possibly brought by a common assembling process is also avoided.

Drawings

Fig. 1 is a schematic structural diagram of a self-powered visual acoustic sensor of the present application.

FIG. 2 is a schematic diagram of electrical signals generated by piezoelectric thin film layers under the action of different acoustic signals.

FIG. 3 is a graph showing the relationship between the luminous intensity and wavelength of a sound-visualized sensor under the action of a sound wave signal and a comparison between non-luminous intensity and luminous intensity of the sensor.

Detailed Description

The following further describes the embodiments of the present invention with reference to the drawings.

The application discloses self-powered visual sound sensor, please refer to fig. 1, and the self-powered visual sound sensor includes a flexible substrate 1, a first transparent electrode layer 2, a piezoelectric thin film layer 3, a second transparent electrode layer 4, an electroluminescent thin film layer 5 and a third transparent electrode layer 6, which are stacked in sequence from bottom to top. The transparent electrode layers on the two sides of the electroluminescent thin film layer 5 and the transparent electrode layers on the two sides of the piezoelectric thin film layer 3 are respectively connected through conductive silver adhesive to form a power-on loop.

The piezoelectric film layer 3 in the self-powered visual acoustic sensor is driven by sound waves to generate vibration, and generates an electrical signal corresponding to a sound wave signal by a piezoelectric effect, where reference is made to a schematic diagram shown in fig. 2 for a corresponding relationship between the sound wave signal and the electrical signal. An electric signal generated by the piezoelectric thin film layer 3 is transmitted to the electroluminescent thin film layer 5 through the power-on loop, the electroluminescent thin film layer 5 generates a photoelectric reaction under the action of the electric signal to generate a light-emitting response corresponding to brightness and a sound wave signal, a graph of a relationship between light-emitting intensity and wavelength of the self-powered visual sound sensor under the action of the sound wave signal refers to the left side of fig. 3, and the right side of fig. 3 is a comparison schematic diagram of non-light-emitting and light-emitting of the self-powered visual sound sensor. Therefore, the self-powered visual sound sensor is based on the sound field-piezoelectric-electroluminescence multi-physical field coupling effect, does not need to be driven by an external power supply, can convert sound signals into visual luminance luminous response, realizes sound visualization, and can realize an intelligent man-machine interaction mode.

Wherein, the piezoelectric coefficient d of the piezoelectric material used for the piezoelectric thin film layer 3₃₃Not less than 25pC/N, so that the electric energy threshold requirement of the luminescence required by driving the electroluminescent thin film layer 5 can be met. Optionally, the piezoelectric material used by the piezoelectric thin film layer 3 is polyvinylidene fluoride (PVDF-TrFe) copolymer or lead zirconate titanate (PZT).

The flexible substrate 1 is made of any one of polyethylene terephthalate (PET), Polydimethylsiloxane (PDMS), imide Plastic (PI), polyethylene film (PE), and mica (AlF2O10Si33 Mg). Optionally, the thickness of the flexible substrate 1 is 0.2-0.4 mm.

The electroluminescent thin film layer 5 is made of at least one material of zinc sulfide (ZnS), manganese-doped zinc sulfide (ZnS: Mn), copper-doped zinc sulfide (ZnS: Cu), chlorine-doped zinc sulfide (ZnS: Cl), and strontium-doped zinc sulfide (ZnS: Sr). The thickness of the electroluminescent thin-film layer 5 is approximately 500 nm.

Each transparent electrode layer adopts In mass ratio₂O₃:SnO₂9:1 transparent Indium Tin Oxide (ITO).

When the self-powered visual sound sensor is manufactured, the first transparent electrode layer 2 is deposited on the flexible substrate 1 through a magnetron sputtering method or an evaporation method, then the piezoelectric thin film layer 3 is prepared on the first transparent electrode layer 2 through a coating method or a magnetron sputtering method, and then the second transparent electrode layer 4 is prepared and formed on the piezoelectric thin film layer 3 through the magnetron sputtering method or the evaporation method. An electroluminescent thin film layer 5 is formed on the second transparent electrode layer 4 by vapor deposition. And finally, preparing and forming a third transparent electrode layer 6 on the electroluminescent film layer 5 by adopting a magnetron sputtering method or an evaporation method.

Since each layer has a plurality of optional preparation materials, the preparation method is specifically described in the following two example material combination modes:

in example 1, PVDF-TrFe polymer was used to fabricate the piezoelectric thin film layer 3, and manganese-doped zinc sulfide (ZnS: Mn) was used to fabricate the electroluminescent thin film layer 5. The specific implementation steps are as follows:

depositing a first transparent electrode layer 2 on a flexible PET substrate by using a magnetron sputtering method, and coating a piezoelectric polymer PVDF-TrFe on the first transparent electrode layer 2 by blade coating to obtain a piezoelectric film layer 3. And putting the piezoelectric film layer 3 into a small magnetron sputtering instrument, manufacturing an ITO transparent full electrode above the piezoelectric film layer by a sputtering method to obtain a second transparent electrode layer 4, and finally obtaining the piezoelectric sound sensitive unit.

And respectively placing ZnS, Mn powder and a certain proportion of high-purity Er on two Ta boats, pumping a high vacuum in an evaporation chamber, and respectively heating the Ta boats to evaporate and deposit the ZnS, Mn and the Er on the second transparent electrode layer 4 together. Wherein the process conditions are as follows: vacuum degree (better than 5X 10)^-5) Ta boat current (190A), substrate temperature (460K), boat-to-electrode distance (about 20cm), deposition time (15 minutes).

After the electroluminescent thin film layer 5 is formed by vapor deposition, a third transparent electrode layer 6 is formed on the electroluminescent thin film layer 5 by magnetron sputtering. The positive and negative electrodes on the upper and lower sides of the electroluminescent thin film layer 5 are respectively connected with the positive and negative electrodes on the upper and lower sides of the piezoelectric thin film layer 3 through conductive silver adhesive, and finally a complete loop is formed.

In example 2, a piezoelectric thin film layer 3 was formed using high-performance PZT, and an electroluminescent thin film layer 5 was formed using strontium-doped zinc sulfide (ZnS: Sr). The specific implementation steps are as follows:

the first transparent electrode layer 2 is deposited on the flexible mica substrate by using a magnetron sputtering method, and the piezoelectric thin film layer 3 of the PZT material is prepared on the first transparent electrode layer 2 by using a sol-gel spin coating method. And putting the piezoelectric film layer 3 into a small magnetron sputtering instrument, manufacturing an ITO transparent full electrode above the piezoelectric film layer by a sputtering method to obtain a second transparent electrode layer 4, and finally obtaining the piezoelectric sound sensitive unit.

Respectively placing ZnS, Sr powder and a certain proportion of high-purity simple substance Er on two Ta boats. And pumping the evaporation chamber into high vacuum, and respectively heating the Ta boats to evaporate and deposit the ZnS, Sr and Er together on the second transparent electrode layer 4. Wherein the process conditions are as follows: vacuum degree (better than 5X 10)^-5) Ta boat current (200A), substrate temperature (470K), boat-to-electrode distance (about 20cm), deposition time (20 minutes).

After the electroluminescent thin film layer 5 is formed by vapor deposition, a third transparent electrode layer 6 is formed on the electroluminescent thin film layer 5 by magnetron sputtering. The positive and negative electrodes on the upper and lower sides of the electroluminescent thin film layer 5 are respectively connected with the positive and negative electrodes on the upper and lower sides of the piezoelectric thin film layer 3 through conductive silver adhesive, and finally a complete loop is formed.

What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.