阅读说明：本技术 一种增强驻波声场特性的声表面波芯片的设计方法 (Design method of surface acoustic wave chip for enhancing standing wave sound field characteristics ) 是由 韩建宁 唐帅 杨鹏 张赛 温廷敦 于 2019-11-08 设计创作，主要内容包括：本发明公开了一种增强驻波声场特性的声表面波芯片的设计方法,在确定普通压电基底材料的声表面波器件对比测试实验基础上构建铜柱阵列微结构的声场增强实验方案,通过实验获取基于声表面波信号控制的声学铜柱阵列微结构的多参数调节规律,并进行数据记录和分析,构建基于声学铜柱阵列微结构的声表面波模型,进行声波频率控制模拟实验,通过计算获得分析结果,获得多参数调节与声场分布特性的变化规律,加工并制作具有声场增强效果的铜柱阵列微结构的声表面波芯片的器件,不同的铜柱间距以及不同的铜柱阵列,对声场的调控以及增强效果是不一样的,实现多尺度、多功能的微流控需要,有效地对表面波声场进行调控,使声表面波芯片做到“按需定制”。(The invention discloses a design method of a surface acoustic wave chip for enhancing standing wave sound field characteristics, which is characterized in that a sound field enhancement experiment scheme of a copper column array microstructure is established on the basis of a comparison test experiment of a surface acoustic wave device of a common piezoelectric substrate material, a multi-parameter regulation rule of the acoustic copper column array microstructure based on surface acoustic wave signal control is obtained through the experiment, data recording and analysis are carried out, a surface acoustic wave model based on the acoustic copper column array microstructure is established, a sound wave frequency control simulation experiment is carried out, an analysis result is obtained through calculation, a change rule of multi-parameter regulation and sound field distribution characteristics is obtained, a device of the surface acoustic wave chip with the copper column array microstructure having the sound field enhancement effect is processed and manufactured, different copper column pitches and different copper column arrays are used for differently regulating and enhancing the sound field, and multi-scale distribution are realized, The surface acoustic wave field is effectively regulated and controlled by the multifunctional microfluidic requirement, so that the surface acoustic wave chip is customized according to the requirement.)

1. A design method of a surface acoustic wave chip for enhancing the characteristics of a standing wave sound field is characterized by comprising the following steps:

firstly, constructing a sound field enhancement experimental scheme of a copper column array microstructure based on a comparison test experiment of a surface acoustic wave device of a common piezoelectric substrate material;

acquiring a multi-parameter regulation rule of the acoustic copper column array microstructure based on surface acoustic wave signal control through experiments, and recording and analyzing data;

constructing a surface acoustic wave model based on the acoustic copper pillar array microstructure, performing an acoustic wave frequency control simulation experiment, and performing acoustic wave simulation and transmission test analysis; obtaining an analysis result through calculation;

step four, processing and manufacturing a device of the surface acoustic wave chip of the copper pillar array microstructure with the sound field enhancement effect according to the experimental data of the step three and the multi-parameter adjustment of the acoustic copper pillar array microstructure and the change rule of the sound field distribution characteristic;

and step five, debugging and perfecting the device of the surface acoustic wave chip with the copper column array microstructure prepared in the step four.

2. The method for designing a surface acoustic wave chip with enhanced standing wave acoustic field characteristics as claimed in claim 1, wherein the process of constructing the surface acoustic wave model in the third step is as follows:

step a, designing a three-dimensional plane schematic diagram of the surface acoustic wave device according to rich CAD drawing tools provided by COMSO L Multiphysics and combining the requirements of the model, and adding a copper pillar array microstructure at a chip at the center of the device;

b, setting physical properties of the material, and selecting material parameters of different components according to the parameter requirements of the model;

step c, gridding, namely refining the chip surface parts of the two interdigital transducers in the model;

and d, constructing a solving model.

3. The method for designing a surface acoustic wave chip with enhanced standing wave acoustic field characteristics as claimed in claim 2, wherein in said step d, the process of constructing the solution model is: once the distribution of particles or cells tends to be stable, a radio frequency RF signal is applied to the two interdigital transducers, and two groups of same surface acoustic wave SAW (SAW) propagating in opposite directions are generated;

the interference of the two groups of surface acoustic waves SAW forms surface acoustic wave standing waves SSAW, and nodes and antinodes which are periodically distributed are formed on the substrate; when the standing surface acoustic wave SSAW meets a liquid medium, longitudinal leakage waves are generated, and pressure fluctuation in the medium is caused; the pressure fluctuation generates an acoustic radiation force acting on suspended particles, and the acoustic radiation force is moved to a pressure node or an antinode in a standing wave SSAW field of the surface acoustic wave;

the main acoustic force exerted on the object by the action region of the standing surface acoustic wave SSAW can be expressed as:

wherein P0, λ and Vc are sound pressure, wavelength and volume, respectively, ρ c, ρ w, β c and β w are density of particles, density of medium, compressibility of particles and compressibility of medium, respectively, and Φ determines equilibrium position of particles, particles will be enriched at pressure node when Φ >0, and particles will be enriched at pressure node when Φ < 0.

4. The method for designing a surface acoustic wave chip with enhanced standing wave acoustic field characteristics as claimed in claim 1, wherein in the fourth step, a laser engraving machine is used to prepare the copper pillar structure required by the surface acoustic wave chip, and then the copper pillar structure is arrayed to complete the preparation of the chip surface microstructure.

5. The method for designing a surface acoustic wave chip with enhanced standing wave acoustic field characteristics as claimed in claim 4, wherein said copper pillar array microstructure comprises:

a substrate for transmitting acoustic signals;

the first transducer is arranged on the substrate and used for receiving an input electric signal, converting the electric signal into an acoustic signal and outputting the acoustic signal to the substrate;

a second transducer disposed on the substrate for receiving the acoustic signal from the substrate, converting the acoustic signal into an electrical signal and outputting the electrical signal;

the copper column array is arranged on the substrate and used for regulating the acoustic signal output by the first transducer and transmitted by the substrate, and regulating the acoustic signal and outputting the regulated acoustic signal to the second transducer through the substrate;

according to the sound field enhancement experiment scheme of the substrate and the copper column array, acquiring a multi-parameter regulation rule of the acoustic copper column array microstructure based on surface acoustic wave signal control through experiments, and recording and analyzing data;

and according to the construction of a surface acoustic wave model of the acoustic copper pillar array microstructure, carrying out acoustic wave simulation and transmission test analysis, and obtaining an analysis result through calculation.

6. The method of designing a saw chip with enhanced standing wave acoustic field characteristics as claimed in claim 5, wherein said copper pillar arrays are divided into two columns, and comprise a first copper pillar array and a second copper pillar array, said first copper pillar array being disposed inside said first transducer, said second copper pillar array being disposed inside said second transducer.

7. The method of designing a saw chip for enhancing standing wave acoustic field characteristics as claimed in claim 5, wherein said first transducer and said second transducer are interdigital transducers.

8. The method for designing a surface acoustic wave chip with an enhanced standing wave acoustic field characteristic as claimed in claim 5, wherein when the acoustic wave generated by the interdigital transducer passes through the surface acoustic wave chip model with the copper pillar array microstructure, the lithium niobate material substrate of the substrate vibrates first under the action of the acoustic wave after the acoustic wave encounters the copper pillar array, so as to drive the copper pillar array to vibrate, thereby performing acoustic field regulation.

9. The method for designing a surface acoustic wave chip for enhancing the sound field characteristics of standing waves as claimed in claim 5, wherein the sound field is regulated and enhanced differently for different copper pillar pitches and different copper pillar arrays, thereby forming a multi-scale and multi-functional microfluidic.

10. A method for designing a surface acoustic wave chip for enhancing the sound field characteristics of a standing wave according to claim 5, wherein the chip body is manufactured by machining; and the copper pillar spacing on the surface acoustic wave chip of the copper pillar array microstructure is different according to different sound field regulation and control requirements.

Technical Field

The invention belongs to the field of artificial acoustic microstructure design, and particularly relates to a design method of an acoustic surface wave chip for enhancing the characteristics of a standing wave sound field.

Background

The acoustic microstructure (including acoustic metamaterials) is one of the leading-edge research hotspots in physics in recent years. The acoustic surface wave chip can provide unprecedented and more flexible control for acoustic waves, a novel propagation rule in an acoustic microstructure opens up a new idea for researching the regulation and control of any frequency of acoustic wave signals, the acoustic surface wave chip also shows a good prospect in multifunctional and multi-scale microfluidic application, and the adjustable characteristic of an internal sound field of the acoustic surface wave chip is used in the fields of particle shunting, cell sorting and the like. Therefore, how to design the acoustic copper pillar array microstructure to realize the sound field regulation phenomenon according to the resonance characteristic of the acoustic copper pillar array microstructure scatterer and the interaction characteristic of the elastic wave and the substrate is a key problem.

The artificial acoustic microstructure (including the acoustic metamaterial) provides a new idea for a multi-scale and multifunctional application mode of the surface acoustic wave device, the artificial acoustic microstructure (including the acoustic metamaterial) greatly breaks through the limitation of natural materials, and a plurality of excellent papers are published in the research field every year.

Although many artificial acoustic ultrastructure (metamaterial) research results are obtained in recent years, application research specific to a certain field is relatively lacked. The phononic crystal is the most typical artificial acoustic metamaterial, the main structure of the current phononic crystal research is mainly embodied in that a model of a one-dimensional phononic crystal and a model of a two-dimensional phononic crystal are implemented under the infinite length condition, the model of the three-dimensional phononic crystal has a good effect in a low-frequency band, reports are few in a high-frequency ultrasonic stage, meanwhile, the three-dimensional crystal is inconvenient to prepare, the results are introduced into the field of surface acoustic wave research, more technical problems exist, and the research on the acoustic metamaterial different from the current phononic crystal is innovatively developed according to the special requirements of sound wave regulation.

Disclosure of Invention

The invention provides a design method for organically combining an acoustic copper pillar array microstructure and a surface acoustic wave chip, aiming at solving the technical problems existing in the prior art. The novel surface acoustic wave chip with the sound field enhancement characteristic is obtained by simple and intuitive calculation, the limitation of single sound field of the traditional surface acoustic wave device can be broken through, and the novel surface acoustic wave chip has practical significance for the application of the related fields such as microfluidics and the like.

In order to achieve the purpose, the invention provides the following technical scheme: a design method of a surface acoustic wave chip for enhancing the characteristics of a standing wave sound field comprises the following steps:

firstly, constructing a sound field enhancement experimental scheme of a copper column array microstructure based on a comparison test experiment of a surface acoustic wave device of a common piezoelectric substrate material;

acquiring a multi-parameter regulation rule of the acoustic copper column array microstructure based on surface acoustic wave signal control through experiments, and recording and analyzing data;

constructing a surface acoustic wave model based on the acoustic copper pillar array microstructure, performing an acoustic wave frequency control simulation experiment, and performing acoustic wave simulation and transmission test analysis; obtaining an analysis result through calculation;

step four, processing and manufacturing a device of the surface acoustic wave chip of the copper pillar array microstructure with the sound field enhancement effect according to the experimental data of the step three and the multi-parameter adjustment of the acoustic copper pillar array microstructure and the change rule of the sound field distribution characteristic;

and step five, debugging and perfecting the device of the surface acoustic wave chip with the copper column array microstructure prepared in the step four.

Further, the process of constructing the surface acoustic wave model in the third step is as follows:

step a, designing a three-dimensional plane schematic diagram of the surface acoustic wave device according to rich CAD drawing tools provided by COMSO L Multiphysics and combining the requirements of the model, and adding a copper pillar array microstructure at a chip at the center of the device;

b, setting physical properties of the material, and selecting material parameters of different components according to the parameter requirements of the model;

step c, gridding, namely refining the chip surface parts of the two interdigital transducers in the model;

and d, constructing a solving model.

Further, in the step d, the process of constructing the solution model includes: once the distribution of particles or cells tends to be stable, a radio frequency RF signal is applied to the two interdigital transducers, and two groups of same surface acoustic wave SAW (SAW) propagating in opposite directions are generated;

the interference of the two groups of surface acoustic waves SAW forms surface acoustic wave standing waves SSAW, and nodes and antinodes which are periodically distributed are formed on the substrate; when the standing surface acoustic wave SSAW meets a liquid medium, longitudinal leakage waves are generated, and pressure fluctuation in the medium is caused; the pressure fluctuation generates an acoustic radiation force acting on suspended particles, and the acoustic radiation force is moved to a pressure node or an antinode in a standing wave SSAW field of the surface acoustic wave; the main acoustic force exerted on the object by the action region of the standing surface acoustic wave SSAW can be expressed as:

wherein P0, λ and Vc are sound pressure, wavelength and volume, respectively, ρ c, ρ w, β c and β w are density of particles, density of medium, compressibility of particles and compressibility of medium, respectively, and Φ determines equilibrium position of particles, particles will be enriched at pressure node when Φ >0, and particles will be enriched at pressure node when Φ < 0.

Further, in the fourth step, a laser engraving machine is used for preparing the copper pillar structure required by the surface acoustic wave chip, and then the copper pillar structure is arrayed to complete the preparation of the chip surface microstructure.

Further, the device of the surface acoustic wave chip with the copper pillar array microstructure comprises the following components.

A substrate for transmitting acoustic signals.

The first transducer is arranged on the substrate and used for receiving an input electric signal, converting the electric signal into an acoustic signal and outputting the acoustic signal to the substrate.

A second transducer disposed on the substrate for receiving the acoustic signal from the substrate, converting the acoustic signal into an electrical signal and outputting the electrical signal.

And the copper column array is arranged on the substrate and used for regulating and controlling the acoustic signal output by the first transducer and transmitted by the substrate, and regulating and controlling the acoustic signal and outputting the regulated and controlled acoustic signal to the second transducer through the substrate.

And acquiring a multi-parameter regulation rule of the acoustic copper pillar array microstructure based on surface acoustic wave signal control through experiments according to the sound field enhancement experiment scheme of the substrate and the copper pillar array, and recording and analyzing data.

And according to the construction of a surface acoustic wave model of the acoustic copper pillar array microstructure, carrying out acoustic wave simulation and transmission test analysis, and obtaining an analysis result through calculation.

Furthermore, the copper column arrays are divided into two rows and comprise a first copper column array and a second copper column array, the first copper column array is arranged on the inner side of the first energy converter, and the second copper column array is arranged on the inner side of the second energy converter.

Further, the first transducer and the second transducer are interdigital transducers.

Further, when sound waves generated by the interdigital transducer pass through the surface acoustic wave chip model with the copper cylinder array microstructure, the sound waves encounter the copper cylinder array, and then the lithium niobate material substrate of the substrate vibrates firstly under the action of the sound waves to drive the copper cylinder array to vibrate so as to regulate and control the sound field.

Furthermore, the regulation and enhancement effects of different copper column distances and different copper column arrays on the sound field are different, so that the multi-scale and multifunctional micro-fluidic is formed.

Further, the chip entity is manufactured by machining; and the copper pillar spacing on the surface acoustic wave chip of the copper pillar array microstructure is different according to different sound field regulation and control requirements.

Drawings

FIG. 1 is a structural diagram of a SAW chip with enhanced standing wave acoustic field characteristics (copper pillar spacing 310 um);

FIG. 2 is a structural diagram of a SAW chip with enhanced standing wave acoustic field characteristics (copper pillar spacing 155 um);

FIG. 3 is a schematic diagram of surface acoustic field distribution of a surface acoustic wave device structure with a copper pillar array microstructure;

fig. 4 is a schematic diagram of surface acoustic field regulation of a surface acoustic wave device structure with a copper pillar array microstructure.

Detailed Description

The present invention will be further described with reference to the following examples.

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple modifications of the method of the present invention based on the concept of the present invention are within the scope of the claimed invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

The embodiment of the invention provides a method for designing a surface acoustic wave chip for enhancing the characteristics of a standing wave sound field. The design method is carried out in five steps.

Step one, constructing a sound field enhancement experimental scheme of a copper column array microstructure based on a comparison test experiment of a surface acoustic wave device of a common piezoelectric substrate material.

And step two, acquiring a multi-parameter regulation rule of the acoustic copper column array microstructure based on the acoustic surface wave signal control through experiments, and recording and analyzing data.

Constructing a surface acoustic wave model based on the acoustic copper pillar array microstructure, performing an acoustic wave frequency control simulation experiment, and performing acoustic wave simulation and transmission test analysis; the analysis results were obtained by calculation.

And step four, processing and manufacturing the device of the surface acoustic wave chip of the copper pillar array microstructure with the sound field enhancement effect according to the experimental data of the step three, the multi-parameter adjustment of the acoustic copper pillar array microstructure and the change rule of the sound field distribution characteristic.

And step five, debugging and perfecting the device of the surface acoustic wave chip with the copper column array microstructure prepared in the step four.

The process of constructing the surface acoustic wave model in the third step is carried out in four steps.

Step a, designing a three-dimensional plane schematic diagram of the surface acoustic wave device according to rich CAD drawing tools provided by COMSO L Multiphysics and combining the requirements of the model, and adding a copper pillar array microstructure at a chip at the center of the device.

Referring to fig. 1, a structure diagram of a design method of a surface acoustic wave chip for enhancing standing wave acoustic field characteristics includes a substrate 1, a first transducer 2, a second transducer 3, and a copper pillar array 4.

Wherein, the substrate 1 is used for transmitting acoustic signals, and the substrate 1 is made of piezoelectric solid material. In the embodiment of the present invention, the substrate 1 is lithium niobate.

The first transducer 2 is disposed on the substrate 1, and receives an input electrical signal and converts the electrical signal into an acoustic signal while outputting the acoustic signal to the substrate 1.

The second transducer 3 is disposed on the substrate 1 for receiving an acoustic signal from the substrate 1 and converting the acoustic signal into an electrical signal while outputting the electrical signal.

The copper column array 4 is arranged on the substrate 1 and used for regulating and controlling the acoustic signal output by the first transducer 2 transmitted through the substrate 1 and outputting the acoustic signal to the second transducer 3 through the substrate 1.

Specifically, the copper pillar arrays 4 are divided into two rows, the first copper pillar array 41 is disposed inside the first transducer 2, and the second copper pillar array 42 is disposed inside the second transducer 3. The first transducer 2 and the second transducer 3 are symmetrically disposed along the centerline of the substrate 1, and the first copper pillar array 41 and the second copper pillar array 42 are also symmetrically disposed along the centerline of the substrate 1. And in the present embodiment the first transducer 2 and the second transducer 3 are interdigital transducers.

In the embodiment of the present invention, the first array of copper pillars 41 and the second array of copper pillars 42 are a row of 7 copper pillars uniformly, and the distance between the two copper pillars is 310 um. It will be understood by those skilled in the art that the spacing between the two copper pillars in the present invention includes, but is not limited to, 310um and 155 um.

Referring to fig. 1, the two copper pillars are spaced apart by 310 um.

Referring to fig. 2, the two copper pillars are spaced apart by 155 um.

And b, setting physical properties of the material, and selecting material parameters of different components according to the parameter requirements of the model.

And c, gridding, and refining the chip surface parts of the two interdigital transducers in the model.

And d, constructing a solving model. Once the distribution of particles or cells has stabilized, a radio frequency RF signal is applied to the two interdigital transducers, which produce two identical sets of surface acoustic wave SAWs propagating in opposite directions. The interference of the two groups of surface acoustic waves SAW forms surface acoustic wave standing waves SSAW, and nodes and antinodes which are distributed periodically are formed on the substrate. When the standing surface acoustic wave SSAW encounters a liquid medium, longitudinal leakage waves are generated, causing pressure fluctuations in the medium. The pressure fluctuations generate acoustic radiation forces that act on the suspended particles and move the acoustic radiation forces to pressure nodes or antinodes in the standing surface acoustic wave SSAW field. The main acoustic force exerted on the object by the action region of the standing surface acoustic wave SSAW can be expressed as:

wherein P0, λ and Vc are sound pressure, wavelength and volume, respectively, ρ c, ρ w, β c and β w are density of particles, density of medium, compressibility of particles and compressibility of medium, respectively, and Φ determines equilibrium position of particles, particles will be enriched at pressure node when Φ >0, and particles will be enriched at pressure node when Φ < 0.

The method is used for simulating and debugging the acoustic surface wave chip of the copper column array microstructure, combines the microstructure design idea, explores the preparation process of the acoustic copper column array microstructure in combination with the simulation experiment, takes the copper columns as research objects, and researches the influence of different numbers, different substrate materials, different array modes and the like on the acoustic vibration frequency performance of the copper column array microstructure.

The prepared material is used as a matrix, the influence of different materials, densities and shapes on the vibration frequency of the surface acoustic wave device is researched, the experimental conditions and the structural composition of the surface acoustic wave chip with the best performance are determined, and the vibration characteristics of the surface acoustic wave chip are deeply researched.

Referring to fig. 3, the sound field enhancement effect can be determined by measuring the distribution of the sound field on the surface of the saw chip. The sound wave generated by the interdigital transducer passes through the surface acoustic wave chip model with the copper pillar array microstructure, and after the sound wave meets the copper pillar array, the lithium niobate material substrate of the substrate 1 vibrates firstly under the action of the sound wave to drive the copper pillar array 4 to vibrate so as to regulate and control the sound field. That is to say, the process of the sound wave transmitted through the copper column array 4 is the process of the common vibration of the internal lithium niobate and the copper column, so that the sound field regulation and control and the enhancement effect are realized.

Referring to fig. 4, (a) shows the sound field of the saw chip without the copper pillar array, (b) shows the sound field of the saw chip with the copper pillar pitch 310um, and (c) shows the sound field of the saw chip with the copper pillar pitch 155 um. The copper column array microstructure, different copper column intervals and different copper column arrays on the surface acoustic wave chip model of the copper column array microstructure have different sound field regulation and enhancement effects, so that the multi-scale and multifunctional microfluidic requirements are met, the surface acoustic wave field is effectively regulated and controlled, and the surface acoustic wave chip is customized as required, please refer to (d) and (e) in the graph in fig. 4.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.