阅读说明：本技术 一种声镊的生成方法及生成系统 (Method and system for generating acoustic tweezers ) 是由 马腾 胡颀 王丛知 肖杨 郑海荣 于 2020-11-17 设计创作，主要内容包括：本申请公开了一种声镊的生成方法及生成系统,其中,在所述声镊的生成方法中,可根据需求,确定声阱刚度满足需求的多个操控声场,并反向确定所述操控声场对应的换能器阵元的发射相位,之后根据各个换能器阵元的发射相位控制所述换能器阵元工作,依次生成所述操控声场序列中的操控声场,实现对换能器阵元的分时复用,形成综合声场控制目标微粒,由于综合声场是由时序上依次排列的多个操控声场形成的,可叠加不同操控生成类型或不同声场参数的操控声场在不同方向的限制能力优势,提高综合声场的限制能力、稳定性以及抗干扰强度。(The application discloses a generation method and a generation system of acoustic tweezers, wherein in the generation method of the acoustic tweezers, a plurality of control sound fields with sound trap rigidity meeting requirements can be determined according to requirements, the emission phases of transducer array elements corresponding to the control sound fields are reversely determined, then the transducer array elements are controlled to work according to the emission phases of the transducer array elements, the control sound fields in a control sound field sequence are sequentially generated, time-sharing multiplexing of the transducer array elements is realized, comprehensive sound field control target particles are formed, and due to the fact that the comprehensive sound field is formed by the plurality of control sound fields sequentially arranged in time sequence, the advantages of the limiting capacities of the control sound fields of different control generation types or different sound field parameters in different directions can be superposed, and the limiting capacity, the stability and the anti-interference strength of the comprehensive sound field are improved.)

1. A method for generating acoustic tweezers is realized based on a transducer module, wherein the transducer module comprises at least one transducer array, each transducer array comprises a plurality of transducer elements arranged in an array, and the method for generating acoustic tweezers comprises:

determining a plurality of control sound fields which are sequentially arranged in a time domain to determine a control sound field sequence; the sound field types or sound field parameters of at least two of the plurality of manipulated sound fields are different;

determining the transmitting phase of a transducer array element corresponding to each manipulation sound field in the manipulation sound field sequence based on an iterative back propagation algorithm;

and controlling the transducer array elements to work according to the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence, and sequentially generating the control sound fields in the control sound field sequence to form comprehensive sound field control target particles.

2. The method of claim 1, wherein the determining the transmit phase of the transducer element corresponding to each of the steered sound fields in the sequence of steered sound fields based on an iterative back propagation algorithm comprises:

determining a preset control focus and an information vector of the preset control focus according to the type of the control sound field;

acquiring position information of transducer array elements in the transducer module and sound source model information of the transducer array elements, and determining propagation coefficients of the preset control focus and each transducer array element in the transducer module according to the preset control focus, the position information of the transducer array elements and the sound source model information of the transducer array elements;

generating a propagation coefficient matrix according to the preset control focus and the propagation coefficients of all transducer array elements in the transducer module;

and determining the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus.

3. The method of claim 2, wherein determining propagation coefficients of the preset control focus and each transducer element in the transducer module according to the preset control focus, the position information of the transducer element and the sound source model information of the transducer element comprises:

when the sound source model information of the transducer array element is a piston type sound source model, substituting the preset control focus and the position information of the transducer array element into a first preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

when the sound source model information of the transducer array element is a point sound source model, substituting the preset control focus and the position information of the transducer array element into a second preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

the first preset formula includes:where k is the wave number of the transducer array element, a is the piston radius of the transducer array element, J₁Is a first order Bessel function, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijThe elevation deflection of a line connecting a preset control focus j and the transducer array element i is achieved;

the second preset formula includes:wherein, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijAnd controlling the elevation deflection of the line connecting the focal point j and the transducer array element i for presetting.

4. The method of claim 2, wherein determining the transmit phase of each transducer element according to the propagation coefficient matrix and the information vector of the preset control focus comprises:

substituting the propagation coefficient matrix and the information vector of the preset control focus into a third preset formula to calculate and obtain the transmitting phase of the transducer array element;

the third preset formula includes:wherein the content of the first and second substances,representing the transducer arrayPhase of transmission of element, H_ijRepresenting said matrix of propagation coefficients, n_jAn information vector representing the preset focus of control, the information vector including a phase and a weight of the preset focus of control, Im () representing a real part, Re () representing an imaginary part.

5. The method of claim 1, wherein the sound field types include at least dual sound traps, vortex sound traps, and partial hollow sound traps, and wherein the sound field parameters include at least duty cycle, amplitude, and frequency of a steered sound field.

6. The method of claim 1, further comprising:

and acquiring the motion state of the target particles and the environmental parameters of the environment where the target particles are located, adjusting the control sound field sequence according to the motion state and the environmental parameters, and returning to the step of determining the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence based on an iterative back propagation algorithm.

7. A system for generating acoustic tweezers, comprising: the device comprises a transducer module and a signal transmitting module; wherein the content of the first and second substances,

the transducer module comprises at least one transducer array, and each transducer array comprises a plurality of transducer elements arranged in an array;

the signal transmitting module is used for determining the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence based on an iterative back propagation algorithm; the control sound field sequence comprises a plurality of control sound fields which are sequentially arranged on a time domain; the sound field types or sound field parameters of at least two of the plurality of manipulated sound fields are different;

and controlling the transducer array elements to work according to the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence, and sequentially generating the control sound fields in the control sound field sequence to form comprehensive sound field control target particles.

8. The system according to claim 7, wherein the signal transmitting module determines the transmitting phase of the transducer element corresponding to each of the steering sound fields in the steering sound field sequence based on an iterative back propagation algorithm, specifically including:

determining a preset control focus and an information vector of the preset control focus according to the type of the control sound field;

acquiring position information of transducer array elements in the transducer module and sound source model information of the transducer array elements, and determining propagation coefficients of the preset control focus and each transducer array element in the transducer module according to the preset control focus, the position information of the transducer array elements and the sound source model information of the transducer array elements;

generating a propagation coefficient matrix according to the preset control focus and the propagation coefficients of all transducer array elements in the transducer module;

and determining the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus.

9. The system according to claim 8, wherein the process of the signal transmitting module determining propagation coefficients of the preset control focus and each transducer element in the transducer module according to the preset control focus, the position information of the transducer element, and the sound source model information of the transducer element specifically includes:

when the sound source model information of the transducer array element is a piston type sound source model, substituting the preset control focus and the position information of the transducer array element into a first preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

when the sound source model information of the transducer array element is a point sound source model, substituting the preset control focus and the position information of the transducer array element into a second preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

the first preset formula includes:where k is the wave number of the transducer array element, a is the piston radius of the transducer array element, J₁Is a first order Bessel function, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijThe elevation deflection of a line connecting a preset control focus j and the transducer array element i is achieved;

the second preset formula includes:wherein, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijAnd controlling the elevation deflection of the line connecting the focal point j and the transducer array element i for presetting.

10. The system according to claim 8, wherein the process of the signal transmitting module determining the transmitting phase of each transducer element according to the propagation coefficient matrix and the information vector of the preset control focus specifically includes:

substituting the propagation coefficient matrix and the information vector of the preset control focus into a third preset formula to calculate and obtain the transmitting phase of the transducer array element;

the third preset formula includes:wherein the content of the first and second substances,representing the transmission phase, H, of said transducer elements_ijRepresenting said matrix of propagation coefficients, n_jAn information vector representing the preset control focus, the information vector including the preset controlThe phase and weight of the focusing point, Im () denotes the real part and Re () denotes the imaginary part.

11. The system of claim 7, wherein the sound field types include at least dual sound traps, vortex sound traps, and partial hollow sound traps, and wherein the sound field parameters include at least duty cycle, amplitude, and frequency of the steering sound field.

12. The system of claim 7, further comprising: a monitoring module;

the monitoring module is configured to acquire a motion state of the target particle and an environmental parameter of an environment in which the target particle is located, adjust the control sound field sequence according to the motion state and the environmental parameter, and trigger the signal transmitting module in a return manner.

Technical Field

The present application relates to the field of acoustic technologies, and in particular, to a method and a system for generating acoustic tweezers.

Background

Acoustic Tweezers, also known as micro acoustic Tweezers (acoustic Tweezers), are a technology for performing non-contact manipulation on a micro object by using the mechanical effect of acoustic waves.

Most of the existing acoustic tweezers manipulation technologies can manipulate particles in the air, the acoustic tweezers are rarely researched to be applied to complex environments such as a living body, the limiting capability of the acoustic tweezers needs to be improved when the acoustic tweezers are used for controlling the particles in the complex environments such as the living body, and the limiting capability of the acoustic tweezers generated by the manipulation technologies in the prior art is difficult to meet the requirements of the limiting capability, the stability and the anti-interference strength of the acoustic tweezers applied to the complex environments.

Disclosure of Invention

In order to solve the technical problems, the application provides a method and a system for generating acoustic tweezers, so as to solve the problems of poor limiting capability, stability and anti-interference strength of the acoustic tweezers generated by the acoustic tweezers generating method in the prior art.

In order to achieve the technical purpose, the embodiment of the application provides the following technical scheme:

a method for generating acoustic tweezers is implemented based on a transducer module, wherein the transducer module comprises at least one transducer array, each transducer array comprises a plurality of transducer elements arranged in an array, and the method for generating acoustic tweezers comprises the following steps:

determining a plurality of control sound fields which are sequentially arranged in a time domain to determine a control sound field sequence; the sound field types or sound field parameters of at least two of the plurality of manipulated sound fields are different;

determining the transmitting phase of a transducer array element corresponding to each manipulation sound field in the manipulation sound field sequence based on an iterative back propagation algorithm;

and controlling the transducer array elements to work according to the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence, and sequentially generating the control sound fields in the control sound field sequence to form comprehensive sound field control target particles.

Optionally, the determining, based on the iterative back propagation algorithm, the transmit phase of the transducer element corresponding to each of the steering sound fields in the steering sound field sequence includes:

determining a preset control focus and an information vector of the preset control focus according to the type of the control sound field;

acquiring position information of transducer array elements in the transducer module and sound source model information of the transducer array elements, and determining propagation coefficients of the preset control focus and each transducer array element in the transducer module according to the preset control focus, the position information of the transducer array elements and the sound source model information of the transducer array elements;

generating a propagation coefficient matrix according to the preset control focus and the propagation coefficients of all transducer array elements in the transducer module;

and determining the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus.

Optionally, the determining, according to the preset control focus, the position information of the transducer array element, and the sound source model information of the transducer array element, propagation coefficients of the preset control focus and each transducer array element in the transducer module includes:

when the sound source model information of the transducer array element is a piston type sound source model, substituting the preset control focus and the position information of the transducer array element into a first preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

when the sound source model information of the transducer array element is a point sound source model, substituting the preset control focus and the position information of the transducer array element into a second preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

the first preset formula includes:where k is the wave number of the transducer array element, a is the piston radius of the transducer array element, J₁Is a first order Bessel function, | r_i-r_jI denotes the distance from a preset control focus j to the transducer element iLinear distance, theta_ijThe elevation deflection of a line connecting a preset control focus j and the transducer array element i is achieved;

the second preset formula includes:wherein, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijAnd controlling the elevation deflection of the line connecting the focal point j and the transducer array element i for presetting.

Optionally, the determining the transmit phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus includes:

substituting the propagation coefficient matrix and the information vector of the preset control focus into a third preset formula to calculate and obtain the transmitting phase of the transducer array element;

the third preset formula includes:wherein the content of the first and second substances,representing the transmission phase, H, of said transducer elements_ijRepresenting said matrix of propagation coefficients, n_jAn information vector representing the preset focus of control, the information vector including a phase and a weight of the preset focus of control, Im () representing a real part, Re () representing an imaginary part.

Optionally, the sound field types at least include a dual sound trap, a vortex sound trap and a partial hollow sound trap, and the sound field parameters at least include a duty ratio, an amplitude and a frequency for manipulating the sound field.

Optionally, the method further includes:

and acquiring the motion state of the target particles and the environmental parameters of the environment where the target particles are located, adjusting the control sound field sequence according to the motion state and the environmental parameters, and returning to the step of determining the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence based on an iterative back propagation algorithm.

A system for generating acoustic tweezers, comprising: the device comprises a transducer module and a signal transmitting module; wherein the content of the first and second substances,

the transducer module comprises at least one transducer array, and each transducer array comprises a plurality of transducer elements arranged in an array;

the signal transmitting module is used for determining the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence based on an iterative back propagation algorithm; the control sound field sequence comprises a plurality of control sound fields which are sequentially arranged on a time domain; the sound field types or sound field parameters of at least two of the plurality of manipulated sound fields are different;

and controlling the transducer array elements to work according to the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence, and sequentially generating the control sound fields in the control sound field sequence to form comprehensive sound field control target particles.

Optionally, the process of determining, by the signal transmitting module, the transmitting phase of the transducer array element corresponding to each of the manipulation sound fields in the manipulation sound field sequence based on an iterative back propagation algorithm specifically includes:

determining a preset control focus and an information vector of the preset control focus according to the type of the control sound field;

acquiring position information of transducer array elements in the transducer module and sound source model information of the transducer array elements, and determining propagation coefficients of the preset control focus and each transducer array element in the transducer module according to the preset control focus, the position information of the transducer array elements and the sound source model information of the transducer array elements;

generating a propagation coefficient matrix according to the preset control focus and the propagation coefficients of all transducer array elements in the transducer module;

and determining the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus.

Optionally, the process of determining, by the signal transmitting module, propagation coefficients of the preset control focus and each transducer array element in the transducer module according to the preset control focus, the position information of the transducer array element, and the sound source model information of the transducer array element specifically includes:

when the sound source model information of the transducer array element is a piston type sound source model, substituting the preset control focus and the position information of the transducer array element into a first preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

when the sound source model information of the transducer array element is a point sound source model, substituting the preset control focus and the position information of the transducer array element into a second preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

the first preset formula includes:where k is the wave number of the transducer array element, a is the piston radius of the transducer array element, J₁Is a first order Bessel function, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijThe elevation deflection of a line connecting a preset control focus j and the transducer array element i is achieved;

the second preset formula includes:wherein, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijAnd controlling the elevation deflection of the line connecting the focal point j and the transducer array element i for presetting.

Optionally, the process of determining, by the signal transmitting module, the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus specifically includes:

substituting the propagation coefficient matrix and the information vector of the preset control focus into a third preset formula to calculate and obtain the transmitting phase of the transducer array element;

the third preset formula includes:wherein the content of the first and second substances,representing the transmission phase, H, of said transducer elements_ijRepresenting said matrix of propagation coefficients, n_jAn information vector representing the preset focus of control, the information vector including a phase and a weight of the preset focus of control, Im () representing a real part, Re () representing an imaginary part.

Optionally, the sound field types at least include a dual sound trap, a vortex sound trap and a partial hollow sound trap, and the sound field parameters at least include a duty ratio, an amplitude and a frequency for manipulating the sound field.

Optionally, the method further includes: a monitoring module;

the monitoring module is configured to acquire a motion state of the target particle and an environmental parameter of an environment in which the target particle is located, adjust the control sound field sequence according to the motion state and the environmental parameter, and trigger the signal transmitting module in a return manner.

It can be seen from the above technical solutions that the embodiments of the present application provide a method and a system for generating acoustic tweezers, wherein, in the method for generating the acoustic tweezers, a plurality of control sound fields with the acoustic trap rigidity meeting the requirements can be determined according to the requirements, and reversely determining the transmitting phase of the transducer array element corresponding to the control sound field, then controlling the transducer array element to work according to the transmitting phase of each transducer array element, sequentially generating the control sound field in the control sound field sequence, realizing time-sharing multiplexing of the transducer array elements, forming a comprehensive sound field control target particle, because the comprehensive sound field is formed by a plurality of control sound fields which are sequentially arranged on a time sequence, the advantages of the limiting capability of the control sound fields of different control generation types or different sound field parameters in different directions can be superposed, and the limiting capability, the stability and the anti-interference strength of the comprehensive sound field are improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic flow chart of a method for generating acoustic tweezers according to an embodiment of the present application;

fig. 2 is an arrangement of a manipulated sound field in a manipulated sound field sequence according to an embodiment of the present application;

fig. 3 is an arrangement of a manipulated sound field in a manipulated sound field sequence according to another embodiment of the present application;

fig. 4 is a schematic diagram of distribution of control focus and sound trap center in a dual sound trap according to an embodiment of the present application;

FIG. 5 is a schematic diagram of the distribution of the control focus and the sound trap center of the vortex sound trap provided by one embodiment of the present application;

fig. 6 is a schematic diagram of distribution of control focus and sound trap center of a local hollow sound trap provided by an embodiment of the present application;

FIG. 7 is a schematic illustration of an acoustic field force potential distribution of a dual sound trap, a vortex sound trap and a partial hollow sound trap provided by an embodiment of the present application;

fig. 8 is a schematic flow chart of a method for generating acoustic tweezers according to another embodiment of the present application;

fig. 9 is a schematic flow chart of a method for generating acoustic tweezers according to another embodiment of the present application;

fig. 10 is a schematic structural diagram of a system for generating acoustic tweezers according to an embodiment of the present application;

FIG. 11 is a schematic diagram of a transducer module according to an embodiment of the present application.

Detailed Description

The biomedical application of the acoustic tweezers has the advantages of no damage, no specific requirements on the physical properties of an operation object and the like, and compared with the optical tweezers, the acoustic tweezers have no requirements on the transparency of a transmission medium and can be applied to various different transmission media. At the same energy, the acoustic radiation force is much larger than the optical radiation force, and larger objects can be manipulated. In addition, the sound wave has better penetrating capacity, and the sound tweezers can realize non-contact control through the wall of the living body. Therefore, in recent years, the acoustic tweezer technology using ultrasonic radiation force has become a focus of academic research, and some progress has been made in manipulation of microparticles in three-dimensional space.

Most application scenes of the existing three-dimensional acoustic tweezers technology are arranged in the air, and the technology for realizing three-dimensional acoustic control of particles in water environment is rare. The technology of the acoustic tweezers in water is preliminarily researched in the prior art, but the formed acoustic tweezers have poor limiting capability and cannot meet the requirement of controlling particles by the acoustic tweezers in a more complex environment.

In view of this, an embodiment of the present application provides a method and a system for generating acoustic tweezers, where in the method for generating acoustic tweezers, a plurality of manipulation sound fields whose sound trap stiffness meets requirements may be determined according to requirements, and emission phases of transducer array elements corresponding to the manipulation sound fields may be reversely determined, and then the transducer array elements may be controlled to work according to the emission phases of the transducer array elements, so as to sequentially generate manipulation sound fields in a manipulation sound field sequence, implement time-division multiplexing of transducer array elements, and form a comprehensive sound field control target particle.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

An embodiment of the present application provides a method for generating acoustic tweezers, which is implemented based on a transducer module, as shown in fig. 1, where the transducer module includes at least one transducer array, each transducer array includes a plurality of transducer units arranged in an array, and the method for generating acoustic tweezers includes:

s101: determining a plurality of control sound fields which are sequentially arranged in a time domain to determine a control sound field sequence; the sound field types or sound field parameters of at least two of the plurality of manipulated sound fields are different;

s102: determining the transmitting phase of a transducer array element corresponding to each manipulation sound field in the manipulation sound field sequence based on an iterative back propagation algorithm;

s103: and controlling the transducer array elements to work according to the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence, and sequentially generating the control sound fields in the control sound field sequence to form comprehensive sound field control target particles.

In step S101, when determining a plurality of manipulation sound fields sequentially arranged in a time domain, it is usually determined according to application scene requirements of the acoustic tweezers, where the plurality of manipulation generations at least include two manipulation sound fields with different sound field types or different sound field parameters, so that when forming a plurality of manipulation sound fields, the advantages of the limiting capability of each manipulation sound field in different directions can be comprehensively utilized, and the limiting capability, stability and anti-interference strength of the comprehensive sound field are improved. In addition, in step S101, the maximization of the sound trap stiffness (i.e., the negative gradient of the radiation force of the manipulation sound field) of each manipulation sound field can be realized by designing the parameters of each control focus in the manipulation sound field, so as to further improve the limiting capability, stability and anti-interference strength of the finally obtained integrated sound field.

For a specific arrangement of the manipulation sound fields in the manipulation sound field sequence, referring to fig. 2 and fig. 3, in fig. 2, the manipulation sound field sequence includes manipulation sound fields of a plurality of different sound field types, in fig. 2, a sound field a, a sound field B, and a sound field C respectively represent manipulation sound fields of different sound field types, and fig. 2 shows 5 possible arrangements of the manipulation sound fields, such as an alternate arrangement (a first row) of the sound field a and the sound field B, an alternate arrangement (a second row) of the sound field a, the sound field B, and the sound field C, an alternate arrangement (a third row) of the sound field a, the sound field B, and the sound field C, and an alternate arrangement (a fifth row) of the sound field a, the sound field B, and the sound field C.

In addition, referring to fig. 3, in the sequence of the steering sound fields, the steering sound fields of different sound field parameters are arranged in sequence, in fig. 3, the multiple steering sound fields in the first row include two different duty ratios, the duty ratios of the 1 st, 2 nd and 5 th sound fields from the left are the same, and the duty ratios of the 3 rd and 4 th sound fields from the left are the same; in fig. 3, the plurality of steering sound fields in the second row include two different amplitudes, the amplitudes of the 1 st, 3 rd and 4 th steering sound fields from the left are the same, and the amplitudes of the 2 nd, 5 th and 6 th steering sound fields from the left are the same; in the third row in fig. 3, the plurality of steering sound fields includes 3 different frequencies, the 1 st steering sound field from the left is a first frequency, the 2 nd and 4 th steering sound fields from the left are a second frequency, the 3 rd and 5 th steering sound fields from the left are a third frequency, and the first frequency, the second frequency and the third frequency are different from each other. Alternatively, in fig. 3, the sound field types of the manipulated sound fields having different sound field parameters may be the same or different.

I.e. optionally, the sound field parameters comprise at least duty cycle, amplitude and frequency for manipulating the sound field. In addition, for the sound field types, the sound field types include at least a dual sound trap, a vortex sound trap, and a partial hollow sound trap. Referring to fig. 4, 5 and 6, fig. 4 shows a distribution diagram of control focuses and sound trap centers in a dual sound trap, fig. 5 shows a distribution diagram of control focuses and sound trap centers of a vortex sound trap, and fig. 6 shows a distribution diagram of control focuses and sound trap centers of a partial hollow sound trap. Each type of trap is laid out with a different number of control foci around the center of the trap, with corresponding phase relationships and weighting values (i.e., weights). The double sound trap is composed of 2 control focuses with opposite phases, if the center of the sound trap is taken as an origin, the two control focuses are both in an xy plane and are symmetrically distributed with the center of the sound trap. The vortex sound trap is uniformly surrounded by 8 control focuses by taking the center of the sound trap as the center of a circle, and is symmetrically distributed in an xy plane by taking the center of the sound trap as the center; the phase of the control focus increases linearly as its phase angle increases in a clockwise or counterclockwise direction. Besides 8 control focuses in the xy plane, 2 control focuses are additionally distributed in the z-axis direction of the local hollow sound trap, so that the radiation force limitation in the axial direction is enhanced, and all the control focuses have the same phase. The coordinate systems in fig. 4-6 are all right-hand coordinate systems established with the center of the sound trap as the origin. Referring to fig. 7, fig. 7 shows the sound field force potential distributions of the dual sound trap (fig. 7(a)), the vortex sound trap (fig. 7(b)) and the partial hollow sound trap (fig. 7(c)), respectively, and fig. 7 shows that the dual sound trap and the vortex sound trap have stronger lateral potential wells by showing the respective optimized sound field lateral force potential distributions and axial force potential distributions; the local hollow sound trap has a stronger axial sound trap. Therefore, the radiation force characteristics of the double-sound trap and the vortex sound trap are met, and the double-sound trap and the vortex sound trap have stronger lateral limitation on particles; the local hollow sound trap has strong axial limitation on particles, different types of control sound fields can be selected for time domain multiplexing according to actual control requirements in the actual application process, and the requirements of improving the limiting capacity, stability and anti-interference strength of the comprehensive sound field are met.

The distribution of different control focuses directly influences the quality of the control sound field; the control focus distribution of each trap is determined by the corresponding geometric parameters, still referring to fig. 4-6, the dual traps are determined by the distance d of the two control focuses; the vortex sound trap is determined by the diameter D of the control focus forming circle; the local hollow sound trap is determined by the circumference diameter s formed by the lateral control focus and the axial control focus interval L.

Further, based on the symmetry of all generated sound traps along the central axis of the transducer element, the optimal control point distribution of each sound trap is obtained by maximizing the lateral sound trap stiffness (i.e. the negative gradient of the lateral radiation force) of each manipulated sound field. And finally determining the transmitting phase of each transducer element in the transducer array according to the optimized control focus setting. And the center position of the sound trap of each control sound field is changed in a mode of electronically deflecting the focus, so that dynamic control in a three-dimensional space is realized.

The embodiment of the application further verifies that the limiting capability, stability and anti-interference strength of the comprehensive sound field formed by the method for forming the acoustic tweezers provided by the embodiment of the application are greatly improved compared with those of a single sound field through numerical simulation and simulation verification.

Specifically, through three-dimensional control of polystyrene particles in a water environment, experiments verify that a comprehensive sound field based on multi-sound-field time-domain multiplexing has better control stability, a comprehensive sound field 1 formed by time-domain multiplexing of a double sound trap and a local hollow sound trap and a comprehensive sound field 2 formed by time-domain multiplexing of a vortex sound trap and the local hollow sound trap are taken as examples, deviation between a position measured by the experiments and a set position of the sound trap refers to tables 1 and 2, table 1 shows stability comparison of a single sound trap and the comprehensive sound field for capturing target particles, and table 2 shows stability comparison of the single sound trap and the comprehensive sound field for moving targets.

TABLE 1 comparison of stability of fixed-point trapped particles for each sonic trap

TABLE 2 comparison of the stability of moving particles for each sound trap

Each specific feasible step of the method for generating acoustic tweezers provided in the embodiment of the present application is described below.

Based on the foregoing embodiments, in an embodiment of the present application, as shown in fig. 8, the determining, based on an iterative back propagation algorithm, a transmit phase of a transducer element corresponding to each of the steering sound fields in the steering sound field sequence includes:

s1021: determining a preset control focus and an information vector of the preset control focus according to the type of the control sound field; the information vector of the preset control focus is a column vector comprising the phase and the weight of the preset control focus.

S1022: acquiring position information of transducer array elements in the transducer module and sound source model information of the transducer array elements, and determining propagation coefficients of the preset control focus and each transducer array element in the transducer module according to the preset control focus, the position information of the transducer array elements and the sound source model information of the transducer array elements;

s1023: generating a propagation coefficient matrix according to the preset control focus and the propagation coefficients of all transducer array elements in the transducer module;

s1024: and determining the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus.

For the sound source model information of different transducer array elements, the determining, in step S1022, a feasible execution manner of the propagation coefficients of the transducer array elements in the transducer module and the preset control focus according to the preset control focus, the position information of the transducer array elements, and the sound source model information of the transducer array elements includes:

s10221: when the sound source model information of the transducer array element is a piston type sound source model, substituting the preset control focus and the position information of the transducer array element into a first preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

s10222: when the sound source model information of the transducer array element is a point sound source model, substituting the preset control focus and the position information of the transducer array element into a second preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

the first preset formula includes:wherein h is_ijRepresenting the propagation coefficient of the transducer elements, k being the wave number of the transducer elements, a being the wave numberPiston radius of energy device array element, J₁Is a first order Bessel function, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijThe elevation deflection of a line connecting a preset control focus j and the transducer array element i is achieved;

the second preset formula includes:wherein, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijFor presetting the elevation deflection of the line connecting the control focus j and the transducer array i, the elevation deflection can be quantified as

Of course, in other embodiments of the present application, the sound source model information of the transducer elements may also be other sound source models besides the piston type sound source model and the point sound source model, and the present application is not exhaustive here.

Correspondingly, in step S1022, determining the transmission phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus includes:

s10223: substituting the propagation coefficient matrix and the information vector of the preset control focus into a third preset formula to calculate and obtain the transmitting phase of the transducer array element;

the third preset formula includes:wherein the content of the first and second substances,representing the transmission phase, H, of said transducer elements_ijRepresenting said matrix of propagation coefficients, n_jAn information vector representing the preset focus of control, the information vector including a phase and a weight of the preset focus of control, Im () representing a real part, Re () representing an imaginary part.

On the basis of the above embodiment, in an optional embodiment of the present application, as shown in fig. 9, the method for generating acoustic tweezers further includes:

s104: and acquiring the motion state of the target particles and the environmental parameters of the environment where the target particles are located, adjusting the control sound field sequence according to the motion state and the environmental parameters, and returning to the step of determining the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence based on an iterative back propagation algorithm.

In this embodiment, the control process may be monitored by using an imaging technology or a sensing technology, and the control sound field sequence is adjusted based on real-time monitoring signals (i.e., the obtained motion state of the target particles and the environmental parameters of the environment where the target particles are located), so as to adjust the transmitting signals provided to each transducer array element, so that the comprehensive sound field may be transformed in real time, and adaptive interactive three-dimensional sound tweezers may be implemented. For example, by monitoring the direction and speed of water flow in the control scene, the intensity and/or type of each control sound field can be adjusted in real time according to the feedback signal, so as to complete more stable control behaviors, and the method is favorable for adapting to more complicated and changeable control scenes. Meanwhile, the position of the particle can be positioned and controlled by using an imaging technology, or the action of avoiding an obstacle can be finished.

The following describes a system for generating acoustic tweezers provided in an embodiment of the present application, and the system for generating acoustic tweezers described below and the method for generating acoustic tweezers described above may be referred to in correspondence.

Correspondingly, an embodiment of the present application further provides a system for generating acoustic tweezers, as shown in fig. 10, including: a transducer module 20 and a signal transmitting module 10; wherein the content of the first and second substances,

the transducer module 20 includes at least one transducer array, each transducer array including a plurality of transducer elements arranged in an array;

the signal transmitting module 10 is configured to determine, based on an iterative back propagation algorithm, a transmitting phase of a transducer array element corresponding to each of the manipulation sound fields in the manipulation sound field sequence; the control sound field sequence comprises a plurality of control sound fields which are sequentially arranged on a time domain; the sound field types or sound field parameters of at least two of the plurality of manipulated sound fields are different;

and controlling the transducer array elements to work according to the transmitting phase of the transducer array element corresponding to each control sound field in the control sound field sequence, and sequentially generating the control sound fields in the control sound field sequence to form a comprehensive sound field control target particle TA.

Referring to fig. 11, several possible configurations of the transducer module 20 are shown in fig. 11, the transducer module 20 may include a rectangular transducer array (e.g., the first diagram from the left in fig. 11, i.e., fig. 11(a)), the transducer module 20 may also include a circular transducer array (e.g., the second diagram from the left in fig. 11, i.e., fig. 11(b)), and the transducer module 20 may also include a combination of transducer arrays (e.g., the third diagram from the left in fig. 11, i.e., fig. 11 (c)). The areas of the transducer elements in each of the rectangular transducer arrays may be the same or different.

Optionally, the process of determining the transmitting phase of the transducer element corresponding to each of the manipulation sound fields in the manipulation sound field sequence by the signal transmitting module 10 based on an iterative back propagation algorithm specifically includes:

determining a preset control focus and an information vector of the preset control focus according to the type of the control sound field;

acquiring position information of transducer array elements in the transducer module 20 and sound source model information of the transducer array elements, and determining propagation coefficients of the preset control focus and each transducer array element in the transducer module 20 according to the preset control focus, the position information of the transducer array elements and the sound source model information of the transducer array elements;

generating a propagation coefficient matrix according to the propagation coefficients of the preset control focus and each transducer element in the transducer module 20;

and determining the transmitting phase of each transducer array element according to the propagation coefficient matrix and the information vector of the preset control focus.

Optionally, the process of determining, by the signal transmitting module 10, propagation coefficients of the preset control focus and each transducer element in the transducer module 20 according to the preset control focus, the position information of the transducer element, and the sound source model information of the transducer element specifically includes:

when the sound source model information of the transducer array element is a piston type sound source model, substituting the preset control focus and the position information of the transducer array element into a first preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

when the sound source model information of the transducer array element is a point sound source model, substituting the preset control focus and the position information of the transducer array element into a second preset formula to calculate and obtain the propagation coefficients of the preset control focus and the transducer array element;

the first preset formula includes:where k is the wave number of the transducer array element, a is the piston radius of the transducer array element, J₁Is a first order Bessel function, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijThe elevation deflection of a line connecting a preset control focus j and the transducer array element i is achieved;

the second preset formula includes:wherein, | r_i-r_jL represents the linear distance from a preset control focus j to the transducer element i, θ_ijAnd controlling the elevation deflection of the line connecting the focal point j and the transducer array element i for presetting.

Optionally, the process of determining the transmission phase of each transducer array element by the signal transmitting module 10 according to the propagation coefficient matrix and the information vector of the preset control focus specifically includes:

substituting the propagation coefficient matrix and the information vector of the preset control focus into a third preset formula to calculate and obtain the transmitting phase of the transducer array element;

the third preset formula includes:wherein the content of the first and second substances,representing the transmission phase, H, of said transducer elements_ijRepresenting said matrix of propagation coefficients, n_jAn information vector representing the preset focus of control, the information vector including a phase and a weight of the preset focus of control, Im () representing a real part, Re () representing an imaginary part.

Optionally, the sound field types at least include a dual sound trap, a vortex sound trap and a partial hollow sound trap, and the sound field parameters at least include a duty ratio, an amplitude and a frequency for manipulating the sound field.

Optionally, still referring to fig. 10, the system for generating acoustic tweezers further comprises: a monitoring module 30;

the monitoring module 30 is configured to obtain a motion state of the target particle TA and an environmental parameter of an environment where the target particle TA is located, adjust the control sound field sequence according to the motion state and the environmental parameter, and trigger the signal transmitting module 10 in a return manner.

To sum up, the embodiment of the present application provides a method and a system for generating acoustic tweezers, wherein in the method for generating acoustic tweezers, a plurality of control sound fields with sound trap stiffness meeting requirements can be determined according to requirements, and the emission phases of transducer array elements corresponding to the control sound fields are reversely determined, and then the transducer array elements are controlled to work according to the emission phases of the transducer array elements, so as to sequentially generate control sound fields in a control sound field sequence, realize time-division multiplexing of transducer array elements, and form comprehensive sound field control target particles.

Features described in the embodiments in the present specification may be replaced with or combined with each other, each embodiment is described with a focus on differences from other embodiments, and the same and similar portions among the embodiments may be referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.