Particle customization control method based on acoustic radiation force and torque

Abstract

The invention belongs to the technical field of sound tweezers, and particularly relates to a particle customization control method based on sound radiation force and torque, and the method comprises the steps: building a needed sound source array, evaluating the stress and torque of a to-be-controlled particle in a sound field, repeatedly adjusting and optimizing the phase and amplitude distribution in an array unit, and obtaining an optimal sound field configuration condition. In this way, the required optimal sound field environment can be determined in advance, so that the optimal control effect on the particles is achieved, and the suspension height and the rotation speed of the particles are accurately controlled. According to the method, particle behaviors can be more accurately regulated and controlled, the control precision is remarkably improved, the adaptability is enhanced, more complex control scenes and particle types can be coped with, and the method is particularly suitable for the situation that customized control particles are needed.

Description

Technical Field

[0001] The present invention belongs to the technical field of acoustic tweezers, and particularly relates to a customized particle manipulation method based on acoustic radiation force and torque. Background Art

[0002] Acoustic particle manipulation technology uses the energy generated by sound waves to achieve non-contact particle manipulation. Sound waves can effectively propagate in fluid media such as air and water, and cause no damage to most materials, having good biocompatibility, and being particularly suitable for the manipulation of micro-particles, cells, and organisms. Compared with traditional electromagnetic field and light field methods, sound waves have broader applicability and flexibility. Sound waves can not only propagate efficiently in liquid media, but also penetrate relatively thick medium layers to flexibly adapt to more complex operating environments. Therefore, acoustic particle manipulation technology has gradually become an important research direction in the field of particle manipulation, and has shown great application potential, especially in the fields of biomedicine, micro sensors, drug delivery, and precision manufacturing, and has extremely high application value.

[0003] However, in the field of air acoustics, existing acoustic particle manipulation methods still face some challenges, mainly reflected in insufficient manipulation accuracy and the inability to accurately predict the manipulation process in advance, and the inability to construct the best sound field environment, which makes it lack systematicness and flexibility when facing more complex manipulation requirements, especially in terms of accuracy, efficiency, and repeatability, there are still certain limitations. In addition, existing related methods usually cannot predict and optimize the sound field configuration in advance, resulting in difficult efficient operation in practical applications, and may even damage the manipulated object. Summary of the Invention

[0004] The purpose of the present invention is to provide a customized particle manipulation method based on acoustic radiation force and torque for the deficiencies of the existing technology, which can not only more precisely regulate particle behavior, significantly improve the manipulation accuracy, but also enhance the applicability, so as to generate a sound field that meets different application scenarios according to the physical characteristics of the particles.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A customized particle manipulation method based on acoustic radiation force and torque, comprising the following steps:

[0007] Step 1: Determine the physical characteristics of the particle to be manipulated, and then construct a sound source array including n×m array units, where the sound pressure amplitude of the array unit O(i,j) is P ij , the delay phase is α ij , and obtain the sound pressure p(x,y,z,t) at any point in space through the relational expression ;

[0008] Step 2. Evaluate the force and torque on the particles to be manipulated in the sound field. By

[0009]

[0010] F x = F·e x ; F y = F·e y ; F z = F·e z ;

[0011]

[0012] Determine the acoustic radiation force F and torque M on the particles z ;

[0013] Step 3. Adjust and optimize the phase and amplitude distribution in the array elements, and use the target optimization model

[0014] Minimize: f(P,α) = ξ 1 |F z (P,α) - G| + ξ 2 |M z (P,α) - T|

[0015] Subject to. F x (P,α) = F y (P,α) = 0

[0016] Further precisely control the shape and distribution of the required sound field, continuously iterate and optimize to determine the optimal sound field configuration conditions, so as to achieve the best manipulation effect on the particles, and achieve precise control of the suspension height and rotation speed of the particles in the optimal sound field;

[0017] where t represents time, i is the imaginary unit, i 2 = -1, k is the wave number, e is the natural logarithm base, ω is the angular frequency, h ij represents the distance from the spatial point to the O(i,j) array element, S ij is the surface area of the O(i,j) array element;

[0018] ρ s is the medium density, c s is the speed of sound, r is the distance from the spatial point to the origin O of the sound field, a is the radius of the suspended particle, Ω represents the particle surface, and Ω represents the integral over the particle surface in the formula, φ is the velocity potential of the sound field, and the velocity potential φ of the sound field is obtained according to e x e y e zThey respectively represent unit vectors along the x, y, and z directions. θ is the angle between the positive projection of the spatial point onto the intersection line of the xoy plane and the origin O and the x direction. is the angle between the intersection line of the spatial point and the origin O and the z direction, and e r represents the unit vector along the direction from the origin O to the spatial point, and e θ represents the unit vector along the direction of θ change. represents along the unit vector along the change direction, and M z represents the torque along the z direction;

[0019] P and α respectively represent the amplitude and phase distributions on the array plane O. f(P,α) represents minimizing the amplitude and phase. G is the desired acoustic radiation force, T is the desired torque, and ξ 1 and ξ 2 are both weight coefficients used to balance the importance of each objective, and F x 、F y 、F z respectively represent the acoustic radiation forces along the x, y, and z directions.

[0020] Furthermore, the third step further includes: constructing an optimal sound field and placing the particles in the optimal sound field to verify the manipulation requirements of the particles.

[0021] Furthermore, the desired torque T in the third step is 10 -8 N·m to 10 -11 N·m.

[0022] Furthermore, ξ 1 in the third step is 0 to 1, and ξ 2 in the third step is 0 to 1000.

[0023] Furthermore, the side length of the cross-section of the array unit is determined by the acoustic wave frequency, and the side length of the cross-section of the array unit is 0.5 times the acoustic wave wavelength.

[0024] Furthermore, the first step further includes: selecting solid particles with a diameter of 1 mm to 4 mm and a density of 10 kg / m 3 to 40 kg / m 3 .

[0025] Furthermore, in the optimization process of the present invention, iconic sound fields (such as vortex sound fields and acoustic bottle beam sound fields) are introduced. Through additional constraint conditions, the rapid convergence of the optimization process is achieved, and the manipulation accuracy and efficiency of the particles are improved. Moreover, these specific sound fields provide a basis for meeting different manipulation requirements and can significantly enhance the adaptability of the optimization process.

[0026] The beneficial effects of the present invention are as follows: By combining phased array and acoustic metasurface technologies, the present invention precisely controls the propagation path and wavefront form of sound waves to achieve high-precision reproduction and optimization of the obtained sound field environment, thereby meeting specific particle manipulation requirements. Through the above method, the present invention can quickly design and generate sound fields that meet different application scenarios with less reliance on experiments, significantly improving the accuracy and applicability of acoustic particle manipulation technology. Description of the Drawings

[0027] Figure 1 It is a flowchart of the operation of the present invention.

[0028] Figure 2 It is a schematic diagram of the optimization process of the present invention.

[0029] Figure 3 It is the theoretical optimization result of Example 1 of the present invention.

[0030] Figure 4 It is the simulation optimization result of Example 1 of the present invention.

[0031] Figure 5 It is the theoretical optimization result of Example 2 of the present invention.

[0032] Figure 6 It is the simulation optimization result of Example 2 of the present invention.

[0033] Figure 7 It is the theoretical optimization result of Example 3 of the present invention.

[0034] Figure 8 It is the simulation optimization result of Example 3 of the present invention. Detailed Description of the Invention

[0035] As certain terms are used in the specification and claims to refer to particular components, those skilled in the art should understand that manufacturers may use different names to refer to the same component. The specification and claims do not use the difference in names as a way to distinguish components, but rather use the difference in functions of components as the criterion for distinction. As the term "comprising" mentioned throughout the specification and claims is an open-ended term, it should be interpreted as "including but not limited to". "Substantially" means within an acceptable error range, and those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0036] The inventors found that acoustic holographic reconstruction is a technique based on the principles of wave interference and diffraction, capable of reconstructing a three-dimensional image of a sound source through the amplitude and phase information of sound waves. The operation process of acoustic holographic reconstruction includes the emission, propagation, interaction with the object to be measured, and the acquisition and processing of acoustic wave data. Additionally, acoustic holography can be classified into types such as conventional acoustic holography, near-field acoustic holography, and far-field acoustic holography according to different application requirements and measurement environments. Specifically, near-field acoustic holography (NAH) has attracted much attention due to its wide applicability, high resolution, and strong operability. It can perform accurate acoustic field reconstruction in different coordinate systems, such as planar, cylindrical, and spherical coordinate systems. In short, acoustic holography records the phase and amplitude information of the wave field and uses appropriate transmitters and receivers to reproduce the original wave field at specific positions and directions. This process can be achieved with the help of reproduction tools such as phased arrays and acoustic metasurfaces.

[0037] The inventors also found that current acoustic particle manipulation methods still rely on empirical design or adjusting manipulation parameters through multiple experimental verifications. In view of the problems such as insufficient manipulation accuracy and unpredictable manipulation process existing in the prior art, the present invention provides a customized particle manipulation design method based on acoustic radiation force and acoustic torque. This method inversely optimizes to obtain the required acoustic field environment starting from the weight of the particle to be manipulated and the required torque. Specifically, first, according to the physical properties of the particle (such as mass, shape, etc.) and the required manipulation accuracy, the corresponding acoustic radiation force and acoustic torque requirements are calculated. Then, the optimal acoustic field configuration is determined through an inverse optimization algorithm to ensure precise manipulation of the particle without relying on a large number of experiments. Among them, there are three key points in the entire inverse optimization process:

[0038] Key point 1 is the calculation of the acoustic field. The inventors accurately solve the three-dimensional acoustic field using the near-field acoustic holography theory. The purpose of this step is to obtain the spatial distribution of the acoustic field through a theoretical model, providing basic data for subsequent force and torque calculations.

[0039] Key point 2 is the calculation of acoustic radiation force and torque. In this process, the inventors calculate the radiation force exerted on a solid particle in an arbitrary acoustic field based on relevant theoretical formulas. Specifically, the inventors derive the acoustic radiation force and torque on a small solid particle in the acoustic field through the method of surface integral of the second-order perturbation term.

[0040] Key point 3 is the optimization of the acoustic field, aiming to further precisely control the shape and distribution of the acoustic field based on the optimization design by adjusting the phase and amplitude distributions in the array elements to achieve the best manipulation effect on the particle.

[0041] To illustrate the design method and application effect of the present invention, the present invention provides three schematic embodiments, which respectively target three manipulation requirements of vertical suspension, rotation of particles, and simultaneous application of vertical force and torque. At the same time, the theoretical optimization and simulation optimization of the present invention are both based on the customized manipulation optimization of particles by acoustic radiation force and acoustic torque.

[0042] The following further elaborates on the present invention in conjunction with the Figures 1-8 accompanying drawings and specific embodiments, but it shall not be construed as a limitation to the present invention.

[0043] In the three schematic embodiments, the number of array units is set to 16×16, and the sound pressure amplitude of each array unit is set to be equal; the frequency of the sound wave is set to 40 kHz, and the cross-sectional size of the array unit is 4.4 mm×4.4 mm; the diameter of the manipulated particle is set to 2 mm, and the density is set to 20 kg / m 3 ; the expected suspension height is 5.5 cm.

[0044] In Embodiment 1, ξ 1 = 1, ξ 2 = 0, and an acoustic bottle beam sound field environment is introduced for optimization.

[0045] In Embodiment 2, ξ 1 = 0, ξ 2 = 1, and a vortex sound field environment is introduced for optimization. The expected applied torque is positioned at 9.35×10 -10 N·m.

[0046] In Embodiment 3, ξ 1 = 1, ξ 2 = 10 3 , and a vortex sound field environment is introduced for optimization. The expected applied torque is positioned at 9.35×10 -10 N·m.

[0047] Figure 2 is a schematic diagram of the design method concept and optimization process for the customized manipulation of particles based on acoustic radiation force and torque of the present invention. This method starts from the expected goals (force, torque, or sound field manipulation effect) and optimizes the phase and amplitude information of each array unit in the array to meet the requirements of the manipulated particle for the sound field environment. As shown in the concept diagram, the optimization process continuously repeats the following process: generating phase and amplitude array information, sound field calculation, force value and torque calculation, comparing with the target value, and entering the next iterative calculation.

[0048] Figure 3 is the theoretical optimization result of Embodiment 1 of the present invention, including the unit phase arrangement information ( Figure 3 a), the theoretical sound field environment ( Figure 3 b, c). The sound pressure amplitude of the optimized result of the unit is 51.38 Pa.

[0049] Figure 4 is the simulation optimization result of Embodiment 1 of the present invention, including the simulated sound field environment ( Figure 4 a, c), the sound field pattern ( Figure 4 b), the comparison of the theoretical and simulated sound radiation force values and torques ( Figure 4 d). The results show that the error between the theoretical and simulated sound radiation force values is 2%.

[0050] Figure 5 is the theoretical optimization result of Embodiment 2 of the present invention, including the unit phase arrangement information ( Figure 5 a), the theoretical sound field environment ( Figure 5 b, c). The unit sound pressure amplitude of the optimization result is 109.19 Pa.

[0051] Figure 6 is the simulation optimization result of Embodiment 2 of the present invention, including the simulated sound field environment ( Figure 6 a, c), the sound field pattern ( Figure 6 b), the comparison of the theoretical and simulated sound radiation force values and torques ( Figure 6 d). The results show that the error between the theoretical and simulated sound radiation torques is 7%.

[0052] Figure 7 is the theoretical optimization result of Embodiment 3 of the present invention, including the unit phase arrangement information ( Figure 7 a), the theoretical sound field environment ( Figure 7 b, c). The unit sound pressure amplitude of the optimization result is 194.67 Pa.

[0053] Figure 8 is the simulation optimization result of Embodiment 3 of the present invention, including the simulated sound field environment ( Figure 8 a, c), the sound field pattern ( Figure 8 b), the comparison of the theoretical and simulated sound radiation force values and torques ( Figure 8 d). The results show that the errors between the theoretical and simulated sound radiation force and torque are 6% and 14% respectively.

[0054] The theoretical and simulation results of Examples 1 to 3 are all the results optimized by the customized manipulation of particles based on acoustic radiation force and acoustic torque, and can all prove the effectiveness and stability of the manipulation method of the present invention. It can be seen that the present invention proposes an inverse design method for particle manipulation based on acoustic radiation force and torque, aiming to achieve multi-dimensional customized manipulation (suspension and rotation) of millimeter-sized particles, which has great application potential and extremely high application value in the fields of biomedicine, micro sensors, drug delivery, and precision manufacturing. This method combines holographic theory, particle mechanics model, and acoustic wave field inverse optimization algorithm. Specifically, the distribution of the acoustic field is calculated through holographic theory, and the force and torque of the particles in the acoustic field are evaluated by combining the surface integral particle mechanics model. With the help of the inverse optimization algorithm, the acoustic field configuration is repeatedly adjusted to finally pre-determine the required optimal acoustic field environment, so as to accurately control the suspension height and rotation speed of the particles. Compared with the traditional technology, the present invention can more precisely regulate the particle behavior based on the manipulation of acoustic radiation force and acoustic torque without relying on multiple experiments, significantly improving the manipulation accuracy and enhancing the adaptability, and can cope with more complex manipulation scenarios and particle types. This method is particularly suitable for situations where customized manipulation of particles is required.

[0055] According to the disclosure and teachings of the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the above specific embodiments, and any obvious improvements, substitutions, or variations made by those skilled in the art on the basis of the present invention all belong to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A customized particle manipulation method based on acoustic radiation force and torque, characterized in that: The following steps are involved: Step 1: Determine the physical properties of the particles to be manipulated, and then construct a sound source array consisting of n×m array units, where the sound pressure amplitude of the array unit O(i, j) is P ij , the delay phase is α ij , through the relation Get the sound pressure p(x,y,z,t) at any point in space; Step 2: Evaluate the force and torque of the particle to be manipulated in the acoustic field by F x =F·e x ;F y =F·e y ;F z =F·e z ; Determine the acoustic radiation force F and torque M on the particle z ; Step 3: Adjust and optimize the phase and amplitude distribution in the array elements using the target optimization model Minimize:f(P,α)=ξ1|F z (P,α)-G|+ξ2|M z (P,α)-T| Subject to.F x (P,α)=F y (P,α)=0 Further accurately control the shape and distribution of the required sound field, continuously iterate and optimize and determine the optimal sound field configuration conditions to achieve the best control effect on particles and achieve precise control of the particle's suspension height and rotation speed in the optimal sound field; Where t represents time, i is the imaginary unit, k is the wave number, e is the natural base, ω is the angular frequency, and h is ij Represents the distance between the spatial point and the O(i,j) array element, S ij is the surface area of ​​the O(i,j) array element, ρ s is the medium density, c s is the speed of sound, r is the distance from the spatial point to the origin O of the sound field, a is the radius of the suspended particle, Ω represents the particle surface, and the velocity potential φ of the sound field is calculated according to Get, M z represents the torque along the z direction, P and α represent the amplitude and phase distribution on the array surface O, G is the desired acoustic radiation force, T is the desired torque, ξ1 and ξ2 are weight coefficients, and F x 、F y 、F z represent the acoustic radiation force along the x, y, and z directions respectively.

2. The particle customized manipulation method based on acoustic radiation force and torque according to claim 1, characterized in that: The step three also includes: constructing an optimal sound field, placing the particles in the optimal sound field to verify the control requirements of the particles.

3. The particle customized manipulation method based on acoustic radiation force and torque as claimed in claim 1, characterized in that: The desired torque T in step 3 is 10 -8 N·m~10 -11 N·m.

4. The particle customized manipulation method based on acoustic radiation force and torque as claimed in claim 1, characterized in that: The ξ1 in step three is 0-1, and the ξ2 in step three is 0-1000.

5. The particle customized manipulation method based on acoustic radiation force and torque as claimed in claim 1, characterized in that: The side length of the cross section of the array unit is determined by the frequency of the sound wave, and the side length of the cross section of the array unit is 0.5 times the wavelength of the sound wave.

6. The particle customized manipulation method based on acoustic radiation force and torque according to claim 1, characterized in that: The step 1 also includes: selecting a diameter of 1 mm to 4 mm and a density of 10 kg / m 3 ~40kg / m 3 of solid particles.

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