Ultrasonic vortex field emission device based on spiral diffraction acoustic grating and ultrasonic vortex particle control method thereof

Abstract

The invention discloses an ultrasonic vortex field emission device based on a spiral diffraction acoustic grating and an ultrasonic vortex particle control method. The ultrasonic vortex field emission device comprises a substrate; the at least one spiral groove is formed in the substrate and is used for carrying out phase modulation on incident plane sound waves; the ultrasonic transducer is used for generating the incident plane sound wave and enabling the incident plane sound wave to be incident in a manner of being vertical to the surface of the substrate; wherein the substrate and the spiral groove form a planar spiral diffraction acoustic grating structure, and after the planar acoustic wave is modulated by the spiral diffraction acoustic grating, an ultrasonic vortex field with a spiral phase wavefront is generated behind an emergent surface. A complex vortex field generation system is simplified into a planar static structure of a substrate and a spiral groove, a complex multi-channel phase control circuit and an independent regulation and control system in an active technology are omitted, and the complexity, the manufacturing cost and the operation difficulty of the system are reduced.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic vortex control technology, and in particular to an ultrasonic vortex field emission device based on a helical diffraction grating and a method for manipulating ultrasonic vortex particles. Background Technology

[0002] Ultrasonic vortex technology, as a non-contact, high-precision particle manipulation technique, has broad application prospects in biomedical fields such as cell manipulation, tissue engineering, and targeted drug delivery. In particular, with the increase of ultrasonic frequency, the size of manipulable particles can be effectively reduced, thereby significantly improving the ability to precisely manipulate tiny particles. Therefore, designing a higher-frequency, higher-order acoustic vortex field emitter to achieve precise manipulation of tiny particles has always been a research hotspot in related fields.

[0003] Currently, there are two main methods for generating ultrasonic vortices: active phase control technology and passive phase modulation technology. The former uses phase control circuits to independently control the phase of each unit in the transducer array, thereby constructing a vortex sound field with a helical phase. The latter uses special structures or metasurface materials to modulate the phase of the wavefront of the incident sound wave, generating a vortex sound field with a fixed topological charge.

[0004] However, both current methods have their own drawbacks and limitations when generating higher-frequency ultrasonic vortex fields. Active phase control technology, with its complex circuitry and independent control mechanisms, incurs high costs and operational difficulties. Furthermore, the higher the frequency of the sound wave, the shorter the wavelength. When the size of a single transducer cannot be fabricated to be much smaller than the wavelength, the array cannot effectively form the required wavefront phase distribution. Therefore, it is difficult to apply to high-frequency scenarios. While passive phase modulation technology overcomes the limitations of complex circuitry, it lacks flexibility and is only designed for fixed frequencies. Moreover, due to helical geometry constraints, its incident and exit ends cannot maintain a planar shape. This non-planar structure also hinders the miniaturization and integration of devices, which is a necessary condition for generating high-frequency ultrasonic vortices. Therefore, existing ultrasonic vortex design methods are insufficient to meet the higher requirements for particle manipulation. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide an ultrasonic vortex field emitting device based on a helical diffraction grating and a method for manipulating ultrasonic vortex particles. This simplifies the complex vortex field generation system into a planar static structure of "substrate + helical groove," eliminating the need for complex multi-channel phased-array circuits and independent control systems found in active technologies. This significantly reduces system complexity, manufacturing costs, and operational difficulty. Furthermore, the planar structure facilitates integration with other systems such as microfluidic chips, laying the foundation for miniaturized, on-chip ultrasonic manipulation platforms.

[0006] The technical solution provided by this invention is: an ultrasonic vortex field emitting device based on a helical diffraction grating, comprising: substrate; At least one helical groove formed on the substrate is used for phase modulation of the incident plane acoustic wave; and An ultrasonic transducer is used to generate the incident plane sound wave and make it incident perpendicular to the surface of the substrate. The substrate and the spiral groove form a planar spiral diffraction grating structure. After the planar sound wave is modulated by the spiral diffraction grating, an ultrasonic vortex field with a spiral phase wavefront is generated behind the exit surface.

[0007] Preferably, the number of spiral grooves is one or more; when the number of spiral grooves is multiple, the multiple spiral grooves are distributed in a rotationally symmetrical manner around the center of the substrate.

[0008] Preferably, the substrate is further provided with a support structure for enhancing structural stability, the support structure extending along the radial direction of the spiral groove.

[0009] Preferably, the number of spiral grooves on the substrate is N, and the helix equation of the m-th spiral groove is: , a1 = 0.598 mm, a2 = 0.648 mm, b is a constant, and θ is a constant.

[0010] Preferably, the operating frequency of the ultrasonic transducer is set to 10MHz. When N is 1, b = 0.029, and the value of θ ranges from 0 to 14.9π; when N is 2, b = 0.057, and the value of θ ranges from 0 to 7.5π; when N is 3, b = 0.085, and the value of θ ranges from 0 to 5π; when N is 4, b = 0.113, and the value of θ ranges from 0 to 3.9π; when N is 5, b = 0.142, and the value of θ ranges from 0 to 3π; when N is 6, b = 0.17, and the value of θ ranges from 0 to 2.5π.

[0011] Based on the same concept, the present invention also provides a method for manipulating ultrasonic vortex particles based on a helical diffraction grating ultrasonic vortex field, comprising the following steps: S1: Drive the ultrasonic transducer to generate a plane sound wave, and make the plane sound wave perpendicularly incident on the spiral diffraction grating; S2: The incident plane sound wave is phase-modulated by the helical diffraction grating to generate an ultrasonic vortex field of a preset order in the fluid medium behind it. S3: Using the ultrasonic vortex field to perform non-contact manipulation of particles placed in the fluid medium.

[0012] Preferably, the non-contact manipulation of the particles described in step S3 includes using the orbital angular momentum of the ultrasonic vortex field to drive the particles to rotate.

[0013] Preferably, the non-contact manipulation of particles described in step S3 includes using the acoustic radiation force of the ultrasonic vortex field to cause multiple particles to self-assemble.

[0014] Preferably, the method further includes adjusting the topological charge of the generated ultrasonic vortex field by selecting the number N of spiral grooves of the spiral diffraction grating, thereby changing the radius of stable particle capture in the vortex field to accommodate particles of different sizes.

[0015] Preferably, the rotational speed of the manipulated particles is controlled by adjusting the excitation voltage driving the ultrasonic transducer to change the sound pressure intensity of the ultrasonic vortex field.

[0016] Based on the same concept, the present invention also provides an electronic device, comprising: a memory for storing a processing program; and a processor, wherein the processor, when executing the processing program, implements the ultrasonic vortex particle manipulation method based on the ultrasonic vortex field of a helical diffraction grating as described above.

[0017] Based on the same concept, the present invention also provides a readable storage medium storing a processing program, which, when executed by a processor, implements the ultrasonic vortex particle manipulation method based on a helical diffraction grating ultrasonic vortex field as described in any one of the above claims.

[0018] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art: The complex vortex field generation system is simplified into a planar static structure of "substrate + spiral groove," eliminating the need for complex multi-channel phase control circuits and independent control systems found in active technologies. This significantly reduces system complexity, manufacturing costs, and operational difficulty. Furthermore, the planar structure facilitates integration with other systems such as microfluidic chips, laying the foundation for miniaturized, on-chip ultrasonic control platforms. Attached Figure Description

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein: Figure 1 Schematic diagram of an acoustic vortex field emitter with a multi-arm spiral diffraction grating and a frequency of 10MHz for orders 1-6; Figure 2 for Figure 1 Simulated phase distribution diagram; Figure 3 The rotation trajectory of a 500-micrometer diameter ps microsphere under the action of a fifth-order vortex field with an excitation voltage of 1500mV; Figure 4 A schematic diagram showing the rotational speed of the microsphere under different excitation voltages; Figure 5 The self-assembly effect of ps microspheres with a diameter of 3 micrometers under the action of a fourth-order vortex field with an excitation voltage of 2V. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] To overcome the shortcomings of existing technologies, this invention proposes a compact high-frequency ultrasonic vortex generation system based on a helical diffraction grating, achieving effective excitation of stable ultrasonic vortex fields from order 1 to 6 at 10 MHz. Through a combination of simulation and implementation, it was verified that adjusting the number of helical arms and the rotation angle can flexibly control the vortex mode and sound field distribution. Further particle manipulation experiments show that the system possesses excellent particle capture and rotational manipulation capabilities, enabling precise manipulation of particles ranging from millimeters to submicron sizes, and allowing synchronous control of the capture radius and rotation speed through order adjustment. This system has a simple structure, is easy to integrate, and has the potential to extend to higher frequencies, providing a new approach for the development of miniaturized ultrasonic manipulation platforms.

[0023] First Embodiment This embodiment provides an ultrasonic vortex field emission device based on a helical diffraction grating, comprising: substrate; At least one helical groove formed on the substrate is used for phase modulation of the incident plane acoustic wave; and An ultrasonic transducer is used to generate the incident plane sound wave and make it incident perpendicular to the surface of the substrate. The substrate and the spiral groove form a planar spiral diffraction grating structure. After the planar sound wave is modulated by the spiral diffraction grating, an ultrasonic vortex field with a spiral phase wavefront is generated behind the exit surface.

[0024] This embodiment simplifies the complex vortex field generation system into a planar static structure of "substrate + spiral groove," eliminating the need for complex multi-channel phase control circuits and independent control systems found in active technologies. This significantly reduces system complexity, manufacturing costs, and operational difficulty. Furthermore, the planar structure facilitates integration with other systems such as microfluidic chips, laying the foundation for miniaturized, on-chip ultrasonic control platforms.

[0025] By utilizing the precise geometric phase modulation of a helical diffraction grating, high-frequency (e.g., 10 MHz) ultrasonic vortex fields with a defined helical phase wavefront can be generated efficiently and stably. This overcomes the difficulties of active arrays in unit size fabrication and wavefront control when the wavelength is shortened, and also avoids the defects of traditional passive metasurface structures, such as non-planarity and fixed frequency. It provides a reliable means for precise manipulation of smaller particles at higher frequencies. The generated high-frequency ultrasonic vortex field carries orbital angular momentum, which can exert acoustic radiation force and torque on particles in fluids. It enables various non-contact precision manipulations, binding particles to the vortex ring or center, and driving single or multiple particles to rotate around the vortex axis. By switching the vortex order (N) to change the capture radius, it can adapt to particles of different sizes; by adjusting the transducer excitation voltage to control the sound field intensity, the rotational speed of the particles can be precisely controlled.

[0026] Preferably, the number of spiral grooves is one or more; when the number of spiral grooves is multiple, the multiple spiral grooves are distributed in a rotationally symmetrical manner around the center of the substrate.

[0027] The acoustic grating structure is customized according to different application requirements (such as the complexity of the required vortex field and the intensity distribution of the control force). A single helical groove is the simplest realization for generating a basic vortex field; multiple helical grooves provide the physical basis for generating more complex, higher-order, or more specialized vortex fields, greatly expanding the functional range of the device.

[0028] When multiple helical grooves exist, their rotationally symmetric distribution around the center of the substrate is a key geometric constraint for generating high-quality, high-purity vortex fields. This rotationally symmetric arrangement ensures that phase modulation is uniform and continuous in the circumferential direction, resulting in a perfect helical phase structure for the generated acoustic wavefront. This effectively suppresses problems such as phase distortion, modal impurities (e.g., contamination with other orders), or uneven sound field intensity distribution that may result from structural asymmetry, ensuring a clear and stable zero-sound-pressure region at the core of the vortex field.

[0029] Preferably, the substrate is further provided with a support structure for enhancing structural stability, the support structure extending along the radial direction of the spiral groove.

[0030] In processing (such as etching and cutting) or subsequent treatments, especially for thin substrates with complex, intricate spiral groove patterns, the support structure effectively resists substrate warping, deformation, or microcracks caused by internal material stress release or external stress. Ensuring that key geometric parameters such as the depth, width, and spiral trajectory of the spiral grooves maintain design accuracy after manufacturing is the physical basis for generating high-quality ultrasonic vortex fields with the expected phase distribution. Without this support, even minor deformations of the structure can lead to acoustic field distortion or a decrease in mode purity.

[0031] Preferably, the number of spiral grooves on the substrate is N, and the helix equation of the m-th spiral groove is: , a1 = 0.598 mm, a2 = 0.648 mm, b is a constant, and θ is a constant.

[0032] This embodiment provides direct, unambiguous engineering drawings for computer-aided design (CAD), numerical control machining (CNC), or micro / nano manufacturing (such as photolithography). The machining path can be generated strictly according to this equation, ensuring a high degree of consistency between the final product and the invention's design intent, a necessary step in realizing the invention. Key dimensional parameters (a1=0.598mm, a2=0.648mm) at a 10MHz operating frequency are given; these parameters determine the initial width and radial position of the helical groove. These specific values ​​are preferred embodiments determined through in-depth theoretical analysis and simulation verification. They are optimized to produce the most effective phase delay (e.g., integer multiples of π) for acoustic waves at this frequency, thereby accurately synthesizing a helical wavefront of the target order (N) at the exit. This guarantees the determinism, effectiveness, and repeatability of the device's performance, and is the core design secret for achieving a "high-frequency (10MHz)" and "stable" vortex field.

[0033] Preferably, the operating frequency of the ultrasonic transducer is set to 10MHz. When N is 1, b = 0.029, and the value of θ ranges from 0 to 14.9π; when N is 2, b = 0.057, and the value of θ ranges from 0 to 7.5π; when N is 3, b = 0.085, and the value of θ ranges from 0 to 5π; when N is 4, b = 0.113, and the value of θ ranges from 0 to 3.9π; when N is 5, b = 0.142, and the value of θ ranges from 0 to 3π; when N is 6, b = 0.17, and the value of θ ranges from 0 to 2.5π.

[0034] This embodiment provides a set of optimal parameter combinations, precisely calculated and experimentally verified, for achieving ultrasonic vortex fields of orders 1 to 6 at an operating frequency of 10 MHz. The parameter combinations clearly show a precise correspondence between the almost linear increase in helical growth rate b with order N (0.029, 0.057, 0.085...) and the regular decrease in helical angular span θ_max with increasing order (14.9π, 7.5π, 5π...). This is the result of in-depth optimization of the helical groove geometry at a high frequency of 10 MHz to achieve a total phase delay of 2πN (the essence of a vortex field). It ensures precise matching of the phase gradient contributed by each groove, thereby synthesizing a helical wavefront with a pure mode and minimal defects at the outlet. This is key to achieving efficient, high-order vortex fields, going beyond simple principle-based designs. The generation of high-frequency (short-wavelength) acoustic vortices requires the acoustic grating feature size to be comparable to the wavelength. These micrometer-level parameters are precisely designed to match the 10 MHz wavelength in water (approximately 0.15 mm). This strongly confirms and protects the invention's specific implementation capability in the 10MHz high-frequency band, achieving the effect of "extending to higher frequencies" as intended by the invention, and directly contrasts with the problem of "difficulty in high-frequency implementation" in the background art.

[0035] See Figure 1 (a) to (f) are multi-armed helical diffraction grating acoustic vortex field emitters with frequencies of 10MHz and ranging from 1st to 6th orders. These are planar structures with a thickness of 0.05mm in the propagation direction (assuming the propagation direction is z-direction) and a side length of 6cm in the xy-plane. By adjusting the number of arms, acoustic vortex fields of corresponding orders can be generated. Simultaneously, to ensure structural stability, four supports with a width of 0.04m are added.

[0036] Figure (a) shows a first-order substrate with a spiral groove. The equations of the two spirals are as follows: and a1 = 0.598 mm, a2 = 0.648 mm, b = 0.029, and θ ranges from 0 to 14.9π.

[0037] Figure (b) shows a second-order substrate with two spiral grooves. The equations of the two spiral lines of the m-th spiral groove are given. and m≤2, m is a positive integer, a1=0.598mm, a2=0.648mm, b=0.057, and θ ranges from 0 to 7.5π.

[0038] Figure (c) shows a three-dimensional substrate with three spiral grooves. The equations of the two spiral lines of the m-th spiral groove are as follows: and m≤3, m is a positive integer, a1=0.598mm, a2=0.648mm, b=0.085, and θ ranges from 0 to 5π.

[0039] Figure (d) shows a fourth-order substrate with four spiral grooves. The equations of the two spiral lines of the m-th spiral groove are as follows: and m≤4, m is a positive integer, a1=0.598mm, a2=0.648mm, b=0.113, and θ ranges from 0 to 3.9π.

[0040] Figure (e) shows a fifth-order substrate with five spiral grooves. The equations of the two spiral lines of the m-th spiral groove are as follows: and m≤5, m is a positive integer, a1=0.598mm, a2=0.648mm, b=0.142, and θ ranges from 0 to 3π.

[0041] Figure (f) shows a sixth-order substrate with six spiral grooves. The equations of the two helices of the m-th spiral groove are as follows: and m≤6, m is a positive integer, a1=0.598mm, a2=0.648mm, b=0.17, and θ ranges from 0 to 2.5π.

[0042] Figure 2 for Figure 1 The simulated phase distribution diagram. For Figure 1 Simulations were performed on six structures (a)-(f), with water as the background medium, 10MHz as the incident sound wave frequency, and stainless steel as the substrate material. Figure 2 The figures show the phase distribution diagrams of the first, second, third, fourth, fifth, and sixth order acoustic vortex fields generated by the corresponding acoustic vortex field generator in a plane at 10 MHz and 13 wavelengths from the output surface. These characteristics are consistent with the properties of the corresponding order acoustic vortex fields, indicating that the designed structure can perfectly generate the required high-frequency acoustic vortex field.

[0043] Because vortex sound beams carry orbital angular momentum, particles placed in water can rotate under the influence of the vortex sound field, thus enabling rotational manipulation of the particles. As the vortex order increases, the vortex radius gradually increases. Therefore, by changing the order of the transmitter, different vortex radii can be obtained, thereby enabling manipulation of particles of different sizes.

[0044] Figure 3The image shows the rotation trajectory of a 500-micrometer diameter PS microsphere under a 5th-order vortex field with an excitation voltage of 1500 mV. When a sinusoidal driving voltage with a center frequency of 10 MHz is applied to the ultrasonic transducer, the 500-micrometer PS microsphere located at the center of the vortex acoustic field rotates rapidly and reaches equilibrium. The microsphere completes a 360° rotation after 1020 ms, with a rotational speed of 0.98 rps.

[0045] Meanwhile, the rotational speed of the microspheres under different excitation voltages was experimentally investigated. The results are as follows: Figure 4 As shown, when the excitation voltage increases from 1150 mV to 1600 mV, the rotational speed increases from 0.48 rps to 1.33 rps. The quadratic fitting curve in the figure shows that the rotational speed has an approximately quadratic relationship with the excitation voltage.

[0046] In addition to controlling particle rotation, the designed device can also assemble microparticles.

[0047] Figure 5 The image shows the self-assembly effect of 3-micrometer diameter PS microspheres under the action of a fourth-order vortex field with an excitation voltage of 2V. It can be seen that after about 5 minutes, the 3-micrometer diameter PS microspheres assemble under the action of the acoustic field.

[0048] This invention, based on the simple physical structure of a helical diffraction grating, successfully generates a high-frequency ultrasonic vortex field. Simulation and experimental verification show that the vortex radius gradually increases with increasing vortex order. Therefore, adjusting the vortex order can effectively control particles of different sizes. Simultaneously, with increasing excitation voltage, the sound pressure at the focusing plane increases, and the particle rotation speed also increases accordingly. Experimental data shows that the particle rotation speed has an approximately quadratic relationship with the excitation voltage. Therefore, by adjusting the excitation voltage, the particle rotation speed can be precisely controlled. This invention has a simple structure, is easy to integrate, and has the potential to extend to higher frequencies, providing new ideas and directions for the future development of miniaturized and integrated ultrasonic manipulation platforms. Ultrasonic vortexes, as a non-contact, high-precision particle manipulation technology, show broad application potential in fields such as biology, chemistry, engineering, and medicine. However, most current ultrasonic vortex systems suffer from frequency limitations, complex structures, and difficulties in integration, especially in achieving high-frequency, high-order vortex fields and their precise control over microparticles, which still faces significant challenges.

[0049] In some embodiments, the phase of the piezoelectric ceramic transducer can be changed to control particles of different sizes, but this is an active method, which is relatively expensive and difficult to miniaturize.

[0050] Second Embodiment Based on the same concept, the present invention also provides a method for manipulating ultrasonic vortex particles based on a helical diffraction grating ultrasonic vortex field, comprising the following steps: S1: Drive the ultrasonic transducer to generate a plane sound wave, and make the plane sound wave perpendicularly incident on the spiral diffraction grating; S2: The incident plane sound wave is phase-modulated by the helical diffraction grating to generate an ultrasonic vortex field of a preset order in the fluid medium behind it. S3: Using the ultrasonic vortex field to perform non-contact manipulation of particles placed in the fluid medium.

[0051] This embodiment defines a clear and linear three-step process from acoustic excitation (S1) to vortex field generation (S2) and then to particle manipulation (S3). This makes acoustic particle manipulation technology, which previously relied on complex equipment and specialized knowledge, streamlined and standardized. Any operator can reliably reproduce non-contact particle manipulation by simply following these steps, greatly reducing the operational threshold and uncertainty of the technology, and facilitating its promotion and industrial application. Step S2 explicitly requires the generation of an ultrasonic vortex field of a "preset order," stemming from the fixed geometric design of the spiral diffraction grating used (e.g., order N). This directly binds the abstract "particle manipulation" target to specific acoustic field physical characteristics (topological charge). Users can pre-select or replace gratings with corresponding orders N according to different manipulation needs (e.g., capturing particles of different sizes), thereby automatically achieving differentiated manipulation functions (e.g., different capture radii) when executing the standard process. This realizes "hardware programmability" or "modular switching" of functions.

[0052] Preferably, the non-contact manipulation of the particles described in step S3 includes using the orbital angular momentum of the ultrasonic vortex field to drive the particles to rotate.

[0053] This embodiment utilizes the inherent physical property of the ultrasonic vortex field generated by the helical diffraction grating—carrying orbital angular momentum. Unlike rotational drive methods that require complex external fields or mechanical contact, this method achieves rotation endogenously: the vortex field is both the generator and the source of the driving force. It fully leverages the acoustic field characteristics generated by the device of this invention, achieving efficient unification and minimal matching between the control method and the physical properties of the acoustic field.

[0054] Preferably, the non-contact manipulation of particles described in step S3 includes using the acoustic radiation force of the ultrasonic vortex field to cause multiple particles to self-assemble.

[0055] Building upon the ability to drive the rotation of individual particles, this method further enables the collective and orderly manipulation of multiple particles, causing them to automatically align and aggregate into specific structures within an acoustic field. The manipulation capability has evolved from simple motion control of individual particles to programming the spatial structure of a group. This provides a non-contact, non-destructive tool for the mass production of ordered particle arrays, complex metamaterials, or biomimetic structures at the microscopic scale, greatly expanding the application dimensions of the technology.

[0056] Preferably, the method further includes adjusting the topological charge of the generated ultrasonic vortex field by selecting the number N of spiral grooves of the spiral diffraction grating, thereby changing the radius of stable particle capture in the vortex field to accommodate particles of different sizes.

[0057] This embodiment overcomes the limitations of traditional single-structure devices with fixed functions. Users can quickly switch the control scale by replacing different acoustic grating modules (similar to changing microscope objectives) without replacing the entire complex system. This significantly improves the device's functional flexibility, application breadth, and cost-effectiveness, creating significant added value for the core invention.

[0058] Preferably, the rotational speed of the manipulated particles is controlled by adjusting the excitation voltage driving the ultrasonic transducer to change the sound pressure intensity of the ultrasonic vortex field.

[0059] By establishing a clear control chain of "excitation voltage -> sound pressure intensity -> rotation speed," the control of complex motions in the microscopic world (particle rotation) becomes as intuitive, linear, and quantifiable as adjusting an instrument knob. Operators can adjust the voltage in real time, either programmatically or manually, according to experimental needs, to achieve stepless, continuous, and reversible precise control of the rotation speed, meeting the requirements for precise control of process parameters in scientific research and industrial applications.

[0060] Based on the same concept, the present invention also provides an electronic device, comprising: a memory for storing a processing program; and a processor, wherein the processor, when executing the processing program, implements the ultrasonic vortex particle manipulation method based on the ultrasonic vortex field of a helical diffraction grating as described above.

[0061] Based on the same concept, the present invention also provides a readable storage medium storing a processing program, which, when executed by a processor, implements the ultrasonic vortex particle manipulation method based on a helical diffraction grating ultrasonic vortex field as described above.

[0062] The ultrasonic vortex particle manipulation method based on a helical diffraction grating ultrasonic vortex field, if implemented as program instructions and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, essentially, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in software. This computer software is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0063] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific identification content executed by the system and device described above can be referred to the corresponding process in the foregoing method embodiments.

[0064] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. An ultrasonic vortex field emission device based on a helical diffraction grating, characterized in that, include: substrate; At least one spiral groove formed on the substrate is used for phase modulation of the incident plane acoustic wave; as well as An ultrasonic transducer is used to generate the incident plane sound wave and make it incident perpendicular to the surface of the substrate; The substrate and the spiral groove form a planar spiral diffraction grating structure. After the planar sound wave is modulated by the spiral diffraction grating, an ultrasonic vortex field with a spiral phase wavefront is generated behind the exit surface.

2. The ultrasonic vortex field emitting device based on a helical diffraction grating according to claim 1, characterized in that, The number of spiral grooves is one or more; when the number of spiral grooves is multiple, the multiple spiral grooves are distributed in a rotationally symmetrical manner around the center of the substrate.

3. The ultrasonic vortex field emitting device based on a helical diffraction grating according to claim 2, characterized in that, The substrate is also provided with a support structure for enhancing structural stability, and the support structure extends along the radial direction of the spiral groove.

4. The ultrasonic vortex field emitting device based on a helical diffraction grating according to claim 1, characterized in that, The number of spiral grooves on the substrate is N, and the helix equation of the m-th spiral groove is: , a1 = 0.598 mm, a2 = 0.648 mm, b is a constant, and θ is a constant.

5. The ultrasonic vortex field emitting device based on a helical diffraction grating according to claim 4, characterized in that, The ultrasonic transducer is set to operate at a frequency of 10 MHz. When N is 1, b = 0.029, and θ ranges from 0 to 14.9π; when N is 2, b = 0.057, and θ ranges from 0 to 7.5π; when N is 3, b = 0.085, and θ ranges from 0 to 5π; when N is 4, b = 0.113, and θ ranges from 0 to 3.9π; when N is 5, b = 0.142, and θ ranges from 0 to 3π; when N is 6, b = 0.17, and θ ranges from 0 to 2.5π.

6. A method for manipulating ultrasonic vortex particles based on a helical diffraction grating ultrasonic vortex field, characterized in that, Includes the following steps: S1: Drive the ultrasonic transducer to generate a plane sound wave, and make the plane sound wave perpendicularly incident on the spiral diffraction grating; S2: The incident plane sound wave is phase-modulated by the helical diffraction grating to generate an ultrasonic vortex field of a preset order in the fluid medium behind it. S3: Using the ultrasonic vortex field to perform non-contact manipulation of particles placed in the fluid medium.

7. The ultrasonic vortex particle manipulation method according to claim 6, characterized in that, The non-contact manipulation of the particles described in step S3 includes using the orbital angular momentum of the ultrasonic vortex field to drive the particles to rotate.

8. The ultrasonic vortex particle manipulation method according to claim 6, characterized in that, The non-contact manipulation of particles described in step S3 includes using the acoustic radiation force of the ultrasonic vortex field to cause multiple particles to self-assemble.

9. The ultrasonic vortex particle manipulation method according to claim 6, characterized in that, The method also includes adjusting the topological charge of the generated ultrasonic vortex field by selecting the number N of spiral grooves of the spiral diffraction grating, thereby changing the radius of stable particle capture in the vortex field to accommodate particles of different sizes.

10. The ultrasonic vortex particle manipulation method according to claim 6, characterized in that, By adjusting the excitation voltage driving the ultrasonic transducer, the sound pressure intensity of the ultrasonic vortex field is changed, thereby controlling the rotational speed of the manipulated particles.

Images