Surface acoustic wave particle screening device and method

Abstract

The surface acoustic wave particle screening device comprises a function signal generator, a plurality of power amplifiers, a power source, a plurality of piezoelectric ceramic pieces and a flat plate, each piezoelectric ceramic piece is fixedly bonded to the upper surface of the flat plate through glue, and the power source is used for supplying power to each power amplifier; the function signal generator is connected with each power amplifier through a coaxial cable, and the function signal generator is used for providing a sine frequency sweeping signal for each power amplifier; after each power amplifier receives a sine frequency sweep signal output by the function signal generator, each power amplifier outputs the sine frequency sweep signal after amplitude amplification to each piezoelectric ceramic piece, each piezoelectric ceramic piece generates vibration, the flat plate absorbs energy of vibration, and surface acoustic waves are generated to drive particles located on the flat plate to move. For particles with different sizes and masses, the amplitude applied to the piezoelectric ceramic piece is changed, so that the movement speed of the different particles can be controlled, and the effect of screening the particles is achieved.

Description

Technical Field

[0001] The present invention relates to surface acoustic wave technology and micro-nano particle manipulation technology, and in particular to a surface acoustic wave particle screening device and method. Background Art

[0002] A convenient and efficient method for separating two particles of different sizes is filtration through a mesh, but this method is prone to mesh clogging and has limited resolution. Acoustic tweezers are an innovative technology based on acoustic principles. They exploit the interaction between sound waves and microscopic objects to achieve contactless manipulation and capture of tiny particles.

[0003] Currently, new acoustic tweezers technologies are emerging, such as microfluidic and holographic acoustic tweezers. However, microfluidic acoustic tweezers are difficult to manipulate over long distances due to the rapid energy loss of high-frequency sound waves in liquids. Holographic acoustic tweezers require a multi-channel transducer array and high-performance computing to generate the sound field, resulting in a complex and costly system. The surface acoustic wave particle screening device provided by the present invention utilizes Rayleigh waves propagating along a solid surface to drive particles, enabling large-scale screening of particles. Furthermore, the device offers significant advantages in particle manipulation due to its simple structure, ease of operation, and low cost. Summary of the Invention

[0004] The present invention provides a surface acoustic wave (SAW) device and method for screening particles, aiming to improve the accuracy, convenience and intelligence of particle screening.

[0005] The technical solution of the present invention is:

[0006] A surface acoustic wave particle screening device includes a function signal generator, a plurality of power amplifiers, a power supply, a plurality of piezoelectric ceramic sheets and a flat plate, wherein:

[0007] Each piezoelectric ceramic sheet is fixedly bonded to the upper surface of the flat plate using glue;

[0008] The power supply is used to supply power to each power amplifier;

[0009] The function signal generator is connected to each power amplifier via a coaxial cable, and is used to provide a sine frequency sweep signal to each power amplifier;

[0010] After each power amplifier receives the sine swept frequency signal output by the function signal generator, it outputs the amplitude-amplified sine swept frequency signal to each piezoelectric ceramic plate. Each piezoelectric ceramic plate vibrates, and the plate absorbs the vibration energy, generating surface acoustic waves to drive the particles on the plate to move.

[0011] According to a surface acoustic wave particle screening device provided by the present invention, a layer of graphite powder, a hydrophobic coating, or a metal film is evenly applied to the central region of the upper surface of the flat plate; sound-absorbing materials are added to the boundary of the flat plate, and the sound-absorbing materials are hot melt adhesives, industrial adhesives, or rubber sheets.

[0012] According to a surface acoustic wave particle screening device provided by the present invention, the surface acoustic wave particle screening device further includes a hammer and a motor. The hammer is located below the flat plate and is used to strike the lower surface of the flat plate. The hammer is fixed to the motor, and the function signal generator is connected to the motor through a coaxial cable. The function signal generator is used to control the amplitude, frequency, and number of rotations of the motor, and thus control the amplitude, frequency, and number of times the hammer strikes the lower surface of the flat plate.

[0013] According to a surface acoustic wave particle screening device provided by the present invention, any two of the plurality of piezoelectric ceramic sheets are in a vertical or parallel relationship.

[0014] According to a surface acoustic wave particle screening device provided by the present invention, the surface acoustic wave particle screening device controls the speed of particle movement by changing the amplitude of the sinusoidal sweep signal received by the piezoelectric ceramic sheet.

[0015] According to a surface acoustic wave particle screening device provided by the present invention, the frequency of the sinusoidal sweep signal emitted by the function signal generator is in the megahertz range.

[0016] According to a surface acoustic wave particle screening device provided by the present invention, each piezoelectric ceramic sheet receives a sinusoidal sweep signal with an amplified amplitude output by a power amplifier.

[0017] According to a surface acoustic wave particle screening device provided by the present invention, the flat plate is a glass plate, an aluminum plate, or a stainless steel plate, the particles are quartz sand, pollen, grass seeds, salt particles, sugar particles, or plastic particles, and the piezoelectric ceramic sheet includes a lead zirconate titanate (PZT) series piezoelectric ceramic material.

[0018] According to a surface acoustic wave particle screening device provided by the present invention, the central region of the flat plate is used to place particles. All the mutually parallel piezoelectric ceramic sheets on one side of the particles are taken as a group. The direction of particle movement is determined by the group of piezoelectric ceramic sheets that generate vibration. The particles move along the direction approaching the vibrating piezoelectric ceramic sheets. The greater the amplitude of vibration of the piezoelectric ceramic sheet, the faster the particles move; at the same amplitude, particles of different masses or sizes move at different speeds. A variety of particles move at different speeds under the action of a group of piezoelectric ceramic sheets, or move back and forth at different speeds under the alternating action of two groups of mutually parallel piezoelectric ceramic sheets, achieving the screening effect.

[0019] The present invention also provides a surface acoustic wave particle screening method, including:

[0020] Transmit a sine sweep signal through the function signal generator;

[0021] Amplify the sine sweep signal through the power amplifier;

[0022] Receive the amplified sine sweep signal through the piezoelectric ceramic sheet, generate vibration, and act on the flat plate;

[0023] Absorb the vibration energy through the flat plate to generate surface acoustic waves, causing the particles on the flat plate to move.

[0024] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the surface acoustic wave particle screening method as described in any one of the above.

[0025] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the surface acoustic wave particle screening method as described in any one of the above.

[0026] For the surface acoustic wave particle screening device and method provided by the present invention, for particles of different sizes and masses, by changing the amplitude applied to the piezoelectric ceramic sheet, the speed of different particle movements can be controlled, making the operation more convenient; two sets of mutually parallel piezoelectric ceramic sheets can be used to make the particles move back and forth on the flat plate to achieve the purpose of multiple screening, thereby improving the particle screening accuracy; further, using a computer program to control the complete screening process can avoid errors caused by manual operation, and the screening process is more intelligent. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 One of the structural schematic diagrams of the surface acoustic wave particle screening device provided by the present invention;

[0029] Figure 2 Another structural schematic diagram of the surface acoustic wave particle screening device provided by the present invention;

[0030] Figure 3 The flow schematic diagram of the surface acoustic wave particle screening method provided by the present invention;

[0031] Figure 4 Under the industrial camera Figure 1 The particle screening effect diagram of the device in

[0032] Figure 5 For the industrial camera Figure 2 Particle screening effect diagram of the device in the middle. Specific implementation manners

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0034] The terms used in one or more embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit one or more embodiments of the present invention. The singular forms "a", "the" and "said" used in one or more embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used in one or more embodiments of the present invention refers to and includes any or all possible combinations of one or more of the associated listed items.

[0035] It should be understood that although the terms first, second, etc. may be used in one or more embodiments of the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present invention, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0036] The following is combined with Figures 1 - 5 to elaborate in detail on the exemplary implementation manners of the present invention.

[0037] Figure 1 It is a schematic structural diagram of the surface acoustic wave particle screening device provided by the present invention. As Figure 1As shown in the figure, the surface acoustic wave particle screening device includes a function signal generator 1, several power amplifiers 2, a power supply 3, several piezoelectric ceramic chips 4, and a flat plate 5. The piezoelectric ceramic chips 4 are fixedly bonded to the upper surface of the flat plate 5 with glue. Among them, the power supply 3 is used to supply power to each power amplifier 2; the function signal generator 1 is connected to each power amplifier 2 through a coaxial cable, and the function signal generator 1 is used to provide a sinusoidal sweep signal to each power amplifier 2; after each power amplifier 2 receives the sinusoidal sweep signal output by the function signal generator 1, each power amplifier 2 outputs an amplitude-amplified sinusoidal sweep signal to each piezoelectric ceramic chip 4, and each piezoelectric ceramic chip 4 generates vibrations. The flat plate 5 absorbs the vibration energy to generate surface acoustic waves to drive the particles 6 located on the flat plate to move. For particles with different sizes and masses, by changing the amplitude applied to the piezoelectric ceramic chip 4, the movement speed of different particles can be controlled to produce a screening effect.

[0038] In the embodiment of the present invention, in order to more clearly introduce the working principle of the surface acoustic wave particle screening device, the following content is used for illustration.

[0039] The function signal generator 1 is used to provide a sinusoidal sweep signal to each power amplifier 2. It should be noted that the frequency of the sinusoidal sweep signal emitted by the function signal generator 1 is in the megahertz range.

[0040] The power amplifier 2 is used to output an amplitude-amplified sinusoidal sweep signal to each piezoelectric ceramic chip 4.

[0041] The power supply 3 is used to supply power to each power amplifier 2.

[0042] In this embodiment, the propagation direction of the sinusoidal sweep signal in the surface acoustic wave particle screening device is successively: function signal generator 1, power amplifier 2, piezoelectric ceramic chip 4, and flat plate 5. In the embodiment of the present invention, the number of the power amplifiers 2 can be set based on actual conditions. Preferably, in order to enable the piezoelectric ceramic chip 4 to achieve the effect of reciprocating movement of the particles, the number of the power amplifiers 2 can be set to 2, so that each group of piezoelectric ceramic chips 4 can receive the amplified signal separately. The piezoelectric ceramic chip 4 converts the electrical signal into vibration. Among them, the number of the piezoelectric ceramic chips 4 can be set based on actual conditions. Preferably, in order to separately control the two directions of particle movement, the piezoelectric ceramic chips 4 can be set to 2 groups. In order to make the surface acoustic waves on the flat plate more uniform, so as to achieve large-area particle screening, the number of the piezoelectric ceramic chips 4 in each group can be set to 2 or more to achieve arbitrary dynamic control of the particles by the piezoelectric ceramic chips.

[0043] The flat plate 5 is used to absorb the vibration energy to generate surface acoustic waves to drive the particles 6 on the flat plate 5 to move.

[0044] It should be noted that the flat plate 5 includes one or more of a glass plate, an aluminum plate, and a stainless steel plate, and the particles 6 include one or more of quartz sand, pollen, grass seeds, salt particles, sugar particles, and plastic particles.

[0045] Specifically, through the inverse piezoelectric effect, after the piezoelectric ceramic sheet 4 converts an electrical signal into vibration, the adhered flat plate 5 absorbs the vibration energy to generate surface acoustic waves, and the particles 6 move under the action of Rayleigh waves. Among them, in order to improve the efficiency of particle screening, a layer of graphite powder, a hydrophobic coating, or a metal film is evenly applied to the central region of the upper surface of the flat plate 5 to reduce the friction between the particles 6 and the upper surface of the flat plate 5. In order to absorb the surface acoustic waves at the boundary and reduce the influence caused by the reflected waves, an acoustic absorption material, such as hot melt adhesive, industrial glue, or rubber skin, can be added to the boundary of the flat plate 5. Additionally, referring to Figure 1 , the direction of movement of the particles is determined by a group of piezoelectric ceramic sheets that generate vibration, and the particles move along the direction approaching the vibrating piezoelectric ceramic sheets. The greater the amplitude of vibration of the piezoelectric ceramic sheet, the faster the particles move; at the same amplitude, particles of different masses or sizes move at different speeds, and multiple particles can move at different speeds under the action of a group of piezoelectric ceramic sheets, or reciprocate at different speeds under the alternating action of two groups of mutually parallel piezoelectric ceramic sheets to achieve the screening effect.

[0046] Preferably, the surface acoustic wave particle screening device further includes a hammer 7 and a motor 8. The hammer 7 is located below the flat plate 5 and is used to strike the lower surface of the flat plate 5. The hammer 7 is fixed on the motor 8, and the motor 8 is connected to the function signal generator 1 through a coaxial cable. Therefore, the function signal generator 1 can control the amplitude, frequency, and number of rotations of the motor 8, and thus control the amplitude, frequency, and number of times the hammer 7 strikes the lower surface of the flat plate 5. The strike of the hammer 7 on the flat plate 5 can cancel the adsorption effect of the static electricity of the flat plate 5 on the particles 6.

[0047] Furthermore, referring to Figure 2 , Figure 2This is the second schematic structural diagram of the surface acoustic wave particle screening device provided by the present invention. In the surface acoustic wave particle screening device, the two groups of piezoelectric ceramic sheets 4 can also be vertically placed. By sequentially and repeatedly driving the two groups of piezoelectric ceramic sheets 4, the particles 6 can move towards the two groups of piezoelectric ceramic sheets 4, and the trajectory is in a stepped shape. In order to achieve a better separation effect, the particles 6 should be aggregated as much as possible before screening, so there is no need to consider the uniformity of the surface acoustic wave on the flat plate 5, and only one piezoelectric ceramic sheet 4 can be used for each group. It should be noted that the vertically placed piezoelectric ceramic sheets 4 can prevent the accumulation of microparticles during the screening process. It can be understood that when the microparticles move in a straight line, the moving microparticles may cause the stationary microparticles to move through collisions, and the stationary microparticles may stop the moving microparticles that collide with them. Therefore, by adding movement in the direction perpendicular to the original movement direction, the probability of collision of the microparticles on the movement path is greatly reduced, and the efficiency of microparticle screening can be improved.

[0048] Through the above solution in the embodiment of the present invention, that is: the surface acoustic wave particle screening device includes a function signal generator, several power amplifiers, a power supply, several piezoelectric ceramic sheets and a flat plate. Each piezoelectric ceramic sheet is fixedly bonded to the upper surface of the flat plate with glue, where: the power supply is used to supply power to each power amplifier; the function signal generator is connected to each power amplifier through a coaxial cable, and the function signal generator is used to provide a sine sweep signal to each power amplifier; after each power amplifier receives the sine sweep signal output by the function signal generator, each power amplifier outputs an amplitude-amplified sine sweep signal to each piezoelectric ceramic sheet, and each piezoelectric ceramic sheet generates vibration, and the flat plate absorbs the vibration energy to generate a surface acoustic wave to drive the particles located on the flat plate to move. For microparticles of different sizes and masses, by changing the amplitude applied to the piezoelectric ceramic sheet, the movement speed of different microparticles can be controlled, making the operation more convenient; two groups of piezoelectric ceramic sheets that are parallel or perpendicular to each other can be used to make the microparticles move on the flat plate, so as to achieve multiple screening or reduce particle collisions, thereby improving the particle screening accuracy; further, by using a computer program to control the complete screening process, the errors caused by manual operation can be avoided, and the screening process is more intelligent.

[0049] The method provided by the present invention will be described below. The surface acoustic wave particle screening method described below can be correspondingly referred to the surface acoustic wave particle screening device described above.

[0050] As Figure 3 shown, a surface acoustic wave particle screening method according to an embodiment of the present invention includes:

[0051] Step S10, emitting a sine sweep signal through the function signal generator 1;

[0052] Step S20, amplifying the sine sweep signal through the power amplifier 2, and the electrical signal is converted into vibration through the inverse piezoelectric effect of the piezoelectric ceramic sheet;

[0053] Step S30: Absorb the vibration energy through the flat plate to form a surface acoustic wave, causing the particles on the flat plate to move.

[0054] Step S40: Make the particles on the flat plate move through the action of two groups of the piezoelectric ceramic sheets, and change the amplitude to achieve the screening effect.

[0055] In this embodiment, specifically, the function signal generator 1 emits a sine sweep signal to the piezoelectric ceramic sheet 4. Among them, the sine sweep signal is amplified in amplitude by the power amplifier 2 and then transmitted to the piezoelectric ceramic sheet 4. Further, the piezoelectric ceramic sheet 4 generates an inverse piezoelectric effect, converting the electrical signal into vibration. Further, the flat plate 5 absorbs the vibration energy to form a surface acoustic wave, causing the particles 6 on the flat plate 5 to move. Further, two groups of piezoelectric ceramic sheets 4 placed in parallel can make the particles 6 move back and forth on the flat plate 5, achieving the purpose of multiple screenings. Reference can be made to Figure 4 , where Figure 4 is the micro-particle screening effect diagram of the device under the industrial camera Figure 1 In addition, two groups of piezoelectric ceramic sheets 4 placed vertically can make the particles 6 move on the flat plate 5 in two mutually perpendicular directions, achieving the purpose of reducing collisions and improving the screening accuracy. Reference can be made to Figure 5 , where Figure 5 is the micro-particle screening effect diagram of the device under the industrial camera Figure 2 Thereby, the particles of different sizes and masses on the flat plate are separated, and there is less mixing.

[0056] As another implementable manner, the hammer 7 is located below the flat plate 5 and fixed on the motor 8. The motor 8 is connected to the function signal generator 1. The knocking of the hammer 7 on the flat plate 5 can offset the adsorption effect of the static electricity of the flat plate 5 on the particles, making the screening more thorough.

[0057] Through the above scheme in the embodiment of the present application, that is, emitting a sine sweep signal through the function signal generator; amplifying the sine sweep signal through the power amplifier, and converting the electrical signal into vibration through the inverse piezoelectric effect of the piezoelectric ceramic sheet; absorbing the vibration energy through the flat plate to form a surface acoustic wave, causing the particles on the flat plate to move; making the particles on the flat plate move through the action of two groups of the piezoelectric ceramic sheets, and changing the amplitude to achieve the screening effect. For micro-particles of different sizes and masses, by changing the amplitude applied to the piezoelectric ceramic sheet, the movement speed of different micro-particles can be controlled, making the operation more convenient; two groups of piezoelectric ceramic sheets that are parallel or perpendicular to each other can be used to make the micro-particles move on the flat plate, achieving the purpose of multiple screenings or reducing particle collisions, thereby improving the particle screening accuracy; further, using a computer program to control the complete screening process can avoid errors caused by manual operation, and the screening process is more intelligent.

[0058] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the surface acoustic wave particle screening method provided by each of the above methods.

[0059] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it realizes the surface acoustic wave particle screening method provided by each of the above methods.

[0060] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Surface acoustic wave particle screening device, characterized in that: The particle device includes a function signal generator, several power amplifiers, a power supply, several piezoelectric ceramic sheets and a flat plate; Each of the piezoelectric ceramic sheets is fixedly bonded to the upper surface of the flat plate using glue; The power supply is used to supply power to each power amplifier; The function signal generator is connected to each power amplifier through a coaxial cable, and the function signal generator is used to provide a sinusoidal sweep signal to each power amplifier; After each power amplifier receives the sinusoidal sweep signal output by the function signal generator, each power amplifier outputs an amplitude-amplified sinusoidal sweep signal to each piezoelectric ceramic sheet, and each piezoelectric ceramic sheet generates vibration, and the flat plate absorbs the vibration energy to generate surface acoustic waves to drive the particles located on the flat plate to move.

2. The surface acoustic wave particle screening device according to claim 1, characterized in that: A layer of graphite powder, a hydrophobic coating or a metal film is evenly applied to the central area of the upper surface of the flat plate; Sound-absorbing materials are added to the four peripheral boundaries of the flat plate, and the sound-absorbing materials are hot melt adhesives, industrial adhesives or rubber skins.

3. The surface acoustic wave particle screening device according to claim 1, characterized in that: The device further includes a hammer and a motor; The hammer is located below the flat plate and is used to strike the lower surface of the flat plate; The hammer is fixed on the motor; The function signal generator is connected to the motor through a coaxial cable; The function signal generator is used to control the amplitude, frequency and number of rotations of the motor, and thus control the amplitude, frequency and number of times the hammer strikes the lower surface of the flat plate.

4. The surface acoustic wave particle screening device according to claim 1, characterized in that: Any two of the several piezoelectric ceramic sheets are in a vertical or parallel relationship.

5. The surface acoustic wave particle screening device according to claim 1, characterized in that: By changing the amplitude of the sinusoidal sweep signal received by the piezoelectric ceramic sheet, the speed of particle movement is controlled.

6. The surface acoustic wave particle screening device according to claim 1, characterized in that: The frequency of the sinusoidal sweep signal emitted by the function signal generator is in the megahertz range.

7. The surface acoustic wave particle screening device according to claim 1, characterized in that: Each piezoelectric ceramic sheet receives an amplitude-amplified sinusoidal sweep signal output by a power amplifier.

8. The surface acoustic wave particle screening device according to claim 1, characterized in that: The flat plate is a glass plate, an aluminum plate or a stainless steel plate; The particles are quartz sand, pollen, grass seeds, salt particles, sugar particles or plastic particles; The piezoelectric ceramic sheet includes lead zirconate titanate series piezoelectric ceramic materials.

9. The surface acoustic wave particle screening device according to claim 1, characterized in that: The central area of the flat plate is used to place particles. All the piezoelectric ceramic sheets that are parallel to each other and located on one side of the particles are grouped together. The direction of particle movement is determined by the group of piezoelectric ceramic sheets that generate vibrations. The particles move along the direction approaching the vibrating piezoelectric ceramic sheets. The greater the amplitude of vibration of the piezoelectric ceramic sheets, the faster the particles move. At the same amplitude, particles of different masses or sizes move at different speeds. Multiple particles move at different speeds under the action of a group of piezoelectric ceramic sheets, or move reciprocally at different speeds under the alternating action of two groups of mutually parallel piezoelectric ceramic sheets, achieving the screening effect.

10. Surface acoustic wave method for screening microparticles, characterized in that The steps of this method include: Step S10: Transmit a sinusoidal sweep signal through a function signal generator. Step S20: Amplify the sinusoidal sweep signal through a power amplifier, and the sinusoidal sweep signal is converted into vibration through the inverse piezoelectric effect of the piezoelectric ceramic sheet. Step S30: Absorb the vibration energy through the flat plate to form a surface acoustic wave, causing the particles on the flat plate to move. Step S40: Make the particles on the flat plate move through the action of two groups of the piezoelectric ceramic sheets, and change the amplitude to achieve the screening effect.

Images