Standing wave multi-mode micro-particle manipulation device and method based on Langevin transducer

Abstract

The present invention discloses a standing wave multi-mode microparticle manipulation device and method based on a Langevin transducer. The multi-mode microparticle manipulation device includes a base, a first fixed seat, a second fixed seat, a first piezoelectric transducer, a second piezoelectric transducer, a vibrating body, a PMDS module, a sorting copper sheet, and a sorting drive unit. The longitudinal vibration frequencies of the first piezoelectric transducer and the second piezoelectric transducer are inconsistent. The first piezoelectric transducer is used to induce a second-order bending vibration mode of the vibrating body distortion, and the second piezoelectric transducer is used to induce a third-order bending vibration mode of the vibrating body distortion. By alternately exciting the two piezoelectric transducers to achieve mode switching, the microspheres are caused to migrate over long distances. During this process, the microsphere morphology is detected by a microscope, and the microspheres are sorted according to the detection results. The device of the present invention is simple and inexpensive, which can reduce the cost of common screening systems and achieve efficient and high-precision screening of microparticles.

Description

Technical Field

[0001] The present invention relates to the fields of micro-manipulation and rapid screening of microparticles, and in particular to a standing wave multi-mode microparticle manipulation device and method based on a Langevin transducer. Background Art

[0002] Laser confinement fusion (ICF) uses a high-power, high-energy-density laser as a driving force. It employs spherical implosion pressurization technology to ignite the nuclear fuel within a spherical target pellet, resulting in a self-sustaining thermonuclear reaction. ICF holds the promise of providing clean, pollution-free energy for humanity. ICF experiments place stringent demands on the geometric parameters and surface defects of the hollow microparticles (target pellets) that serve as nuclear fuel containers. The quality of the target pellets directly impacts the success of ICF experiments. The tiny size (100-1000 μm in diameter), fragile structure, and strong viscosity of the target pellets pose significant challenges for their inspection. Currently, the equipment used to measure the geometric parameters of microparticles includes X-ray machines, white-light interferometers, and atomic force microscopes. These instruments offer high precision (reaching the micrometer or even nanometer range). Due to the spherical shape of the target pellet, comprehensive characterization of its morphology requires multiple movements and rotations. However, these detection devices all control the movement of the target pellet through a multi-degree-of-freedom mobile platform. This hard-contact method is prone to secondary damage to the target pellet surface when adjusting its posture, resulting in low target pellet detection efficiency and pass rate. Micromanipulation technology using acoustic waves as a driving source has the advantages of high biocompatibility and stable microscale manipulation. This means that micromanipulation technology can be applied to the non-destructive testing and screening of microparticles. Through multiple positioning, the complete morphological characterization of the target pellet can be achieved. By coordinating and switching between different vibration modes, targets of different masses can be concentrated in different areas, thereby meeting the requirements of non-destructive and high-precision manipulation during the target pellet detection process. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a standing wave multi-mode micro-particle manipulation device and method based on a Langevin transducer in order to address the defects mentioned in the background technology.

[0004] The present invention adopts the following technical solutions to solve the above technical problems:

[0005] A standing wave multi-mode micro-particle manipulation device based on a Langevin transducer includes a base, a first fixing seat, a second fixing seat, a first piezoelectric transducer, a second piezoelectric transducer, a vibrating body, a PMDS module, a sorting copper sheet, and a sorting drive unit;

[0006] The first piezoelectric transducer and the second piezoelectric transducer each comprise a variable amplitude beam, a front beam, 2n piezoelectric ceramic sheets, a clamping sheet, a pre-tightening bolt and a rear beam;

[0007] The pre-tightening bolt comprises a nut and a stud;

[0008] The front beam includes an amplitude-changing portion and a connecting portion, wherein the connecting portion is a column; the amplitude-changing portion is a column with a cross-sectional area gradually decreasing from bottom to top, and its lower end surface has the same cross-sectional shape as the connecting portion and is coaxially fixedly connected to the upper end surface of the connecting portion for amplifying the amplitude;

[0009] The rear beam is a column with the same cross-sectional shape as the front beam connecting portion, a threaded hole matching the pre-tightening bolt is provided at the center of the lower end surface of the front beam connecting portion, and a countersunk through hole matching the pre-tightening bolt is provided at the center of the lower end surface of the rear beam body;

[0010] The 2n piezoelectric ceramic sheets are stacked in sequence from top to bottom, are polarized along the thickness direction, and the polarization directions of adjacent piezoelectric ceramic sheets are opposite;

[0011] The area of the clamping piece is larger than the cross-sectional area of the rear beam, and a through hole is provided at the center thereof for the pre-tightening bolt to pass through;

[0012] The studs of the pre-tightening bolts sequentially pass through the countersunk through-holes of the rear beam, the through-holes in the center of the clamping plate, the 2n piezoelectric ceramic sheets, and the threaded holes of the front beam to press the 2n piezoelectric ceramic sheets.

[0013] The first fixing seat and the second fixing seat are both columns whose lower end surfaces are fixed to the base, and their upper end surfaces are respectively provided with grooves for mounting the first piezoelectric transducer and the second piezoelectric transducer;

[0014] The clamping piece of the first piezoelectric transducer is fixedly connected to the upper end surface of the first fixing seat, so that the back beam of the first piezoelectric transducer is located in the groove of the first fixing seat and does not contact the first fixing seat; the clamping piece of the second piezoelectric transducer is fixedly connected to the upper end surface of the second fixing seat, so that the back beam of the second piezoelectric transducer is located in the groove of the second fixing seat and does not contact the second fixing seat;

[0015] The vibrating body is a rectangular parallelepiped, and a mounting groove for placing the PDMS module is provided on its upper surface, and its lower end surface is fixedly connected to the upper end surface of the amplitude-changing portion of the front beam of the first piezoelectric transducer and the second piezoelectric transducer respectively; the vibrating body is symmetrical about the plane where the axis of the front beam of the first piezoelectric transducer and the second piezoelectric transducer is located, and the vibrating body is asymmetrical about the mid-section in the longitudinal direction thereof;

[0016] The longitudinal vibration frequencies of the first piezoelectric transducer and the second piezoelectric transducer are inconsistent; the first piezoelectric transducer is used to induce a second-order bending vibration mode of the vibration body distortion, and the second piezoelectric transducer is used to induce a third-order bending vibration mode of the vibration body distortion; the first piezoelectric transducer is located to the left and upstream of the second piezoelectric transducer, so that the first piezoelectric transducer is arranged at the first antinode on the left side of the second-order out-of-plane bending vibration mode of the vibration body distortion, and the second piezoelectric transducer is arranged at the first antinode on the right side of the third-order out-of-plane bending vibration mode of the vibration body distortion;

[0017] The base is fixed on the air-floating platform so that the vibrating body is horizontal;

[0018] The PDMS module includes a box body, a first partition piece and a second partition piece, wherein the box body is a hollow rectangular parallelepiped with the same shape as the groove of the vibrating body and an open upper end, is made of PDMS material, and is fixed in the installation groove by PDMS glue; the first partition piece and the second partition piece are both made of PDMS material, are arranged in parallel at the downstream end of the box body, and are respectively vertically and tightly connected to the side wall in the width direction of the box body and the bottom surface of the box body, dividing the downstream of the box body into a first outlet flow channel, a second outlet flow channel, and a third outlet flow channel of equal width;

[0019] The mounting groove of the vibrating body is provided with a rectangular through groove with the same width as the box body upstream of the first partition piece and the second partition piece; the sorting copper sheet is pasted on the center of the lower end face of the box body in the rectangular through groove; the sorting driving unit adopts a rectangular piezoelectric ceramic sheet, which is pasted on the center of the lower end face of the sorting copper sheet and polarized along its thickness direction to excite the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the box body, so that a sorting flow channel is formed in the box body upstream of the first partition piece and the second partition piece; the part of the box body upstream of the sorting flow channel is a migration flow channel.

[0020] As a further optimization solution of the standing wave multi-mode micro-particle manipulation device based on the Langevin transducer of the present invention, the base is a rectangular plate with through holes on the four corners for fixing to the air flotation platform.

[0021] As a further optimization solution of the standing wave multi-mode micro-particle manipulation device based on the Langevin transducer of the present invention, the n is 2.

[0022] The present invention also discloses a method for controlling the standing wave multi-mode micro-particle control device based on the Langevin transducer, comprising the following steps:

[0023] Step 1), injecting a carrier fluid into the upstream of the migration channel and releasing the microspheres;

[0024] Step 2) applying a preset second simple harmonic voltage signal to the second piezoelectric transducer to stimulate its longitudinal vibration, inducing a third-order out-of-plane bending vibration mode of the vibrating body in its longitudinal direction. The microparticles move along the migration channel with the carrying fluid until they reach the second node of the distorted third-order bending vibration. They are then positioned at this node under the action of the acoustic radiation force and the drag force generated by the acoustic flow. At this point, the microparticles are subjected to a first morphological examination using a microscope.

[0025] Step 3) The second piezoelectric transducer is powered off, and a preset first simple harmonic voltage signal is applied to the first piezoelectric transducer to excite its longitudinal vibration, inducing a second-order out-of-plane bending vibration mode of the vibrating body in the longitudinal direction of the vibration. When the microparticles continue to move along the carrier fluid in the migration channel to the center of the sorting channel, the first piezoelectric transducer is powered off to position the particles. At this time, a second morphological examination of the microparticles is performed using a microscope;

[0026] Step 4) judging the surface quality of the microparticles based on the two test results and sorting them according to their quality;

[0027] In step 4.1), if the microspheres are of inferior quality, a preset third simple harmonic voltage signal is applied to the sorting drive unit to stimulate the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the vibrating body, so that the microspheres move to the entrance of the first outlet flow channel;

[0028] In step 4.2, if the microspheres are of medium mass, a preset fourth simple harmonic voltage signal is applied to the sorting drive unit to stimulate the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the vibrating body, causing the microspheres to move to the entrance of the third outlet channel;

[0029] In step 4.3), if the microspheres are high-quality microspheres, the separation drive unit is not driven, and the microspheres are located at the entrance of the second outlet flow channel;

[0030] Step 5) applying a preset second simple harmonic voltage signal to the second piezoelectric transducer so that the microspheres continue to move to the corresponding outlet flow channel after sorting.

[0031] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0032] 1. The equipment is simple and inexpensive, which can reduce the cost of common screening systems;

[0033] 2. Micromanipulation devices using piezoelectric excitation can achieve non-destructive and contactless manipulation of microparticles. Manipulation methods include positioning manipulation, migration manipulation, and sorting manipulation.

[0034] 3. While manipulating the microparticles to achieve different movements, a microscope is used to analyze the quality of parameters such as their size and surface morphology, thereby controlling the aggregation of microparticles with different surface qualities in different areas to achieve efficient and high-precision screening of microparticles. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the present invention;

[0036] Figure 2 is a schematic structural diagram of the first piezoelectric transducer in the present invention;

[0037] Figure 3 is a cross-sectional view of a first piezoelectric transducer in the present invention;

[0038] Figure 4 is an exploded view of the first piezoelectric transducer of the present invention;

[0039] Figure 5 It is a schematic structural diagram of the cooperation between the first fixing seat, the second fixing seat and the base in the present invention;

[0040] Figure 6 It is a schematic diagram of the structure of the PDMS module and the vibrating body in the present invention;

[0041] Figure 7 is a top view of the PDMS module of the present invention;

[0042] Figure 8 It is a structural schematic diagram of the vibrating body in the present invention;

[0043] Figure 9 This is a schematic diagram of the structure of the sorting copper sheet, sorting drive unit, vibrator, and PDMS module in the present invention;

[0044] Figure 10 Schematic diagram of the vibration mode of the second-order out-of-plane bending vibration of the distorted left-right asymmetric vibrating body excited by the piezoelectric ceramic in the first piezoelectric transducer of the present invention;

[0045] Figure 11 Schematic diagram of the mode shape of the third-order out-of-plane bending vibration of the distorted left-right asymmetric vibrating body excited by the piezoelectric ceramic in the second piezoelectric transducer of the present invention;

[0046] Figure 12 Schematic diagram of the first-order out-of-plane bending vibration mode and electrical signal application method of the sorted copper sheet excited by the sorted piezoelectric ceramic in the present invention;

[0047] Figure 13 This is a schematic diagram of the particle motion position after switching between even-order and odd-order modes under standard bending vibration mode;

[0048] Figure 14Schematic diagram of particle motion position after switching between even-order and odd-order modes under the distortion bending vibration mode of the present invention;

[0049] Figure 15 This is a schematic diagram of the principle of the standing wave multi-mode microparticle manipulation device based on the Langevin transducer in the present invention to achieve multiple positioning, migration and classification of microparticles.

[0050] In the figure, 1-base, 2-vibrating body, 3-PDMS module, 4-first piezoelectric transducer, 5-second piezoelectric transducer, 6-first fixing seat, 7-second fixing seat, 8-front beam, 9-piezoelectric ceramic sheet, 10-clamping sheet, 11-back beam, 12-pre-tightening bolt, 13-box body, 14-first partition sheet, 15-second partition sheet, 16-migration channel, 17-sorting channel, 18-first outlet channel, 19-second outlet channel, 20-third outlet channel, 21-rectangular through groove, 22-sorting copper sheet, 23-sorting drive unit, 1.1- "Concave" boss, 2.1-PDMS flow channel, 2.2-vibrating body, 2.3-upper end outlet for inferior microparticles, 2.4-middle outlet for high-quality microparticles, 2.5-lower end outlet for inferior microparticles, 2.6-sorting channel, 2.1.1-straight migration flow channel, 2.1.2-sorting flow channel, 2.1.3-upper end PDMS partition, 2.1.4-lower end PDMS partition, 2.2.1-groove, 4.1-variable cross-section prism part, 4.2-piezoelectric ceramics, 4.3-rectangular rear end cover, 4.4-hexagonal socket head screw, 4.3.1-through hole. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings:

[0052] The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0053] It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements, components, and / or parts, these elements, components, and / or parts are not limited by these terms. These terms are merely used to distinguish elements, components, and / or parts from each other. Therefore, the first element, component, and / or part discussed below can become the second element, component, or part without departing from the teachings of the present invention.

[0054] like Figure 1As shown, the present invention discloses a standing wave multi-mode micro-particle manipulation device based on a Langevin transducer, characterized in that it includes a base, a first fixing seat, a second fixing seat, a first piezoelectric transducer, a second piezoelectric transducer, a vibrating body, a PMDS module, a sorting copper sheet and a sorting drive unit;

[0055] like Figure 2 、 Figure 3 As shown, the first piezoelectric transducer and the second piezoelectric transducer each include a variable amplitude beam, a front beam, 2n piezoelectric ceramic sheets, a clamping sheet, a pre-tightening bolt and a rear beam;

[0056] The pre-tightening bolt comprises a nut and a stud;

[0057] The front beam includes an amplitude-changing portion and a connecting portion, wherein the connecting portion is a column; the amplitude-changing portion is a column with a cross-sectional area gradually decreasing from bottom to top, and its lower end surface has the same cross-sectional shape as the connecting portion and is coaxially fixedly connected to the upper end surface of the connecting portion for amplifying the amplitude;

[0058] The rear beam is a column with the same cross-sectional shape as the front beam connecting portion, a threaded hole matching the pre-tightening bolt is provided at the center of the lower end surface of the front beam connecting portion, and a countersunk through hole matching the pre-tightening bolt is provided at the center of the lower end surface of the rear beam body;

[0059] The 2n piezoelectric ceramic sheets are stacked in sequence from top to bottom, and are polarized along the thickness direction, and the polarization directions of adjacent piezoelectric ceramic sheets are opposite, such as Figure 4 As shown;

[0060] The area of the clamping piece is larger than the cross-sectional area of the rear beam, and a through hole is provided at the center thereof for the pre-tightening bolt to pass through;

[0061] The studs of the pre-tightening bolts sequentially pass through the countersunk through-holes of the rear beam, the through-holes in the center of the clamping plate, the 2n piezoelectric ceramic sheets, and the threaded holes of the front beam to press the 2n piezoelectric ceramic sheets.

[0062] like Figure 5 As shown, the first fixing seat and the second fixing seat are both columns whose lower end surfaces are fixedly connected to the base, and their upper end surfaces are respectively provided with grooves for mounting the first piezoelectric transducer and the second piezoelectric transducer;

[0063] The clamping piece of the first piezoelectric transducer is fixedly connected to the upper end surface of the first fixing seat, so that the back beam of the first piezoelectric transducer is located in the groove of the first fixing seat and does not contact the first fixing seat; the clamping piece of the second piezoelectric transducer is fixedly connected to the upper end surface of the second fixing seat, so that the back beam of the second piezoelectric transducer is located in the groove of the second fixing seat and does not contact the second fixing seat;

[0064] The vibrating body is a rectangular parallelepiped, and a mounting groove for placing the PDMS module is provided on its upper surface, and its lower end surface is fixedly connected to the upper end surface of the amplitude-changing portion of the front beam of the first piezoelectric transducer and the second piezoelectric transducer respectively; the vibrating body is symmetrical about the plane where the axis of the front beam of the first piezoelectric transducer and the second piezoelectric transducer is located, and the vibrating body is asymmetrical about the mid-section in the longitudinal direction thereof;

[0065] The longitudinal vibration frequencies of the first piezoelectric transducer and the second piezoelectric transducer are inconsistent; the first piezoelectric transducer is used to induce the second-order bending vibration mode of the vibration body distortion, and the second piezoelectric transducer is used to induce the third-order bending vibration mode of the vibration body distortion; the first piezoelectric transducer is located on the left and upstream of the second piezoelectric transducer, and the first piezoelectric transducer is set at the first antinode on the left side of the second-order out-of-plane bending vibration mode of the vibration body distortion, such as Figure 10 As shown, the second piezoelectric transducer is set at the first antinode on the right side of the third-order out-of-plane bending vibration mode of the vibration body distortion, as shown in Figure 11 As shown;

[0066] The base is fixed on the air-floating platform so that the vibrating body is horizontal;

[0067] like Figure 6 As shown, the PDMS module includes a box body, a first partition piece and a second partition piece, wherein the box body is a hollow cuboid with the same shape as the groove of the vibrating body and an open upper end, made of PDMS material, and fixed in the mounting groove by PDMS glue; the first partition piece and the second partition piece are both made of PDMS material, and are arranged in parallel at the downstream end of the box body, and are respectively and vertically sealed and fixedly connected to the side wall in the width direction of the box body and the bottom surface of the box body, dividing the downstream of the box body into a first outlet flow channel, a second outlet flow channel, and a third outlet flow channel of equal width, as shown in FIG. Figure 7 As shown;

[0068] The installation groove of the vibrator is provided with a rectangular through groove with the same width as the box body upstream of the first partition piece and the second partition piece. Figure 8 As shown; the sorting copper sheet is pasted on the center of the lower end surface of the box body in the rectangular through groove; the sorting drive unit adopts a rectangular piezoelectric ceramic sheet, which is pasted on the center of the lower end surface of the sorting copper sheet, as shown Figure 9 As shown, the sorting drive unit is polarized along its thickness direction, which is used to excite the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the box body, so that a sorting flow channel is formed in the box body upstream of the first partition piece and the second partition piece; the part of the box body upstream of the sorting flow channel is a migration flow channel, as shown in FIG. Figure 7 shown.

[0069] The base is preferably a rectangular plate, with through holes provided on the four corners for fixing to the air floating platform; n is preferably 2.

[0070] The first and second piezoelectric transducers can have different longitudinal vibration frequencies due to their different lengths. The vibrating body is asymmetrical about its longitudinal mid-section. This asymmetric structure can adjust the standard bending vibration mode of the vibrating body to a distorted bending vibration mode, achieving misalignment of the antinodes and nodes between vibration modes of different orders.

[0071] The first partition piece and the second partition piece divide the downstream of the box body into the first outlet flow channel, the second outlet flow channel, and the third outlet flow channel of equal width, thereby realizing the planning of the movement path of the microparticles and avoiding the problem of the required vibration mode being unable to be excited due to direct planning of the flow channel on the vibrating body. At the same time, the bottom surface of the box body is a closed structure to prevent leakage of the microparticle-carrying liquid due to the design of the sorting flow channel.

[0072] Microspheres with sizes ranging from micrometers to millimeters are manipulated to achieve multiple positioning, long-distance migration and classification in the PDMS flow channel. After each positioning of the microspheres, the microscopic morphology of the microspheres is detected under microscope observation. After the detection is completed, the microspheres are further moved to the flow channel outlet through mode switching. After reaching the last positioning node, the high-quality and low-quality microspheres are classified and manipulated according to the detection results of the microscope, so that microspheres of different qualities are gathered at different outlets.

[0073] like Figure 15 As shown, the present invention also discloses a control method of the standing wave multi-mode micro-particle control device based on the Langevin transducer, which is characterized by comprising the following steps:

[0074] Step 1), injecting a carrier fluid into the upstream of the migration channel and releasing the microspheres;

[0075] In step 2, a preset second simple harmonic voltage signal is applied to the second piezoelectric transducer to excite its longitudinal vibration, thereby inducing a third-order out-of-plane bending vibration mode of the vibration body in the longitudinal direction, such as Figure 11 As shown in the figure, the microparticles move along the migration channel with the carrying fluid until they reach the second node of the distorted third-order bending vibration. Under the action of the acoustic radiation force and the drag force generated by the acoustic flow, they are positioned at this node. At this time, the microparticles are first examined for their morphology using a microscope.

[0076] In step 3), the second piezoelectric transducer is powered off, and a preset first simple harmonic voltage signal is applied to the first piezoelectric transducer to stimulate its longitudinal vibration, thereby inducing a second-order out-of-plane bending vibration mode of the vibration body in the longitudinal direction, such as Figure 10 As shown, when the microparticles continue to move along with the carrier fluid in the migration channel to the center of the sorting channel, the first piezoelectric transducer is powered off to position the particles. At this time, the microparticles are subjected to a second morphology inspection using a microscope.

[0077] Step 4) judging the surface quality of the microparticles based on the two test results and sorting them according to their quality;

[0078] In step 4.1), if the microspheres are of inferior quality, a preset third simple harmonic voltage signal is applied to the sorting drive unit to excite the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the vibrating body, such as Figure 12 As shown, the microspheres are moved to the inlet of the first outlet flow channel;

[0079] In step 4.2, if the microspheres are of medium mass, a preset fourth simple harmonic voltage signal is applied to the sorting drive unit to stimulate the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the vibrating body, causing the microspheres to move to the entrance of the third outlet channel;

[0080] In step 4.3), if the microspheres are high-quality microspheres, the separation drive unit is not driven, and the microspheres are located at the entrance of the second outlet flow channel;

[0081] Step 5) applying a preset second simple harmonic voltage signal to the second piezoelectric transducer so that the microspheres continue to move to the corresponding outlet flow channel after sorting.

[0082] like Figure 13 As shown in the figure, in the standard bending vibration mode, the central antinode of the odd-order bending vibration mode coincides with the central node of the even-order bending vibration mode in spatial position, and the central antinodes of all odd-order bending vibration modes coincide with each other in spatial position, and the central nodes of all even-order bending vibration modes coincide with each other in spatial position, which results in the microparticles gathered at the central node of the even-order bending vibration mode remaining motionless under the action of the acoustic radiation force after switching to the vibration mode of other orders of the oscillator, and cannot accurately achieve the required direction of migration movement. Figure 14 As shown, through the asymmetric characteristics of the vibrating body, the positions of the central nodes and central antinodes of different bending vibration modes are adjusted to achieve spatial dislocation of the central nodes and central antinodes between different vibration orders, thereby realizing long-distance migration control of microparticles.

[0083] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the art to which this invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as such, will not be interpreted in an idealized or overly formal sense.

[0084] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A standing wave multi-mode microparticle manipulation device based on a Langevin transducer, characterized in that: It includes a base, a first fixing seat, a second fixing seat, a first piezoelectric transducer, a second piezoelectric transducer, a vibrating body, a PDMS module, a sorting copper sheet and a sorting drive unit; The first piezoelectric transducer and the second piezoelectric transducer each comprise a front beam, 2n piezoelectric ceramic sheets, a clamping sheet, a pre-tightening bolt and a rear beam; The pre-tightening bolt comprises a nut and a stud; The front beam includes an amplitude-changing portion and a connecting portion, wherein the connecting portion is a column; the amplitude-changing portion is a column with a cross-sectional area gradually decreasing from bottom to top, and its lower end surface has the same cross-sectional shape as the connecting portion and is coaxially fixedly connected to the upper end surface of the connecting portion for amplifying the amplitude; The rear beam is a column with the same cross-sectional shape as the front beam connecting portion, a threaded hole matching the pre-tightening bolt is provided at the center of the lower end surface of the front beam connecting portion, and a countersunk through hole matching the pre-tightening bolt is provided at the center of the lower end surface of the rear beam body; The 2n piezoelectric ceramic sheets are stacked in sequence from top to bottom, are polarized along the thickness direction, and the polarization directions of adjacent piezoelectric ceramic sheets are opposite; The area of the clamping piece is larger than the cross-sectional area of the rear beam, and a through hole is provided at the center thereof for the pre-tightening bolt to pass through; The studs of the pre-tightening bolts sequentially pass through the countersunk through-holes of the rear beam, the through-holes in the center of the clamping plate, the 2n piezoelectric ceramic sheets, and the threaded holes of the front beam to press the 2n piezoelectric ceramic sheets. The first fixing seat and the second fixing seat are both columns whose lower end surfaces are fixed to the base, and their upper end surfaces are respectively provided with grooves for mounting the first piezoelectric transducer and the second piezoelectric transducer; The clamping piece of the first piezoelectric transducer is fixedly connected to the upper end surface of the first fixing seat, so that the back beam of the first piezoelectric transducer is located in the groove of the first fixing seat and does not contact the first fixing seat; the clamping piece of the second piezoelectric transducer is fixedly connected to the upper end surface of the second fixing seat, so that the back beam of the second piezoelectric transducer is located in the groove of the second fixing seat and does not contact the second fixing seat; The vibrating body is a rectangular parallelepiped, and a mounting groove for placing the PDMS module is provided on its upper surface, and its lower end surface is fixedly connected to the upper end surface of the amplitude-changing portion of the front beam of the first piezoelectric transducer and the second piezoelectric transducer respectively; the vibrating body is symmetrical about the plane where the axis of the front beam of the first piezoelectric transducer and the second piezoelectric transducer is located, and the vibrating body is asymmetrical about the mid-section in the longitudinal direction thereof; The longitudinal vibration frequencies of the first piezoelectric transducer and the second piezoelectric transducer are inconsistent; the first piezoelectric transducer is used to induce a second-order bending vibration mode of the vibration body distortion, and the second piezoelectric transducer is used to induce a third-order bending vibration mode of the vibration body distortion; the first piezoelectric transducer is located to the left and upstream of the second piezoelectric transducer, so that the first piezoelectric transducer is arranged at the first antinode on the left side of the second-order out-of-plane bending vibration mode of the vibration body distortion, and the second piezoelectric transducer is arranged at the first antinode on the right side of the third-order out-of-plane bending vibration mode of the vibration body distortion; The base is fixed on the air-floating platform so that the vibrating body is horizontal; The PDMS module includes a box body, a first partition piece and a second partition piece, wherein the box body is a hollow rectangular parallelepiped with the same shape as the groove of the vibrating body and an open upper end, is made of PDMS material, and is fixed in the installation groove by PDMS glue; the first partition piece and the second partition piece are both made of PDMS material, are arranged in parallel at the downstream end of the box body, and are respectively vertically and tightly connected to the side wall in the width direction of the box body and the bottom surface of the box body, dividing the downstream of the box body into a first outlet flow channel, a second outlet flow channel, and a third outlet flow channel of equal width; The mounting groove of the vibrating body is provided with a rectangular through groove with the same width as the box body upstream of the first partition piece and the second partition piece; the sorting copper sheet is pasted on the center of the lower end face of the box body in the rectangular through groove; the sorting driving unit adopts a rectangular piezoelectric ceramic sheet, which is pasted on the center of the lower end face of the sorting copper sheet and polarized along its thickness direction to excite the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the box body, so that a sorting flow channel is formed in the box body upstream of the first partition piece and the second partition piece; the part of the box body upstream of the sorting flow channel is a migration flow channel.

2. The standing wave multi-mode microparticle manipulation device based on Langevin transducer according to claim 1, characterized in that: The base is a rectangular plate, and four corners of the base are provided with through holes for fixing to the air floating platform.

3. The standing wave multi-mode microparticle manipulation device based on Langevin transducer according to claim 1, characterized in that: The n is 2.

4. The control method of the standing wave multi-mode micro-particle control device based on the Langevin transducer according to claim 1, characterized in that: The following steps are involved: Step 1), injecting a carrier fluid into the upstream of the migration channel and releasing the microspheres; Step 2) applying a preset second simple harmonic voltage signal to the second piezoelectric transducer to stimulate its longitudinal vibration, inducing a third-order out-of-plane bending vibration mode of the vibrating body in its longitudinal direction. The microparticles move along the migration channel with the carrying fluid until they reach the second node of the distorted third-order bending vibration. They are then positioned at this node under the action of the acoustic radiation force and the drag force generated by the acoustic flow. At this point, the microparticles are subjected to a first morphological examination using a microscope. Step 3) The second piezoelectric transducer is powered off, and a preset first simple harmonic voltage signal is applied to the first piezoelectric transducer to excite its longitudinal vibration, inducing a second-order out-of-plane bending vibration mode of the vibrating body in the longitudinal direction of the vibration. When the microparticles continue to move along the carrier fluid in the migration channel to the center of the sorting channel, the first piezoelectric transducer is powered off to position the particles. At this time, a second morphological examination of the microparticles is performed using a microscope; Step 4) judging the surface quality of the microparticles based on the two test results and sorting them according to their quality; In step 4.1), if the microspheres are of inferior quality, a preset third simple harmonic voltage signal is applied to the sorting drive unit to stimulate the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the vibrating body, so that the microspheres move to the entrance of the first outlet flow channel; In step 4.2, if the microspheres are of medium mass, a preset fourth simple harmonic voltage signal is applied to the sorting drive unit to stimulate the first-order out-of-plane bending vibration mode of the sorting copper sheet in the width direction of the vibrating body, causing the microspheres to move to the entrance of the third outlet channel; In step 4.3), if the microspheres are high-quality microspheres, the separation drive unit is not driven, and the microspheres are located at the entrance of the second outlet flow channel; Step 5) applying a preset second simple harmonic voltage signal to the second piezoelectric transducer so that the microspheres continue to move to the corresponding outlet flow channel after sorting.

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