Apparatus and system for manipulating particles

Abstract

The application discloses a device and method for capturing and manipulating particles, and belongs to the technical field of acoustic manipulation. In view of the fact that the prior art cannot realize a contactless, flexible, selective and universal manipulation method for particles, the application discloses a photoacoustic tweezers, an electro / photoacoustic transducer is formed by using a photoacoustic transducer unit and an electroacoustic transducer unit, weak sound waves and strong sound waves are respectively generated by signal excitation, the strong sound waves are used as a gain medium, and the acoustic radiation force of the weak sound waves is amplified. The application realizes contactless and label-free particle manipulation, and compared with other optical methods, the amplified acoustic radiation force needs lower optical power, thereby improving the biocompatibility. The application can selectively manipulate multiple particles at the same time, can manipulate particles of different sizes from 1 mu m to 1 mm, and provides a possibility for realizing particle assembly. The application can realize the regulation and control of a dynamically reconfigurable acoustic field, the direction of the acoustic radiation force can be reversed by adjusting the phase difference, the manipulation behaviors of repelling and attracting particles are realized, and the application has high flexibility in manipulation.

Description

Technical Field

[0001] This invention relates to the field of acoustic control technology, and more specifically, to a device and system for capturing and manipulating particles. Background Technology

[0002] In 1986, Arthur Ashkin first publicly disclosed an optical method for capturing and manipulating particles. This method uses the force applied by a strongly focused laser beam to capture and move objects ranging in size from tens of nanometers to tens of micrometers. This method can achieve high spatial resolution and high selectivity of particle manipulation, but it can only manipulate a small number of submicron-sized particles at the same time. Furthermore, high-intensity lasers can easily cause overheating physical damage to cells or other biological organisms.

[0003] Currently, in the research of particle capture and manipulation technologies, in addition to optical methods, more biocompatible methods such as magnetic methods, electrical methods (electrophoresis, dielectrophoresis), hydrodynamic methods, and acoustic methods have also been developed. These methods can be used in various particle manipulation applications, such as capture, focusing, and sequencing. Among them, acoustic tweezers are unaffected by the optical properties, magnetism, and optical characteristics of the medium during application, making them a label-free, non-contact control method.

[0004] In existing technologies, developed particle manipulation methods cannot simultaneously satisfy the requirements of biocompatibility, label-free operation, media insensitivity, selectivity, and high-throughput manipulation. For example, magnetic field-driven particle manipulation requires labeling by coupling magnetic particles with antibodies on the surface of the manipulated particles, which can be expensive in terms of time and money, as each cell type may require a specific antibody. Electrophoresis (EP) / dielectrophoresis (DEP) methods are related to particle polarizability and require low-conductivity media, which affects biocompatibility (cells in unsuitable media often die quickly due to bioincompatibility).

[0005] Acoustic tweezers, as an emerging technology, have been widely used in the field of particle manipulation. However, for selective and complex particle manipulation, flexible acoustic arrays or mobile sound sources must be designed. Even the latest selective acoustic vortex transducers can only achieve low-flux manipulation and can only manipulate one particle at a time.

[0006] Table 1 below compares different non-contact particle manipulation methods:

[0007] Table 1

[0008]

[0009]

[0010] None of the aforementioned methods can simultaneously satisfy the requirements of flexibility, biocompatibility, and selectivity, particularly the selective simultaneous manipulation of multiple particles without affecting adjacent particles, and the manipulation of particles of different sizes. Photoacoustic generation (PA) combined with holographic technology can generate virtually arbitrary sound fields in space, exhibiting excellent temporal characteristics such as high frequency and broadband. This method offers flexibility in the selection of substrate materials and aperture sizes. However, the main problem with the PA method is the low efficiency of the light-to-sound conversion; most of the light is converted into heat rather than sound waves, and excessively high temperatures can damage cell activity. Summary of the Invention

[0011] To address the limitations of existing technologies in achieving non-contact, flexible, selective, and universal particle manipulation, this invention discloses a photoacoustic tweezers. This device comprises a photoacoustic transducer unit and an electroacoustic transducer unit, forming an electro / photoacoustic apparatus. Weak and strong acoustic waves are generated through signal excitation. The strong acoustic wave is used as a gain medium to amplify the acoustic radiation force of the weak acoustic wave, enabling selective and flexible capture and manipulation of particles. Because the gain medium amplifies the acoustic radiation force, the required laser power is lower, thus achieving biocompatibility for particle manipulation.

[0012] The objective of this invention is achieved through the following technical solutions.

[0013] An electro / photoacoustic device includes an electroacoustic transducer unit and a photoacoustic transducer unit, wherein the photoacoustic transducer unit and the electroacoustic transducer unit are acoustically connected to a control medium. The electroacoustic transducer unit is used to generate strong sound waves, and the photoacoustic transducer unit is used to generate weak sound waves. The strong sound waves and the weak sound waves interfere with each other, and the strong sound waves act as a gain medium to amplify the acoustic radiation force of the weak sound waves.

[0014] Preferably, the electroacoustic transducer unit includes electrodes and a piezoelectric material. Preferably, the piezoelectric material has an impedance of approximately 50Ω and a size just larger than the control area.

[0015] Preferably, the electrode is deposited on the piezoelectric material.

[0016] Preferably, the piezoelectric material and the electrode are transparent.

[0017] Preferably, the photoacoustic transducer unit includes a photoacoustic conversion material, and more preferably, it is a high-efficiency photoacoustic conversion material.

[0018] Preferably, the photoacoustic conversion material has spectral selectivity and is transparent to certain wavelengths, allowing the observation of manipulated particles and cells.

[0019] Preferably, the photoacoustic conversion material is an AuNP-PDMS nanocomposite material.

[0020] Preferably, the acoustic connection includes a contact connection or a non-contact connection through an intermediate layer, and the photoacoustic transducer unit and the electroacoustic transducer unit achieve acoustic connection through a manipulation medium.

[0021] This invention proposes a novel photoacoustic tweezers that can selectively and flexibly manipulate particles of various sizes ranging from 1 μm to 1 mm. It can also form arbitrary sound fields by modulating optical signals and selectively manipulate multiple particles simultaneously, enabling particle assembly. The photoacoustic tweezers are designed using a general approach, utilizing a photoacoustic transducer unit to generate weak sound waves and an electroacoustic transducer unit to generate strong sound waves. These strong sound waves serve as a gain medium to amplify the acoustic radiation of the weak sound waves.

[0022] A particle manipulation system, the device comprising a signal generator, an optical module, and an electro / photoacoustic device; the signal generator comprising a laser generator and a radio frequency generator, wherein the laser generator emits a laser beam that passes through the optical module to irradiate the electro / photoacoustic device to generate a weak acoustic wave, and the radio frequency generator excites the electro / photoacoustic device to generate a strong acoustic wave.

[0023] Preferably, the optical module includes an optical microscope.

[0024] Preferably, the electro / photoacoustic device is placed on the stage of an optical microscope.

[0025] Preferably, the optical module includes a spatial light modulator.

[0026] Preferably, the reconfigurable sound field of the electro / photoacoustic device is spatially modulated using a spatial light modulator. This invention eliminates the need for flexible acoustic array design, enabling the generation of a reconfigurable sound field by modulating optical signals, forming multiple capture points, and simultaneously selectively manipulating multiple particles.

[0027] Preferably, the laser generator is a pulsed laser.

[0028] Preferably, the laser generator is a nanosecond pulse laser.

[0029] Preferably, the radio frequency generator includes a radio frequency power amplifier and a signal generator, with the radio frequency power amplifier connected to the signal generator. Preferably, the radio frequency generator can be driven by any mode, such as a sine wave, sawtooth wave, triangle wave, or pulse wave.

[0030] Preferably, the laser generator and the radio frequency generator are excited synchronously.

[0031] Preferably, the synchronous excitation of the laser generator and the radio frequency generator can be performed simultaneously, or there can be an adjustable excitation delay.

[0032] Preferably, the optical module is coupled with the electro / optical device to generate an acoustic radiation force that captures particles, and the direction of the acoustic radiation force can be reversed by adjusting the excitation delay of the laser generator and the radio frequency generator.

[0033] This invention is a photoacoustic tweezers device with gain dielectric amplification, wherein the frequencies and amplitudes of the strong and weak sound waves are 1Hz to 1GHz and 1Pa to 10, respectively. 10 Pa, 1Hz~1GHz, 1Pa~10 8 Pa. The tweezers disclosed in this invention can be used to manipulate particles from 1 μm to 1 mm, and have the characteristics of selectivity, biocompatibility and flexibility. They can achieve simultaneous selective manipulation of multiple particles and manipulation of particles of different sizes without the need for complex acoustic array design or high-intensity laser.

[0034] Compared with existing technologies, the novel tweezers of this invention have the following advantages:

[0035] (1) The present invention is operated under low power laser irradiation, which can better protect cell vitality and avoid damage to cells caused by overheating. It is also a non-contact, label-free operation, which is conducive to the high biocompatibility of particle operation.

[0036] (2) The present invention can reconstruct the photoacoustic field to realize particle manipulation, and selective manipulation can be achieved without complex acoustic arrays or sound source movement;

[0037] (3) The present invention can realize the manipulation of particles of various sizes, and the particle size range is from 1μm to 1mm. The present invention can also realize the manipulation of multiple particles simultaneously without affecting neighboring particles, and can be used for particle assembly manipulation.

[0038] (4) The photoacoustic transducer has high light absorption and a uniform surface structure, which is beneficial to improving the photoacoustic conversion efficiency.

[0039] (5) The piezoelectric material (LiNbO3) and its electrode (ITO) used to generate strong acoustic waves are optically transparent. In addition, the composite material used for photoacoustic conversion is also spectrally selective (transparent to some wavelengths of light), so the operation can be directly visualized. Attached Figure Description

[0040] This description will be better understood from the following detailed description and accompanying drawings. The details of the invention regarding its structure and operation can be best understood by referring to the accompanying drawings, wherein like reference numerals and identifiers refer to like elements.

[0041] Figure 1 This is a schematic diagram of the photoacoustic tweezers of Embodiment 1 of the present invention;

[0042] Figure 2This is a schematic diagram of the photoacoustic tweezers of Embodiment 2 of the present invention;

[0043] Figure 3 This is a schematic diagram of the photoacoustic tweezers in Embodiment 3 of the present invention;

[0044] Figure 4 This is a schematic diagram of the photoacoustic tweezers in Embodiment 4 of the present invention;

[0045] Figure 5 This is a schematic diagram illustrating the manufacturing process of the photoacoustic tweezers of the present invention;

[0046] Figure 6 This is a schematic diagram of the particle manipulation system of the present invention;

[0047] Figure 7 This invention relates to an excitation method for the electro / optical-acoustic transducer.

[0048] The labels in the diagram indicate:

[0049] 100. Glass slide; 101. LiNbO3 piezoelectric material; 102. AuNP-PDMS composite material; 103. Piezoelectric ceramic sheet; 104. ITO electrode; 105. PDMS microchannel;

[0050] 201. Laser; 202. Mirror; 203. 300mm lens; 204. Half-wave plate; 205. Beam expander; 206. 150mm lens; 207. Spatial light modulator (SLM); 208. 175mm lens; 209. Filter; 210. Objective lens; 211. Photoacoustic tweezers. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] The photoacoustic tweezers of the present invention include a photoacoustic transducer unit and an electroacoustic transducer unit. The photoacoustic transducer unit is used to generate strong sound waves when excited, and the electroacoustic transducer unit is used to generate weak sound waves when excited. The strong sound wave gain medium amplifies the acoustic radiation force of the weak sound waves to achieve particle capture and manipulation.

[0054] like Figure 1 The photoacoustic tweezers include a LiNbO3 (Y-cut 36°) piezoelectric material 101, an ITO electrode 104, and an AuNP-PDMS composite material 102. The ITO electrode is deposited on the upper and lower surfaces of the LiNbO3 piezoelectric material 101, and the AuNP-PDMS composite material 102 is generated on the surface of the LiNbO3 piezoelectric material 101 with the electrode deposited by an in-situ synthesis method.

[0055] A LiNbO3 piezoelectric material 101 coated with electrodes is used as an electroacoustic transducer unit to generate strong sound waves, while an AuNP-PDMS composite material 102, coated with a thin PDMS interlayer on the electroacoustic transducer unit, is used as a photoacoustic transducer unit to generate weak sound waves. The strong sound waves act as a gain medium, amplifying the acoustic radiation force of the weak sound waves, thus achieving high selectivity, high throughput, and highly flexible particle capture and manipulation.

[0056] Figure 1 In the photoacoustic tweezers shown, the electroacoustic transducer unit and the photoacoustic transducer unit are connected together through a thin PDMS interlayer, achieving a non-contact acoustic connection through a manipulation medium. The manipulation medium is an aqueous solution containing polystyrene particles, which is injected into the PDMS microchannels attached above the photoacoustic transducer units. The particles can be solid particles, or cells, microorganisms, or small tissue samples. In this embodiment, the particles are polystyrene particles.

[0057] Figure 5 The following steps are shown in the fabrication process of the photoacoustic tweezers of the present invention:

[0058] Step 1: Create PDMS microchannels;

[0059] The fabrication of PDMS microchannels uses conventional techniques, which will not be elaborated here.

[0060] Step 2: Deposit electrodes on the surface of the piezoelectric material and spin-coat PDMS;

[0061] When depositing electrodes on the surface of LiNbO3 piezoelectric material, transparent indium tin oxide (ITO) electrodes are deposited on the upper and lower surfaces of lithium niobate (LiNbO3) piezoelectric material by physical vapor deposition to form LiNbO3 transducers with ITO coating on the upper and lower surfaces, which are used as electroacoustic transducer units to generate strong sound waves.

[0062] Step 3: Synthesize composite materials;

[0063] Tetrachloroauric acid (TCA) was dissolved in isopropanol to prepare a stock solution. The solution was filtered to remove impurities using a 0.22 μm filter. Electroacoustic transducer units coated with PDMS were immersed in the TCA isopropanol stock solution for 48 h to generate AuNP-PDMS composite material on the surface. The surface of the TCA solution was rinsed with water and then dried with nitrogen gas for later use.

[0064] AuNP-PDMS composite material is used as a photoacoustic transducer unit to convert laser pulses into photoacoustic pulses. When using a laser, the AuNP-PDMS composite material generates weak acoustic waves through the photoacoustic effect.

[0065] Step 4: Combine the PDMS microchannel with the composite material to finally form the photoacoustic tweezers of this embodiment.

[0066] The following section provides a detailed description of one implementation method for the production process.

[0067] PDMS microchannels are formed by creating a mold using photolithography. PDMS (base material and curing agent weight ratio of 10:1) is poured into the mold, degassed for 30 minutes, and then solidified in a 60°C oven for 2 hours. The solidified PDMS is then peeled off the mold to obtain PDMS microchannels with a depth of 200 μm.

[0068] First, the fabrication process of the electroacoustic transducer unit is as follows: 180 nm thick ITO is sputtered onto both sides of a 500 μm thick LiNbO3 (Y-cut 36°) piezoelectric material 101 that has been polished on both sides by physical vapor deposition. The ITO acts as transparent top and bottom electrodes. Then, the piezoelectric material is cut into 25 mm × 25 mm dimensions using a laser cutter to be used as the electroacoustic transducer unit to generate strong sound waves.

[0069] A 75 μm thick layer of PDMS (matrix to curing agent weight ratio of 10:1) was spin-coated onto the surface of a 25 mm × 25 mm electroacoustic transducer unit using spin-coating parameters of 1150 rpm and 30 s, and cured overnight in a 70 °C oven. Then, the PDMS-coated electroacoustic transducer unit was immersed in a 0.015 mol / L TCA isopropanol solution. The container was sealed with film to prevent evaporation and wrapped with aluminum foil to protect it from light. After 48 hours, an AuNP-PDMS composite material 102 was formed on the surface. The surface of the prepared composite material was rinsed with water and dried with nitrogen. This AuNP-PDMS composite material 102 serves as the acoustic connection between the photoacoustic transducer unit and the electroacoustic transducer unit via a manipulating medium, forming photoacoustic tweezers. The prepared PDMS microchannel was gently pressed onto the photoacoustic tweezers, ensuring no air bubbles at the contact interface to prevent leakage.

[0070] The photoacoustic tweezers described in this embodiment are made of LiNbO3 piezoelectric material 101 coated with ITO electrodes 104 on both sides. This piezoelectric material serves as an electroacoustic transducer unit to generate strong acoustic waves. The synthesized AuNP-PDMS composite material 102 serves as a photoacoustic transducer unit to convert laser pulses into photoacoustic pulses, generating weak acoustic waves. The strong and weak acoustic waves interfere with each other, and the gain medium of the strong acoustic waves amplifies the acoustic radiation force of the weak acoustic waves, achieving highly selective and flexible capture and manipulation of high-flux particles.

[0071] Example 2

[0072] This embodiment is basically the same as the structure of Embodiment 1. The difference is that the electroacoustic transducer unit and the photoacoustic transducer unit in the photoacoustic tweezers disclosed in this embodiment have a different structural relationship.

[0073] like Figure 2 As shown, the photoacoustic tweezers described in this embodiment include a piezoelectric ceramic sheet 103, a transparent glass slide 100, an AuNP-PDMS composite material 102, and a PDMS microchannel 105. The piezoelectric ceramic sheet 103 is adhesively bonded to the transparent glass slide 100, and the AuNP-PDMS composite material 102 is prepared in the PDMS microchannel 105 using an in-situ synthesis method. The piezoelectric ceramic sheet 103 bonded to the glass slide 100 serves as an electroacoustic transducer unit for generating strong sound waves, while the AuNP-PDMS composite material 102 prepared in the PDMS microchannel 105 serves as a photoacoustic transducer for generating weak sound waves. This strong sound wave acts as a gain medium, amplifying the acoustic radiation force of the weak sound wave, achieving high selectivity, high throughput, and highly flexible particle capture and manipulation.

[0074] The electroacoustic transducer unit and the photoacoustic transducer unit are connected in a non-contact acoustic manner through an intermediate control medium (shaped like a sandwich). The PDMS microchannel 105, which is prepared with AuNP-PDMS composite material 102, is attached to the glass slide 100, and an aqueous solution containing polystyrene particles is injected into the microchannel.

[0075] Example 3

[0076] This embodiment is basically the same as Embodiment 1, except that the electroacoustic transducer unit and the photoacoustic transducer unit in the photoacoustic tweezers disclosed in this embodiment have a different structural relationship.

[0077] like Figure 3 As shown, the photoacoustic tweezers described in this embodiment include a LiNbO3 (Y-cut 36°) piezoelectric material 101, an ITO electrode 104, an AuNP-PDMS composite material 102, and a PDMS microchannel 105. The ITO electrode 104 is deposited on the upper and lower surfaces of the LiNbO3 piezoelectric material 101, and the AuNP-PDMS composite material 102 is prepared in the PDMS microchannel 105 by in-situ synthesis.

[0078] The LiNbO3 piezoelectric material 101 coated with electrodes is used as an electroacoustic transducer unit to generate strong sound waves, while the AuNP-PDMS composite material 102 prepared in the PDMS microchannel 105 is used as a photoacoustic transducer unit to generate weak sound waves. The strong sound wave serves as a gain medium, amplifying the acoustic radiation force of the weak sound wave, thereby achieving highly selective, high-throughput, and highly flexible particle capture and manipulation.

[0079] The electroacoustic transducer unit and the photoacoustic transducer unit are connected in a non-contact acoustic manner through an intermediate control medium (shaped like a sandwich). The PDMS microchannel 105, which is prepared with AuNP-PDMS composite material 102, is placed on the electroacoustic transducer unit, and an aqueous solution containing polystyrene particles is injected into the microchannel.

[0080] Example 4

[0081] This embodiment is basically the same as embodiment 2, except that this embodiment discloses another structural relationship between the electroacoustic transducer unit and the photoacoustic transducer unit in the photoacoustic tweezers.

[0082] like Figure 4 As shown, the photoacoustic tweezers described in this embodiment include a piezoelectric ceramic sheet 103, a transparent glass slide 100, and an AuNP-PDMS composite material 102. The piezoelectric ceramic sheet 103 is glued onto the transparent glass slide 100, and the AuNP-PDMS composite material 102 is prepared on the glass slide 100 coated with a thin PDMS interlayer by an in-situ synthesis method.

[0083] A piezoelectric ceramic sheet 103, adhered to a glass slide 100, serves as an electroacoustic transducer unit to generate strong sound waves. An AuNP-PDMS composite material 102, coated on the glass slide with a thin PDMS interlayer, serves as a photoacoustic transducer unit to generate weak sound waves. This strong sound wave acts as a gain medium, amplifying the acoustic radiation force of the weak sound wave, achieving high selectivity, high throughput, and highly flexible particle capture and manipulation.

[0084] The electroacoustic transducer unit and the photoacoustic transducer unit are connected together through a PDMS interlayer, achieving a non-contact acoustic connection through an intermediate manipulation medium. This manipulation medium is an aqueous solution containing polystyrene particles, which is injected into the PDMS microchannels attached above the photoacoustic transducer unit.

[0085] Example 5

[0086] Based on the photoacoustic tweezers disclosed in Examples 1 to 4, this example discloses a particle manipulation system.

[0087] The system includes a laser generator, a radio frequency generator, an electro / photoacoustic device, and a series of optical modules; the laser beam emitted by the laser generator illuminates the electro / photoacoustic device through the optical modules to generate weak sound waves; the radio frequency generator drives the electro / photoacoustic device to generate strong sound waves.

[0088] like Figure 6As shown, the laser beam is generated by a nanosecond pulse laser 201 with a pulse wavelength of 520 nm and a pulse width of 65 ns. The laser beam is reflected by a mirror 202 and then passes sequentially through two 300 mm lenses 203, a half-wave plate 204, and a beam expander 205. The beam expander 205 expands the laser beam by a factor of three. The laser beam then passes through a 150 mm lens 206, a mirror 202, and a liquid crystal spatial light modulator 207 (LC-SLM, Thorlabs.inc). The photosensitive area of ​​the spatial light modulator 207 modulates the laser signal. The array size of this SLM is 15.42 mm × 9.66 mm, the panel resolution is 1920 × 1200, and the pixel pitch is 8 μm. The laser beam, modulated by the spatial light modulator 207, then passes sequentially through the reflector 202 and the 175mm lens 208, with the lens 208 adjusting the focusing plane. The pulsed laser beam then enters the fluorescence microscope (IX71), passing through the microscope filter 209 (excitation filter: 531nm, emission filter: 593nm, dichroic mirror) and the objective lens 210, finally illuminating the photoacoustic tweezers 211, which consists of an AuNP-PDMS composite material and a LiNbO3 transducer. The microscope filter 209 allows light near the excitation wavelength to pass through, filtering out unnecessary wavelengths of the laser beam. The objective lens 210 is used to magnify a portion of the passed beam at different magnifications, such as 4x, 10x, 20x, and 40x. The dichroic mirror reflects the laser beam but is transparent to a wide range of light wavelengths, thus allowing particle observation via fluorescence or bright-field imaging.

[0089] This invention utilizes a nanosecond pulsed laser (NPL52C) to emit a 520nm excitation wavelength and a 65ns pulse length, which is excited via channel 1 of a digital delayed pulse generator (BNC, Model 525). A PicoScope 5000 is used as the excitation source for the electroacoustic transducer, with an excitation voltage of 300mV and an excitation frequency of 7.6MHz. This electrical signal is amplified by a 50W amplifier (AR Worldwide 50W1000B) connected to photoacoustic tweezers. Figure 7 As shown, the PicoScope 5000 oscilloscope generates a strong acoustic wave triggered by channel 2 of the digital delay pulse generator. Upon triggering, the PicoScope 5000 emits five consecutive sine wave cycles to generate the strong acoustic wave. The strong and weak acoustic waves interfere in the microchannel, producing amplified acoustic radiation forces for particle manipulation. The digital delay pulse generator allows adjustment of the relative phase between the weak and strong waves.

[0090] In this embodiment, the manipulated particles are fluorescent polystyrene particles (laser wavelength 532 nm, emission wavelength 610 nm). The manipulation medium is an aqueous solution containing 0.5% (w / w) Triton X-100 surfactant, 1% (w / w) polyethylene glycol (PEG400), and 7.8% (w / w) NaCl to prevent particles from sticking together, sinking, or adhering to the bottom of the substrate. 30 μL of the particle solution is injected into the PDMS microchannel. After the solution stabilizes and there is no obvious fluid flow, particle manipulation is achieved, and the particle movement is recorded and observed using a camera.

[0091] This embodiment achieves precise particle manipulation through a gain medium. The frequency range of the strong sound waves is 1 Hz to 1 GHz, and the amplitude range is 1 Pa to 10 Pa. 10 Pa, the frequency range of weak sound waves is 1 Hz to 1 GHz, and the amplitude range is 1 Pa to 10 Pa. 8 Pa, the amplitude of the sound wave field after interference is proportional to the product of the strong sound wave and the weak sound wave. Since the strong sound wave has spatial homogeneity, it can be regarded as a constant gain acting on the weak sound wave, that is, the medium in the strong sound wave is the gain medium.

[0092] A photoacoustic transducer unit and an electroacoustic transducer unit together form an electro / photoacoustic transducer, which is essentially a photoacoustic tweezer. The two transducer units are connected non-contactly via a manipulation medium. The photoacoustic tweezers generate weak acoustic waves by driving the photoacoustic transducer unit and strong acoustic waves by driving the electroacoustic transducer unit. A manipulation medium containing suspended particles is injected into PDMS microchannels attached to the surface of the tweezers to achieve particle capture and manipulation.

[0093] Strong sound waves are spatially uniform plane waves, and particles cannot move in a plane perpendicular to the propagation axis when only strong sound waves are present. Conversely, the acoustic radiation force generated by weak sound waves is insufficient to manipulate particles. Therefore, this photoacoustic tweezers utilizes strong sound waves acting on a manipulation medium as a gain medium to amplify the acoustic radiation force of weak sound waves. In other words, when the two form effective interference, highly selective, flexible, and high-throughput particle manipulation can be achieved.

[0094] This invention enables the capture and manipulation of particles of different sizes ranging from 1 μm to 1 mm, and allows for the simultaneous manipulation of multiple particles to achieve particle assembly. This invention uses laser pulses to generate weak acoustic waves; however, generating acoustic waves through photoacoustic effects is only one method of achieving weak acoustic waves, and this invention does not limit the method of generating weak acoustic waves.

[0095] The invention and its embodiments have been described above illustratively. This description is not restrictive, and the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. The accompanying drawings are only one embodiment of the invention, and the actual structure is not limited thereto. No reference numerals in the claims should limit the scope of the claims. Therefore, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the invention, such design should fall within the scope of protection of this patent. Furthermore, the word "comprising" does not exclude other elements or steps, and the word "a" preceding an element does not exclude the inclusion of "a plurality" of that element. Multiple elements stated in the product claims may also be implemented by a single element through software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any specific order.

Claims

1. An electro / photoacoustic device, characterized in that, It includes an electroacoustic transducer unit and a photoacoustic transducer unit, which are connected by an intermediate layer. The intermediate layer contains a microchannel, and the microchannel contains a manipulation medium. The photoacoustic transducer unit and the electroacoustic transducer unit are acoustically connected through the manipulation medium. The electroacoustic transducer unit is used to generate strong sound waves, and the photoacoustic transducer unit is used to generate weak sound waves. The strong and weak sound waves interfere with each other. After the strong sound wave acts on the manipulation medium, it acts as a gain medium to amplify the acoustic radiation force of the weak sound wave to manipulate particles.

2. The electro / photoacoustic device according to claim 1, characterized in that, The electroacoustic transducer unit includes electrodes and piezoelectric materials.

3. The electro / photoacoustic device according to claim 2, characterized in that, The electrode is deposited on the piezoelectric material.

4. The electro / photoacoustic device according to claim 2, characterized in that, The piezoelectric material and the electrode are optically transparent.

5. The electro / photoacoustic device according to claim 1, characterized in that, The photoacoustic transducer unit includes a photoacoustic conversion material.

6. The electro / photoacoustic device according to claim 5, characterized in that, The photoacoustic conversion material has spectral selectivity.

7. An electro / photoacoustic device according to claim 6, characterized in that, The photoacoustic conversion material is an AuNP-PDMS nanocomposite material.

8. The electro / photoacoustic device according to claim 1, characterized in that, The acoustic connection includes a contact connection or a non-contact connection through an intermediate layer.

9. A particle manipulation system, characterized in that, The control system includes a signal generator, an optical module, and an electro / photoacoustic device according to any one of claims 1-8; the signal generator includes a laser generator and a radio frequency generator, the laser generator emits a laser beam that irradiates the electro / photoacoustic device through the optical module to generate weak sound waves, and the radio frequency generator excites the electro / photoacoustic device to generate strong sound waves.

10. A particle manipulation system according to claim 9, characterized in that, The optical module includes an optical microscope.

11. A particle manipulation system according to claim 10, characterized in that, The electro / photoacoustic device is placed on the stage of an optical microscope.

12. A particle manipulation system according to claim 9, characterized in that, The optical module includes a spatial light modulator.

13. A particle manipulation system according to claim 12, characterized in that, The reconfigurable acoustic field of the electro / photoacoustic device can be spatially modulated by a spatial light modulator.

14. A particle manipulation system according to claim 9, characterized in that, The laser generator is a pulsed laser.

15. A particle manipulation system according to claim 14, characterized in that, The laser generator is a nanosecond pulse laser.

16. A particle manipulation system according to claim 9, characterized in that, The radio frequency generator includes a radio frequency power amplifier and a signal generator, with the radio frequency power amplifier connected to the signal generator.

17. A particle manipulation system according to claim 9, characterized in that, The laser generator and the radio frequency generator are excited synchronously.

18. A particle manipulation system according to claim 17, characterized in that, The laser generator and the radio frequency generator are excited simultaneously, or there is an adjustable excitation delay.

19. A particle manipulation system according to claim 18, characterized in that, The optical module is coupled with the electro / optical device to generate an acoustic radiation force that captures particles. The direction of the acoustic radiation force is reversed by adjusting the excitation delay of the laser generator and the radio frequency generator.

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