Cell cluster stretching and compressing method and device based on surface acoustic wave harmonic regulation and control

Abstract

The invention discloses a cell cluster stretching and compressing method and device based on surface acoustic wave harmonic regulation and control. The device comprises a central processing unit, a power amplifier, a signal generator, a micro-fluidic cavity module and a surface acoustic wave driving chip, according to the invention, by utilizing the harmonic multiplexing interdigital transducer and matching excitation signals with different frequencies and amplitudes, an adjustable sound field is constructed in the micro-channel cavity, so that cells are converged, and cell clusters are stretched and compressed to stimulate; due to the influence of dynamic excitation on cell clusters, the medicine is accelerated to enter the cells, so that the medicine screening aiming at the cells is promoted; the harmonic multiplexing interdigital transducer is optimized through finite element simulation, and a required sound field is excited and set under the condition that excitation frequency, power, the size of an interdigital electrode and the boundary condition of a micro-channel cavity are matched; and the excitation power of the surface acoustic wave can be selectively regulated and controlled so as to excite different forms of sound fields for excitation.

Description

Technical Field

[0001] The present invention relates to the field of analytical instruments, and in particular to a method and a device for stretching and compressing a cell cluster based on surface acoustic wave harmonic regulation. Background Art

[0002] Tumor is a serious threat to human health, and there are still great challenges in finding more effective anti-tumor drugs. Traditional drug screening methods can only provide limited information and cannot fully simulate the response of tumor spheres in complex physiological environments. Therefore, seeking new drug screening methods is an important topic in current tumor research.

[0003] In recent years, artificial stimulation of tumor spheres in the environment of anti-tumor drugs has become an attractive drug screening method. By applying different degrees of dynamic stimulation, such as dynamic stretching or compression, the behavior of tumor spheres in different tissue environments can be simulated, and the effects of drugs on tumor growth, invasion and metastasis can be evaluated. In order to more realistically reflect the mechanism of action of drugs in vivo and provide more accurate efficacy evaluation data, researchers have developed a variety of technologies for dynamic stimulation of tumor spheres, such as atomic force microscopy, electrical excitation, magnetic excitation, and micropipette loading. However, although these methods can apply mechanical stimulation to a certain extent, they also have many limitations, such as low processing throughput, cumbersome processing, and the need for special labeling, which will have a greater impact on cell activity.

[0004] Research on ultrasound-assisted drug screening has been verified in multiple application fields. These systems can perform high-throughput and non-invasive processing of biological samples and maintain cell activity. Similar to other contact methods, sound waves can also stimulate the cell clusters composed of tumor spheres with acoustic radiation forces, but it is necessary to design an acoustic field with sufficiently high precision and a stable and specified force field. Therefore, it is a challenging task to develop a set of stretching and compression stimulation methods for tumor cell clusters regulated by sound waves to achieve high-throughput screening of bio-friendly and contact-free tumor drugs. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention proposes a method and device for stretching and compressing cell clusters based on surface acoustic wave harmonic regulation. The method and device can well achieve stretching and compressing stimulation of cell clusters and accelerate drug screening.

[0006] One object of the present invention is to provide a cell cluster stretching and compression device based on surface acoustic wave harmonic regulation.

[0007] The cell cluster stretching and compression device based on surface acoustic wave harmonic regulation of the present invention comprises: a central processing unit, a power amplifier, a signal generator, a microfluidic cavity module and a surface acoustic wave driving chip; wherein the microfluidic cavity module is located under the surface acoustic wave driving chip; the surface acoustic wave driving chip is connected to the power amplifier, the power amplifier is connected to the signal generator, and the signal generator is connected to the central processing unit;

[0008] The microfluidic cavity module includes a liquid inlet, a liquid outlet and a microfluidic cavity; the surface of the microfluidic cavity is an opening, the interior is a cavity, and the liquid inlet and the liquid outlet are respectively arranged on two opposite sides of the microfluidic cavity;

[0009] The surface acoustic wave driving chip includes a substrate and a harmonic multiplexing interdigital transducer, and the harmonic multiplexing interdigital transducer includes a plurality of interdigital electrodes connected in series; a plurality of interdigital electrodes are respectively arranged on the substrate, and the plurality of interdigital electrodes are connected in series to the output end of the power amplifier; each interdigital electrode has a different finger width, and the different finger widths correspond to different center frequencies of the interdigital electrodes, and the center frequency of the interdigital electrodes is adjusted by the finger width; the surface acoustic wave driving chip is inverted on the microfluidic cavity module, that is, the harmonic multiplexing interdigital transducer is directly opposite to the microfluidic cavity of the microfluidic cavity module;

[0010] According to the required sound field, the corresponding frequency and power of the required sound field are obtained; the central processing unit sends a digital signal to the signal generator, and controls different output channels of the signal generator to send excitation signals of different frequencies and corresponding powers according to the parameterized scanning results; the signal generator converts the digital signal into an electrical signal, outputs excitation signals of different frequencies from each output channel, and transmits them to the power amplifier after superposition; the power amplifier converts the electrical signal into an amplified power signal, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form the required sound field; by designing different forms of harmonic multiplexing interdigital transducers, the frequency and power of the excitation signal are changed to generate a specified sound field, so that the sound field respectively produces the effects of clustering, positioning, stretching and compressing on the cells in turn.

[0011] The microfluidic chamber module is used to culture cells and store the nutrients required by the cells to maintain the environment required for cell survival. The height of the microfluidic cavity is 50-1000μm, and the length and width are 5-20mm. A flow valve is set at the inlet or outlet of the microfluidic cavity through an external catheter. After the valve is closed, the liquid in the catheter and the microfluidic cavity will no longer flow. The drug is injected into the liquid inlet of the microfluidic cavity. The drug is paclitaxel, cisplatin or 5-fluorouracil, etc., with a concentration of 0-1000μM. The material properties of the microfluidic cavity are polydimethylsiloxane (PDMS).

[0012] Furthermore, it also includes a microscopic observation device, which includes a fluorescence microscope and a CCD camera. The microfluidic cavity module is placed on the sample stage of the fluorescence microscope; wherein a charge-coupled device CCD camera is arranged on the fluorescence microscope, and the CCD camera is connected to a central processing unit. The fluorescence microscope is used to capture the shape changes of cell clusters after tensile and compressive mechanical loading, as well as the fluorescence phenomenon exhibited after acoustic radiation force stimulation and drug treatment. The CCD camera converts the image into an electrical signal and inputs it into the central processing unit, which displays the deformation state and fluorescence expression state of the cell and analyzes it.

[0013] The harmonic multiplexing interdigital transducer on the surface acoustic wave driver chip includes multiple interdigital electrodes, each of which has a different finger width of 20 to 100 μm, an index of 10 to 30 pairs, a center frequency range of 10 to 50 MHz, and an applied power range of 100 to 1000 mW. The center frequency is determined by the finger width, and the relationship between the finger width and the center frequency is w = c / (4f0), w is the finger width, c is the substrate wave velocity, which is generally 3960 m / s in the lithium niobate substrate, and f0 is the center frequency.

[0014] In general, in order to produce different forms of stimulation of the acoustic field with appropriate accuracy, the frequency of the interdigital transducer is generally optimally between 10 and 50 MHz, and the corresponding interdigital width is between 20 and 100 μm. The height of the microfluidic cavity is generally 2 to 5 times the size of the cell cluster. The width of the microfluidic cavity is mainly matched with the effective size of the substrate acoustic field. In order to ensure high-throughput loading, the width of the microfluidic cavity is usually set to accommodate a 10×10 cell cluster array. In order to reduce the loss of surface acoustic waves during propagation and ensure that the bonding is firm and leak-proof, the thickness of the inner wall of the microfluidic cavity is optimally 5 to 10 wavelengths of the surface acoustic wave.

[0015] Another object of the present invention is to provide a method for stretching and compressing a cell cluster based on surface acoustic wave harmonic regulation.

[0016] The cell cluster stretching and compression method based on surface acoustic wave harmonic regulation of the present invention comprises the following steps:

[0017] 1) Injecting cells into the microfluidic cavity;

[0018] 2) According to the required convergent acoustic field, the corresponding frequency and power are obtained, and the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form a convergent acoustic field, so that the cells are aggregated;

[0019] 3) Waiting for the cells to cross-link and form cell clusters;

[0020] 4) According to the required convergent acoustic field, the corresponding frequency and power are obtained, and the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form a convergent acoustic field, so that the initial cell cluster is recaptured at the acoustic pressure node position;

[0021] 5) After observing that the cell clusters are growing well through the microscopic observation module, inject the drug from the liquid inlet of the microfluidic cavity;

[0022] 6) According to the required stretch-shaped acoustic field, the required frequency and power are obtained, the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and gradually increases the applied power from low to high, and transmits it to the harmonic multiplexing interdigital transducer; the harmonic multiplexing interdigital transducer is stimulated to generate surface acoustic waves and transfer them to the flow field in the set area, the sound pressure nodes in the set area migrate to both sides, and the corresponding cell clusters are subjected to the acoustic radiation force toward both sides, thereby generating a tensile load on the cell clusters;

[0023] 7) According to the required compressive sound field, the required frequency and power of the sound field are obtained, and the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and transmits it to the harmonic multiplexing interdigital transducer; the harmonic multiplexing interdigital transducer is stimulated to generate surface acoustic waves and transfer them to the flow field in the set area to form a convergent sound field, and the sound pressure nodes in the set area will migrate inward, and the corresponding cell clusters will be subjected to the sound radiation force toward the inside, thereby generating a compressive load on the cell clusters;

[0024] 8) Repeating 6) and 7) to repeatedly stretch and compress the cell cluster to achieve repeated dynamic stimulation of the cell cluster; the dynamic stimulation can produce a traction effect of stretching and compressing the cell membrane of the cell, accelerating the entry of the drug into the cell; at the same time, it can make the drug penetrate into the cells inside the cell cluster, accelerating the effect on the entire cell cluster;

[0025] 9) Collecting image signals and fluorescence signals through a CCD camera and a fluorescence microscope;

[0026] 10) The image signal represents the deformation state of the cell cluster after the stretching and compression stimulation, and the fluorescence signal represents the drug treatment state of the cell cluster after the stimulation. The image signal and the fluorescence signal are analyzed by the central processing unit.

[0027] Wherein, in step 1), the size of the cells is 10 μm to 30 μm, and the flow rate at which the cells are injected into the microfluidic cavity is 0.5 to 10 μl / min.

[0028] In step 2), the applied frequency is 10 to 50 MHz, the applied power is 100 to 500 mW, and the excitation time is 30 to 60 s.

[0029] In step 3), the waiting time is 6 to 24 hours.

[0030] In step 4), the applied frequency is 10-50 MHz, the applied power is 100-500 mW, and the excitation time is when the cell cluster is recaptured at the acoustic pressure node position and then stopped.

[0031] In step 5), the drug is paclitaxel, cisplatin or 5-fluorouracil, etc., and the concentration is 0 to 1000 μM.

[0032] In step 6), the applied frequency is 10-50 MHz, the applied power is slowly increased from low to high in the range of 0-1000 mW, the step length of the applied power is 5-20 s, and the excitation time is 10-30 s.

[0033] In step 7), the applied frequency is 10 to 50 MHz, the applied power is 100 to 1000 mW, and the excitation time is 10 to 30 s.

[0034] In steps 2), 4), 6) and 7), according to the required sound field, the frequency and power are parametrically scanned by finite element to obtain the frequency and power corresponding to the required sound field. The signal generator converts the digital signal into an electrical signal, outputs excitation signals of different frequencies from each output channel, and transmits them to the power amplifier after superposition; the power amplifier converts the electrical signal into an amplified power signal and transmits it to the harmonic multiplexing interdigital transducer;

[0035] Advantages of the present invention:

[0036] (1) The present invention utilizes a harmonic multiplexing interdigital transducer and designs an interdigital electrode with multiple center frequencies. By matching excitation signals of different frequencies and powers, an adjustable acoustic field is constructed in the microfluidic cavity, thereby converging cells and stimulating cell clusters to stretch and compress. Due to the influence of dynamic excitation on cell clusters, the drug is accelerated to enter the cell interior, thereby promoting drug screening for cells.

[0037] (2) The harmonic multiplexing interdigital transducer can be optimized through COMSOL finite element simulation. Under the condition of matching the excitation frequency, power, size of the interdigital electrodes and boundary conditions of the microfluidic cavity, the required acoustic field can be excited. The surface acoustic wave excitation power can be selectively adjusted to excite different forms of acoustic fields for excitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the cell cluster stretching and compression device based on surface acoustic wave harmonic regulation of the present invention Figure 1 A schematic diagram of an embodiment;

[0039] Figure 2 This is a simulation effect diagram of the dynamic control of the acoustic field obtained by an embodiment of the cell cluster stretching and compression device based on surface acoustic wave harmonic control of the present invention;

[0040] Figure 3 Schematic diagram of parameters of series-connected interdigitated electrodes of an embodiment of the cell cluster stretching and compression device based on surface acoustic wave harmonic regulation of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0042] like Figure 1 As shown, the cell cluster stretching and compression device based on surface acoustic wave harmonic regulation of this embodiment includes: a central processing unit 1, a signal generator 2, a power amplifier 3, a surface acoustic wave driving chip 4, a microfluidic cavity module 5, a fluorescence microscope 6 and a CCD camera 7; wherein the microfluidic cavity module 5 is located under the surface acoustic wave driving chip 4; the surface acoustic wave driving chip 4 is connected to the power amplifier 3, the power amplifier 3 is connected to the signal generator 2, and the signal generator 2 is connected to the central processing unit 1;

[0043] The microfluidic cavity module 5 includes a liquid inlet, a liquid outlet and a microfluidic cavity; the surface of the microfluidic cavity is an opening, the interior is a cavity, and the liquid inlet and the liquid outlet are respectively arranged on opposite sides of the microfluidic cavity;

[0044] The surface acoustic wave driving chip 4 includes a substrate and a harmonic multiplexing interdigital transducer, and the harmonic multiplexing interdigital transducer includes a plurality of interdigital electrodes connected in series; a plurality of interdigital electrodes are respectively arranged on the substrate, and the plurality of interdigital electrodes are connected in series to the output end of the power amplifier 3; each interdigital electrode has a different finger width, and different finger widths correspond to different center frequencies of the interdigital electrodes, and the center frequency of the interdigital electrodes is adjusted by the finger width; the surface acoustic wave driving chip 4 is inverted on the microfluidic cavity module 5, that is, the counter microfluidic cavity of the harmonic multiplexing interdigital transducer positive microfluidic cavity module 5;

[0045] A CCD camera 7 is arranged on the fluorescence microscope 6 , and the CCD camera 7 is connected to the central processor 1 .

[0046] In this embodiment, the substrate is made of lithium niobate, and the wave speed in lithium niobate is 3960m / s; the material of the microfluidic cavity is polydimethylsiloxane PDMS; the harmonic multiplexing interdigital transducer includes two interdigital electrodes connected in series, with finger widths of 50μm and 100μm respectively, an interdigital spacing of 50μm, and an index of 13 pairs, corresponding to center frequencies of 20MHz and 10MHz. The finite element simulation results of harmonic mixing 10MHz and 20MHz signal excitation and single-frequency 20MHz signal excitation are shown in Figure 1. Figure 2 As shown in the simulation results, it can be found that after the signal switching, the generated sound field form has undergone a significant change: in some areas, after the harmonic signal switching, the sound pressure node position of the sound field has moved to both sides; while in other areas, after the harmonic signal switching, the sound pressure node position of the sound field can be maintained. The parameter diagram of the interdigital electrode is shown in Figure 3 shown.

[0047] The principle of the harmonic surface acoustic wave field regulation provided by the present invention to achieve cell cluster control is:

[0048] When in a far-field liquid environment, particles will be mainly affected by the acoustic radiation force. The magnitude and direction of the acoustic radiation force are related to the gradient of the Gor'kov potential energy. At the extreme point of the Gor'kov potential energy, the acoustic radiation force is 0. Under the action of the acoustic radiation force, the particles will converge to the position of the Gor'kov potential well. Therefore, particle manipulation can be achieved by designing the position of the Gor'kov potential well. The relationship between the acoustic radiation force and the Gor'kov potential energy is:

[0049]

[0050] Among them, F rad is the acoustic radiation force, U is the Gor'kov potential energy, and <> represents the time average within the period.

[0051] Traditional particle / cell manipulation based on surface acoustic waves is mainly aimed at fixed-form interdigital transducers, which are usually designed to be arranged at equal intervals, have only one center frequency, and a single sound field distribution pattern. Through the superposition of multi-frequency harmonic sound fields and the regulation of the sound pressure amplitude and phase distribution of the surface acoustic wave substrate, the regulation of various radiation sound field potential wells can be achieved, and the manipulation of the graphics or trajectories of particles / cells can be achieved. Therefore, by setting a specified sound field form, the stimulation effect of stretching and compressing the cell group can be achieved.

[0052] The relationship between the excitation amplitude and time of a single electrical signal is:

[0053] F1(t)=V1sin(2πf1t)

[0054] Wherein, V1 is the first peak-to-peak value of the amplitude, and f1 is the first frequency.

[0055] When there are multiple electrical signals in the circuit, the relationship between the superimposed signal and time is obtained by superimposing the excitation signal waveforms:

[0056] F(t)=F1(t)+F2(t)+…=V1sin(2πf1t)+V2sin(2πf2t)+··

[0057] Wherein, V2 is the second peak-to-peak value, and f2 is the second frequency.

[0058] The signal generator 2 sends a voltage signal with respect to time, and the power amplifier 3 amplifies the voltage; however, since the impedance (resistance) of each device is different, the power will be different. In the experiment, the output power of the power amplifier 3 is usually measured, and the voltage of the signal generator 2 is adjusted to match the actual power.

[0059] The cell cluster stretching and compression method based on surface acoustic wave harmonic regulation of this embodiment includes the following steps:

[0060] 1) Injecting single tumor cell samples into the microfluidic cavity;

[0061] 2) According to the required convergent acoustic field, the frequency and power are parametrically scanned through COMSOL finite element simulation, and the superposition of 10 MHz and 20 MHz is obtained as the excitation signal, the applied power is 300 mW, the signal generator 2 converts the digital signal into an electrical signal, the central processor 1 controls the signal generator 2 to output the excitation signal of the corresponding frequency and power to the power amplifier 3 for amplification; the power amplifier 3 converts the electrical signal into an amplified power signal, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves of corresponding power through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area, and the excitation time is 30 to 60 seconds to form a convergent acoustic field, so that the cells are aggregated;

[0062] 3) Wait for about 24 hours for the cells to cross-link and form cell clusters;

[0063] 4) According to the required convergent acoustic field, 10 MHz and 20 MHz are superimposed as the excitation signal through finite element simulation, and the applied power is 100-500 mW; the harmonic multiplexing interdigital transducer generates surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form a convergent acoustic field, so that the initial cell cluster is recaptured at the acoustic pressure node position;

[0064] 5) After observing that the tumor cell spheres are growing well through the microscopic observation module, anti-tumor drugs are injected from the liquid inlet of the microfluidic cavity. The drugs preferentially act on the outer cells of the cell cluster and then penetrate into the cells layer by layer;

[0065] 6) According to the required stretch-shaped acoustic field, a single frequency of 20 MHz is used as the excitation signal, and the applied power is slowly increased from low to high. The power cannot be applied in pulses. The step length is 5 to 20 seconds. The sound pressure nodes in the set area migrate to both sides, and the corresponding cell clusters are subjected to the acoustic radiation force toward both sides, thereby generating a tensile load on the cell clusters;

[0066] 7) According to the required compressive sound field, 10MHz and 20MHz are superimposed as the excitation signal, and the applied power is 300-1000mW to form a convergent sound field. The sound pressure nodes in the set area will migrate inward, and the corresponding tumor cell clusters will be subjected to the sound radiation force toward the inside, thereby generating a compressive load on the cell clusters;

[0067] 8) Repeating 6) and 7) to repeatedly stretch and compress the cell cluster to achieve repeated dynamic stimulation of the cell cluster; the dynamic stimulation can produce a traction effect of stretching and compressing the cell membrane of the tumor cell, accelerating the entry of the drug into the cell; at the same time, it can make the drug penetrate into the cells inside the cell cluster, accelerating the effect on the entire cell cluster;

[0068] 9) collecting image signals and fluorescence signals through CCD camera 7 and fluorescence microscope 6 for analysis;

[0069] 10) The image signal represents the deformation state of the cell cluster after the stretching and compressing stimulation, and the fluorescence signal represents the drug treatment state of the cell cluster after the stimulation. The image signal and the fluorescence signal are analyzed by the central processor 1.

[0070] By introducing anti-tumor drugs, we can study the drug response of tumor cells after mechanical stimulation, and by evaluating the effect of drugs on tumor cells, we can select more effective anti-tumor drugs and further develop personalized treatment plans. In other specific areas, since the position of the sound pressure node has not changed, when the frequency is switched, it will not affect the tumor cell cluster at that position. Therefore, it can be used as a control group for comparison with the stimulated tumor cell cluster.

[0071] Finally, it should be noted that the purpose of publishing the embodiments is to help further understand the present invention, but those skilled in the art can understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the contents disclosed in the embodiments, and the scope of protection claimed by the present invention shall be subject to the scope defined in the claims.

Claims

1. A cell cluster stretching and compression device based on surface acoustic wave harmonic regulation, characterized in that: The cell cluster stretching and compression device comprises: a central processing unit, a power amplifier, a signal generator, a microfluidic cavity module and a surface acoustic wave driving chip; wherein the microfluidic cavity module is located under the surface acoustic wave driving chip; the surface acoustic wave driving chip is connected to the power amplifier, the power amplifier is connected to the signal generator, and the signal generator is connected to the central processing unit; The microfluidic cavity module includes a liquid inlet, a liquid outlet and a microfluidic cavity; the surface of the microfluidic cavity is an opening, the interior is a cavity, and the liquid inlet and the liquid outlet are respectively arranged on two opposite sides of the microfluidic cavity; The surface acoustic wave driving chip includes a substrate and a harmonic multiplexing interdigital transducer, and the harmonic multiplexing interdigital transducer includes a plurality of interdigital electrodes connected in series; a plurality of interdigital electrodes are respectively arranged on the substrate, and the plurality of interdigital electrodes are connected in series to the output end of the power amplifier; each interdigital electrode has a different finger width, and the different finger widths correspond to different center frequencies of the interdigital electrodes, and the center frequency of the interdigital electrodes is adjusted by the finger width; the surface acoustic wave driving chip is inverted on the microfluidic cavity module, that is, the harmonic multiplexing interdigital transducer is directly opposite to the microfluidic cavity of the microfluidic cavity module; According to the required sound field, the corresponding frequency and power of the required sound field are obtained; the central processing unit sends a digital signal to the signal generator, and controls different output channels of the signal generator to send excitation signals of different frequencies and corresponding powers according to the parameterized scanning results; the signal generator converts the digital signal into an electrical signal, outputs excitation signals of different frequencies from each output channel, and transmits them to the power amplifier after superposition; the power amplifier converts the electrical signal into an amplified power signal, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form the required sound field; by designing different forms of harmonic multiplexing interdigital transducers, the frequency and power of the excitation signal are changed to generate a specified sound field, so that the sound field respectively produces the effects of clustering, positioning, stretching and compressing on the cells in turn.

2. The cell cluster stretching and compression device according to claim 1, characterized in that: The microchannel cavity has a height of 50 to 1000 μm, and a length and width of 5 to 20 mm.

3. The cell cluster stretching and compression device according to claim 1, characterized in that: It also includes a microscopic observation device, which includes a fluorescence microscope and a charge-coupled device (CCD) camera. The microfluidic cavity module is placed on the sample stage of the fluorescence microscope. The CCD camera is arranged on the fluorescence microscope and is connected to a central processing unit.

4. The cell cluster stretching and compression device according to claim 1, characterized in that: The finger width of the interdigitated electrode is 20-100 μm, the index is 10-30 pairs, the center frequency range is 10-50 MHz, and the applied power range is 100-1000 mW.

5. A stretching and compression method of a cell cluster stretching and compression device based on surface acoustic wave harmonic regulation as claimed in claim 1, characterized in that: The stretching and compression method comprises the following steps: 1) Injecting cells into the microfluidic cavity; 2) According to the required convergent acoustic field, the corresponding frequency and power are obtained, and the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form a convergent acoustic field, so that the cells are aggregated; 3) Waiting for the cells to cross-link and form cell clusters; 4) According to the required convergent acoustic field, the corresponding frequency and power are obtained, and the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and transmits it to the harmonic multiplexing interdigital transducer; the interdigital electrodes whose center frequency is consistent with the frequency of the excitation signal generate surface acoustic waves through the inverse piezoelectric effect, and the surface acoustic waves are transferred to the flow field in the set area to form a convergent acoustic field, so that the initial cell cluster is recaptured at the acoustic pressure node position; 5) After observing that the cell clusters are growing well through the microscopic observation module, inject the drug from the liquid inlet of the microfluidic cavity; 6) According to the required stretch-shaped acoustic field, the required frequency and power are obtained, the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and gradually increases the applied power from low to high, and transmits it to the harmonic multiplexing interdigital transducer; the harmonic multiplexing interdigital transducer is stimulated to generate surface acoustic waves and transfer them to the flow field in the set area, the sound pressure nodes in the set area migrate to both sides, and the corresponding cell clusters are subjected to the acoustic radiation force toward both sides, thereby generating a tensile load on the cell clusters; 7) According to the required compressive sound field, the required frequency and power of the sound field are obtained, and the central processing unit controls the signal generator to output the excitation signal of the corresponding frequency and power to the power amplifier for amplification, and transmits it to the harmonic multiplexing interdigital transducer; the harmonic multiplexing interdigital transducer is stimulated to generate surface acoustic waves and transfer them to the flow field in the set area to form a convergent sound field, and the sound pressure nodes in the set area will migrate inward, and the corresponding cell clusters will be subjected to the sound radiation force toward the inside, thereby generating a compressive load on the cell clusters; 8) Repeating 6) and 7) to repeatedly stretch and compress the cell cluster to achieve repeated dynamic stimulation of the cell cluster; the dynamic stimulation can produce a traction effect of stretching and compressing the cell membrane of the cell, accelerating the entry of the drug into the cell; at the same time, it can make the drug penetrate into the cells inside the cell cluster, accelerating the effect on the entire cell cluster; 9) collecting image signals and fluorescence signals through a charge coupled device (CCD) camera and a fluorescence microscope; 10) The image signal represents the deformation state of the cell cluster after the stretching and compression stimulation, and the fluorescence signal represents the drug treatment state of the cell cluster after the stimulation. The image signal and the fluorescence signal are analyzed by the central processing unit.

6. The stretching and compression method according to claim 5, characterized in that: In step 1), the size of the cells is 10 μm to 30 μm, and the flow rate of the cells injected into the microfluidic channel cavity is 0.5 to 10 μl / min.

7. The stretching and compression method according to claim 5, characterized in that: In step 2), the applied frequency is 10 to 50 MHz, the applied power is 100 to 500 mW, and the excitation time is 30 to 60 s.

8. The stretching and compression method according to claim 5, characterized in that: In step 4), the applied frequency is 10 to 50 MHz, and the applied power is 100 to 500 mW.

9. The stretching and compression method according to claim 5, characterized in that: In step 6), the applied frequency is 10 to 50 MHz, the applied power ranges from 0 to 1000 mW, and the excitation time is 10 to 30 s.

10. The stretching and compression method according to claim 5, characterized in that: In step 7), the applied frequency is 10 to 50 MHz, the applied power is 100 to 1000 mW, and the excitation time is 10 to 30 s.

Images