A device for rapid lysis of bacteria using surface acoustic waves

Abstract

The application discloses a surface acoustic wave device for rapid lysis of bacteria. The device comprises an interdigital transducer, the interdigital transducer comprises a piezoelectric substrate and interdigital electrodes arranged on the piezoelectric substrate, the interdigital electrodes are located at one end of the piezoelectric substrate, the other end of the piezoelectric substrate is provided with a microneedle array, the microneedle array is enclosed in a bacterial lysis chamber, the bacterial lysis chamber is respectively provided with a liquid inlet hole and an exhaust hole at two ends, the piezoelectric substrate is made of lithium niobate sheet, the interdigital electrodes are composed of a titanium layer and a gold layer, the titanium layer is located above the lithium niobate sheet, and the gold layer is located above the titanium layer, and the microneedle array is a silicon microneedle array. The application provides controllable liquid oscillation driving force through the surface acoustic wave, and the silicon microneedle array provides fixed and stable mechanical scratch structure, and the two cooperate to make the bacteria collide with the microneedle and collide with each other in the chamber, so that the bacteria are lysed in a short time in a broad-spectrum, efficient and reagent-free manner.

Description

Technical Field

[0001] This invention relates to the field of biological detection technology, and more specifically to a surface acoustic wave device for rapid bacterial lysis. Background Technology

[0002] Bacterial lysis is a crucial sample pretreatment step in nucleic acid detection, protein detection, pathogen identification, and bacterial resistance analysis. Current bacterial lysis techniques can be categorized into physical, chemical, and enzymatic methods. Physical methods, including sonication, high-pressure homogenization, and repeated freeze-thaw cycles, are the most widely used due to the absence of reagent residue. However, physical methods also have drawbacks. Sonication can generate localized high temperatures that denature intracellular substances and results in poor lysis uniformity. High-pressure homogenization equipment is bulky, cumbersome, and energy-intensive. Repeated freeze-thaw cycles are time-consuming, inefficient, and prone to degrading intracellular substances. Chemical methods are simple to operate and low in cost, utilizing surfactants or alkalis to disrupt bacterial cell walls and release intracellular substances. However, chemical reagents are prone to residue, which can damage intracellular active substances, interfere with subsequent analysis, affect the accuracy of test results, and potentially cause environmental pollution. Enzymatic methods have the advantages of being gentle and causing minimal damage to intracellular substances, but are limited by low lysis efficiency and high enzyme preparation costs, making them unsuitable for large-scale, rapid lysis scenarios. Therefore, in scenarios involving rapid detection and on-site testing of pathogenic microorganisms, there is an urgent need for a miniaturized, rapid, low-damage bacterial lysis technology that does not introduce exogenous lysis reagents.

[0003] Surface acoustic wave (SAW) microfluidics, characterized by concentrated energy, precise electrical signal control, small device size, and easy integration with microfluidic channels, has been used for cell manipulation, mixing, sorting, enrichment, and lysis. It utilizes interdigital transducers, consisting of a piezoelectric substrate and interdigitated electrodes deposited on its surface, to convert electrical energy into SAW waves. This induces liquid oscillations, driving bacterial movement. Bacterial collisions with the transducer wall and between bacteria lead to lysis. This method eliminates the need for chemical reagents and does not affect subsequent analysis. However, relying solely on bacterial collisions with a flat surface is insufficient to effectively disrupt bacterial cell walls, necessitating measures to improve lysis efficiency. Existing technologies have also proposed methods using fixed structures such as silicon nanoblades and silicon nanotipples to pierce cell membranes. Using nanotipples to rapidly and directly disrupt bacterial cell walls can quickly lead to leakage of cell contents. Furthermore, nanotip structures are easily integrated onto SAW substrates, significantly improving bacterial lysis efficiency.

[0004] However, methods utilizing nano-tip techniques often rely on pressure-driven or passive flow to allow cells to pass through the tip structure region. The frequency of cell-tip contact is affected by the flow channel design and flow rate, making it difficult to achieve stable and efficient lysis of multiple types of bacteria in a short time. Therefore, there is a need for a rapid bacterial lysis device that directly integrates surface acoustic wave-driven liquid oscillation with a fixed silicon microneedle array to increase the frequency of bacteria-tip collisions without introducing free particles and lysis reagents. The device utilizes surface acoustic waves to provide controllable liquid oscillation driving force and silicon microneedle arrays to provide a fixed and stable mechanical tearing structure. The two work together to cause multiple bacteria-microneedle collisions and bacteria-bacteria collisions within the chamber, thereby achieving broad-spectrum, efficient, and reagent-free lysis in a short time. Summary of the Invention

[0005] To address the aforementioned limitations of existing technologies, the present invention aims to provide a surface acoustic wave (SAW) device for rapid bacterial lysis. This invention involves mounting an interdigital transducer and a silicon microneedle array on the same lithium niobate piezoelectric substrate, and sealing a PDMS-based bacterial lysis chamber above the silicon microneedle array. The SAW provides a controllable liquid oscillation driving force, while the silicon microneedle array provides a fixed and stable mechanical tearing structure. Together, these components induce multiple bacterial-microneedle and bacterial-bacterial collisions within the chamber, thereby achieving broad-spectrum, efficient, and reagent-free lysis in a short time.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a surface acoustic wave device for rapid bacterial lysis, comprising an interdigital transducer; the interdigital transducer includes a piezoelectric substrate and interdigital electrodes disposed on the piezoelectric substrate; the interdigital electrodes are located at one end of the piezoelectric substrate, and a microneedle array is disposed at the other end of the piezoelectric substrate; a bacterial lysis chamber is disposed above the silicon microneedle array, and the silicon microneedle array is located in the bottom inner region of the bacterial lysis chamber; an inlet port and an outlet port are respectively disposed at both ends of the bacterial lysis chamber; the piezoelectric substrate is made of lithium niobate; the interdigital electrodes are composed of a titanium layer and a gold layer, the titanium layer being located above the lithium niobate sheet, and the gold layer being located above the titanium layer; the microneedle array is a silicon microneedle array.

[0007] Preferably, the lithium niobate sheet is a lithium niobate sheet cut in the YX direction at 128°; the thickness of the titanium layer is 10-50 nm; and the thickness of the gold layer is 50-200 nm.

[0008] Preferably, the interdigitated electrode has 20-40 interdigitated pairs, and the width of the electrode strip and the distance between adjacent electrode strips are both 40-100 μm; the center frequency of the interdigitated transducer is 10-25 MHz.

[0009] Preferably, the silicon microneedle array is an α-Si microneedle array; the height of the silicon microneedles on the silicon microneedle array is 0.5-3.0 μm, the bottom diameter is 0.3-2.0 μm, and the spacing between adjacent silicon microneedles is 3-20 μm.

[0010] Preferably, the height of the bacterial lysis chamber is 100-1000 μm, the length is 5-20 mm, and the width is 0.5-5 mm.

[0011] A second aspect of the invention provides the application of a surface acoustic wave device for rapid bacterial lysis in rapidly and with low damage lysis of bacteria without introducing exogenous lysis reagents, said bacteria including Gram-positive and / or Gram-negative bacteria.

[0012] A third aspect of the present invention provides a method for preparing a surface acoustic wave device for rapid bacterial lysis, comprising the following steps: (1) Spin-coat a layer of photoresist on the surface of one end of the piezoelectric substrate, and expose the pattern of interdigitated electrodes on the piezoelectric substrate by photolithography. Sequentially deposit a layer of titanium and gold on the surface of the piezoelectric substrate, and use acetone to remove the photoresist to obtain interdigitated electrodes on the surface of the piezoelectric substrate. (2) A layer of α-Si is deposited on the other end of the piezoelectric substrate by plasma-enhanced chemical vapor deposition. A layer of photoresist is spin-coated on the α-Si surface. A chromium film is deposited on the photoresist surface by electron beam evaporation. After demolding, an array composed of separated chromium disks is obtained. The chromium disks are used as etching masks to etch α-Si by inductively coupled plasma. The chromium disks are removed by wet etching to obtain an α-Si microneedle array. (3) Make an acrylic plate positive mold with a raised surface to replicate the geometry of the chamber. Mix PDMS prepolymer and curing agent, and pour the mixture into the acrylic plate positive mold after the gas is discharged in a vacuum drying oven. Heat and cure the mixture, and demold to obtain the bacterial lysis chamber. Make a hole on each side of the top of the bacterial lysis chamber as a liquid inlet and an exhaust outlet, respectively. The exhaust outlet is used to discharge the gas in the chamber during sample injection and for the recovery of the sample after lysis. (4) The surfaces of the piezoelectric substrate and the bacterial lysis chamber are treated with oxygen plasma, and the bacterial lysis chamber is attached to the silicon microneedle array surface of the piezoelectric substrate to achieve sealing, thus obtaining a surface acoustic wave device for rapid bacterial lysis.

[0013] A fourth aspect of the present invention provides a method for rapidly lysing bacteria using a surface acoustic wave device, the method comprising: A bacterial liquid sample is injected into a bacterial lysis chamber; a sinusoidal pulse electrical signal is output by a function generator and amplified by a radio frequency amplifier before being sent to an interdigital transducer; the interdigital transducer generates surface acoustic waves on the surface of a lithium niobate sheet, and the surface acoustic waves radiate into the bacterial liquid sample to form liquid oscillations and drive the bacteria to move; during the movement, the bacteria collide with the silicon microneedle array and are scratched by the tips of the silicon microneedles, while the collision between bacteria promotes lysis.

[0014] Preferably, the frequency of the sinusoidal pulse electrical signal is 10-25 MHz, the duty cycle is 10-50%, and the processing time is 0.5-5 min.

[0015] Preferably, the bacteria include Gram-positive bacteria and / or Gram-negative bacteria, wherein the Gram-positive bacteria are selected from one or more of Streptococcus mutans, Listeria monocytogenes, Streptococcus pneumoniae, Enterococcus faecalis, Streptococcus pyogenes, and Staphylococcus aureus; and the Gram-negative bacteria are selected from one or more of Acinetobacter baumannii, Klebsiella pneumoniae, Neisseria meningitidis, and Pseudomonas aeruginosa.

[0016] The beneficial effects of this invention are: (1) This invention combines surface acoustic waves with a nano-tip array to achieve rapid and convenient bacterial lysis. This technology uses surface acoustic waves as the driving force to induce liquid oscillation to drive bacterial movement, resulting in low energy consumption; it utilizes the collision between bacteria and nano-tip and between bacteria to achieve lysis, minimizing damage to intracellular substances; it can achieve effective bacterial lysis in 3 minutes, resulting in high efficiency; it does not introduce chemical reagents and does not affect subsequent analysis; the device can be reused, resulting in low operating costs, demonstrating the application prospects of this bacterial lysis device in the processing of bacteria and even all types of cell samples.

[0017] (2) The lysis process of the present invention does not use surfactants, strong bases, lysozymes or other chemical / biological lysis agents, thus avoiding inhibition of subsequent nucleic acid amplification and protein detection; it does not add free microspheres, magnetic beads or nanowires to the sample, thus avoiding particle residue and secondary separation steps; the silicon microneedle array is fixed on the surface of the piezoelectric substrate, which is structurally stable and reusable; the surface acoustic wave provides active oscillation driving force, which significantly increases the collision frequency between bacteria and microneedle tips, and can achieve high lysis efficiency for Gram-positive and Gram-negative bacteria within minutes; the overall device is small in size and requires less sample, making it suitable for integration with nucleic acid detection chips, protein detection modules and on-site rapid detection platforms. Attached Figure Description

[0018] Figure 1 Photograph of interdigital electrodes; Figure 2 SEM image of silicon microneedle array; Figure 3The diagram shows the structure of a surface acoustic wave device, where 1 is a piezoelectric substrate, 2 is a bacterial lysis chamber, 3 is an interdigitated electrode, 4 is a silicon microneedle array, 5 is a liquid inlet, and 6 is an exhaust port. Figure 4 Photograph of a surface acoustic wave device; Figure 5 A comparison of DNA concentrations released by six Gram-positive bacteria through high-temperature lysis and surface acoustic wave lysis. Figure 6 A comparison of DNA concentrations released by four types of Gram-negative bacteria through high-temperature lysis and surface acoustic wave lysis. Figure 7 A comparison of DNA concentrations released by lysis of six Gram-positive bacteria via high-temperature lysis and lysis via a microneedle-free surface acoustic wave device. Figure 8 This is a comparison of the DNA concentrations released by four types of Gram-negative bacteria through high-temperature lysis and lysis using a microneedle-free surface acoustic wave device. Detailed Implementation

[0019] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0020] As introduced in the background section, to improve the efficiency of mechanical lysis, techniques have emerged that utilize free particles such as microspheres, magnetic beads, and nanowires to collide with cells under acoustic flow, or use fixed structures such as silicon nanoblades and silicon nanotipples to pierce cell membranes. The former requires the addition of exogenous particles to the sample, and the particles still need to be separated after lysis, which may introduce particle residues and interference with subsequent detection; the latter mostly relies on pressure-driven or passive flow to allow cells to pass through the tip structure region, and the frequency of cell-tip contact is affected by the flow channel design and flow rate, making it difficult to achieve stable and efficient lysis of multiple types of bacteria in a short time.

[0021] Based on this, the purpose of this invention is to provide a surface acoustic wave (SAW) device for rapid bacterial lysis. An interdigital transducer and a silicon microneedle array are mounted on the same lithium niobate piezoelectric substrate, and a PDMS lysis chamber is sealed above the silicon microneedle array. The SAW provides a controllable driving force for liquid oscillation, while the silicon microneedle array provides a fixed and stable mechanical tearing structure. Together, they induce multiple bacterial-microneedle and bacterial-bacterial collisions within the chamber, achieving broad-spectrum, efficient, and reagent-free lysis in a short time. A function generator produces a sinusoidal pulse, which is amplified by an RF amplifier and transmitted to the interdigital transducer, generating SAW on the lithium niobate surface. The wave energy radiates into the liquid, causing it to oscillate and inducing bacterial movement. Rapid lysis is achieved through the tearing of bacteria by the silicon microneedles and collisions between bacteria. This device is small in size, easy to operate, has a fast lysis speed, is reusable, and avoids the introduction of impurities, making it a highly efficient method for bacterial lysis.

[0022] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0023] The test materials used in the embodiments of this invention are all conventional test materials in the art and can be purchased through commercial channels.

[0024] Example 1: Preparation of a surface acoustic wave device for rapid bacterial lysis (1) A lithium niobate sheet with a length of 2.5 cm and a width of 2.3 cm was cut along the 128°YX direction to serve as a piezoelectric substrate. First, the lithium niobate sheet was immersed in acetone, isopropanol and anhydrous ethanol in sequence and sonicated for 5 minutes. It was then rinsed with deionized water and dried with nitrogen. A photoresist with a thickness of about 2.3 μm (photoresist type: AZ n-lof 2035, spin coating parameters: 4000 rpm / 30 s, pre-baking parameters: 105℃ / 90 s) was spin-coated on one end of the lithium niobate surface. The interdigitated electrode pattern area was exposed by photolithography (exposure time: 12 s, development time: 60 s). Then, a 20 nm titanium layer and a 100 nm gold layer were deposited sequentially by electron beam evaporation (vacuum degree during the evaporation of the two metals: 3×10 -6 Torr (evaporation temperature: 25℃, evaporation power: Ti 30 W, Au 40 W, evaporation rate: Ti 0.5 Å / s, Au 0.8 Å / s, evaporation time: Ti 400 s, Au 1250 s), the photoresist was sequentially soaked in acetone, isopropanol, and anhydrous ethanol for 20 min, 5 min, and 5 min, respectively, then rinsed with deionized water and manually peeled off to obtain interdigitated electrodes. The interdigitated electrodes and lithium niobate sheets constitute an interdigitated transducer with a center frequency of approximately 15 MHz, 30 interdigitated pairs, an electrode strip width and distance between electrode strips of 67 μm, and a distance of 9 mm between two electrodes. Figure 1 As shown.

[0025] (2) A silicon microneedle array was fabricated on the other end of the piezoelectric substrate. A 1.2 μm thick α-Si layer was deposited on the piezoelectric substrate surface by plasma-enhanced chemical vapor deposition (piezoelectric substrate temperature: 200℃, gas pressure: 800 mTorr, RF power: 30 W, SiH4 flow rate: 50 sccm, H2 flow rate: 50 sccm, Ar / He flow rate: 500 sccm, deposition rate: 1 nm / s). A photoresist with a thickness of about 2.3 μm was spin-coated on the α-Si surface (photoresist type and process parameters are the same as in step (1)). A 60 nm thick chromium film was deposited on the photoresist surface by electron beam evaporation (evaporation rate: 0.8 Å / s, evaporation power: 40 W, vacuum degree during evaporation: 3×10⁻⁶). -6 Torr (evaporation temperature: 25℃); then, the image was sequentially immersed in acetone, isopropanol, and anhydrous ethanol for 20 min, 5 min, and 5 min, respectively, and rinsed with deionized water to release the photoresist, obtaining an array composed of chromium disks with a diameter of approximately 2 μm and a spacing of approximately 8 μm; subsequently, using the chromium disks as an etching mask, the α-Si layer was etched by inductively coupled plasma (ICP) (etching time: 10³ s, temperature: -10℃, pressure: 8 mtorr, ICP power: 800 W, RF power: 15 W, SF6 flow rate: 25 sccm, CHF3 flow rate: 100 sccm); finally, the chromium disk mask was removed by wet etching for 5 min to obtain the α-Si microneedle array. The SEM image of the α-Si microneedle array is shown below. Figure 2 As shown, the bottom of the α-Si microneedle is a circle with a diameter of about 0.8 μm and a height of about 1.2 μm, and the top gradually tapers into a sharp tip. The spacing between adjacent silicon microneedles is about 8 μm.

[0026] (3) Preparation of bacterial lysis chambers using PDMS. An acrylic plate mold with a raised chamber geometry was fabricated, with a chamber height of 500 μm, a length of 11 mm, and a width of 1.5 mm. PDMS prepolymer and curing agent (Sylgard™ silicate elastomer kit, Dow Corning (China) Investment Co., Ltd.) were mixed at a mass ratio of 10:1, degassed in a vacuum drying oven, poured into the mold, and heated at 80°C for 2 h to cure, resulting in a bacterial lysis chamber with a thickness of approximately 1 mm. After demolding, a punch was used to form an inlet hole and an vent hole with a diameter of approximately 1 mm on both sides of the top of the bacterial lysis chamber.

[0027] (4) The surface of the piezoelectric substrate with silicon microneedle array and the surface of the bacterial lysis chamber are treated with oxygen plasma. Then the bacterial lysis chamber is attached to the surface of the silicon microneedle array of the piezoelectric substrate, so that the chamber covers the silicon microneedle array and is sealed, thereby obtaining a surface acoustic wave device for rapid bacterial lysis.

[0028] Figure 3 and Figure 4 The images show a schematic diagram and a photograph of a surface acoustic wave (SAW) device.

[0029] Example 2: Bacterial lysis 5 µL of 10 logarithmic growth phase bacteria (Acinetobacter baumannii (concentration: 0.22 × 10⁻⁶) were added. 10 cells / mL), Streptococcus mutans (concentration: 1.40 × 10⁻⁶ ... 10 cells / mL), Listeria monocytogenes (concentration: 0.80×10⁻⁶ ...). 10 cells / mL), Klebsiella pneumoniae (concentration: 0.45 × 10⁻⁶ ...). 10 cells / mL), Streptococcus pneumoniae (concentration: 0.21×10⁻⁶ ...). 10 cells / mL), Enterococcus faecalis (concentration: 0.16×10⁻⁶) 10 cells / mL), Streptococcus pyogenes (concentration: 0.90×10⁻⁶ cells / mL), 10 cells / mL), Staphylococcus aureus (concentration: 0.22×10⁻⁶ ...). 10 cells / mL), Neisseria meningitidis (concentration: 0.45 × 10⁻⁶ cells / mL), 10 cells / mL), Pseudomonas aeruginosa (concentration: 1.15 × 10⁻⁶ cells / mL), 10 Physiological saline dispersions (cells / mL) were injected into the bacterial lysis chambers of the bacterial lysis apparatus prepared in Example 1 and Comparative Example 1, and the physiological saline dispersions of bacteria were treated at 100°C for 10 min for lysis as a control group.

[0030] The devices in Example 2 and Comparative Example 1 output a 3-minute sinusoidal pulse electrical signal (power: -15 dBm, operating frequency: 14.4 MHz, pulse period: 69.44 μs, duty cycle: 25%, with on-time: 69.44 × 25% μs and off-time: 69.44 × 75% μs) from a function generator (model: DG4202, manufacturer: Mini-Circuits, gain: 43 dB) and then send it to an interdigital transducer (actual power input to the interdigital transducer: 28 dBm), which is converted into vibration of the piezoelectric substrate, generating surface acoustic waves at the substrate-liquid interface.

[0031] Surface acoustic waves (SAWs) induce liquid oscillations, driving bacterial movement. Rapid lysis is achieved through scratching and collisions between bacteria using silicon microparticles. Lysed samples are recovered through an exhaust vent and centrifuged at 10,000 rpm for 2 minutes. The supernatant is collected, and its absorbance is measured using an ultra-micro UV spectrophotometer to calculate the concentration of DNA released from the lysed bacteria. High-temperature treatment is widely considered an efficient method for bacterial lysis. A control group of bacterial samples with the same concentration was treated at 100°C for 10 minutes, and its absorbance was measured to calculate the concentration of DNA released from the lysed bacteria. All lysis experiments were performed in triplicate. The lysis effect of the SAW device relative to high-temperature treatment on 10 bacterial species was calculated. The DNA concentrations released from the lysis of six Gram-positive bacteria (Streptococcus mutans, Listeria monocytogenes, Streptococcus pneumoniae, Enterococcus faecalis, Streptococcus pyogenes, and Staphylococcus aureus, respectively) and four Gram-negative bacteria (Acinetobacter baumannii, Klebsiella pneumoniae, Neisseria meningitidis, and Pseudomonas aeruginosa, respectively) via high-temperature lysis and surface acoustic wave lysis are compared as follows: Figure 5 and Figure 6 As shown in Table 1, the surface acoustic wave device can lyse Gram-positive bacteria with thick cell walls and Gram-negative bacteria with thin cell walls for 3 minutes, achieving 90.48%~96.54% of the DNA lysed by the high-temperature lysing control group (hereinafter referred to as the control group), demonstrating excellent lysing performance.

[0032] Table 1. Lysis effect of microneedle surface acoustic wave device on 10 kinds of bacteria. Comparative Example A surface acoustic wave (SAW) device for rapid bacterial lysis was prepared according to the steps of Example 1, except that a silicon microneedle array was not prepared after depositing a 1.2 μm thick α-Si layer on the piezoelectric substrate. Ten types of bacteria were lysed according to the steps of Example 2, this time lysis was achieved solely through liquid oscillation to induce collisions between bacteria. A physiological saline dispersion of bacteria treated at 100°C for 10 min was used as a control group for lysis. The DNA concentrations released from lysis of six Gram-positive bacteria (Streptococcus mutans, Listeria monocytogenes, Streptococcus pneumoniae, Enterococcus faecalis, Streptococcus pyogenes, and Staphylococcus aureus, respectively) and four Gram-negative bacteria (Acinetobacter baumannii, Klebsiella pneumoniae, Neisseria meningitidis, and Pseudomonas aeruginosa, respectively) by high-temperature lysis and lysis using the microneedle-free SAW device were compared as follows: Figure 7 and Figure 8 As shown in Table 2, the amount of DNA lysed by the surface acoustic wave device for Gram-positive bacteria with thick cell walls and Gram-negative bacteria with thin cell walls reached 16.00%~37.68% of that obtained by high-temperature treatment within 3 minutes. The lysis performance was significantly lower than that of the surface acoustic wave device with microneedles, indicating that microneedle rupture plays an important role in bacterial lysis.

[0033] Table 2. Lysis effect of the needle-free surface acoustic wave device on 10 kinds of bacteria. The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A surface acoustic wave device for rapid bacterial lysis, characterized in that, The device includes an interdigital transducer; the interdigital transducer includes a piezoelectric substrate and interdigital electrodes disposed on the piezoelectric substrate; the interdigital electrodes are located at one end of the piezoelectric substrate, and a microneedle array is disposed at the other end of the piezoelectric substrate; a bacterial lysis chamber is disposed above the silicon microneedle array, and the silicon microneedle array is located in the bottom inner region of the bacterial lysis chamber; the bacterial lysis chamber has a liquid inlet and a vent at both ends; the piezoelectric substrate is made of lithium niobate; the interdigital electrodes are composed of a titanium layer and a gold layer, with the titanium layer located above the lithium niobate sheet and the gold layer located above the titanium layer; the microneedle array is a silicon microneedle array.

2. The surface acoustic wave device for rapid bacterial lysis according to claim 1, characterized in that, The lithium niobate sheet is a lithium niobate sheet cut in the YX direction at 128°; the thickness of the titanium layer is 10-50 nm; and the thickness of the gold layer is 50-200 nm.

3. The surface acoustic wave device for rapid bacterial lysis according to claim 1, characterized in that, The interdigitated electrode has 20-40 interdigitated fingers, and the width of the electrode strip and the distance between adjacent electrode strips are both 40-100 μm; the center frequency of the interdigitated transducer is 10-25 MHz.

4. The surface acoustic wave device for rapid bacterial lysis according to claim 1, characterized in that, The silicon microneedle array is an α-Si microneedle array; the silicon microneedles on the silicon microneedle array have a height of 0.5-3.0 μm, a bottom diameter of 0.3-3.0 μm, and a spacing of 3-20 μm between adjacent silicon microneedles.

5. The surface acoustic wave device for rapid bacterial lysis according to claim 1, characterized in that, The bacterial lysis chamber has a height of 100-1000 μm, a length of 5-20 mm, and a width of 0.5-5 mm.

6. The application of the surface acoustic wave device for rapid bacterial lysis according to any one of claims 1 to 5 in the rapid and low-damage lysis of bacteria without introducing exogenous lysis reagents, characterized in that, The bacteria include Gram-positive and / or Gram-negative bacteria.

7. The method for preparing the surface acoustic wave device for rapid bacterial lysis according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Spin-coat a layer of photoresist on the surface of one end of the piezoelectric substrate, and expose the pattern of interdigitated electrodes on the piezoelectric substrate by photolithography. Sequentially deposit a layer of titanium and gold on the surface of the piezoelectric substrate, and use acetone to remove the photoresist to obtain interdigitated electrodes on the surface of the piezoelectric substrate. (2) A layer of α-Si is deposited on the other end of the piezoelectric substrate by plasma-enhanced chemical vapor deposition. A layer of photoresist is spin-coated on the α-Si surface. A chromium film is deposited on the photoresist surface by electron beam evaporation. After demolding, an array composed of separated chromium disks is obtained. The chromium disks are used as etching masks to etch α-Si by inductively coupled plasma. The chromium disks are removed by wet etching to obtain an α-Si microneedle array. (3) Make an acrylic plate positive mold with a raised surface to replicate the geometry of the chamber. Mix PDMS prepolymer and curing agent, remove the gas in a vacuum drying oven and pour into the acrylic plate positive mold. Heat and cure. Demold to obtain the bacterial lysis chamber. Make a hole on each side of the top of the bacterial lysis chamber as a liquid inlet and an exhaust outlet, respectively. The exhaust outlet is used to remove the gas in the chamber during sample injection and for the recovery of the sample after lysis. (4) The surfaces of the piezoelectric substrate and the bacterial lysis chamber are treated with oxygen plasma, and the bacterial lysis chamber is attached to the silicon microneedle array surface of the piezoelectric substrate to achieve sealing, thus obtaining a surface acoustic wave device for rapid bacterial lysis.

8. The method for lysing bacteria using a surface acoustic wave device for rapid bacterial lysis according to any one of claims 1 to 5, characterized in that, The method is as follows: A bacterial liquid sample is injected into a bacterial lysis chamber; a sinusoidal pulse electrical signal is output by a function generator and amplified by a radio frequency amplifier before being sent to an interdigital transducer; the interdigital transducer generates surface acoustic waves on the surface of a lithium niobate sheet, and the surface acoustic waves radiate into the bacterial liquid sample to form liquid oscillations and drive the bacteria to move; during the movement, the bacteria collide with the silicon microneedle array and are scratched by the tips of the silicon microneedles, while the collision between bacteria promotes lysis.

9. The method according to claim 8, characterized in that, The frequency of the sinusoidal pulse electrical signal is 10-25 MHz, the duty cycle is 10-50%, and the processing time is 0.5-5 min.

10. The method according to claim 8, characterized in that, The bacteria include Gram-positive and / or Gram-negative bacteria, wherein the Gram-positive bacteria are selected from one or more of Streptococcus mutans, Listeria monocytogenes, Streptococcus pneumoniae, Enterococcus faecalis, Streptococcus pyogenes, and Staphylococcus aureus; and the Gram-negative bacteria are selected from one or more of Acinetobacter baumannii, Klebsiella pneumoniae, Neisseria meningitidis, and Pseudomonas aeruginosa.

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