Nanofilter with self-cleaning function and method of use

Abstract

The application relates to a nanofilter with a self-cleaning function, a cover body and a container form a sealed cavity, the cover body is provided with a sample inlet; a filter membrane support is arranged in the cavity, the filter membrane support is provided with a net-shaped supporting part, a nanofilter membrane is fixed on the net-shaped supporting part of the filter membrane support, the filter membrane support and the nanofilter membrane divide the cavity into two parts; a bulk acoustic resonator, the acoustic wave of the bulk acoustic resonator can be coupled with a fluid in the upper part of the cavity; the lower part of the cavity comprises a vacuum cavity and a waste liquid cavity, the filter membrane is provided with a through hole, the filter membrane support is communicated with the waste liquid cavity at the through hole of the nanofilter membrane, and the filter membrane support is provided with a valve plate at the through hole; the vacuum cavity is located below the net-shaped supporting part of the filter membrane support; the vacuum cavity and the waste liquid cavity are respectively communicated with a first vacuum pump and a second vacuum pump. The bulk acoustic resonator can generate acoustic radiation force and acoustic drag force on the surface of the nanofilter membrane, the filter cake on the surface of the filter membrane and the blockage in the membrane hole, and self-cleaning is realized.

Description

Technical Field

[0001] This application relates to the field of nanofilter technology, and in particular to nanofilters with self-cleaning function and methods of using them. Background Technology

[0002] Some diseases, such as conjunctivitis, tuberculosis, Alzheimer's disease, and cancer, often present with subtle symptoms and are difficult to diagnose in their early stages. However, by the time patients develop more pronounced symptoms, the optimal treatment period has often been missed. Early diagnosis can effectively prevent the worsening of symptoms and is crucial for improving recovery rates. Proteins, exosomes, bacteria, viruses, and circulating tumor cells are important biological substances for early diagnosis, and their research has consistently been a hot topic in medicine, life sciences, and pharmacology.

[0003] Extracellular vesicles (EVs) are membrane-bound substances released by cells into their external environment. They participate in intercellular communication and can be formed in prokaryotes, higher eukaryotes, and plants. Based on size, nanovesicles with a diameter ranging from 30 to 180 nm are called exosomes. Current research indicates that exosomes play important roles in tumor development and metastasis, inflammation, and adaptive immunity, thus attracting considerable attention. Exosomes are widely present in bodily fluids such as blood, urine, cerebrospinal fluid, and pleural effusion. They contain abundant biomarkers, such as proteins, lipids, DNA, and RNA, reflecting the composition of the cells or tissues from which they originate. These diverse biomarkers are associated with the development of various diseases and are of great significance for the early diagnosis of tumor liquid biopsies, neurological diseases, and respiratory diseases.

[0004] However, the lack of standardized tools to consistently separate high-yield, high-purity, and intact exosomes poses a significant obstacle to downstream analysis. Based on the physicochemical properties of exosomes, such as density, size, and surface-specific markers, the main separation methods include ultracentrifugation, differential centrifugation, chemical precipitation, immunosorbent assay (IMA), and inertial flow / viscoelastic flow methods. Currently, ultracentrifugation is the most commonly used separation method in research. Although it can process large volumes of samples without adding other reagents, it is far from meeting clinical application standards. Its main drawbacks are high labor intensity, long processing time, low purity and low yield of separated EVs, and even damage to the integrity of exosomes. Differential centrifugation is similar to ultracentrifugation, requiring extensive operation and expensive equipment. Chemical precipitation uses salt solutions or polymers, typically polyethylene glycol, as precipitants to precipitate exosomes from solution. While this method is simple to operate, its main drawbacks are interference from the precipitant in downstream analysis, and the co-precipitation of non-exosome particles (including proteins and polymers) leading to a decrease in exosome separation rate. Immunosorbent assays typically utilize antibodies modified on microspheres or microstructures to bind to specific antigens on the surface of exosomes. While this method offers high separation efficiency, its reagent costs are prohibitively high, and identifying corresponding antibody-antigen pairs is essential before identifying different types of exosomes. Inertial flow and viscoelastic flow, on the other hand, leverage the mechanical properties of exosomes in fluids for separation. The biggest advantage of these methods is their high throughput, allowing for the processing of large numbers of samples in a short time. However, their resolution is limited; separation becomes impossible when the particle size is too small.

[0005] Besides exosomes, the separation of particles such as proteins, bacteria, viruses, and circulating tumor cells often faces limitations similar to those of the separation methods mentioned above. Therefore, there is an urgent need to find methods that can achieve high throughput, high resolution, high recovery, and high purity to solve the aforementioned problems. Summary of the Invention

[0006] In view of the above-mentioned problems of the prior art, this application provides a nanofilter with self-cleaning function and a method of using it, which can not only achieve filtration and separation, but also achieve self-cleaning to ensure high throughput.

[0007] To achieve the above objectives, the first aspect of this application provides a nanofilter with self-cleaning function, comprising:

[0008] The lid has a container underneath it, and the lid and container form a sealed cavity. The lid has a sample inlet.

[0009] A filter membrane support is provided inside the cavity. The filter membrane support has a mesh support portion. A nanofiber filter membrane is fixed on the mesh support portion of the filter membrane support. The filter membrane support and the nanofiber filter membrane divide the cavity into upper and lower parts.

[0010] At least one bulk acoustic resonator, wherein the acoustic waves of the bulk acoustic resonator can be coupled with the fluid in the upper part of the cavity to generate an acoustic radiation force toward the nanofilter membrane and an acoustic drag force parallel to the nanofilter membrane at the surface of the nanofilter membrane, and to generate an acoustic radiation force of the nanofilter membrane within the pores of the nanofilter membrane.

[0011] The lower part of the cavity includes a vacuum chamber and a waste liquid chamber. The filter membrane has a through hole. The filter membrane support is connected to the waste liquid chamber at the through hole of the nanofilter membrane, and the filter membrane support has a valve plate at the through hole.

[0012] The vacuum chamber in the lower part of the cavity is located below the mesh support of the filter membrane holder;

[0013] The vacuum chamber and waste liquid chamber in the lower part of the cavity are respectively connected to the first vacuum pump and the second vacuum pump.

[0014] Therefore, this application can achieve filtration and separation functions, such as filtering and separating particles like exosomes, proteins, bacteria, viruses, and circulating tumor cells. Furthermore, by influencing the fluid in the upper part of the cavity through a bulk acoustic resonator, the fluid can be disturbed during filtration, reducing deposition on the filter membrane surface and minimizing the impact of deposition on the filter membrane surface and blockage inside the filter membrane pores, thus promoting durable and high-throughput filtration. Additionally, during the cleaning process, the bulk acoustic resonator generates acoustic radiation forces towards the nanofilter membrane and acoustic drag forces parallel to the nanofilter membrane at the nanofilter membrane surface, as well as acoustic radiation forces within the nanofilter membrane pores, removing or reducing particles and filter cake deposited on the filter membrane surface and inside the filter membrane pores, thereby restoring high-throughput filtration performance.

[0015] As one possible implementation of the first aspect, the bulk acoustic resonator is located on the lower surface of the cover and is uniformly distributed corresponding to the nanofiber membrane.

[0016] As described above, multiple uniformly distributed bulk acoustic resonators can effectively and uniformly act on the deposits on the surface of the nanofiltration membrane and inside the pores of the membrane, thereby removing or reducing the particles and filter cake deposited on the surface of the membrane and inside the pores.

[0017] As one possible implementation of the first aspect, the filter membrane support includes an upwardly facing snap-fit ​​portion that snaps into a washer, the lower end of which presses against the nanofiltration membrane.

[0018] As one possible implementation of the first aspect, the valve plate is controllably closed or opened to correspond to the nanofilter being in a filtration state or a self-cleaning state.

[0019] A second aspect of this application provides a method of using a nanofilter with a self-cleaning function, wherein the nanofilter, when in a filtration state, includes:

[0020] Close the valve plate at the through hole of the filter membrane holder and shut down the second vacuum pump connected to the waste liquid chamber;

[0021] Turn on the first vacuum pump connected to the vacuum chamber, and use negative pressure to filter the liquid entering through the inlet through the nanofiltration membrane.

[0022] As a possible implementation of the second aspect, when the nanofilter is in a self-cleaning state, it includes: closing the valve plate at the through hole of the filter membrane support corresponding to the filter membrane support, closing the second vacuum pump connected to the waste liquid chamber, and closing the first vacuum pump connected to the vacuum chamber;

[0023] The fluid entering the upper part of the cavity through the inlet is positioned above the nanofiltration membrane; the bulk acoustic resonator is activated, and the generated sound waves couple with the fluid in the upper part of the cavity, producing an acoustic radiation force towards the nanofiltration membrane and an acoustic drag force parallel to the nanofiltration membrane at the surface of the nanofiltration membrane, as well as an acoustic radiation force of the nanofiltration membrane within the pores of the nanofiltration membrane.

[0024] Open the valve plate at the through hole of the filter membrane holder, turn on the second vacuum pump connected to the waste liquid chamber, and use negative pressure to discharge the fluid in the upper part of the chamber into the waste liquid chamber.

[0025] As a possible implementation of the second aspect, when the nanofilter is in the filtering state, it further includes: activating the body acoustic resonator to operate, and the generated acoustic waves couple with the fluid in the upper part of the cavity to disturb the fluid in the upper part of the cavity. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the EXODUS ultra-fast separation system for detecting exosomes;

[0027] Figure 2a This is a cross-sectional view of a nanofilter with self-cleaning function provided in an embodiment of this application;

[0028] Figure 2b yes Figure 2a A schematic diagram of the filtrate and waste liquid trajectories during operation;

[0029] Figure 2c yes Figure 2a A schematic diagram of SMR in the image;

[0030] Figure 2d yes Figure 2a Schematic diagram of the filter membrane base;

[0031] Figure 2e yes Figure 2d A cross-sectional view of the filter membrane base shown;

[0032] Figure 2f yes Figure 2d The perspective view of the main view of the filter membrane base shown;

[0033] Figure 3 This is a schematic diagram of SMR acting on a filter membrane.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. SMR support; 2. SMR; 3. Vacuum chamber; 4. Filtrate outlet; 5. Waste liquid chamber and its outlet; 6. Filter membrane support; 7. Nanofiltration membrane; 8. Silicone gasket; 9. Rubber gasket; 10. PMMA gasket; 11. Sample inlet.

[0036] It should be understood that the dimensions and shapes of the blocks in the above structural diagrams are for reference only and should not constitute an exclusive interpretation of the embodiments of the present invention. The relative positions and inclusion relationships between the blocks presented in the structural diagrams are only schematic representations of the structural relationships between the blocks, and are not intended to limit the physical connection methods of the embodiments of the present invention. Detailed Implementation

[0037] The technical solutions provided in this application will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the system architecture and business scenarios provided in the embodiments of this application are mainly for illustrating possible implementations of the technical solutions of this application and should not be construed as the sole limitation on the technical solutions of this application. Those skilled in the art will recognize that the technical solutions provided in this application are equally applicable to similar technical problems as system architectures evolve and new business scenarios emerge.

[0038] It should be understood that in the various embodiments of the self-cleaning nanofilter provided in this application, since the principles of these technical solutions to solve the problem are the same or similar, some repeated parts may not be described again in the following description of specific embodiments, but it should be regarded as that these specific embodiments have referenced each other and can be combined with each other.

[0039] Unless otherwise defined, 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 belongs. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0040] Filtration is a label-free separation method based on the size of the target substance. Under pressure, the liquid to be separated is forced through a nanomembrane with a specific pore size. Substances smaller than the nanomembrane pore size pass through, while those larger are retained. Based on this principle, it can be divided into two types: dead-end filtration and tangential flow filtration. Specifically: In dead-end filtration, the fluid enters the nanopores perpendicular to the membrane surface, easily causing particles larger than the nanopore size to gradually accumulate on the membrane surface, forming a filter cake, i.e., fouling. With increasing filtration time, the filter cake layer thickness increases, leading not only to increased filtration pressure (transmembrane pressure) but also to a decrease in the recovery rate of the desired target substance in the filtrate. In tangential flow filtration, the fluid passes through the nanopores parallel to the membrane surface. During this process, the tangential flow helps to clean the filter cake from the membrane surface, thus preventing clogging. However, with increasing filtration cycles, the membrane will eventually fail due to clogging.

[0041] For example, Figure 1 A schematic diagram of an ultrafast separation system (EXODUS) for detecting exosomes is shown, wherein: Figure 1 The 'a' in the diagram illustrates the mechanism that generates periodic positive and negative pressure oscillations (AP, positive pressure; NP, negative pressure). Figure 1 Figure b shows a physical diagram of the EXODUS filter chamber, including: chamber; porous alumina (AAO) membrane; piezoelectric transducer (PZT); harmonic oscillator at the left outlet; base (NP to AP switch). Figure 1 The diagram in 'c' shows a schematic of the EXODUS resonator control module. Figure 1 The image shown in Figure d depicts a physical diagram of the EXODUS system with the EXODUS filter chamber installed. Figure 1 The figure 'e' shows the pressure change curve over time. The dynamic control of NP and AP is applied to the two outlets (L and R) of the EXODUS filter chamber. Figure 1 f in the diagram illustrates the active tuning of the resonator: low frequency (via positive and negative voltage switching) and high frequency (via piezoelectric transducer) on the EXODUS device.

[0042] Figure 1The technique described introduces dual-coupled harmonic oscillations into the nanomembrane to generate a self-cleaning method. By switching between positive and negative pressures (±30 kPa), periodic oscillations are generated on the nanomembrane, allowing particulate matter on the inner surface of the membrane to resuspend in the solution. Simultaneously, a piezoelectric transducer (PZT) is attached to the outer wall of the chamber, enabling acoustic waves to be coupled to the nanomembrane at a resonant frequency of 6250 Hz, causing the membrane to vibrate. In these two oscillation modes, the combination of acoustic waves and fluid inhibits the formation of fouling on the membrane surface, preventing a decrease in filtration flux due to clogging. This improves the processing speed, yield, and purity of exosome separation and purification. EXODUS applications include plasma, saliva, cell culture media, and tears. Furthermore, the performance of EXODUS has been demonstrated by processing urine samples from urinary tract cancer patients and control participants, followed by RNA sequencing (RNA-seq) with transcriptional profiling analysis.

[0043] The drawbacks of this technology are: the AAO membrane used is expensive and has weak mechanical properties, making it easily damaged under excessive pressure. In addition, although the AAO membrane has high porosity, it is also thick, about 50-60 μm, and the shape of the nanopores is irregular, with poor verticality and roughness inside the pores, which can easily cause blockage inside the pores, and the generated sound waves cannot clean the particles inside the pores.

[0044] Based on this, embodiments of this application provide a nanofilter with self-cleaning function, comprising:

[0045] The lid has a container underneath it, and the lid and container form a sealed cavity. The lid has a sample inlet.

[0046] A filter membrane support is disposed within the cavity. The filter membrane support has a mesh support portion, on which a nanofiltration membrane is fixed. The filter membrane support and the nanofiltration membrane divide the cavity into upper and lower parts. In some embodiments, the filter membrane support includes an upwardly facing snap-fit ​​portion, which snaps a washer in place. The lower end of the washer presses against the nanofiltration membrane.

[0047] At least one bulk acoustic resonator is provided, the sound waves of which can couple with the fluid in the upper part of the cavity, generating an acoustic radiation force toward the nanofilter membrane and an acoustic drag force parallel to the nanofilter membrane at the surface of the nanofilter membrane, as well as an acoustic radiation force of the nanofilter membrane within the pores of the nanofilter membrane. In some embodiments, the bulk acoustic resonators are located on the lower surface of the cover and are uniformly distributed corresponding to the nanofilter membrane. By using a plurality of uniformly distributed bulk acoustic resonators, deposits on the surface of the nanofilter membrane and inside the pores of the membrane can be effectively and uniformly acted upon, thereby removing or reducing particles and filter cake deposited on the surface of the membrane.

[0048] The lower portion of the cavity includes a vacuum chamber and a waste liquid chamber. The filter membrane has a through-hole, and the filter membrane support is connected to the waste liquid chamber at the through-hole of the nanofilter membrane. The filter membrane support also has a valve plate at the through-hole. In some embodiments, the valve plate is controllably closed or opened to correspond to the nanofilter being in a filtration state or a self-cleaning state.

[0049] The vacuum chamber in the lower part of the cavity is located below the mesh support of the filter membrane holder.

[0050] The vacuum chamber and waste liquid chamber in the lower part of the cavity are respectively connected to the first vacuum pump and the second vacuum pump.

[0051] This application correspondingly provides a method for using the aforementioned self-cleaning nanofilter, wherein the nanofilter can be in a filtration state and a self-cleaning state, as detailed below:

[0052] When in filtration mode, the valve plate at the through hole of the filter membrane support is closed, and the second vacuum pump connected to the waste liquid chamber is closed; the first vacuum pump connected to the vacuum chamber is turned on, and the liquid entering through the inlet is filtered through the nanofiltration membrane by negative pressure.

[0053] In self-cleaning mode, firstly, the valve plate at the through hole of the filter membrane support is closed, the second vacuum pump connected to the waste liquid chamber is closed, and the first vacuum pump connected to the vacuum chamber is closed; the fluid entering the upper part of the cavity through the inlet is positioned above the nanofiltration membrane; the bulk acoustic resonator is activated, and the generated sound waves couple with the fluid in the upper part of the cavity, generating an acoustic radiation force towards the nanofiltration membrane and an acoustic drag force parallel to the nanofiltration membrane at the surface of the nanofiltration membrane, as well as an acoustic radiation force of the nanofiltration membrane within the pores of the nanofiltration membrane; after a period of time, the valve plate at the through hole of the filter membrane support is opened, and the second vacuum pump connected to the waste liquid chamber is turned on, using negative pressure to discharge the fluid in the upper part of the cavity into the waste liquid chamber.

[0054] In some embodiments, when in the filtration state, the bulk acoustic resonator can also be activated, and the generated sound waves couple with the fluid in the upper part of the cavity, disturbing the fluid in the upper part of the cavity, thereby reducing the deposition on the filter membrane surface and inside the filter membrane pores, reducing the impact of deposition on the filter membrane surface, and facilitating the longevity of the filtration function and high throughput.

[0055] Therefore, the nanofilter of this application can achieve filtration and separation functions, such as filtering and separating particles like exosomes, proteins, bacteria, viruses, and circulating tumor cells. Furthermore, by influencing the fluid in the upper part of the cavity through a bulk acoustic resonator, the fluid can be disturbed during the filtration process, reducing deposition on the filter membrane surface and inside the filter membrane pores. This minimizes the impact of deposition on the filter membrane surface, promoting durable filtration and high throughput. Additionally, during the cleaning process, the bulk acoustic resonator generates acoustic radiation forces towards the nanofilter membrane and acoustic drag forces parallel to the nanofilter membrane at the nanofilter membrane surface, as well as acoustic radiation forces within the nanofilter membrane pores, removing or reducing particles and filter cake deposited on the filter membrane surface, thereby restoring high-throughput filtration performance.

[0056] In some embodiments, the provided self-cleaning nanofilter, comprising a bulk acoustic resonator (SMR) and a vacuum pump, combined with a polycarbonate (PC) nanomembrane, is capable of separating particles with sizes ranging from 30 to 2000 nm (e.g., exosomes, proteins, bacteria, viruses, circulating tumor cells, etc.) from various bodily fluid samples. It features high throughput, high purity, and high recovery rate, meeting clinical needs. Simultaneously, the acoustic fluid generated by the coupling of sound waves and fluid can automatically clean particles clogging the membrane surface and interior, improving the filtration efficiency and reusability of the membrane.

[0057] To achieve filtration of particles ranging from 30 to 2000 nm in size while meeting the requirements of high throughput, high purity, and high recovery rate, a bulk acoustic resonator (SMR) can be integrated with a polycarbonate (PC) membrane. Integration can be achieved by combining the filter membrane with an SMR array to achieve high-throughput filtration. In this integration, the coupling between the SMR array and the filter membrane cleans the membrane surface and the interior of the pores through acoustic flow, and the combined acoustic flow can screen particles of different sizes. In other embodiments, the integration method can be rotary centrifugal, where the filter membrane itself can rotate. Combined with the acoustic flow cleaning effect of the SMR, this rotary integration method uses a micro-rotating motor to drive the filter module to rotate, forming a radial tangential flow on the filter membrane surface, which can effectively clear blockages. In other embodiments, the integration method can also be non-rotational, where a unidirectional tangential flow is combined with acoustic flow. In this non-rotational integration method, the tangential flow is formed solely by fluid action.

[0058] During filtration, the SMR is intermittently turned on and off. When on, the acoustic jet cleans the membrane surface of blockages (due to large particles being larger than the pore size and unable to pass through the membrane) and the interior of the pores of blockages (caused by the aggregation of small particles). Large particles on the membrane surface are cleared into the waste liquid chamber under shear force, while blockages inside the pores are flushed out by the jet. After the blockages are cleared, the SMR is turned off, and filtration continues.

[0059] The SMR structure used in this invention mainly includes upper and lower electrodes and a piezoelectric layer in the middle. It utilizes the inverse piezoelectric effect, whereby a high-frequency electrical signal is applied to the upper and lower electrodes, which is then converted into high-frequency mechanical vibration, ultimately generating sound waves. The generated high-frequency sound waves (0.5GHz-10GHz) exist in the fluid as pressure waves, producing sound pressure and acoustofluid effects. The coupling between the sound waves and the fluid manifests as acoustic radiation force and acoustic drag force. In this invention, the jet generated by the acoustic radiation force is mainly utilized to interact with the filter membrane, thereby cleaning the surface and internal dirt of the nanopores.

[0060] like Figures 2a-2f This diagram illustrates a self-cleaning nanofilter and its components according to another embodiment of this application. The filter module, from top to bottom, consists of an SMR support 1, an SMR 2 mounted inside the support, an upper PMMA gasket 10 and a silicone gasket 8 pressing the filter membrane 7 together to secure it, and a bottom filter membrane support 6 supporting the filter membrane 7. Filtrate can enter the lower vacuum chamber 3 through the slot. A rubber gasket 9 is placed between the filter module and the vacuum chamber 3 to maintain a certain vacuum level within the chamber. Below the filter membrane support 6 is a waste liquid chamber 5, from which large particles can be discharged. The vacuum module consists of a vacuum pump and a PU gas tube. Filtrate is collected from the filtrate outlet 4. The SMR is mounted inside the top SMR support 1, and the sample inlet 11 is located on one side of the SMR support 1.

[0061] like Figure 3 This illustration shows a schematic diagram of the SMR acting on the filter membrane in a self-cleaning nanofilter provided in an embodiment of this application. Figure 3 In the diagram, the vertically downward arrows represent acoustic radiation force, and the circular arrows represent acoustic drag force. The horizontal arrows represent large particles moving from the membrane surface into the waste liquid chamber.

[0062] Experiments have shown that this application can accurately separate particles with sizes ranging from 30 to 2000 nm. By using acoustic flow to clean the filter membrane surface and the interior of the nanopores to remove blockages, the transmembrane pressure is reduced. The flux is 200 μL / min, the recovery rate can reach over 90%, and the purity can reach over 95%. It truly achieves the goals of high flux, high recovery rate, and high purity. Moreover, the filter membrane can work for a long time without serious blockage, reducing the cost of filter membrane replacement.

[0063] The terms "first, second, third, etc." or similar terms such as module A, module B, and module C used in the specification and claims are only used to distinguish similar objects and do not represent a specific ordering of objects. It is understood that a specific order or sequence may be interchanged where permitted so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0064] In the above description, the labels of the steps involved, such as S110, S120, etc., do not mean that the steps will necessarily be executed. The order of the steps can be interchanged or executed simultaneously if permitted.

[0065] The term "comprising" as used in the specification and claims should not be construed as limiting itself to what follows; it does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the mentioned feature, integral, step, or component, but does not exclude the presence or addition of one or more other features, integrals, steps, or components, or groups thereof. Thus, the statement "device comprising means A and B" should not be limited to a device consisting solely of components A and B.

[0066] The terms "an embodiment" or "an embodiment" as used in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in at least one embodiment of this application. Therefore, the terms "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics can be combined in any suitable manner, as will be apparent to those skilled in the art from this disclosure.

[0067] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, all of which fall within the scope of protection of this application.

Claims

1. A nanofilter with self-cleaning function, characterized in that, include: The lid has a container underneath it, and the lid and container form a sealed cavity. The lid has a sample inlet. A filter membrane support is provided inside the cavity. The filter membrane support has a mesh support portion. A nanofiber filter membrane is fixed on the mesh support portion of the filter membrane support. The filter membrane support and the nanofiber filter membrane divide the cavity into upper and lower parts. At least one bulk acoustic resonator, wherein the high-frequency acoustic waves of 0.5GHz-10GHz generated by the bulk acoustic resonator are coupled to the fluid in the upper part of the cavity, and an acoustic radiation force toward the nanofilter membrane and an acoustic drag force parallel to the nanofilter membrane are generated at the surface of the nanofilter membrane, and the jet generated by the acoustic radiation force acts inside the pores of the nanofilter membrane. The bulk acoustic resonator is located on the lower surface of the cover and is uniformly distributed corresponding to the nanofiber membrane; The lower part of the cavity includes a vacuum chamber and a waste liquid chamber. The filter membrane has a through hole. The filter membrane support is connected to the waste liquid chamber at the through hole of the nanofilter membrane. The filter membrane support has a valve plate at the through hole. The valve plate is controllably closed or opened to correspond to the nanofilter being in a filtering state or a self-cleaning state. The vacuum chamber in the lower part of the cavity is located below the mesh support of the filter membrane holder; The vacuum chamber and waste liquid chamber in the lower part of the cavity are respectively connected to the first vacuum pump and the second vacuum pump.

2. The nanofilter according to claim 1, characterized in that, The filter membrane support includes an upwardly facing snap-fit ​​portion, which snaps a washer in place, and the lower end of the washer presses the nanofiltration membrane against the filter membrane.

3. A method of using a nanofilter with self-cleaning function as described in claim 1 or 2, characterized in that, When the nanofilter is in filtration mode, it includes: Close the valve plate at the through hole of the filter membrane holder and shut down the second vacuum pump connected to the waste liquid chamber; Turn on the first vacuum pump connected to the vacuum chamber, and use negative pressure to filter the liquid entering through the inlet through the nanofiltration membrane; When the acoustic resonator is activated, the generated sound waves couple with the fluid in the upper part of the cavity, disturbing the fluid in the upper part of the cavity.

4. The method of use according to claim 3, characterized in that, When the nanofilter is in a self-cleaning state, it includes: Close the valve plate at the through hole of the filter membrane holder, close the second vacuum pump connected to the waste liquid chamber, and close the first vacuum pump connected to the vacuum chamber; The fluid entering the upper part of the cavity through the inlet is positioned above the nanofiltration membrane; When the body acoustic resonator is activated, the generated sound waves couple with the fluid in the upper part of the cavity, producing an acoustic radiation force towards the nanofiltration membrane and an acoustic drag force parallel to the nanofiltration membrane at the surface of the nanofiltration membrane, as well as an acoustic radiation force of the nanofiltration membrane within the pores of the nanofiltration membrane. Open the valve plate at the through hole of the filter membrane holder, turn on the second vacuum pump connected to the waste liquid chamber, and use negative pressure to discharge the fluid in the upper part of the chamber into the waste liquid chamber.

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