Pathogen separation device based on acoustic microfluidics and preparation method thereof

Abstract

The invention relates to a pathogen separation device based on acoustic microfluidics and a preparation method thereof. The pathogen separation device comprises an ultrasonic transducer, a bottom glass layer, a bottom glass gasket, a glass separation sheet, a top glass gasket, a PDMS layer and a top glass layer from bottom to top. According to the invention, sheath flow consumption for extruding a sample flow can be reduced, acoustic standing waves in the vertical direction can be effectively generated, a pressure node is located in the middle of a fluid channel, efficient separation of particles and cells is promoted, and the device has practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of microfluidics, and particularly relates to a pathogen separation device based on acoustic microfluidics and a preparation method thereof. Background Art

[0002] The separation and purification of micron-sized particles and cells are key steps in biological and biomedical research, especially in cell therapy, environmental monitoring, and pathogen detection. Microfluidic technology has become a core technology for separating and manipulating biomolecules and cells due to its ability to precisely control the separation force. Currently, a variety of microfluidic separation methods have been developed, including inertial separation, hydrodynamic filtration, electrokinetics, dielectrophoresis, magnetophoresis, optical tweezers, and acoustofluidics. Among them, acoustofluidic technology has received extensive attention due to its non-contact, unlabeled, high biocompatibility, and flexible adjustment of acoustic wave parameters.

[0003] Acoustofluidic technology uses acoustic radiation force to manipulate particles and cells in the micron to submillimeter scale and is suitable for cell and particle separation. However, there is a problem of insufficient throughput in cell sorting, usually less than 1 mL / min, which is difficult to meet the needs of large-scale applications such as cell-based therapy, environmental monitoring, and foodborne pathogen detection. Although several high-throughput acoustic separation technologies have been developed, which can process samples of about 10 mL / min, developing a high-throughput and biocompatible acoustic separation device that can process large-volume samples is still an important research direction. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a pathogen separation device based on acoustic microfluidics and a preparation method thereof. The device can reduce the sheath flow consumption for squeezing the sample flow and effectively generate a vertical acoustic standing wave with a pressure node in the middle of the fluid channel, which promotes the efficient separation of particles and cells and has practical application value.

[0005] The present invention provides a pathogen separation device based on acoustic microfluidics. The pathogen separation device includes an ultrasonic transducer, a bottom glass layer, a bottom glass gasket, a glass separation sheet, a top glass gasket, a PDMS layer, and a top glass layer from bottom to top.

[0006] Further, the bottom glass layer, the bottom glass gasket, the glass separation sheet, the top glass gasket, the PDMS layer, and the top glass layer form a separation chamber with a single wide and shallow microchannel inside.

[0007] Further, the ultrasonic transducer is bonded to the separation chamber by epoxy resin.

[0008] Further, the bottom glass layer, the bottom glass gasket, the glass separation sheet, and the top glass gasket are laminated by a UV adhesive to obtain a multi-layer structure A.

[0009] Further, the PDMS layer and the top glass layer are bonded by plasma bonding to obtain a multi-layer structure B.

[0010] The present invention also provides a method for preparing a pathogen separation device based on acoustic microfluidics, comprising the following steps:

[0011] (1) Five glass plates with different shapes are processed by laser cutting to obtain a bottom glass layer, a bottom glass gasket, a glass separation sheet, a top glass gasket and a top glass layer;

[0012] (2) The bottom glass layer, the bottom glass washer, the glass separation sheet and the top glass washer are laminated with UV glue to obtain a multi-layer structure A;

[0013] (3) The PDMS is bonded to the top glass layer by plasma bonding, and the PDMS at the holes of the top glass plate is removed by a punch to obtain a multi-layer structure B;

[0014] (4) The multi-layer structure A and the multi-layer structure B are bonded by plasma to form a separation chamber with a single wide and shallow microchannel inside;

[0015] (5) The piezoelectric transducer is bonded to the bottom of the separation chamber with epoxy resin to obtain a pathogen separation device based on acoustic microfluidics.

[0016] Beneficial effects

[0017] The present invention can reduce the sheath flow consumption for squeezing the sample flow, effectively generate acoustic standing waves in the vertical direction, with the pressure node located in the middle of the fluid channel, promoting the efficient separation of particles and cells, and has practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a top view of the pathogen separation device based on acoustic microfluidics of the present invention.

[0019] Figure 2 It is a three-dimensional structure display diagram of the pathogen separation device based on acoustic microfluidics of the present invention.

[0020] Figure 3 It is a front view of the pathogen separation device based on acoustic microfluidics of the present invention.

[0021] Figure 4 It is a separation principle diagram of the pathogen separation device based on acoustic microfluidics of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0023] Example 1

[0024] This embodiment provides a pathogen separation device based on acoustic microfluidics. The pathogen separation device includes, from bottom to top, an ultrasonic transducer, a bottom glass layer, a bottom glass gasket, a glass separation sheet, a top glass gasket, a PDMS layer, and a top glass layer, as Figure 2 shown. As Figure 1 shown, when particles enter the channel, they will be subject to an acoustic radiation force in the vertical direction. When the ultrasonic transducer operates at its resonance frequency, the PDMS layer and the fluid channel form an acoustic standing wave in the vertical direction, and the pressure node (minimum value) is higher than half of the channel height. PDMS is selected because its impedance matches very well with the impedance of water, which makes the sound field roughly the same as the sound field without the PDMS layer. Therefore, the height of the fluid channel can be reduced without affecting the distribution of the half-wavelength acoustic resonance sound field between the top glass plate and the bottom glass plate, which indicates that the consumption of the sheath flow can be reduced, thereby forming a laminar flow between the top glass plate and the bottom glass plate. Buffer and sample. In addition, PDMS is a widely used material in microfluidics and has excellent biocompatibility.

[0025] This embodiment provides a preparation method for a pathogen separation device based on acoustic microfluidics, including the following steps:

[0026] Five glass plates (22×56mm) with different shapes are processed by laser cutting, including a bottom glass layer (thickness: 1mm), a bottom glass gasket (thickness: 300μm), a glass separation sheet (thickness: 100μm), a top glass gasket (thickness: 200μm), and a top glass layer (thickness: 1.5mm).

[0027] First, the bottom glass layer, the bottom glass washer, the glass separator, and the top glass washer are laminated with UV glue to obtain a multi-layer structure A. Secondly, a layer of PDMS is bonded to the top glass by plasma bonding, and the PDMS at the holes of the top glass plate is removed by a punch to obtain a multi-layer structure B. Thirdly, the multi-layer structures obtained in the above two steps are plasma-bonded together to form a separation chamber with a single wide and shallow microchannel (100mm×40mm×0.7mm) inside. Finally, a 20mm×20mm×2mm piezoelectric transducer is bonded to the bottom of the fluid chamber with epoxy resin to obtain a pathogen separation device based on acoustic microfluidics.

[0028] The pathogen separation device of the present invention is mounted on a thermally conductive silicone sheet to ensure close contact. The temperature is monitored by a K-type thermocouple detector and maintained at 25 °C using a Peltier element. The sample and buffer solution are delivered by an injection pump at a flow rate of 15 mL / min. The acoustic transducer is driven by a radio frequency signal generator and a power amplifier. The resonance frequency of the acoustic transducer after being bonded to the fluid chamber is measured using an impedance analyzer.

[0029] The pathogen separation device of the present invention realizes rapid, efficient and biocompatible separation by introducing a PDMS layer into the microfluidic channel. The device adds a PDMS layer between two opposing glass slides, reducing the consumption of sheath fluid while decreasing the height of the fluid channel. Using a layer-by-layer assembly manufacturing process, a half-wavelength resonance can be formed between the fluid channel and the PDMS layer, thereby achieving efficient separation.

[0030] The device is assembled layer by layer from glass slides and PDMS films. Since the impedance of PDMS is very close to that of water, PDMS serves as the fluid boundary while the glass wall serves as the acoustic boundary. In this way, the consumption of sheath flow used to squeeze the sample flow can be reduced, and an acoustic standing wave in the vertical direction can be effectively generated, with the pressure node located in the middle of the fluid channel. This method promotes the efficient separation of particles and cells and has practical application value.

[0031] In summary, the pathogen separation device is applicable to high-throughput and biocompatible particle and cell separation applications through a simple manufacturing method.

Claims

1. A pathogen separation device based on acoustic microfluidics, characterized in that: The pathogen separation device includes, from bottom to top, an ultrasonic transducer, a bottom glass layer, a bottom glass gasket, a glass separation sheet, a top glass gasket, a PDMS layer, and a top glass layer.

2. The pathogen isolation device according to claim 1, characterized in that: The bottom glass layer, the bottom glass gasket, the glass separation sheet, the top glass gasket, the PDMS layer, and the top glass layer form a separation chamber with a single wide and shallow microchannel inside.

3. The pathogen isolation device according to claim 2, wherein: The ultrasonic transducer is bonded to the separation chamber with epoxy resin.

4. The pathogen separation device according to claim 1, wherein: The bottom glass layer, the bottom glass gasket, the glass separation sheet, and the top glass gasket are laminated with a UV adhesive layer to obtain a multi-layer structure A.

5. The pathogen separation device according to claim 1, wherein: The PDMS layer and the top glass layer are bonded by plasma bonding to obtain a multi-layer structure B.

6. A preparation method of a pathogen separation device based on acoustic microfluidics, comprising the following steps: (1) Five glass plates with different shapes are processed by laser cutting to obtain a bottom glass layer, a bottom glass gasket, a glass separation sheet, a top glass gasket, and a top glass layer; (2) The bottom glass layer, the bottom glass washer, the glass separation sheet, and the top glass washer are laminated with a UV adhesive layer to obtain a multi-layer structure A; (3) PDMS is bonded to the top glass layer by plasma bonding, and the PDMS at the hole of the top glass plate is removed by a punch to obtain a multi-layer structure B; (4) The multi-layer structure A and the multi-layer structure B are bonded by plasma to form a separation chamber with a single wide and shallow microchannel inside; (5) A piezoelectric transducer is bonded to the bottom of the separation chamber with epoxy resin to obtain a pathogen separation device based on acoustic microfluidics.

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