CN219218041U

CN219218041U - Microfluidic electrophysiological chip containing flexible electrode

Info

Publication number: CN219218041U
Application number: CN202223327916.7U
Authority: CN
Inventors: 吕品; 王子杰; 潘挺睿
Original assignee: Suzhou Institute Of Higher Studies University Of Science And Technology Of China
Current assignee: Suzhou Institute Of Higher Studies University Of Science And Technology Of China
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2023-06-20
Anticipated expiration: 2032-12-13

Abstract

The utility model discloses a microfluidic electrophysiological chip containing a flexible electrode, which mainly comprises a bottom plate, a flexible microelectrode array and a cell chamber plate; the cell chamber plate is fixed on the bottom plate and forms a sealed chamber with a perfusion channel communicated with the outside through a micro-chamber, a micro-channel and a through hole on the bottom plate; the microelectrode array point of the metal electrode of the flexible microelectrode array is positioned in the sealed cavity, and the lead port is exposed on the surface of the microfluidic electrophysiology chip. The utility model has a sealing chamber for culturing cells, which not only can realize continuous dynamic perfusion and electric information collection of cells cultured in the sealing chamber, but also can effectively avoid the problem of liquid leakage caused by dynamic perfusion and realize reliable sealing.

Description

Microfluidic electrophysiological chip containing flexible electrode

Technical Field

The utility model belongs to the technical field of electrophysiological information acquisition of cells in biomedical engineering, and particularly relates to a microfluidic electrophysiological chip containing a flexible electrode.

Background

The research of cell electrophysiology is of great significance to the exploration of the synergistic effect of cell populations, the disclosure of information transmission among cells and the development of medicines. The traditional electrophysiological signal detection means mainly comprise a patch clamp mode and a microelectrode array (MEA) mode. Most patch clamps mainly comprise metal microfilaments and glass electrodes, and have the defects of small detection channel number and complicated operation.

Along with the development of micro-electromechanical systems (MEMS), the processing technology is more advanced, and the micro-electrode array can be easily prepared by adopting the MEMS technology at present, so that the high-resolution detection of electrophysiological cells can be realized, the experimental steps can be greatly simplified, and the number of detection channels can be increased. In the prior art, electrophysiological signal detection means based on microelectrode arrays are mainly realized through MEA plates, and the MEA plates are mainly used for transmitting and detecting single cell action potential change conditions and local field potentials of a plurality of cells. The MEA plate is manufactured by depositing metal on a glass plate through MEMS processing, and forming a passivation layer, an electrode and a lead, and the manufacturing process is complex. Currently, commercial cell culture vessels containing MEA plates are typically of open construction, which makes it difficult to achieve a real-time dynamic perfusion of the culture fluid in the cells, and since the environment in which the cells are cultured on the MEA plates is open, it is also susceptible to environmental factors. At present, though a sealed cell culture cavity can be obtained through bonding of a microfluidic chip and an MEA plate to realize real-time dynamic perfusion of cells cultured in the cell culture cavity, the cell culture cavity is limited by a bonding technology, and liquid leakage phenomenon often occurs at a part containing an electrode connecting line, so that reliable sealing is difficult to realize.

Disclosure of Invention

In order to solve the problems, the utility model provides a micro-fluidic electrophysiological chip containing a flexible electrode, wherein the chip adopts a flexible microelectrode array to replace a traditional MEA plate, and the flexible microelectrode array is packaged in the micro-fluidic chip by using a bonding process, and a sealed cavity which can be used for culturing cells is arranged in the chip, so that continuous dynamic perfusion and electric information acquisition of cells cultured in the sealed cavity can be realized, the problem of liquid leakage caused by dynamic perfusion can be effectively avoided, and reliable sealing is realized.

The utility model discloses a microfluidic electrophysiological chip containing a flexible electrode, which mainly comprises a bottom plate, a flexible microelectrode array and a cell chamber plate; the bottom plate is provided with a groove for placing the flexible microelectrode array; the flexible microelectrode array is arranged in the groove and comprises a flexible substrate and metal electrodes, microelectrode array points and lead ports are respectively arranged at two ends of each metal electrode, and the other parts except the microelectrode array points and the lead ports are covered in the flexible substrate; the cell chamber plate comprises a micro-chamber and at least two micro-channels which are arranged on the surface adjacent to the bottom plate, and at least two through holes which are communicated with the cell chamber plate, wherein one end of each micro-channel is connected with the micro-chamber, and the other end of each micro-channel is correspondingly connected with one through hole; the cell chamber plate is fixed on the bottom plate and forms a sealed chamber with a perfusion channel communicated with the outside through the micro-chamber, the micro-channel and the through hole; the microelectrode array point of the metal electrode is positioned in the sealed cavity, and the lead port is exposed on the surface of the microfluidic electrophysiological chip.

Optionally, the shape and the size of the groove are consistent with those of the flexible microelectrode array, and the depth of the groove is basically consistent with the thickness of the flexible microelectrode array.

Optionally, the bottom plate and the cell chamber plate are made of any one of polymethyl methacrylate, polycarbonate, polystyrene and cycloolefin copolymer materials.

Optionally, the flexible substrate is made of a biocompatible material.

Optionally, the material of the flexible substrate is any one of polyethylene terephthalate, polyimide and polyethylene naphthalate.

Optionally, an outer included angle formed between the side wall connected with the channel and the micro-channel in the micro-chamber is greater than 90 degrees.

Optionally, the micro-chamber is a regular hexagon, and the pouring channels are respectively arranged at two opposite vertex angles of the regular hexagon.

Optionally, the micro-channels have two, and the through holes have two, so as to form two filling channels, one inlet and one outlet.

Optionally, the microelectrode array point of the metal electrode is located at the midpoint of the sealed chamber.

Optionally, the flexible microelectrode array is fixed in a groove of the cell chamber plate by solvent bonding; the bottom plate and the cell chamber plate are fixedly connected in a solvent bonding mode.

The micro-fluidic electrophysiological chip containing the flexible electrode has the following beneficial effects:

(1) According to the utility model, the flexible microelectrode array is packaged in the microfluidic chip, so that dynamic perfusion can be performed when cells are cultured in the sealed chamber, and electrophysiological information of the cells in the micro chamber can be acquired through the flexible microelectrode array; in addition, most of the metal electrodes of the flexible microelectrode array in the microfluidic electrophysiological chip are coated in the flexible substrate, so that the problem of liquid leakage caused by long-term dynamic pouring can be effectively avoided, and the service life of the chip is greatly prolonged.

(2) The utility model can fix the flexible substrate of the flexible microelectrode array in the groove of the bottom plate in a solvent bonding mode and the like, and form strong adhesion between the flexible substrate and the bottom plate and between the flexible substrate and the cell chamber plate, thereby further improving the sealing effect and the reliability.

(3) The micro-fluidic electrophysiological chip adopts a relatively closed sealed cavity to culture cells, and is not polluted by external air and environment.

Drawings

FIG. 1 is a schematic structural diagram of a microfluidic electrophysiological chip;

FIG. 2 is an exploded view of a microfluidic electrophysiological chip;

FIG. 3 is a schematic diagram of the structure of a flexible microelectrode array;

FIG. 4 is a schematic view of the structure of a cell chamber plate;

the drawings are marked: 1-bottom plate, 11-groove, 2-flexible microelectrode array, 21-flexible substrate, 22-metal electrode, 221-microelectrode array spot, 221-lead port, 3-cell chamber plate, 31-microcavity, 32-microchannel, 33-through hole.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described below with reference to specific embodiments and drawings, and it is apparent that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, if terms indicating an azimuth or a positional relationship such as "upper", "lower", "inner", "outer", etc., are presented, they are based on the azimuth or the positional relationship shown in the drawings, only for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element in question must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present utility model. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion, but may include other elements not expressly listed or inherent to such product or apparatus.

Referring to fig. 1 to 4, a microfluidic electrophysiological chip with a flexible electrode is disclosed in the embodiment, and mainly comprises a bottom plate 1, a flexible microelectrode array 2 and a cell chamber plate 3. The base plate 1 is a plate-like structure made of PMMA (polymethyl methacrylate) plate, and in other embodiments, the base plate 1 may be made of PC (polycarbonate), PS (polystyrene), COC (cyclic olefin copolymer) or the like, as long as solvent bonding is achieved. The middle part of the bottom plate 1 is provided with a groove 11. The grooves 11 may in particular be formed using micro-milling finishing, the grooves 11 being used for placing the flexible microelectrode array 2. Preferably, the shape and size of the groove 11 and the flexible microelectrode array 2 are matched to avoid shaking and displacement of the flexible microelectrode array 2. The depth of the grooves 11 on the base plate is also substantially the same as the thickness of the flexible microelectrode array 2, for example, the flexible microelectrode array is about 50 μm thick and the depth of the grooves is also 50 μm, thereby ensuring the sealing property after bonding.

The flexible microelectrode array 2 can be fixed in the groove 11 of the PMMA bottom plate 1 in a solvent bonding mode and is used for collecting electric signals during cell culture. As shown in fig. 3, the flexible microelectrode array 2 mainly includes a flexible substrate 21 and a metal electrode 22 formed on the flexible substrate, and two ends of the metal electrode 22 may be respectively designed into a circular arc shape and a rectangular shape for distinguishing, wherein the circular arc end is provided with a plurality of microelectrode array points 221 and a rectangular end lead port 222. Each microelectrode array spot 221 (abbreviated as "electrode spot") represents a detection channel, and the number of electrode spots can be designed according to the detection requirements, and in an embodiment, the metal electrode contains 9 electrode spots, i.e. 9 detection channels. The lead port 222 is used to connect with an external electrophysiological instrument to transmit the acquired signals to the electrophysiological instrument. Therefore, only one end of the electrode point is required to be packaged in the microfluidic chip. The flexible substrate 21 may be made of biocompatible materials such as PI (polyimide), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate).

Taking flexible PI material as an example, when the flexible microelectrode array 2 is manufactured, a layer of metal electrode 22 is deposited on the flexible PI substrate, then a layer of PI material is spin-coated on the surface of the metal electrode 22, the metal electrode 22 is coated in the flexible PI material, and then the electrode array point 221 and the lead port 222 are exposed through a photolithography process.

The cell chamber plate 3 has a plate-like structure made of PMMA (polymethyl methacrylate) material, and in other embodiments, the cell chamber plate 3 may be made of PC (polycarbonate), PS (polystyrene), COC (cyclic olefin copolymer) or the like, as long as solvent bonding is achieved. As shown in fig. 4, a micro-chamber 31 and two micro-channels 32 are formed on the back surface of the cell chamber plate 3, that is, the surface adjacent to the PMMA bottom plate 1, two through holes 33 are further formed on the cell chamber plate 3, the through holes 33 penetrate through the front and back surfaces of the cell chamber plate 3, one end of each micro-channel 32 is communicated with the micro-chamber 31, and the other end of each micro-channel 32 is connected with one through hole 33. In use, cells and culture medium enter through the through-holes 33 and are poured into the microcavities 31 through the microchannels 32. The cell chamber plate 3 may be fixed to the surface of the base plate 1 by solvent bonding or the like, and at least the circular arc end of the flexible microelectrode array 2 including the microelectrode array spot 221 should be covered so that the microelectrode array spot 221 is located in the microcavity 31. After encapsulation, a relatively closed sealed chamber is formed between the cell chamber plate 3 and the bottom plate 1 at the micro chamber 31, one through hole 33 is used as an inlet, the other through hole 33 is used as an outlet, and two perfusion channels for communicating the sealed chamber with the outside are formed one by one for culturing cells. Preferably, the microchannel 32 forms an angle A with the side wall of the microcavity 31 (the side wall directly connected to the microchannel 32) of greater than 90 to prevent dead volume (i.e., liquid not flowing in the container) from occurring in the microcavity. In this embodiment, the micro chamber 31 is in a regular hexagonal design, and in other embodiments, the micro chamber 31 may have a circular shape or an oval shape. It should be noted that the electrode array spot 221 in the flexible microelectrode array should be located as centrally as possible in the chip chamber after packaging, so that the electrode spot can contact more cells in the chamber. In this embodiment, the bottom plate 1 and the cell chamber plate 3 are both rectangular plate structures, the length of the cell chamber plate 3 is consistent with the width of the bottom plate 1, and when in packaging, the edges of the two plates can be aligned, i.e. the long side of the cell chamber plate 3 is aligned with the short side of the bottom plate 1, so as to realize rapid alignment, and ensure that the electrode point is in the middle position of the micro chamber 31. In other embodiments, the bottom plate 1 and the cell chamber plate 3 may have other shapes, and the two plates may be aligned quickly by providing alignment marks or the like.

The preparation method of the microfluidic electrophysiological chip in the embodiment is as follows:

as shown in fig. 2 and 3, first, the bottom plate 1 having the grooves 11 and the cell chamber plate 3 having the micro-chambers 31, the micro-channels 32 and the through-holes 33 are processed using PMMA material by a milling machine. Wherein the shape of the groove 11 is matched with the shape of the flexible microelectrode array 2 to be embedded; the depth of the recess 11 is 50 μm, matching the thickness of the 50 μm flexible electrode. The bottom plate 1 and the cell chamber plate 3 are both rectangular plate-shaped structures with the thickness of 2mm, the length of the cell chamber plate 3 is consistent with the width of the bottom plate 1, and when the cell chamber plate 3 and the cell chamber plate are assembled, the edge alignment of the cell chamber plate 3 and the cell chamber plate is ensured as much as possible, and the electrode array point 221 of the flexible microelectrode array 2 placed in the groove 11 after the edge alignment is positioned in the center of the micro chamber 31 as shown in fig. 1. The micro-chamber 31 in the cell chamber plate 3 adopts a regular hexagonal design with a side length of 5mm and a depth of 500 μm; the microchannel 32 has a width of 500 μm and a depth of 100 μm; the diameter of the through hole 33 was 500. Mu.m.

After the bottom plate 1 and the cell chamber plate 3 are prepared, spraying a layer of acetic acid solution on the lower surface of the flexible microelectrode array 2; then the flexible microelectrode array 2 is placed in the groove 11 of the bottom plate 1, the surface coated with acetic acid solution is fully contacted with the bottom of the groove 11 and kept flat, and the flexible microelectrode array 2 is completely embedded in the groove 11 in a solvent bonding mode.

After the flexible microelectrode array 2 is fixed in the groove 11, a layer of toluene is coated on the upper surface of the flexible microelectrode array 2, then the cell chamber plate 3 is covered on the upper surface of the flexible microelectrode array 2, the positions are adjusted to align the edges, at the moment, the electrode array point 221 of the flexible microelectrode array 2 is exactly positioned in the center of the micro chamber 31, and the fixed connection between the cell chamber plate 3 and the bottom plate 1 is realized through a solvent bonding mode.

After standing for 1 hour, the stable adhesion of the bottom plate 1, the flexible microelectrode array 2 and the cell chamber plate 3 is realized, so that the microfluidic electrophysiological chip containing the flexible electrode array can be obtained.

In summary, the micro-fluidic chip containing the flexible MEA disclosed by the utility model can obtain a relatively sealed cell culture environment, and can continuously and dynamically perfuse culture solution into a sealed cavity through the through hole 33 by means of an external device micro-pump, and electric signals such as action potential, local field potential and the like generated by cells can be collected through the micro-electrode array points 221 of the metal electrode 22 and connected to a connected electrophysiological instrument through the lead port 222 of the metal electrode 22 so as to analyze electrophysiological information of the cells. Compared with the traditional method that the metal electrode is directly contacted with the micro-fluidic chip material and is not coated by the flexible material, in the utility model, the metal electrode 22 is coated in the flexible substrate 21 except the micro-electrode array point 221 and the lead port 222, and after being treated by organic solvents such as acetic acid solution, pure toluene solution and the like, the strong adhesion between the flexible substrate 21 and the bottom plate 1 and the cell chamber plate 3 can be realized, so that the problem that the part containing the metal electrode is easy to leak during long-term dynamic pouring is effectively avoided.

Finally, it should be noted that while the above describes embodiments of the utility model in terms of drawings, the present utility model is not limited to the above-described embodiments and fields of application, which are illustrative, instructive, and not limiting. Those skilled in the art, having the benefit of this disclosure, may effect numerous forms of the utility model without departing from the scope of the utility model as claimed.

Claims

1. A microfluidic electrophysiological chip containing a flexible electrode is characterized by comprising a bottom plate, a flexible microelectrode array and a cell chamber plate;

the bottom plate is provided with a groove for placing the flexible microelectrode array;

the flexible microelectrode array is arranged in the groove and comprises a flexible substrate and metal electrodes, microelectrode array points and lead ports are respectively arranged at two ends of each metal electrode, and the other parts except the microelectrode array points and the lead ports are covered in the flexible substrate;

the cell chamber plate comprises a micro-chamber and at least two micro-channels which are arranged on the surface adjacent to the bottom plate, and at least two through holes which are communicated with the cell chamber plate, wherein one end of each micro-channel is connected with the micro-chamber, and the other end of each micro-channel is correspondingly connected with one through hole; the cell chamber plate is fixed on the bottom plate and forms a sealed chamber with a perfusion channel communicated with the outside through the micro-chamber, the micro-channel and the through hole; the microelectrode array point of the metal electrode is positioned in the sealed cavity, and the lead port is exposed on the surface of the microfluidic electrophysiological chip.

2. The microfluidic electrophysiological chip of claim 1, wherein the grooves are shaped and sized to conform to the shape and size of the flexible microelectrode array, and wherein the grooves have a depth substantially consistent with the thickness of the flexible microelectrode array.

3. The microfluidic electrophysiological chip of claim 1, wherein the bottom plate and the cell chamber plate are each any one of polymethyl methacrylate, polycarbonate, polystyrene, and cyclic olefin copolymer materials.

4. The microfluidic electrophysiological chip of claim 1, wherein the flexible substrate is made of a biocompatible material.

5. The microfluidic electrophysiological chip of claim 4, wherein the flexible substrate is made of any one of polyethylene terephthalate, polyimide, and polyethylene naphthalate.

6. The microfluidic electrophysiological chip of claim 1, wherein the outer angle formed between the side wall of the microcavity connected to the channel and the microchannel is greater than 90 degrees.

7. The microfluidic electrophysiological chip of claim 1, wherein the micro-chambers are regular hexagons, and the perfusion channels are respectively arranged at two opposite vertex angles of the regular hexagons.

8. The microfluidic electrophysiological chip of claim 1, wherein the number of micro-channels is two, and the number of through-holes is two to form two perfusion channels one in and one out.

9. The microfluidic electrophysiological chip of claim 1, wherein the microelectrode array spot of the metal electrode is located at the midpoint of the sealed chamber.

10. The microfluidic electrophysiological chip of any one of claims 1 to 9, wherein the flexible microelectrode array is fixed in a recess of a cell chamber plate by solvent bonding; the bottom plate and the cell chamber plate are fixedly connected in a solvent bonding mode.