Piezoelectric ultrasonic microinjection device based on flexible hinge mechanism

The present invention discloses a piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism. The device includes: a cover, a flexible hinge mechanism, a base, a screw cap and an end cap fixedly assembled together, the base being provided with a pump interface; and a micropipette fixedly mounted in the base, the screw cap and the end cap and extending outward, the micropipette being in communication with the pump interface; wherein the flexible hinge mechanism comprises a housing, a piezoelectric ceramic package module encapsulated in the housing, a central shaft fixedly mounted with the piezoelectric ceramic package module and the base, and a vibration output shaft extending from the piezoelectric ceramic package module into the central shaft, a plurality of flexible hinge beams being disposed between the central shaft and the housing.

This application is the National Stage Application of PCT/CN2018/087759, filed on May 22, 2018, which claims priority to Chinese Patent Application No.: 201810454388.0, filed on May 14, 2018, which is incorporated by reference for all purposes as if fully set forth herein.

TECHNICAL FIELD

The present invention relates to the field of microinjection technology, in particular to a piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism.

BACKGROUND

With the rapid development of biotechnology, microinjection technology has become an important means of cell engineering research such as transgenic injection, cloning technology, artificial assisted reproductive technology. Membrane rupture technology is the key technology of microinjection. When rupturing the membrane, the micropipette penetrates into the cell body, and then completes the corresponding injection tasks, such as foreign gene injection and nuclear transplantation. During the microinjection, the accuracy of the injection device directly affects the activity of the injected cells.

The piezoelectric rupture membrane injection method has been widely used in cell microinjection operations as a technique for cell micro-deformation and high injection success rate . However, the traditional piezoelectric injection device has the defects of large harmful vibration, which greatly affects the cell survival rate. In addition, the clamping device of the traditional micro-injector has poor sealing performance, and most of them adopt spiral seal or ordinary flat gasket seal. Under the ultrasonic excitation of piezoelectric ceramic, “gas leakage” and “liquid leakage” phenomenon are easy to occur, resulting in errors or pollution during experiment, which reduces the success rate of the experiment.

Therefore, in view of the above technical problems, it is necessary to provide a piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism.

SUMMARY

In view of this, an object of the present invention is to provide a piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism, which can effectively inhibit the harmful radial vibration of the micropipette tip during the microinjection operation, reduce the cell damage, improve injection success rate and greatly improve the sealing property of the device.

In order to achieve the above object, the technical solution provided by an embodiment of the present invention is as follows:

A piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism, the device comprising:

a cover, a flexible hinge mechanism, a base, a screw cap and an end cap fixedly assembled together, the base being provided with a pump interface; and

a micropipette fixedly mounted in the base, the screw cap and the end cap and extending outward, the micropipette being in communication with the pump interface;

wherein the flexible hinge mechanism comprises a housing, a piezoelectric ceramic package module encapsulated in the housing, a central shaft fixedly mounted with the piezoelectric ceramic package module and the base, and a vibration output shaft extending from the piezoelectric ceramic package module into the central shaft, a plurality of flexible hinge beams being disposed between the central shaft and the housing.

As a further improvement of the present invention, the end cap and the screw cap as well as the screw cap and the base are respectively fixedly mounted to each other through a thread.

As a further improvement of the present invention, a gasket is disposed between the end cap and the screw cap and/or between the screw cap and the base, and two sides of the gasket are different first and second tapered faces.

As a further improvement of the present invention, the end cap comprises an end cap body and an end cap mounting portion, an outer diameter of the end cap body being greater than that of the end cap mounting portion, and an outer side of the end cap mounting portion being provided with a first thread fixedly mounted to the screw cap.

As a further improvement of the present invention, a first cavity and a second cavity are formed in the end cap in a direction from the end cap body toward the end cap mounting portion, the second cavity being tapered.

As a further improvement of the present invention, the screw cap comprises a screw cap body and a screw cap mounting portion, an outer diameter of the screw cap body being greater than that of the screw cap mounting portion, an inner side of the screw cap body being provided with a second thread fixedly mounted to the end cap, and an outer side of the screw cap mounting portion being provided with a third thread fixedly mounted to the base.

As a further improvement of the present invention, a third cavity, a fourth cavity and a fifth cavity are formed in the screw cap in a direction from the screw cap body to the screw cap mounting portion, the fifth cavity being tapered.

As a further improvement of the present invention, the base comprises a bent section fixedly mounted to the screw cap, and a horizontal section fixedly mounted with the flexible hinge mechanism, the bent section and the horizontal section being respectively fixedly mounted to the screw cap and the flexible hinge mechanism through a thread.

As a further improvement of the present invention, an inner side of the bent section is provided with a fourth thread fixedly mounted to the screw cap.

As a further improvement of the present invention, a sixth cavity and a seventh cavity are provided in the bent section, and an eighth cavity is provided in the horizontal section, the seventh cavity being tapered, and the sixth cavity being in communication with the pump interface through the seventh cavity and a micro flow channel.

As a further improvement of the present invention, an inner side of the horizontal section is provided with a fifth thread, an outer side of an end of the central shaft of the flexible hinge mechanism is provided with a sixth thread, and the base and the flexible hinge mechanism are fixedly mounted through the fifth thread and the sixth thread.

As a further improvement of the present invention, an end of the horizontal section is provided with a first flange, and a plurality of first reinforcing ribs is provided between the first flange and the horizontal section.

As a further improvement of the present invention, the central shaft of the flexible hinge mechanism is provided with a second flange, and a plurality of second reinforcing ribs is provided between the second flange and the central shaft.

As a further improvement of the present invention, the flexible hinge beam is provided with a plurality of V-shaped recesses.

As a further improvement of the present invention, the flexible hinge beam is distributed in an circumferential array with an equal angle of 120 [deg.] centered on the central shaft, and the flexible hinge beam in each direction is distributed in a parallel linear array of equidistant double flexible hinge beams at a certain distance in the axial direction.

As a further improvement of the present invention, the central shaft is provided with a mounting hole, and a screw is fixedly mounted in the mounting hole to fix the central shaft and the vibration output shaft.

aiming at the harmful radial vibration transmitted by the piezoelectric ceramic package module to the micropipette tip, a three-dimensional flexible hinge mechanism is designed for the piezoelectric ceramic package module, which can effectively filter and buffer the radial harmful vibration of the vibration output shaft while maintaining a high energy transmission efficiency, thereby reducing lateral harmful vibrations of the micropipette tip;

the double-tapered face shaped gasket self-sealing mechanism effectively realizes the functions of air sealing and liquid sealing, and the mechanism has better clamping and stabilizing effect on the micropipette; and

the “flexible hinge mechanism-base” ultrasonic energy transfer connection is optimized, that is, the design of flange surface contact and the reinforcing rib greatly reduces the overall quality of the mechanism and improves the energy transfer efficiency of piezoelectric ceramics without impairing the overall strength and function of the micropipette.

DETAILED DESCRIPTION

In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

Referring toFIG. 1,FIG. 2,FIG. 11a,FIG. 11b,FIG. 12andFIG. 13, a specific embodiment of the present invention discloses a piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism, which mainly includes a micropipette clamping and self-sealing module, a flexible hinge filtering mechanism and an energy transmission mechanism, and specifically includes:

a cover10, a flexible hinge mechanism20, a base30, a screw cap40and an end cap50fixedly assembled together, the base30being provided with a pump interface35; and

a micropipette60fixedly mounted in the base, the screw cap and the end cap and extending outward, the micropipette60being in communication with the pump interface35;

wherein the flexible hinge mechanism20includes a housing21, a piezoelectric ceramic package module22encapsulated in the housing, a central shaft23fixedly mounted to the piezoelectric ceramic package module and the base, and a vibration output shaft24extending from the piezoelectric ceramic package module22into the central shaft23, a plurality of flexible hinge beams25being disposed between the central shaft23and the housing21.

In this embodiment, the end cap50and the screw cap40as well as the screw cap40and the base30are respectively fixedly mounted to each other through a thread.

As shown inFIG. 3toFIG. 5, the end cap50includes an end cap body51and an end cap mounting portion52. An outer diameter of the end cap body51is greater than that of the end cap mounting portion52. An outer side of the end cap mounting portion52is provided with a first thread521fixedly mounted with the screw cap. A first cavity501and a second cavity502are formed in the end cap50in a direction from the end cap body51toward the end cap mounting portion52. The second cavity502is tapered.

Specifically, the end cap50in the embodiment is a second-order stepped shaft-shaped part, and is provided with an external thread on one side of a small cylindrical surface, a tapered face hole on an end face of the small cylindrical surface, and a fully through glossy face hole at a central axis which passes through the entire part, with an inner diameter of 1.2 mm slightly greater than the outer diameter of the micropipette60which is 1 mm for the purpose of facilitating the mounting of the micropipette.

As shown inFIGS. 1-3, 6, and 7, the screw cap40includes a screw cap body41and a screw cap mounting portion42. An outer diameter of the screw cap body41is greater than that of the screw cap mounting portion42. An inner side of the screw cap body41is provided with a second thread411fixedly mounted to the end cap50. An outer side of the screw cap mounting portion42is provided with a third thread421fixedly mounted to the base30. A third cavity401, a fourth cavity402, and a fifth cavity403are formed in the screw cap40in a direction from the screw cap body to the screw cap mounting portion. The fifth cavity403is tapered.

Specifically, in this embodiment, the screw cap40is matched with the end cap50. The screw cap40is also a second-step stepped shaft-shaped part. A large-diameter end of the screw cap40is provided with an internal thread matched with the end cap50with a thread length slightly less than that of an external thread of the end cap50in order to fully screw the end cap50into the internal thread of the screw cap40. As shown inFIG. 7, an end face of the internal thread of the screw cap40is provided with a tapered face hole surface with a large diameter being the outer diameter of the internal thread. An outer cylindrical surface of the other end (small diameter) of the screw cap40is provided with an external thread with a size parameter being the same as that of the external thread of the end cap50. In addition, similar to the design of the end cap50, the screw cap40is provided with a tapered face hole at an end face of the external thread with a size parameter being the same as that of the tapered face hole of the end cap50. At the same time, for the through mounting of the micropipette60, a through hole having an inner diameter of 1.2 mm is also formed in the central shaft.

As shown inFIGS. 1-3 and 6-9, the base30includes a bent section31fixedly mounted to the screw cap40, and a horizontal section32fixedly mounted to the flexible hinge mechanism20. The bent section31and the horizontal section32are respectively fixedly mounted to the screw cap and the flexible hinge mechanism through a thread.

A fourth thread (not shown) fixedly mounted to the screw cap is disposed on an inner side of the bent section31. A sixth cavity3011and a seventh cavity3012are disposed in the bent section31. An eighth cavity304is disposed in the horizontal section32. The seventh cavity3012is tapered. The sixth cavity3011is in communication with the pump interface35through the seventh cavity3012and a micro flow channel302.

An inner side of the horizontal section32is provided with a fifth thread (not shown). An outer side of an end of the central shaft of the flexible hinge mechanism20is provided with a sixth thread. The base30and the flexible hinge mechanism20are fixedly mounted by the fifth thread and the sixth thread.

In addition, an end of the horizontal section32is provided with a first flange33. A plurality of first reinforcing ribs34is disposed between the first flange33and the horizontal section32.

Specifically, the base30is divided into two sections, and is divided into a bent section31and a horizontal section32during mounting. The bent section31is provided with an internal thread matched with the external thread of the screw cap40with a thread length slightly smaller than that of the external thread of the screw cap40, in order to completely screw the screw cap40into an internal thread of the base30. Similarly, a tapered face hole is formed at an end face of the internal thread in the base30with a size being the same as that of the tapered face hole at the end face of the internal thread of the screw cap40. In addition, as shown inFIG. 9, a microchannel302is provided in the horizontal section32extending from the pump interface35at the upper end to the end face of the internal thread of the bent section32. As shown inFIG. 3, an end face of the horizontal section of the base30is provided with an internal thread matched with the external thread of the central shaft of the flexible hinge mechanism20. The flexible hinge mechanism20filters and buffers the ultrasonic energy generated by the piezoelectric ceramic package module22through the flexible hinge and transmits it to the base30through the vibration output shaft24.

Referring toFIG. 1,FIG. 3,FIG. 10a, andFIG. 10b, a gasket80is disposed between the end cap50and the screw cap40and between the screw cap40and the base30. Two sides of the gasket80are different first tapered face81and second tapered face82.

Specifically, two ends of the gasket80are both tapered faces which are divided into a first tapered face81and a second tapered face82. The gasket80has a through hole at a central axis the size of which is exactly the outer diameter of the micropipette60. During assembly, the gasket80is first mounted into the tapered face hole at the bottom of the internal thread of the base30, the first tapered face81is matched with the tapered face hole of the base30, and then the screw cap40is screwed but not tightened. Similarly, a gasket80is placed at the bottom of the internal thread of the screw cap40, the first tapered face81of the gasket80is matched therewith, and then the end cap50is screwed but not tightened. Finally, the micropipette60is adjusted to be properly inserted from the end face hole of the first tapered face81of the end cap50until the end face of the micropipette60is brought to the position of the microchannel302of the base30to stop. Finally, the screw cap40and the end cap50are tightened at the same time until they are screwed to the limit position and cannot rotate any more. The second tapered face82of the gasket80is matched with the tapered face hole at the end face of the external thread of the screw cap40. The tapered face of the gasket80is slightly greater in size than the matched tapered face hole.

The design purpose of the gasket80is as follows: in the process of screwing the end cap50into the internal threaded hole of the screw cap40, due to the elastic deformation characteristic of the gasket80, the first tapered face81of the gasket80is subjected to a tightening force to press the wall of the tapered face hole at the bottom of the internal thread of the base30, and at the same time, the gasket80is subjected to a reaction force so that the second tapered face82of the gasket80presses the wall of the tapered face hole at the external thread of the screw cap40, thereby achieving a self-sealing effect.

In addition, since the tapered face of the gasket80is subjected to a tightening force, when mechanically decomposed, due to the stress of the tapered face, a radial force is generated on the surface of the micropipette wall of the micropipette60, so that the inner cylindrical hole wall of the gasket80and the outer cylindrical surface of the micropipette60achieves an automatic sealing effect during the tightening process. When the experimenter tightens the screw cap40, the gasket80reaches the limit of elastic deformation, thereby pressing the inner wall, and forming a multi-directional multi-angle self-sealing environment through the surface contact. Similarly, during the process of screwing the end cap50into the internal thread of the screw cap40, the first tapered face81of the gasket80also presses the wall of the tapered face hole at the bottom of the internal threaded hole in the screw cap40. At the same time, due to being subjected to a reaction force, the second tapered face82of the gasket80presses the tapered face hole of the end face of the external thread of the end cap50, and the inner hole wall of the gasket80presses the outer wall of the micropipette60to achieve a self-sealing effect.

As shown inFIG. 3, since the micropipette60needs to perform micromanipulation under the high frequency vibration of the piezoelectric ceramic package module22when rupturing the cell, the two-point supporting design of the micropipette60for clamping can effectively avoid the radial vibration of the micropipette60, and can transmit the axial vibration transmitted by the vibration output shaft24of the flexible hinge mechanism more efficiently. In addition, since the gasket80and the micropipette60are in surface contact herein, compared with the conventional point contact and hard contact, the design of the gasket80can better fix and clamp the micropipette60and prevent the micropipette60and the clamping mechanism from relative displacement, thereby reducing the mechanical wear between the micropipette60and the clamping screw cap40, the base30and the end cap50. Therefore, the design of the gasket80being matched with the corresponding base30, the screw cap40, and the tapered face hole of the end cap50not only can achieve a better sealing effect, but also has a more stable and firm clamping and fixing of the micropipette60. Problems such as “radial rotation” and “axial slip” of the micropipette60will not occur during use.

Referring toFIG. 3,FIG. 8,FIG. 11a,FIG. 11b, andFIG. 12, a first flange33is disposed on the end face of the horizontal section32of the base30. A second flange26is disposed on the central shaft23of the flexible hinge mechanism20. The first flange33and the second flange26are correspondingly disposed. The second flange26is provided with a threaded hole at the end face thereof which is exactly the same as the outer circle diameter of the end face of the central shaft23of the flexible hinge mechanism and matched with the external thread section of the central shaft23of the flexible hinge structure. During the actual assembly process, the central shaft23of the flexible hinge mechanism is completely screwed into the internal threaded hole of the end face of the first flange33of the base30until the end face of the central shaft23of the flexible hinge mechanism20is matched with the end face of first flange33of the horizontal section of the base30to achieve surface contact.

As shown inFIG. 8, a first rib is sequentially disposed in the “3 o'clock”, “6 o'clock”, “9 o'clock”, and “12 o'clock” directions between the first flange33and the outer cylinder of the horizontal section of the base30. The purpose is to enhance the structural strength of the base30when the vibration output shaft24of the flexible hinge mechanism20transmits the high frequency vibration to the base30through the central shaft23, and at the same time, to reduce its own weight and improve the energy transfer efficiency.

As shown inFIG. 3,FIG. 11a,FIG. 11bandFIG. 12, the flexible hinge mechanism20is a single piece. The housing21is a cylindrical housing. The central shaft23and the inner wall of the housing21are connected by a flexible hinge beam25. The flexible hinge beam25is a “V” type flexible hinge beam provided with a plurality of V-shaped recesses. The flexible hinge beam is distributed in a circumferential array with an equal angle of 120° at positions of 0°, 120°, 240° in the end face direction centered on the central shaft23, and the flexible beams in each direction are distributed in a parallel linear array of equidistant double flexible hinge beams at a certain distance in the axial direction. Therefore, a total of six flexible hinge beams25are connected to the housing21on the center shaft23.

Through theoretical calculation and finite element analysis, the “V” type flexible hinge beam design has the best axial vibration transmission efficiency, and the filtering effect on the radial residual vibration is also the best. A threaded hole is provided at the end face of the center shaft23to be matched with the external thread of the vibration output shaft24of the piezoelectric ceramic package module22. In addition, in order to strengthen the strength between the central shaft23and the vibration output shaft24of the piezoelectric ceramic package module, and to ensure the transmission efficiency of the ultrasonic vibration energy, a plurality of second reinforcing ribs27is provided between the second flange26and the center shaft23which is in the middle of three flexible hinge beams25, and is also distributed in an array of 120° centered on the axis. In the process of transmitting the ultrasonic vibration into the central shaft23of the flexible hinge mechanism20by the piezoelectric ceramic package module22through the vibration output shaft24, in order to avoid loosening of the screw connection between the two under high frequency vibration, the cylindrical surface of the central shaft23of the flexible hinge mechanism20is provided with a threaded through hole. When the threaded section of the vibration output shaft24of the piezoelectric ceramic package module22is completely screwed into the threaded hole of the end face of the flexible hinge mechanism center shaft23, the connection between the central shaft23and the vibration output shaft24is strengthened and prevented from loosening by screwing a set screw28.

As shown inFIG. 3,FIG. 12andFIG. 13, the cover10is a second-order stepped shaft part. An external thread (not shown) is provided at a small diameter section of the cover10. A glossy face through hole is provided at a large-diameter end face of the cover10. The extremity of the inner wall of the end of the flexible hinge mechanism20is provided with an internal thread at a corresponding position which is matched with the external thread at the small shaft end of the cover10. A fixing rod70is also a second-order stepped shaft part, which is provided with an external thread at the cylindrical surface of the small-shaft diameter section of the end face.

The assembly process of the flexible hinge mechanism20, the piezoelectric ceramic package module22, the cover10, the fixing rod70, and the set screw28is as follows: firstly the vibration output shaft24of the piezoelectric ceramic package module22is screwed into the threaded hole at the end face of the central shaft23of the flexible hinge mechanism20, the set screw28is then screwed into a mounting hole231on the cylindrical surface of the central shaft23, so that the head of the set screw28abuts against the external thread surface of the vibration output shaft24, thereby relaxing and reinforcing. The external thread of the small shaft end of the cover10is then matched with the internal thread at the end face of the flexible hinge mechanism20. Next, the small shaft end of the fixing rod70is inserted into the glossy face through hole of the large shaft end face of the cover10, and the external thread of the small shaft end of the fixing rod70is screwed into the internal thread at the end face of the tail of the piezoelectric ceramic package module22. Finally, by continuously tightening the fixing rod70, the end face of the tail of the piezoelectric ceramic package module22and the end face of the small diameter section of the cover10are continuously fitted and tightened, and the piezoelectric ceramic package module22is also driven to rotate, so that the vibration output shaft24of the piezoelectric ceramic package module22is continuously tightened and fixed with the threaded hole of the central shaft23of the flexible hinge mechanism20, and the end face of the stepped shaft of the fixing rod70and the end face of the large shaft diameter section of the cover10are tightly fitted, thereby realizing the assembly and fastening process of the piezoelectric ceramic package module22, the fixing rod.70, the cover10and the flexible hinge mechanism housing21.

The working principle of the piezoelectric ultrasonic microinjection device based on a flexible hinge mechanism in the present invention is as follows:

The fixed rod70is fixed to the frame and remains absolutely stationary relative to the static ground. The end face thread of the head of the fixing rod70is screwed through the through hole of the cover10into the threaded hole of the end face of the piezoelectric ceramic package module22, and the cover10, the piezoelectric ceramic package module22and the fixing rod70are fixed by screwing. Moreover, the flexible hinge mechanism housing21is also fixed to the cover10by a screw connection, so the flexible hinge mechanism housing21, the cover10, the fixing rod70, and the piezoelectric ceramic package module22are all fixed ends. After the piezoelectric ceramic package module22is connected to a power source, the vibration output shaft24generates high-frequency vibration, and the vibration is transmitted into the central shaft23of the flexible hinge mechanism20through the screw connection between the vibration output shaft24and the center shaft23. Since the piezoelectric ceramic package module22generates a small amount of irregular radial vibration during actual motion, if the energy is directly transmitted to the base30without any filtering and buffering, the radial residual vibration will be amplified to a large lateral vibration of the micropipette tip of the micropipette60after being transported over a long distance to the micropipette tip, which is conducive to cell microinjection and membrane rupture. In the V-shaped flexible hinge beam, the central shaft can only be displaced along the axial direction due to the restraining action of the three-way flexible hinge, and any radial residual vibration will be absorbed by the three-way flexible hinge beam. Therefore, the central shaft, the ribs, the flanges and the output shaft of the flexible hinge mechanism are integral, all of which are movable ends, and the whole is linearly high-frequency reciprocating with respect to the fixed end section (stationary reference). The central shaft finally transmits the filtered ultrasonic vibration energy to the vibration output shaft, and finally transmits the vibration energy to the base through the screw connection of the vibration output shaft and the base.

It can be seen from the above technical solutions that the present invention has the following beneficial effects:

aiming at the harmful radial vibration transmitted by the piezoelectric ceramic package module to the micropipette tip, a three-dimensional flexible hinge mechanism is designed for the piezoelectric ceramic package module, which can effectively filter and buffer the radial harmful vibration of the vibration output shaft while maintaining a high energy transmission efficiency, thereby reducing lateral harmful vibrations of the micropipette tip;

the double-tapered face shaped gasket self-sealing mechanism effectively realizes the functions of air sealing and liquid sealing, and the mechanism has better clamping and stabilizing effect on the micropipette; and

the “flexible hinge mechanism-base” ultrasonic energy transfer connection is optimized, that is, the design of flange surface contact and the reinforcing rib greatly reduces the overall quality of the mechanism and improves the energy transfer efficiency of piezoelectric ceramics without impairing the overall strength and function of the micropipette.

Therefore, the present invention can meet bioengineering micromanipulation experiments of different needs, such as: nuclear transfer, single sperm injection, transgenic injection, and the like. At the same time, because the micropipette clamping section adopts a reinforcing rib design, the overall quality of the micropipette is greatly reduced, and the three-dimensional flexible hinge mechanism is adopted to effectively reduce the radial vibration of the micropipette tip caused by the piezoelectric ceramic, thereby effectively alleviating the mechanical damage caused by injection to the cells and improve the success rate of the experiment. At the same time, the present invention has the advantages of simple structure, good interchangeability of components, easy assembly, and relatively low processing cost, which simplifies the experimental cost and complexity of the microinjection experiment operation.

It is apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the present invention is defined by the appended claims instead of the above description. All changes falling within the meaning and scope of equivalent elements of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim.

In addition, it should be understood that although the description is described in terms of embodiments, not every embodiment includes only one independent technical solution. The narration of the specification is merely for the sake of clarity, and those skilled in the art should regard the specification as a whole. The technical solutions in the respective embodiments may also be combined as appropriate to form other embodiments that can be understood by those skilled in the art.