Biological material liquid drop spraying device

Abstract

The invention discloses a biological material droplet spraying device which comprises a fixed part and a non-fixed part convenient to disassemble, the fixed part comprises a shell, an upper limiting threaded column, an upper limiting piece, a piezoelectric ceramic stack, a lower limiting piece and a large spring, and an upper through hole and a lower through hole which are coaxial are formed in the top end and the bottom end of the shell respectively; the upper through hole is in threaded connection with part of the upper limiting threaded column, and the upper limiting piece, the piezoelectric ceramic pile, the lower limiting piece and the large spring are sequentially arranged in the shell from top to bottom; the non-fixed part comprises a circular ring piece, a cylindrical sleeve, a small spring, a cylindrical sleeve vertical guide and a liquid storage cylindrical needle, the lower through hole is in threaded connection with the part of the cylindrical sleeve vertical guide, and the circular ring piece and the small spring are arranged in the large spring. The device is small in size and convenient to disassemble and assemble, high-viscosity bio-ink can be printed, and the size and frequency of jet biological material liquid drops can be flexibly adjusted.

Description

Technical Field

[0001] The invention belongs to the technical field of biomaterial jetting, and in particular relates to a biomaterial droplet jetting device. Background Art

[0002] 3D printing technology has been maturely applied in the field of engineering. This technology is no longer limited to the field of engineering. It has gradually played an important role in leading innovation in the field of bioprinting. At present, biological 3D printing technology is still a novel and interdisciplinary frontier technology to be developed. This technology can accurately regulate biological materials such as cells and active factors. In the study of biological 3D printing, the commonly used technologies are extrusion, laser-assisted, photocuring and inkjet bioprinting technology. Extrusion bioprinting is widely used in bioprinting research due to its simple process and has developed rapidly. This technology does not have particularly strict requirements for biological materials. Biological materials such as cell spheres and microcarriers can be printed by extrusion. However, extrusion bioprinting is more suitable for making larger structures, and its ability to print microstructures is obviously insufficient. The frequency of biological droplets formed by laser-assisted bioprinting technology can reach kilohertz, which far exceeds the printing rate of other technologies. Although laser-assisted bioprinting technology has the advantage of high speed, this technology is very complicated and costly, and the instantaneous high temperature and high pressure generated by the laser act on the biological material, which can easily reduce the activity of the printed biological material. Photocuring bioprinting technology uses the physical property of photosensitive materials that can be cured by light to perform 3D printing. It must use photosensitive materials as printing materials, so there are relatively few types of biomaterials that can be selected. In addition, the ultraviolet light it usually uses also has a very adverse effect on the activity of biomaterials. Inkjet bioprinting technology has high requirements for the solid content and viscosity of the biomaterial ink to be sprayed. The viscosity of the sprayed biomaterial can only be in a relatively low range (usually less than 20mPas). Bioinks with low viscosity are not conducive to the suspension of biomaterials such as cells, so that the biomaterials in the ink cannot be sprayed out evenly with droplets. In order to solve the problems of reduced survival rate of biomaterials such as cells and active factors in biological 3D printing; uneven generation of droplets containing biomaterials such as cells and active factors; high cost; complex process; low viscosity of printable ink; and easy clogging of the nozzle, the present invention proposes an on-demand spraying device for spraying biomaterials such as cells and active factors under the action of water hammer. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention proposes a biomaterial droplet injection device, which has a reasonable design, solves the shortcomings of the prior art and has good effects.

[0004] A biomaterial droplet ejection device, comprising a fixed part and a non-fixed part that can be easily disassembled, wherein the fixed part comprises a housing, an upper limit threaded column, an upper limit plate, a piezoelectric ceramic stack, a lower limit plate and a large spring, wherein the top and bottom ends of the housing are respectively provided with a coaxial upper through hole and a lower through hole, wherein the upper through hole is threadedly connected to a portion of the upper limit threaded column, and the upper limit plate, the piezoelectric ceramic stack, the lower limit plate and the large spring are sequentially arranged inside the housing from top to bottom;

[0005] The non-fixed part includes an annular piece, a cylindrical sleeve, a small spring, a cylindrical sleeve vertical guide and a liquid storage cylinder needle. The lower through hole is threadedly connected with the part of the cylindrical sleeve vertical guide. The annular piece and the small spring are arranged inside the large spring.

[0006] Furthermore, the bottom surface of the large spring is adhered to the inner bottom surface of the shell, and the top of the large spring is in contact with the bottom surface of the lower limit plate.

[0007] Furthermore, the top surface of the lower limit plate and the bottom surface of the upper limit plate are respectively provided with first grooves, so that the top end and the bottom end of the piezoelectric ceramic stack are respectively embedded in the two first grooves;

[0008] The upper limit plate has an arc-shaped concave surface on its top surface, and a hemispherical protrusion is provided at the bottom end of the upper limit threaded column, and the hemispherical protrusion contacts the arc-shaped concave surface;

[0009] The bottom surface of the lower limiting plate is provided with a second groove, and part of the annular plate is embedded in the second groove.

[0010] Furthermore, the vertical guide of the cylindrical sleeve is a 4-layer annular step structure with increasing diameters from top to bottom. The top first-layer step structure is located inside the small spring, one end of the small spring rests against the circular ring sheet, and the other end rests against the horizontal surface of the second-layer step structure; parts of the third-layer step structure and the fourth-layer step structure are threadedly connected to the lower through hole.

[0011] Furthermore, vertical through holes are provided in the upper limit threaded column, upper limit plate, piezoelectric ceramic stack, lower limit plate and cylindrical sleeve vertical guide, and each vertical through hole, large spring, small spring and circular ring plate are coaxial with the upper through hole and the lower through hole, and the two ends of the upper limit threaded column and the cylindrical sleeve vertical guide extend out of the upper through hole and the lower through hole respectively.

[0012] Furthermore, the cylindrical sleeve is sequentially inserted into the vertical through hole of the annular sheet, the small spring and the vertical guide of the cylindrical sleeve, and is bonded and fixed to the inner wall of the annular sheet, and the bottom end of the cylindrical sleeve extends out of the vertical guide of the cylindrical sleeve;

[0013] The liquid storage cylindrical needle is sequentially inserted into the upper limit spiral column, the upper limit plate, the piezoelectric ceramic, the vertical through hole of the lower limit plate and the cylindrical sleeve, and the end of the liquid storage cylindrical needle is bonded and fixed to the inside of the end of the cylindrical sleeve, the bottom end of the liquid storage cylindrical needle extends out of the cylindrical sleeve, and the top end extends out of the upper limit threaded column.

[0014] Furthermore, the large spring is compressed by rotating the upper limit threaded column downward, so that the entire fixed part fits tightly together and forms a certain pre-tightening force;

[0015] The non-fixed part makes the small spring in a compressed state by rotating the cylindrical sleeve vertically upward, so that the whole non-fixed part is closely matched together and forms a certain pre-tightening force.

[0016] Furthermore, the shell, upper limit plate, lower limit plate, annular plate, cylindrical sleeve, and cylindrical sleeve vertical guide are made of hard materials that are not easily deformed, and the liquid storage cylindrical needle is made of a material that does not damage the biomaterial ink. The biomaterial ink is continuously injected through the opening at the top of the liquid storage cylindrical needle, and a small hole is opened at the bottom of the liquid storage cylindrical needle as a nozzle for spraying the biomaterial ink.

[0017] Furthermore, after the signal generator and the power amplifier are connected to the piezoelectric ceramic stack, biomaterial ink is injected into the liquid storage cylindrical needle, and the piezoelectric ceramic stack is driven by the signal generator and the power amplifier to expand and contract, thereby driving the cylindrical sleeve to move up and down rapidly. The liquid storage cylindrical needle also moves up and down rapidly following the cylindrical sleeve; the large spring and the small spring remain in a compressed state after assembly, providing a certain preload force for the fixed and non-fixed parts of the device.

[0018] The diameter of the liquid sprayed from the biomaterial can be greatly adjusted by replacing the liquid storage cylinder needle with different nozzle diameters; the amplitude and frequency of the signal generator can be adjusted to change the amplitude of the up and down movement of the liquid storage cylinder needle and the time required for one cycle of up and down movement, which is equivalent to changing the spray force and movement speed of the liquid storage cylinder needle of the device, thereby adapting to biomaterial inks of different viscosities and achieving fine-tuning of the diameter of the biomaterial droplets sprayed from the same nozzle diameter.

[0019] Beneficial technical effects brought by the present invention:

[0020] 1. It is convenient to use cylindrical needles with different nozzle holes for printing. The injection of biomaterial droplets of different diameters can be achieved by replacing liquid storage cylindrical needles with different nozzle diameters. This method can greatly adjust the diameter of the injected droplets of biomaterials. And according to different inks and printing requirements, cylindrical needles with different nozzle hole sizes can be used. Large-hole needles are used for efficient printing, and small-hole needles are used for high-precision printing. The overall structure of the present invention is divided into a fixed part that is no longer disassembled after assembly, and a non-fixed part that can be easily disassembled. The non-fixed part is for the convenience of replacing the liquid storage cylindrical needle, so as to facilitate the replacement of the biomaterial in the liquid storage cylindrical needle.

[0021] 2. The device can flexibly adjust the size and frequency of the biomaterial droplets. The present invention uses the water hammer principle to spray biomaterial droplets, uses a signal generator and a power amplifier to drive the device, and then causes the liquid storage cylinder needle to move up and down quickly, driving part of the biomaterial inside the needle to form droplets through the nozzle at the bottom of the needle. By adjusting the waveform parameters in the signal generator, the speed, amplitude and printing spray frequency of the device nozzle can be accurately controlled. This method can quickly achieve fine-tuning of the biomaterial droplet size without replacing the liquid storage cylinder needle.

[0022] 3. The injection pressure is moderate and will not adversely affect the activity of the biomaterial. This device uses the inertial force of the biomaterial ink itself to generate the pulse pressure required for injection. Its pressure amplitude is much smaller than the pressure amplitude generated by laser injection, and the injection process has little effect on the activity of the biomaterial.

[0023] 4. Low device cost, no nozzle blockage, and high printable viscosity. The device has a small overall size, few parts, and direct drive, which avoids problems such as insensitive response caused by too many parts and transmissions. It is also low-cost and has no nozzle blockage. By adjusting the amplitude and frequency parameters of the signal generator, the action force and time of the liquid storage cylinder needle can be changed to adapt to biomaterial inks of different viscosities. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a perspective view of a biomaterial droplet ejection device according to the present invention;

[0025] Figure 2 It is a front view of the biomaterial droplet ejection device of the present invention;

[0026] Figure 3 is a cross-sectional view of the biomaterial droplet ejection device of the present invention;

[0027] Figure 4 It is a schematic diagram of the fixed part in the present invention;

[0028] Wherein (a) is a cross-sectional view of the fixing part; (b) is a perspective view of the fixing part;

[0029] Figure 5 is a cross-sectional view of a non-fixed portion of the present invention;

[0030] Among them, 1-upper limit threaded column; 2-shell; 3-upper limit plate; 4-piezoelectric ceramic stack; 5-lower limit plate; 6-circular ring plate; 7-large spring; 8-small spring; 9-cylindrical sleeve vertical guide; 10-cylindrical sleeve; 11-liquid storage cylinder needle; DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described below in conjunction with specific embodiments:

[0032] A biomaterial droplet ejection device, such as Figure 1-5 As shown, it includes a fixed part and a non-fixed part that can be easily disassembled, the fixed part includes a shell 2, an upper limit threaded column 1, an upper limit plate 3, a piezoelectric ceramic stack, a lower limit plate 5 and a large spring 7, the top and bottom ends of the shell are respectively provided with a coaxial upper through hole and a lower through hole, the upper through hole is threadedly connected with the middle part of the upper limit threaded column 1, both ends of the upper limit threaded column 1 extend out of the upper through hole, the upper limit plate 3, the piezoelectric ceramic stack, the lower limit plate 5 and the large spring 7 are sequentially arranged inside the shell 2 from top to bottom;

[0033] The non-fixed part includes an annular piece 6, a cylindrical sleeve 10, a small spring 8, a cylindrical sleeve vertical guide 9 and a liquid storage cylindrical needle 11. The lower through hole is threadedly connected to a part of the cylindrical sleeve vertical guide 9. Both ends of the cylindrical sleeve vertical guide 9 extend out of the lower through hole. The annular piece 6 and the small spring 8 are arranged inside the large spring 7 from top to bottom.

[0034] The bottom surface of the large spring 7 is adhered to the inner bottom surface of the housing 2 by epoxy resin, and the top of the large spring 7 is in contact with the bottom surface of the lower limit plate 5.

[0035] The top surface of the lower limit plate 5 and the bottom surface of the upper limit plate 3 are respectively provided with first grooves, so that the top and bottom ends of the piezoelectric ceramic stack are respectively embedded in the two first grooves;

[0036] The top surface of the upper limit plate 3 is provided with an arc-shaped concave surface, and the center position of the bottom end of the upper limit threaded column is provided with a hemispherical protrusion, the bottom of the hemispherical protrusion contacts the arc-shaped concave surface, and the cross-sectional area of ​​the upper limit threaded column is smaller than the cross-sectional area of ​​the upper limit plate, so that the bottom end edge of the upper limit threaded column can contact the arc-shaped concave surface;

[0037] A second groove is provided on the bottom surface of the lower limit plate 5, and a portion of the annular plate 6 is embedded in the second groove;

[0038] The cylindrical sleeve vertical guide 9 is a 4-layer annular step structure with increasing diameters from top to bottom, including a first step structure, a second step structure, a third step structure, and a fourth step structure from top to bottom. The first step structure and the second step structure are located inside the large spring 7. Since the small spring 8 is located inside the large spring 7, the first step structure is located inside the small spring 8. One end of the small spring 8 abuts against the annular sheet 6, and the other end abuts against the horizontal surface of the second step structure. Parts of the third step structure and the fourth step structure have external threads, which are threadedly connected to the lower through hole, and the remaining part of the fourth step structure extends out of the lower through hole.

[0039] The upper limit plate 3 and the lower limit plate 5 are very close to the inner wall of the shell 2 on both sides, and a certain gap is maintained to ensure that when the upper limit threaded column 1 is rotated downward to fit the entire fixed part tightly together, the components will not deviate, so that the components remain on the central axis of the entire device. In addition, each limit plate is provided with a groove in the center to cooperate, so that the through hole in the center of each component is on the central axis of the entire device. Finally, the cylindrical sleeve 10 is sequentially inserted into the vertical through holes of the circular ring plate 6, the small spring 8 and the cylindrical sleeve vertical guide 9, and is fixed to the inner wall of the circular ring plate 6 by epoxy resin bonding, and the bottom end of the cylindrical sleeve 10 extends out of the cylindrical sleeve vertical guide 9;

[0040] The upper limit threaded column 1, the upper limit plate 3, the piezoelectric ceramic stack 4, the lower limit plate 5 and the cylindrical sleeve vertical guide 9 are all provided with vertical through holes, and each vertical through hole, the large spring 7, the small spring 8 and the annular plate 6 are coaxial with the upper through hole and the lower through hole.

[0041] The liquid storage cylindrical needle 11 is sequentially inserted into the upper limit spiral column, the upper limit plate 3, the piezoelectric ceramic, the vertical through hole of the lower limit plate 5 and the cylindrical sleeve 10, and the end of the liquid storage cylindrical needle is bonded and fixed to the inside of the end of the cylindrical sleeve using strong glue. The bottom end of the liquid storage cylindrical needle extends out of the cylindrical sleeve 10, and the top end extends out of the upper limit threaded column 1.

[0042] By rotating the upper limit threaded column downward, the large spring 7 is put into a compressed state, so that the entire fixed part fits tightly together and forms a certain pre-tightening force;

[0043] By rotating the cylindrical sleeve vertical guide 9 upward, the non-fixed part makes the small spring 8 in a compressed state, so that the entire non-fixed part is closely matched together and a certain pre-tightening force is formed.

[0044] The housing 2, the upper limit plate 3, the lower limit plate 5, the annular plate 6, the cylindrical sleeve 10, and the cylindrical sleeve vertical guide 9 are made of hard materials that are not easily deformed. The liquid storage cylinder needle 11 is made of a material that does not damage the biomaterial ink, and a small hole is opened at the bottom of the liquid storage cylinder needle 11 as a nozzle for spraying the biomaterial ink. The biomaterial ink is continuously injected through the top opening of the liquid storage cylinder needle 11.

[0045] When it is necessary to replace the liquid storage cylindrical needle 11 with a different nozzle diameter in order to spray biomaterial droplets of different diameters, it is only necessary to rotate the cylindrical sleeve vertical guide 9 downward to remove the non-fixed part of the liquid storage cylindrical needle 11. After replacing the liquid storage cylindrical needle 11 with the required aperture, the cylindrical sleeve vertical guide 9 can be rotated upward to install the non-fixed part, which is convenient and quick.

[0046] The biomaterial droplets ejected by the present invention are generated by the water hammer effect between the biomaterial ink and the liquid storage cylindrical needle. After the signal generator and the power amplifier are connected to the piezoelectric ceramic stack 4, the biomaterial ink is injected into the liquid storage cylindrical needle 11, and the piezoelectric ceramic stack 4 is driven by the signal generator and the power amplifier to expand and contract, thereby driving the cylindrical sleeve 10 to move up and down rapidly. Since the liquid storage cylindrical needle is fixedly connected to the cylindrical sleeve 10, the liquid storage cylindrical needle will also move up and down rapidly following the cylindrical sleeve 10; wherein the large spring 7 and the small spring 8 are kept in a compressed state after being assembled, providing a certain pre-tightening force for the fixed part and the non-fixed part of the device.

[0047] The diameter of the liquid sprayed from the biomaterial can be greatly adjusted by replacing the liquid storage cylinder needle with different nozzle diameters; the amplitude and frequency of the signal generator can be adjusted to change the amplitude of the up and down movement of the liquid storage cylinder needle and the time required for one cycle of up and down movement, which is equivalent to changing the spray force and movement speed of the liquid storage cylinder needle of the device, thereby adapting to biomaterial inks of different viscosities and achieving fine-tuning of the diameter of the biomaterial droplets sprayed from the same nozzle diameter.

[0048] Example 1: Jet printing of 1% viscosity sodium alginate using a 50 micron nozzle

[0049] Biomaterial ink is injected into the liquid storage cylindrical needle 11 with a 50-micron nozzle hole, so that the entire needle cavity is filled with biomaterial. A bottom plate is placed at the lower end of the device, and the bottom end of the liquid storage cylindrical needle 11 is about 1 mm away from the top surface of the bottom plate. A signal generator and a power amplifier drive device are used to make the liquid storage cylindrical needle 11 move up and down quickly. In this embodiment, the voltage amplitude is 20V, and the single up and down movement time is within 500 microseconds. After multiple consecutive triggers, uniform 70-micron biomaterial droplets are obtained, and the diameter difference is less than 4 microns.

[0050] Example 2: Jet printing of 1% viscosity sodium alginate using a 150 μm nozzle

[0051] Biomaterial ink is injected into the liquid storage cylindrical needle 11 with a 150 micron nozzle, so that the entire needle cavity is filled with biomaterial. A bottom plate is placed at the lower end of the device, and the bottom end of the liquid storage cylindrical needle 11 is about 1 mm away from the top surface of the bottom plate. A signal generator and a power amplifier drive device are used to make the liquid storage cylindrical needle 11 move up and down quickly. In this embodiment, the voltage amplitude is 30V, and the single up and down movement time is within 200 microseconds. After multiple consecutive triggers, uniform 210 micron biomaterial droplets are obtained, and the diameter difference is less than 10 microns.

[0052] Example 3: Preparation of bio-ink for jet printing

[0053] HEK293H cells used for cell printing were routinely maintained in DMEM supplemented with 10% FCS, 200 mM L-533 glutamine, and 100 U / ml penicillin / streptomycin at 37°C and 5% CO2. When preparing bio-ink, HEK293H cells were trypsinized with 0.05% trypsin-EDTA at 37°C for 3 minutes and then collected by centrifugation at 1500 rpm for 5 minutes. The cell pellet was then centrifuged in the absence of Ca2+. 2+ The final concentrations of the bio-ink were 40 mM CaCl2, 40 IOWA Units / ml thrombin and 6 x 10 6 cells / ml DMEM. Printing was performed in air. The results show that printing conditions are mild and cell survival rates are high or suitable for viscous liquids containing biological cells. The cell survival rate measured directly after printing is higher than 93%.

[0054] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A biomaterial droplet ejection device, characterized in that: It includes a fixed part and a non-fixed part that can be easily disassembled, the fixed part includes a shell, an upper limit threaded column, an upper limit plate, a piezoelectric ceramic stack, a lower limit plate and a large spring, the top and bottom ends of the shell are respectively provided with a coaxial upper through hole and a lower through hole, the upper through hole is partially threadedly connected with the upper limit threaded column, and the upper limit plate, the piezoelectric ceramic stack, the lower limit plate and the large spring are sequentially arranged inside the shell from top to bottom; The non-fixed part includes an annular piece, a cylindrical sleeve, a small spring, a cylindrical sleeve vertical guide and a liquid storage cylinder needle. The lower through hole is threadedly connected with the part of the cylindrical sleeve vertical guide. The annular piece and the small spring are arranged inside the large spring.

2. A biomaterial droplet ejection device according to claim 1, characterized in that: The bottom surface of the large spring is adhered to the inner bottom surface of the shell, and the top of the large spring is in contact with the bottom surface of the lower limit plate.

3. A biomaterial droplet ejection device according to claim 2, characterized in that: The top surface of the lower limit plate and the bottom surface of the upper limit plate are respectively provided with first grooves, so that the top end and the bottom end of the piezoelectric ceramic stack are respectively embedded in the two first grooves; The upper limit plate has an arc-shaped concave surface on its top surface, and a hemispherical protrusion is provided at the bottom end of the upper limit threaded column, and the hemispherical protrusion contacts the arc-shaped concave surface; The bottom surface of the lower limiting plate is provided with a second groove, and part of the annular plate is embedded in the second groove.

4. A biomaterial droplet ejection device according to claim 3, characterized in that: The vertical guide of the cylindrical sleeve is a 4-layer annular step structure with increasing diameters from top to bottom. The top first-layer step structure is located inside the small spring. One end of the small spring rests against the circular ring sheet, and the other end rests against the horizontal surface of the second-layer step structure. Parts of the third-layer step structure and the fourth-layer step structure are threadedly connected to the lower through hole.

5. A biomaterial droplet ejection device according to claim 4, characterized in that: The upper limit threaded column, upper limit plate, piezoelectric ceramic stack, lower limit plate and cylindrical sleeve vertical guide are all provided with vertical through holes, and each vertical through hole, large spring, small spring and circular ring plate are coaxial with the upper through hole and the lower through hole, and the two ends of the upper limit threaded column and the cylindrical sleeve vertical guide extend out of the upper through hole and the lower through hole respectively.

6. A biomaterial droplet ejection device according to claim 5, characterized in that: The cylindrical sleeve is sequentially inserted into the vertical through hole of the circular ring sheet, the small spring and the vertical guide of the cylindrical sleeve, and is bonded and fixed to the inner wall of the circular ring sheet, and the bottom end of the cylindrical sleeve extends out of the vertical guide of the cylindrical sleeve; The liquid storage cylindrical needle is sequentially inserted into the upper limit spiral column, the upper limit plate, the piezoelectric ceramic, the vertical through hole of the lower limit plate and the cylindrical sleeve, and the end of the liquid storage cylindrical needle is bonded and fixed to the inside of the end of the cylindrical sleeve, the bottom end of the liquid storage cylindrical needle extends out of the cylindrical sleeve, and the top end extends out of the upper limit threaded column.

7. A biomaterial droplet ejection device according to claim 6, characterized in that: The large spring is compressed by rotating the upper limit threaded column downward, so that the entire fixed part fits tightly together and forms a certain preload force; The non-fixed part makes the small spring in a compressed state by rotating the cylindrical sleeve vertically upward, so that the whole non-fixed part is closely matched together and forms a certain pre-tightening force.

8. A biomaterial droplet ejection device according to claim 7, characterized in that: The shell, upper limit plate, lower limit plate, annular plate, cylindrical sleeve, and cylindrical sleeve vertical guide are made of hard materials that are not easily deformed. The liquid storage cylindrical needle is made of a material that does not damage the biomaterial ink. The biomaterial ink is continuously injected through the opening at the top of the liquid storage cylindrical needle. A small hole is opened at the bottom of the liquid storage cylindrical needle as a nozzle for spraying the biomaterial ink.

9. A biomaterial droplet ejection device according to claim 8, characterized in that: After the signal generator and the power amplifier are connected to the piezoelectric ceramic stack, the biomaterial ink is injected into the liquid storage cylindrical needle, and the piezoelectric ceramic stack is driven by the signal generator and the power amplifier to expand and contract, thereby driving the cylindrical sleeve to move up and down rapidly, and the liquid storage cylindrical needle will also move up and down rapidly following the cylindrical sleeve; wherein the large spring and the small spring are kept in a compressed state after being assembled, providing a certain preload force for the fixed part and the non-fixed part of the device; The diameter of the liquid sprayed from the biomaterial can be greatly adjusted by replacing the liquid storage cylinder needle with different nozzle diameters; the amplitude and frequency of the signal generator can be adjusted to change the amplitude of the up and down movement of the liquid storage cylinder needle and the time required for one cycle of up and down movement, which is equivalent to changing the spray force and movement speed of the liquid storage cylinder needle of the device, thereby adapting to biomaterial inks of different viscosities and achieving fine-tuning of the diameter of the biomaterial droplets sprayed from the same nozzle diameter.

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