3D printing forming method of ceramic microneedle structure

Abstract

A 3D printing forming method of ceramic microneedle structure relates to a microneedle structure forming method.The present application solves the problem that the needle tip of the existing 3D printed ceramic material is difficult to realize submicron and micron level.The method comprises the following steps: one, slurry preparation;two, 3D printing;three, drying and sintering.The present application is used for the 3D printing forming of ceramic microneedle structure.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of microneedle structure forming method. BACKGROUND

[0002] Ceramic microneedle is a kind of sharp tip micron size sharp cone structure, conventional processing method is difficult to realize the precision machining of such structure, 3D printing technology, especially high-precision light-cured 3D printing technology can realize the 3D printing preparation of microneedle structure, but for ceramic material, it is difficult to realize the needle tip structure to be sub-micron or micron level, and high-precision light-cured 3D printing equipment is expensive, and the production cost is higher.There is currently a lack of a low-cost, simple and effective ceramic microneedle structure forming method. SUMMARY

[0003] The present application solves the problem that the existing 3D printing ceramic material is difficult to realize the needle tip to be sub-micron and micron level, and further provides a kind of 3D printing forming method of ceramic microneedle structure.

[0004] A kind of 3D printing forming method of ceramic microneedle structure, it is carried out according to the following steps:

[0005] I. slurry preparation:

[0006] According to mass fraction, 10-20 parts of ordinary solvent, 10-40 parts of fast-drying solvent, 0.5-20 parts of high molecular binder, 0.2-5 parts of surfactant, 1-15 parts of rheological modifier, 50-85 parts of ceramic powder and 1-15 parts of ceramic sintering aid are mixed uniformly, then vacuum degassing stirring is carried out, to obtain the premixed slurry, the premixed slurry is dispersed, and finally vibration degassing is carried out, to obtain the degassed slurry;

[0007] II. 3D printing:

[0008] The degassed slurry is loaded into the 3D printer barrel, the needle head aperture is 0.025mm-10mm, the slurry extrusion pressure is 20Psi-100Psi, the needle head lifting speed is 0.2mm / s-50mm / s, and the platform temperature is-20℃-80℃.Under the condition, the needle head is vertically lifted upward, the slurry is extruded and printed on the platform, then the extrusion pressure is closed, the needle head is inclined upward at a lifting speed of 0.1mm / s-20mm / s, and the platform temperature is-20℃-80℃.The slurry is thinned until it is broken, to obtain a ceramic microneedle blank;

[0009] III. drying and sintering:

[0010] The ceramic microneedle blank is dried, then organic matter decomposition treatment is carried out in the degassing furnace, and finally high-temperature sintering treatment is carried out, to obtain a ceramic microneedle.

[0011] The present application has the advantages that:

[0012] This invention addresses the challenges of fabricating micron- and submicron-sized ceramic microneedles, as well as hollow ceramic microneedle structures. It proposes a low-cost, high-precision direct-write 3D printing method for fabricating micron- and submicron-sized ceramic microneedles. When the needle is a coaxial dual-needle design, the minimum pore size of the fabricated ceramic microneedle tip is 30μm to 100μm. This method can be applied to fields such as superhydrophobic structures, microneedle sensors, and high-precision 3D printing technology.

[0013] Instruction manual illustrations

[0014] Figure 1 This is a particle size distribution diagram of the ceramic powder described in step one of Example 1;

[0015] Figure 2 The image shown is a scanning electron microscope (SEM) image of the ceramic powder described in step one of Example 1.

[0016] Figure 3 The rheological curve of the deaerated slurry prepared in step one of Example 1;

[0017] Figure 4 The stress-modulus curves of the deaerated slurry prepared in step one of Example 1 are shown below. 1 is the rheological curve of loss modulus, and 2 is the rheological curve of storage modulus.

[0018] Figure 5 Electron micrograph of the outer diameter of the ceramic microneedles prepared in Example 1;

[0019] Figure 6 Electron micrograph of the inner diameter of the ceramic microneedles prepared in Example 1;

[0020] Figure 7 The side surface morphology of the ceramic microneedles prepared in Example 1;

[0021] Figure 8 Here is a photograph of the ceramic microneedles prepared in Example 1;

[0022] Figure 9 The particle size distribution diagram of the ceramic powder sampled three times in step one of Example 2 is shown below. 1 represents the first sample, 2 represents the second sample, and 3 represents the third sample.

[0023] Figure 10 This is a scanning electron microscope image of the ceramic powder described in step one of Example 2;

[0024] Figure 11 The stress-modulus curve of the deaerated slurry prepared in step one of Example 2;

[0025] Figure 12 Rheological curve of the deaerated slurry prepared in step one of Example 2;

[0026] Figure 13 A photograph of the ceramic microneedle prepared for Example Two;

[0027] Figure 14 An inner diameter size electron microscope image of the ceramic microneedle prepared for Example Three;

[0028] Figure 15 A photograph of the ceramic microneedle prepared for Example Three. DETAILED DESCRIPTION

[0029] Specific embodiment one: the present embodiment is a 3D printing forming method of a ceramic microneedle structure, which is performed according to the following steps:

[0030] I. Preparation of slurry:

[0031] 10-20 parts of ordinary solvent, 10-40 parts of fast-drying solvent, 0.5-20 parts of polymer binder, 0.2-5 parts of surfactant, 1-15 parts of rheological modifier, 50-85 parts of ceramic powder and 1-15 parts of ceramic sintering aid are weighed according to the mass fraction, and then mixed uniformly, followed by vacuum degassing stirring to obtain the premixed slurry. The premixed slurry is subjected to dispersion treatment, and finally vibration degassing to obtain the degassed slurry;

[0032] II. 3D printing:

[0033] The degassed slurry is loaded into the 3D printer barrel. Under the conditions of a needle head aperture of 0.025-10 mm, a slurry extrusion pressure of 20-100 Psi, a needle head lifting speed of 0.2-50 mm / s and a platform temperature of -20-80℃, the needle head is lifted vertically upward, the slurry is extruded and printed on the platform, then the extrusion pressure is closed, the needle head is tilted upward at a lifting speed of 0.1-20 mm / s and a platform temperature of -20-80℃, and the slurry is thinned until it is broken, to obtain a ceramic microneedle body;

[0034] III. Drying and sintering:

[0035] The ceramic microneedle body is dried, then subjected to organic matter decomposition treatment in a degassing furnace, and finally high-temperature sintering treatment to obtain a ceramic microneedle.

[0036] Principle:

[0037] The ceramic slurry with certain fluidity (the phase of the slurry changes under the action of shear stress) is prepared by using ceramic powder, solvent with specific composition and polymer system. The ceramic slurry is extruded on the printing platform by using a direct writing 3D printing device. Then, the printing feed pressure is closed, and the printing head is lifted, so that the slurry is stretched into micro fibers under the traction of the printing head. Since the specific surface area of the slurry increases after being stretched, the volatile solvent in the slurry quickly evaporates and dries, and the modulus of the slurry quickly increases. The microstructure is quickly maintained during the drying process, so that the needle tip structure with micron and sub-micron size is obtained. In particular, when a double needle structure is used for operation, the inner needle is extruded by air, and the outer needle is extruded by slurry, so that the ceramic microneedle with hollow structure is obtained.

[0038] The beneficial effects of the embodiment are:

[0039] The embodiment proposes a direct writing 3D printing preparation method for micron and sub-micron structure ceramic microneedle, which can solve the problem of difficult preparation of micron, sub-micron ceramic microneedle and hollow ceramic microneedle structure. When the needle is a coaxial double needle, the minimum aperture of the needle tip of the prepared ceramic microneedle is 30 μm to 100 μm. It can be applied to the fields of super-hydrophobic structure, microneedle sensor and high-precision 3D printing technology.

[0040] Specific implementation method two: the difference between the embodiment and the specific implementation method one is that the vacuum degassing stirring in step one is specifically under the condition that the rotation speed is 500 r / min to 2400 r / min and the vacuum degree is 10 kPa to 60 kPa, and the vacuum degassing stirring is 5 min to 30 min. The others are the same as the specific implementation method one.

[0041] Specific implementation method three: the difference between the embodiment and one of the specific implementation method one or two is that the dispersion treatment in step one is performed by using a three-roll grinder or a high-pressure homogenizer. When the three-roll grinder is used for dispersion treatment, the specific implementation is as follows: under the condition that the roller rotation speed is 300 rpm to 800 rpm, the grinding is 5 times to 10 times. When the high-pressure homogenizer is used for dispersion treatment, the specific implementation is as follows: under the condition that the pressure is 15000 Psi to 30000 Psi, the treatment is 2 min to 20 min. The others are the same as the specific implementation method one or two.

[0042] Specific implementation method four: the difference between the embodiment and one of the specific implementation methods one to three is that the vibration degassing in step one is specifically performed as follows: under the condition that the vibration frequency is 10 Hz to 1000 Hz, the degassing is 10 min to 30 min. The others are the same as the specific implementation methods one to three.

[0043] Embodiment five: the difference between this embodiment and one of the embodiments one to four is that: the molecular weight of the polymer binder in step one is 400-200000; the common solvent in step one is one or a mixture of several of deionized water, ethylene glycol, terpineol and ethylene glycol monomethyl ether; the fast-drying solvent in step one is one or a mixture of several of anhydrous ethanol, isopropyl alcohol, butanone, acetone, cyclohexanone, ethyl acetate and butyl acetate; the polymer binder in step one is one or a mixture of several of ethyl cellulose, methyl cellulose, carboxymethyl cellulose, polyvinyl alcohol and polyvinyl butyral; the surfactant in step one is one or a mixture of several of sodium dodecyl benzene sulfonate, triton, tween and polyvinyl pyrrolidone; the rheological modifier in step one is one or a mixture of several of castor oil, glycerol, nanoclay, graphene and boron nitride; the ceramic powder in step one is one or a mixture of several of alumina, zirconia, silicon nitride, silicon oxide, aluminum nitride and silicon carbide; the ceramic sintering aid in step one is one or a mixture of several of yttria, magnesia, calcia, lanthana, potassia and boria. The others are the same as embodiments one to four.

[0044] Embodiment six: the difference between this embodiment and one of the embodiments one to five is that: the particle size of the ceramic powder in step one is one or a mixture of both of micron and nanometer. The others are the same as embodiments one to five.

[0045] Embodiment seven: the difference between this embodiment and one of the embodiments one to six is that: the needle in step two is single-hole needle or coaxial double-needle; the type of the needle in step two is straight cylinder or sharp nozzle; the slurry in step two is extruded by gas pressure or screw pressure. The others are the same as embodiments one to six.

[0046] Embodiment eight: the difference between this embodiment and one of the embodiments one to seven is that: the needle in step two is tilted upwardly, the included angle between the needle and the vertical platform surface is 10-30 degrees; the total lifting height of the needle before and after the extrusion pressure is closed is 1-80 mm. The others are the same as embodiments one to seven.

[0047] Specific implementation nine: the difference between this embodiment and one of the specific implementation one to eight is that the drying in step three is specifically vacuum drying or air drying at a drying temperature of 25℃-150℃; the organic matter decomposition treatment in the degreasing oven in step three is specifically heating to 250℃-500℃ at a heating rate of 0.1℃ / min-5℃ / min, and the organic matter decomposition treatment is performed at a temperature of 250℃-500℃ for 0.5h-4h; the high-temperature sintering treatment in step three is specifically high-temperature sintering treatment at a temperature of 1000℃-2000℃ for 1h-24h. The others are the same as specific implementation one to eight.

[0048] Specific implementation ten: the difference between this embodiment and one of the specific implementation one to nine is that when the needle in step two is a coaxial double needle, the minimum pore size of the ceramic microneedle tip prepared in step three is 30μm-100μm. The others are the same as specific implementation one to nine.

[0049] The beneficial effects of the application are verified by the following examples:

[0050] Example one:

[0051] A 3D printing forming method of a ceramic microneedle structure, which is performed according to the following steps:

[0052] I. Preparation of slurry:

[0053] 10 parts of ordinary solvent, 10 parts of quick-drying solvent, 5 parts of high molecular binder, 1 part of surfactant, 3 parts of rheological modifier, 70 parts of ceramic powder and 1 part of ceramic sintering aid are weighed according to the mass fraction and mixed uniformly, then vacuum degassing stirring is performed, to obtain the premixed slurry, the premixed slurry is dispersed by a three-roll grinder, and finally vibration degassing is performed to obtain the degassed slurry;

[0054] II. 3D printing:

[0055] The degassed slurry is loaded into the 3D printer barrel, the needle is vertically lifted 10mm under the conditions of slurry extrusion pressure of 100Psi, needle lifting speed of 1mm / s and platform temperature of 30℃, the slurry is extruded and printed on the platform, then the extrusion pressure is closed, the needle is tilted and lifted 5mm under the conditions of needle lifting speed of 0.5mm / s and platform temperature of 30℃, and the slurry is thinned until it is broken, to obtain a ceramic microneedle blank;

[0056] III. Drying and sintering:

[0057] The ceramic microneedle blank is dried, then the organic matter decomposition treatment is performed in the degreasing oven, and finally the high-temperature sintering treatment is performed, to obtain the ceramic microneedle.

[0058] The vacuum defoaming stirring in step one is specifically 60s under the conditions of 10kPa vacuum degree and 500r / min rotating speed, 60s under the conditions of 10kPa vacuum degree and 1500r / min rotating speed, 120s under the conditions of 10kPa vacuum degree and 2400r / min rotating speed, and 60s under the conditions of 10kPa vacuum degree and 1800r / min rotating speed.

[0059] The dispersion treatment of the premixed slurry in step one is performed by a three-roll grinder, specifically by the following steps: 10 times of grinding under the conditions of 500rpm rotating speed of the roller.

[0060] The vibration defoaming in step one is specifically by the following steps: 10min of defoaming under the conditions of 10Hz vibration frequency.

[0061] The molecular weight of the polymer binder in step one is 448.474; the common solvent in step one is a mixture of ethylene glycol, terpineol and ethylene glycol monomethyl ether in a mass ratio of 2:2:6; the fast-drying solvent in step one is a mixture of anhydrous ethanol, isopropyl alcohol, butanone, ethyl acetate and butyl acetate in a mass ratio of 5:2:1:1:1; the polymer binder in step one is ethyl cellulose; the surfactant in step one is a mixture of sodium dodecyl benzene sulfonate and triton in a mass ratio of 0.5:0.5; the rheological modifier in step one is a mixture of castor oil and glycerol in a mass ratio of 1:2; the ceramic powder in step one is alumina; and the ceramic sintering aid in step one is boron oxide.

[0062] The shape of the ceramic powder in step one is a mixture of block and spherical shape; and the median particle size of the ceramic powder in step one is 0.599 microns.

[0063] The needle in step two is a coaxial double needle, the inner needle has a diameter of 0.5mm, the outer needle has a diameter of 1mm, and the gap between the inner and outer needles is a slurry extrusion channel; the needle type in step two is straight cylinder type; and the slurry is extruded by gas pressure in step two.

[0064] The needle is inclined upward in step two, and the straight line angle between the needle and the vertical platform surface is 30 degrees; and the total lifting height of the needle is 15mm before and after the extrusion pressure is closed in step two.

[0065] The drying in step three is vacuum drying at a drying temperature of 70℃; the organic matter decomposition treatment in the degreasing oven in step three is organic matter decomposition treatment in the degreasing oven at a temperature rising rate of 5℃ / min, rising the temperature to 500℃, and treating at a temperature of 500℃ for 2h; and the high-temperature sintering treatment in step three is high-temperature sintering treatment at a temperature of 1800℃ for 3h.

[0066] The minimum pore size of the ceramic microneedle tip prepared in step three is 363μm.

[0067] Example Two: This example is different from example one in that: in step one, 10 parts of ordinary solvent, 10 parts of fast-drying solvent, 3 parts of high molecular binder, 5 parts of surfactant, 1 part of rheological modifier, 70 parts of ceramic powder and 1 part of ceramic sintering aid are taken by mass fraction and mixed uniformly; in step one, the slurry is dispersed by a high-pressure homogenizer, specifically by the following steps: under a pressure of 18000Psi, treat for 6min, and then under a pressure of 25000Psi, treat for 6min; the molecular weight of the high molecular binder in step one is 432.904; the ordinary solvent in step one is a mixture of deionized water, ethylene glycol, terpineol and ethylene glycol monomethyl ether in a mass ratio of 5:1:2:2; the fast-drying solvent in step one is a mixture of anhydrous ethanol, isopropyl alcohol, cyclohexanone and ethyl acetate in a mass ratio of 3:5:1:1; the high molecular binder in step one is polyvinyl butyral; the surfactant in step one is polyvinylpyrrolidone (also acts as a dispersant for the powder); the rheological modifier in step one is a mixture of nano-clay, graphene and boron nitride in a mass ratio of 0.2:0.7:0.1; the ceramic powder in step one is aluminum nitride; the ceramic sintering aid in step one is a mixture of yttrium oxide and magnesium oxide in a mass ratio of 0.5:0.5; the shape of the ceramic powder in step one is a mixture of spherical and spheroidal; and the median particle size of the ceramic powder in step one is 50nm. The rest is the same as example one.

[0068] Example three: the difference between this example and example one is that: the needle type in step two is sharp mouth type; in step two, the defoamed slurry is loaded into the 3D printer cartridge, under the conditions of slurry extrusion pressure of 80 Psi, needle lifting speed of 0.2 mm / s and platform temperature of 30℃, the needle is lifted vertically upward by 15 mm, the slurry is extruded and printed on the platform, then the extrusion pressure is closed, under the conditions of needle lifting speed of 0.1 mm / s and platform temperature of 30℃, the needle is tilted upward by 15 mm, the slurry is attenuated until it is pulled off, and the ceramic microneedle blank is obtained; in step two, the needle is tilted upward, the straight line angle between the needle and the vertical platform surface is 10 degrees; in step two, the total lifting height of the needle before and after the extrusion pressure is closed is 30 mm; in step two, the needle is coaxial double needle, the inner needle diameter is 5 mm, and the outer needle diameter is 10 mm; in step three, the minimum pore size of the ceramic microneedle tip prepared is 77 μm. The others are the same as example one.

[0069] Figure 1 The particle size distribution graph of the ceramic powder described in step one of the example; table 1 is the particle size distribution table of the ceramic powder described in step one of the example; Figure 2 The scanning electron microscope graph of the ceramic powder described in step one of the example; the physical properties of the ceramic particles, such as particle size distribution, morphology, etc. significantly affect the viscosity and dispersion state of the ceramic slurry and other indicators. The wet method of laser particle size analyzer is used to measure the particle size distribution of ceramic powder particles, and the D50 of the median particle size of the particles is measured to be 0.599 μm, the particle size distribution is concentrated between 0.2 μm and 5 μm, and the particle distribution is relatively uniform.

[0070] Table 1

[0071]

[0072] Under room temperature conditions, the volatilization amount test of the defoamed slurry prepared in step one of the example is carried out, and the test is carried out every 2 min, and the volatilization amount of the solvent in the slurry is measured to be 56% after 10 min. The slurry volatilization speed is fast, and the morphology of the ceramic microneedle can be maintained after extrusion printing.

[0073] Figure 3 The rheological curve of the defoamed slurry prepared in step one of the example; Figure 4The stress-modulus curve of the defoamed slurry prepared in step one of the example, 1 is the rheological curve of loss modulus, and 2 is the rheological curve of storage modulus; the rheological properties of the ceramic slurry affect the flowability of the slurry and the printing accuracy, and then directly affect the mechanical properties of the ceramic part after sintering. The rheometer was used for testing, the temperature was set to 28℃, the shear rate γ was changed from 0 to 60 (1 / s), and the viscosity η value was tested. The viscosity of the slurry is above 10 Pa*s, and the viscosity decreases with the increase of the shear rate, which can be continuously extruded under pressure. The rheological curve of the modulus changing with the shear stress at a constant temperature is shown in FIG. 1. When τ = 630 Pa, the two curves of G' and G" intersect, the phase state of the surface slurry changes, G' storage modulus > G" loss modulus: the material is more biased towards the characteristics of elastic solid, when τ > 630 Pa, the slurry is in viscous liquid state, which shows that the slurry in viscoelastic solid state is relatively stable before stress is applied, and the slurry can be successfully printed when the stress is applied to the phase transition. Figure 4

[0074] The porosity and bulk density of the ceramic microneedle prepared in example one were determined by the Archimedes drainage method. The measured bulk density was 2.5857 g / cm 3 , and the porosity was 32%.

[0075] The mechanical strength of the ceramic microneedle was characterized by TA.XTC-20 microneedle strength tester, the average strength of the microneedle prepared in example one was 25.719 N, the fracture stress was 25.757 N, the average fracture displacement of the microneedle was 0.475 mm, the elastic modulus was 390 GPa, and the Vickers hardness was 2000 HV.

[0076] Figure 5 The outer diameter size electron microscope graph of the ceramic microneedle prepared in example one is shown in FIG. 4. Figure 6 The inner diameter size electron microscope graph of the ceramic microneedle prepared in example one is shown in FIG. 5. As shown in the figure, the outer diameter of the needle tip at the top of the ceramic microneedle is 455 μm, and the inner diameter is 362.9 μm.

[0077] Figure 7 The side surface morphology of the ceramic microneedle prepared in example one is shown in FIG. 6. As shown in the figure, the surface after sintering is relatively dense.

[0078] Figure 8 The actual object graph of the ceramic microneedle prepared in example one is shown in FIG. 7. As shown in the figure, the slurry prepared in example one can realize the smooth printing of the ceramic microneedle.

[0079] Figure 9 The particle size distribution graph of the ceramic powder sampled three times in step one of example two is shown in FIG. 8, 1 is the first sampling, 2 is the second sampling, and 3 is the third sampling; the particle size distribution is between 10 nm and 140 nm, mainly concentrated between 25 nm and 85 nm. ​

[0080] Figure 10 The scanning electron microscope image of the ceramic powder prepared in step one of Example Two; as can be seen from the figure, the morphology of the nano-aluminum nitride powder presents a spherical or spherical-like morphology, and part of the remaining non-spherical morphology.

[0081] The volatilization amount of the defoamed slurry prepared in step one of Example Two was tested at room temperature, and the mass of the slurry before and after volatilization was tested after 10 min, and the volatilization amount of the solvent in the slurry was calculated to be 50%, the slurry volatilization speed was fast, and the morphology of the ceramic microneedle could be maintained after extrusion printing.

[0082] Figure 11 The stress-modulus curve of the defoamed slurry prepared in step one of Example Two; as can be seen from the figure, when τ = 139 Pa, the phase of the slurry changes, and with the change of shear stress, the slurry changes from viscoelastic liquid to solid state, which can maintain the precision and morphology of the printed ceramic microneedle.

[0083] Figure 12 The rheological curve of the defoamed slurry prepared in step one of Example Two; as can be seen from the figure, with the increase of shear stress, the trend of viscosity curve gradually changes and gradually becomes stable, which indicates that the nano-aluminum nitride is uniformly dispersed in the dispersion system, which is beneficial to the smooth printing of the slurry.

[0084] The porosity and bulk density of the ceramic microneedle ceramic prepared in Example Two were determined by Archimedes drainage method. The measured bulk density was 3.3672 g / cm 3 , and the porosity was 23%.

[0085] The TA.XTC-20 microneedle strength tester was used to characterize the mechanical strength of the ceramic microneedle, and the average strength of the microneedle prepared in Example Two was 30.210 N, the fracture stress was 30.223 N, the average fracture displacement of the microneedle was 0.649 mm, the elastic modulus was 308 GPa, and the Vickers hardness was 1800 HV.

[0086] Figure 13 The actual picture of the ceramic microneedle prepared in Example Two; as can be seen from the figure, the slurry prepared in Example Two can realize the smooth printing of the ceramic microneedle.

[0087] Figure 14 The inner diameter size electron microscope image of the ceramic microneedle prepared in Example Three; as can be seen from the figure, the diameter of the hollow part of the needle tip is 0.077 mm.

[0088] Figure 15 The actual picture of the ceramic microneedle prepared in Example Three; as can be seen from the figure, the ceramic microneedle surface is smooth, and the needle tip is clear.

Claims

1. A 3D printing method of ceramic microneedle structure, characterized in that It is carried out in the following steps: I. Preparation of slurry: Take 10-20 parts of ordinary solvent, 10-40 parts of fast-drying solvent, 0.5-20 parts of high molecular binder, 0.2-5 parts of surfactant, 1-15 parts of rheological modifier, 50-85 parts of ceramic powder and 1-15 parts of ceramic sintering aid by mass fraction, and mix them uniformly, then vacuum degassing stirring to get the premixed slurry, disperse the premixed slurry, and finally shake degassing to get the degassed slurry; The ordinary solvent is a mixture of ethylene glycol, terpineol and ethylene glycol monomethyl ether in a mass ratio of 2:2:6; the fast-drying solvent is a mixture of anhydrous ethanol, isopropyl alcohol, butanone, ethyl acetate and butyl acetate in a mass ratio of 5:2:1:1:1; The high molecular binder is ethyl cellulose; The surfactant is a mixture of sodium dodecyl benzene sulfonate and triton in a mass ratio of 0.5:0.5; The rheological modifier is a mixture of castor oil and glycerol in a mass ratio of 1:2; The ceramic powder is a mixture of one or more of alumina, zirconia, silicon nitride, silicon oxide, aluminum nitride and silicon carbide; The ceramic sintering aid is a mixture of one or more of yttrium oxide, magnesium oxide, calcium oxide, lanthanum oxide, potassium oxide and boron oxide; II. 3D printing: Load the degassed slurry into the 3D printer cartridge, under the conditions of needle hole diameter 0.025-10 mm, slurry extrusion pressure 20-100 Psi, needle lifting speed 0.2-50 mm / s and platform temperature-20-30℃, vertically upwardly lift the needle, extrude the slurry on the platform, then turn off the extrusion pressure, under the conditions of needle lifting speed 0.1-20 mm / s and platform temperature-20-30℃, tilt the needle upwardly, the straight line angle between the needle and the vertical platform surface is 10-30 degrees, the slurry is attenuated until it is broken, and the ceramic microneedle blank is obtained; The needle is a coaxial double needle; III. Drying and sintering: Dry the ceramic microneedle blank, then perform organic matter decomposition treatment in a degassing oven, and finally perform high temperature sintering treatment to obtain the ceramic microneedle; The organic matter decomposition treatment in the degassing oven is specifically carried out in the degassing oven at a temperature rising rate of 0.1-5℃ / min, the temperature is raised to 250-500℃, and the organic matter decomposition treatment is carried out at a temperature of 250-500℃ for 0.5-4h; the high temperature sintering treatment is specifically carried out at a temperature of 1800-2000℃ for 1-24h.

2. A 3D printing method of ceramic microneedle structure according to claim 1, characterized in that The vacuum degassing stirring in step I is specifically carried out at a rotation speed of 500-2400r / min and a vacuum degree of 10-60kPa for 5-30min.

3. A 3D printing method of ceramic microneedle structure according to claim 1, characterized in that The dispersion treatment in step one is performed by using a three-roll grinder or a high-pressure homogenizer; when using a three-roll grinder, the dispersion treatment is performed by the following steps: grinding for 5-10 times under the condition of a roller rotating speed of 300-800 rpm; when using a high-pressure homizer, the dispersion treatment is performed by the following steps: treating for 2-20 min under the condition of a pressure of 15000-30000 Psi.

4. The method of claim 1, wherein the ceramic microneedle structure is formed by 3D printing. The vibration defoaming in step one is performed by the following steps: defoaming for 10-30 min under the condition of a vibration frequency of 10-1000 Hz.

5. The method of claim 1, wherein the ceramic microneedle structure is formed by 3D printing. The molecular weight of the polymer binder in step one is 400-200000.

6. A 3D printing method of ceramic microneedle structure according to claim 1, characterized in that The particle size of the ceramic powder in step one is one of micron level and nanometer level or a mixture of both.

7. The method of claim 1, wherein the ceramic microneedle structure is formed by 3D printing. The needle type in step two is straight or sharp; a gas pressure or a screw pressure is used to extrude the slurry in step two.

8. A 3D printing method of ceramic microneedle structure according to claim 1, characterized in that The total lifting height of the needle before and after the extrusion pressure is closed is 1-80 mm.

9. The method of claim 1, wherein the ceramic microneedle structure is formed by 3D printing. The drying in step three is performed by vacuum drying or air blowing drying under the condition of a drying temperature of 25-150℃.

Images