Method for manufacturing micro-nano injection needles based on plant villi and micro-nano injection needles

Abstract

The present invention discloses a method for manufacturing a micro-nano injection needle based on plant villi and the micro-nano injection needle; the method for manufacturing a micro-nano injection needle based on plant villi includes the following steps: Step S1, preparing a plant villi mold by a freezing method; Step S2, casting the plant villi mold by a casting method to obtain an injection needle model with nano-channels based on plant villi; Step S3, etching a micro-channel above the injection needle model with nano-channels obtained in Step S2 by a laser method to obtain a micro-nano injection needle. The method for manufacturing a micro-nano injection needle based on plant villi and the micro-nano injection needle disclosed by the present invention utilize the villi on the surface of plant leaves to manufacture the micro-nano injection needle by obtaining a plant villi mold with nano-channels, and have the advantages of simple preparation process, low preparation cost, and easy mass production.

Description

Technical Field

[0001] The present invention relates to the field of microelectromechanical technology, and particularly relates to a method for manufacturing a micro-nano injection needle based on plant villi and a micro-nano injection needle. Background Art

[0002] With the rapid development of micro-nano technology and the wide application of micro-nano injection needles, it is urgent to develop low-cost and high-precision micro-nano injection needles.

[0003] In the prior art, micro-nano injection needles can be manufactured by the heat stretching method. By heating and stretching the material, micro-nano scale injection needles are obtained. This method has a simple operation process, but it is difficult to precisely control the size of the injection needles and they are prone to damage. In the prior art, micro-nano injection needles can also be manufactured by combining the angle forming and peeling method with the casting method. First, a silicon nano concave mold is prepared by the angle forming and peeling method, then a PDMS nano convex mold is obtained by the casting method, and further a micro-nano injection needle convex mold is prepared by printing convex lines. Finally, an unbonded polymer micro-nano injection needle is obtained by the casting method, which is bonded with a PDMS injection needle cover plate and inserted with a steel needle to obtain the final product. This method has relatively flexible manufacturing processes, can achieve plug-and-play, but has more steps in the preparation process, is relatively complex, and has high technical requirements for experimental personnel.

[0004] Therefore, how to manufacture high-precision micro-nano injection needles with low cost and high throughput is one of the key problems that need to be solved urgently at present. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a method for manufacturing a micro-nano injection needle based on plant villi and a micro-nano injection needle. By using the villi on the surface of plant leaves to obtain a plant villi mold with nano-channels, the micro-nano injection needle is manufactured, which has the advantages of simple preparation process, low preparation cost, and easy mass production.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for manufacturing a micro-nano injection needle based on plant villi, comprising the following steps:

[0007] Step S1, preparing a plant villi mold by the freezing method;

[0008] Step S2, casting the plant villi mold by the casting method to obtain an injection needle model based on plant villi with nano-channels;

[0009] Step S3, etching a micro-channel above the injection needle model with nano-channels obtained in Step S2 by the laser method to obtain a micro-nano injection needle.

[0010] In a preferred embodiment of the present invention, the step of preparing a plant villi mold by the freezing method in Step S1 comprises the following steps:

[0011] Step S1.1: Obtain a plant body with plant villi, and the cross-sectional diameter of the plant villi includes the nanoscale;

[0012] Step S1.2: Pretreat the plant body with plant villi;

[0013] Step S1.3: Lay and fix the plant body with plant villi after being processed in Step S1.2 on a glass substrate;

[0014] Step S1.4: Freeze and fix the plant body with plant villi on the glass substrate by the freezing method, and spray trimethylchlorosilane on the plant body with plant villi during freezing to obtain a plant villi mold.

[0015] In a preferred embodiment of the present invention, in Step S1.2, pretreating the plant body with plant villi includes the following steps:

[0016] Step S1.2.1: Place the plant body with plant villi in deionized water for ultrasonic cleaning;

[0017] Step S1.2.2: Dry the plant body with plant villi after ultrasonic cleaning;

[0018] Step S1.2.3: Trim the plant body with plant villi after drying treatment;

[0019] The freezing method includes:

[0020] Step S1.4.1: Spray deionized water mist on the plant body with plant villi fixed on the glass substrate to obtain a moist plant body with plant villi;

[0021] Step S1.4.2: Place the moist plant body with plant villi in a freezing environment for freezing.

[0022] In a preferred embodiment of the present invention, in Step S2, the casting method includes the following steps:

[0023] Step S2.1: Let the PDMS mixed solution flow uniformly from the periphery to the center of the plant villi mold and cover the plant villi mold to obtain a PDMS plant villi mold;

[0024] Step S2.2: Place the PDMS plant villi mold on a leveled horizontal platform for curing.

[0025] Step S2.3: Separate the cured PDMS solid in the PDMS plant villi mold from the plant villi mold to obtain a needle spray model with nanochannels.

[0026] In a preferred embodiment of the present invention, in step S3, a laser method is used to etch a microchannel above the needle model with nanochannels obtained in step S2 to obtain a micro-nano needle, including the following steps:

[0027] Place the clean needle model with nanochannels on a laser three-dimensional platform, and use the laser etching method to print a microchannel with a diameter of 50 - 200 μm that communicates with the nanochannels in the needle model above the clean needle model with nanochannels. Each microchannel communicates with several nanochannels to obtain a PDMS needle model with microchannels and nanochannels;

[0028] In a preferred embodiment of the present invention, the micro-nano needle obtained in step S3 is a single-channel micro-nano needle, including the following steps:

[0029] Place the clean needle model with nanochannels on a laser three-dimensional platform, and use the laser etching method to print one-to-one a microchannel with a diameter of 50 - 200 μm that communicates with the nanochannels in the needle model above the clean needle model with nanochannels. Each microchannel communicates with 1 nanochannel to obtain a single-channel needle model with microchannels and nanochannels; wherein, the printing laser is a carbon dioxide laser, the laser power is 10 - 20 W, and the speed is 20 - 30 mm / s; Take one group of connected microchannels and nanochannels as a group, and use a coated tool to divide the single-channel needle model with microchannels and nanochannels into groups, and insert a steel needle after oxygen plasma surface treatment into the microchannel for interference fit to obtain a single-channel micro-nano needle.

[0030] And / or, the micro-nano needle obtained in step S3 is a multi-channel micro-nano needle, including the following steps:

[0031] Place the clean needle model with nanochannels on a laser three-dimensional platform, and use the laser etching method to print one-to-one a microchannel with a diameter of 50 - 200 μm that communicates with the nanochannels in the needle model above the clean needle model with nanochannels. Each microchannel communicates with 1 nanochannel to obtain a multi-channel needle model with microchannels and nanochannels; wherein the printing laser is a carbon dioxide laser, the laser power is 10 - 20 W, and the speed is 20 - 30 mm / s; Cut the multi-channel needle model with microchannels and nanochannels into parts using a coated tool, and each part has 2 - 4 connected microchannels and nanochannels, and insert a steel needle after oxygen plasma surface treatment into the microchannel for interference fit to obtain a multi-channel micro-nano needle.

[0032] And / or, the micro-nano needle obtained in step S3 is an array micro-nano needle, including the following steps:

[0033] Place the clean needle model with nanochannels on a laser three-dimensional platform, and use laser etching to print a microchannel with a diameter of 50 - 200 μm connected to the nanochannels in the needle model above the clean needle model with nanochannels. Each microchannel corresponds to 2 - 4 connected nanochannels to obtain an array needle model with microchannels and nanochannels. The printing laser is a carbon dioxide laser, with a laser power of 20 - 30 W and a speed of 20 - 30 mm / s. Cut the array needle model with microchannels and nanochannels into parts using a coating tool. Each part has 1 microchannel corresponding to 2 - 4 connected nanochannels, and insert a steel needle after oxygen plasma hydrophilic treatment into the microchannel for interference fit to obtain an array of micro-nano needles.

[0034] In a preferred embodiment of the present invention, in step S1.2.1, place the plant body with plant hairs in deionized water for ultrasonic cleaning; the working time is 15 - 25 min, the power is 20 - 60 W, and the temperature is 20 - 30 °C;

[0035] And / or, in step S1.2.2, place the plant body with plant hairs after ultrasonic cleaning in a room temperature condition for drying for 6 - 8 h to remove the moisture on the surface of the plant hairs of the plant body to achieve drying treatment;

[0036] And / or, in step S1.2.3, use a coating tool to cut the plant body with plant hairs after drying treatment into leaf strips with a width of 5 - 10 mm, and select the leaf strips that meet the preparation requirements; achieve trimming of the plant body with plant hairs after drying treatment;

[0037] And / or, in step S1.4.2, place the moist plant body with plant hairs in a freezing environment at - 30 ~ - 15 °C for 3 - 5 h.

[0038] In a preferred embodiment of the present invention, the preparation method of the PDMS mixed solution in step S2.1 includes: mixing the base material of PDMS and the curing agent in a volume ratio of 5:1 - 10:1, stirring for 5 - 10 min to obtain a PDMS mixed solution, and placing the PDMS mixed solution in a vacuum box for 20 - 30 min for degassing to remove the internal bubbles in the PDMS mixed solution;

[0039] And / or, in step S2.2, place the PDMS plant hair mold on a leveled horizontal platform and cure it at room temperature for 18 - 32 h;

[0040] And / or, in step S2.3, after separating the cured PDMS solid in the PDMS plant hair mold from the plant hair mold, the following steps are further included: placing the PDMS needle model with nanochannels downward with the nanochannels facing down in deionized water and ultrasonically cleaning to remove the residual plant hairs in the nanochannels; and placing it on a hot plate for heating to obtain a clean needle model with nanochannels.

[0041] In a preferred embodiment of the present invention, the plant body with plant hairs used for preparing the plant hair mold includes one of Parthenocissus tricuspidata leaves, lotus flowers, and water lilies.

[0042] And / or, when ultrasonically cleaning the plant body with plant hairs, placing the leaf face down can effectively protect the plant hairs and facilitate the discharge of dirt between the hairs.

[0043] And / or, when selecting the leaf strips of the plant body with plant hairs, selecting the leaf strips in which each hair on the leaf strip is arranged longitudinally in a single row.

[0044] And / or, in step S2.3, placing the concave surface of the needle model with nanochannels downward, the power of ultrasonic cleaning is 100 - 300 W to remove the residual plant hairs.

[0045] And / or, in step S2.3, the heating temperature when placed on the hot plate for heating is 60 - 90 °C, and the heating time is 20 - 30 min.

[0046] In a preferred embodiment of the present invention, a micro-nano needle based on plant hairs is prepared by using the micro-nano needle manufacturing method based on plant hairs.

[0047] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are:

[0048] The micro-nano needle manufacturing method and micro-nano needle based on plant hairs of the present invention utilize the hairs on the plant leaf surface to manufacture micro-nano needles by obtaining a plant hair mold with nanochannels, and have the advantages of simple preparation process, low preparation cost, and easy mass production.

[0049] 1. The present invention is based on the hairs of Parthenocissus tricuspidata leaves and uses the freeze-casting method and the strategy of "surrounding the center from all sides" to manufacture nano-needle channels.

[0050] 2. The present invention uses the laser etching method to manufacture microchannels, and obtains single-channel micro-nano needles, multi-channel micro-nano needles, and array micro-nano needles through different cutting methods. Brief Description of the Drawings

[0051] The present invention will be further described below with reference to the drawings and embodiments.

[0052] Figure 1 It is the flow chart of the pretreatment of Parthenocissus tricuspidata leaves in the preferred embodiment of the present invention;

[0053] Figure 2 It is the flow chart of the nanochannel of the injection needle prepared by the freeze-casting method in the preferred embodiment of the present invention;

[0054] Figure 3 It is the flow chart of the microchannel of the injection needle prepared by the laser etching method in the preferred embodiment of the present invention;

[0055] Figure 4 It is the structural schematic diagram of the single-channel micro-nano injection needle in the preferred embodiment of the present invention;

[0056] Figure 5 It is the structural schematic diagram of the multi-channel micro-nano injection needle in the preferred embodiment of the present invention;

[0057] Figure 6 It is the structural schematic diagram of the array micro-nano injection needle in the preferred embodiment of the present invention;

[0058] Figure 7 It is the high-magnification tool microscope image of the plant hairs on the surface of Parthenocissus tricuspidata leaves in the preferred embodiment of the present invention;

[0059] Figure 8 It is the SEM image of the cross-section of the nanochannel of the single-channel micro-nano injection needle in the PDMS micro-nano injection needle in the preferred embodiment of the present invention;

[0060] Figure 9 It is the SEM image of the cross-section of the nanochannel of the multi-channel micro-nano injection needle in the PDMS micro-nano injection needle in the preferred embodiment of the present invention;

[0061] In the figure: 1. Parthenocissus tricuspidata leaf; 2. Ultrasonic cleaner; 3. Sprayer; 4. Leaf strips; 5. Freezing environment; 6. PDMS solidified body; 7. Injection needle model; 8. Hot plate; 10. Nanochannel; 11. Microchannel; 12. Steel needle. Detailed implementation manners

[0062] Now, the present invention will be further described in detail with reference to the drawings and embodiments. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0063] It should be noted that if there are directional indications (such as up, down, bottom, top, etc.) involved in the embodiments of the present invention, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture. If the specific posture changes, then the directional indications will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] As Figures 1-6 shown, a method for manufacturing a micro-nano injection needle based on plant villi includes the following steps:

[0065] Step S1, preparing a plant villi mold by a freezing method.

[0066] Preparing a plant villi mold by a freezing method includes the following steps:

[0067] Step S1.1, obtaining a plant body with plant villi, and the cross-sectional diameter of the plant villi includes the nanoscale. In this embodiment, the plant body with plant villi used for preparing the plant villi mold is Parthenocissus tricuspidata leaf 1. However, it is not limited thereto. In other embodiments, other plant bodies with plant villi can be selected according to actual usage requirements, and the diameter of the plant villi includes the nanoscale.

[0068] Step S1.2, preprocessing the plant body with plant villi;

[0069] Preprocessing the plant body with plant villi in Step S1.2 includes the following steps:

[0070] Step S1.2.1, placing the plant body with plant villi in deionized water in an ultrasonic cleaner 2 for ultrasonic cleaning. Specifically, in Step S1.2.1, the plant body with plant villi is placed in deionized water for ultrasonic cleaning; the working time is 15 - 25 min, the power is 20 - 60 W, and the temperature is 20 - 30 °C. More specifically, when ultrasonic cleaning the plant body with plant villi, the leaf is placed with the front side facing down, which can effectively protect the plant villi and is conducive to the discharge of dirt between the villi.

[0071] Step S1.2.2: Dry the plant body with plant villi after ultrasonic cleaning. Specifically, in step S1.2.2, place the plant body with plant villi after ultrasonic cleaning in the room temperature condition and air it for 6 - 8 hours to remove the moisture on the surface of the plant villi of the plant body, thus achieving the drying process.

[0072] Step S1.2.3: Trim the plant body with plant villi after the drying process. Specifically, in step S1.2.3, use a coated tool to cut the plant body with plant villi after the drying process into leaf strips 4 with a width of 5 - 10 mm, and select the leaf strips 4 that meet the preparation requirements; thus achieving the trimming of the plant body with plant villi after the drying process. More specifically, when selecting the leaf strips 4 of the plant body with plant villi, select the leaf strips 4 in which each root of the villi on the leaf strip 4 is arranged longitudinally in a single row.

[0073] Step S1.3: Lay and fix the plant body with plant villi after being processed in step S1.2 on a glass substrate. However, it is not limited to this. In other embodiments, the glass substrate can also be replaced with substrates of other materials as long as they can meet the preparation requirements in this application.

[0074] Step S1.4: Freeze and fix the plant body with plant villi on the glass substrate by the freezing method, and spray trimethylchlorosilane on the plant body with plant villi during the freezing process to obtain a hydrophobic plant villi mold with a certain hardness. The hydrophobic range is 70 - 110°.

[0075] The freezing method includes:

[0076] Step S1.4.1: Spray deionized water mist on the plant body with plant villi fixed on the glass substrate through a sprayer 3 to obtain a moist plant body with plant villi;

[0077] Step S1.4.2: Freeze the moist plant body with plant villi in a freezing environment 5. Specifically, in step S1.4.2, freeze the moist plant body with plant villi in a freezing environment 5 at - 30 - - 15 °C for 3 - 5 hours.

[0078] Step S2: Cast the plant villi mold by the casting method to obtain a needle spray model 7 with nanochannels 10 based on the plant villi.

[0079] In step S2, the casting method includes the following steps:

[0080] Step S2.1: The PDMS mixed solution flows uniformly from the periphery to the center of the plant hair mold and covers the plant hair mold to obtain a PDMS plant hair mold. Specifically, the preparation method of the PDMS mixed solution in step S2.1 includes: mixing the base material of PDMS and the curing agent at a volume ratio of 5:1 to 10:1, stirring for 5 to 10 minutes to obtain the PDMS mixed solution, and placing the PDMS mixed solution in a vacuum box for 20 to 30 minutes for degassing to remove the internal bubbles in the PDMS mixed solution.

[0081] Step S2.2: Place the PDMS plant hair mold on a leveled horizontal platform for curing. Specifically, in step S2.2, place the PDMS plant hair mold on a leveled horizontal platform and cure it at room temperature for 18 to 32 hours.

[0082] Step S2.3: Separate the cured PDMS solid 6 in the PDMS plant hair mold from the plant hair mold to obtain a needle model 7 with nanochannels 10. Specifically, after separating the cured PDMS solid 6 in the PDMS plant hair mold from the plant hair mold in step S2.3, it further includes: placing the nanochannels 10 of the PDMS needle model with nanochannels 10 facing down in deionized water in an ultrasonic cleaner 2 for ultrasonic cleaning to remove the residual plant hairs in the nanochannels 10; and placing it on a hot plate 8 for heating to obtain a clean needle model 7 with nanochannels 10. More specifically, in step S2.3, place the needle model 7 with nanochannels 10 with the concave surface facing down, the power of ultrasonic cleaning is 100 to 300 W to remove the residual plant hairs; the heating temperature for placing it on the hot plate 8 for heating is 60 to 90 °C, and the heating time is 20 to 30 minutes.

[0083] Step S3: Use the laser method to etch a microchannel 11 above the needle model 7 with nanochannels 10 obtained in step S2 to obtain a micro-nano needle.

[0084] In step S3, using the laser method to etch a microchannel 11 above the needle model 7 with nanochannels 10 obtained in step S2 to obtain a micro-nano needle includes the following steps:

[0085] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use the laser etching method to print a microchannel 11 with a diameter of 50 to 200 μm that is connected to the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 corresponds to and connects several nanochannels 10 to obtain a needle model 7 with microchannels 11 and nanochannels 10.

[0086] In one embodiment, the micro-nano needle obtained in step S3 is a single-channel micro-nano needle, including the following steps:

[0087] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use laser etching to print one-to-one above the clean needle model 7 with nanochannels 10 a microchannel 11 with a diameter of 50-200 μm that is connected to the nanochannels 10 in the needle model. Each microchannel 11 is correspondingly connected to one nanochannel 10 to obtain a single-channel needle model with microchannels 11 and nanochannels 10. Among them, the printing laser is a carbon dioxide laser, the laser power is 10-20 W, and the speed is 20-30 mm / s. Take one connected microchannel 11 and nanochannel 10 as a group, use a coated tool to group and divide the single-channel needle model with microchannels 11 and nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit to obtain a single-channel micro-nano needle.

[0088] In another embodiment, the micro-nano needle obtained in step S3 is a multi-channel micro-nano needle, including the following steps:

[0089] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use laser etching to print one-to-one above the clean needle model 7 with nanochannels 10 a microchannel 11 with a diameter of 50-200 μm that is connected to the nanochannels 10 in the needle model 7. Each microchannel 11 is correspondingly connected to one nanochannel 10 to obtain a multi-channel needle model with microchannels 11 and nanochannels 10. Among them, the printing laser is a carbon dioxide laser, the laser power is 10-20 W, and the speed is 20-30 mm / s. Use a coated tool to cut the multi-channel needle model with microchannels 11 and nanochannels 10 in parts, and each part has 2-4 connected microchannels 11 and nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit to obtain a multi-channel micro-nano needle.

[0090] In another embodiment, the micro-nano needle obtained in step S3 is an array micro-nano needle, including the following steps:

[0091] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform. Using the laser etching method, print micron channels 11 with a diameter of 50 - 200 μm that are connected to the nanochannels 10 in the needle model 7 above the clean needle model 7 with nanochannels 10. Each micron channel 11 corresponds to and is connected to 2 - 4 nanochannels 10 to obtain an array needle model with micron channels 11 and nanochannels 10. The printing laser is a carbon dioxide laser, with a laser power of 20 - 30 W and a speed of 20 - 30 mm / s. Cut the array needle model with micron channels 11 and nanochannels 10 into parts using a coating tool. Each part has 1 micron channel 11 corresponding to and connected to 2 - 4 nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the micron channel 11 for interference fit to obtain an array of micro-nano needles. Example 1

[0092] As Figures 1-6 shown, to achieve the above object, the technical solution adopted by the present invention is: a method for manufacturing micro-nano needles based on plant villi, including the following steps:

[0093] Step S1, prepare a plant villi mold by the freezing method.

[0094] Preparing a plant villi mold by the freezing method includes the following steps:

[0095] Step S1.1, obtain a plant body with plant villi, and the diameter of the plant villi includes the nanoscale. In this embodiment, the plant body with plant villi used to prepare the plant villi mold is Parthenocissus tricuspidata leaf 1. However, it is not limited to this. In other embodiments, other plant bodies with plant villi can be selected according to actual usage requirements, and the diameter of the plant villi includes the nanoscale.

[0096] Step S1.2, preprocess the plant body with plant villi;

[0097] Preprocessing the plant body with plant villi in step S1.2 includes the following steps:

[0098] Step S1.2.1, place the plant body with plant villi in deionized water in an ultrasonic cleaner 2 for ultrasonic cleaning (as Figure 1 shown in 1a). Specifically, in step S1.2.1, place the plant body with plant villi in deionized water for ultrasonic cleaning; the working time is 15 min, the power is 20 W, and the temperature is 20 °C. More specifically, when ultrasonic cleaning the plant body with plant villi, place the leaf face down, which can effectively protect the plant villi and facilitate the discharge of dirt between the villi.

[0099] Step S1.2.2, drying the plant body with plant hair after ultrasonic cleaning. Specifically, in step S1.2.2, the plant body with plant hair after ultrasonic cleaning is placed in the sun at room temperature for 6 hours to remove moisture on the surface of the plant hair of the plant body and achieve drying.

[0100] Step S1.2.3, trimming the plant body with plant hair after drying. Specifically, in step S1.2.3, the coated cutter is used to cut the plant body with plant hair after drying into leaf strips 4 with a width of 5 mm (such as Figure 1 1b), select leaf strips 4 that meet the preparation requirements; and trim the plant body with plant hairs after drying. More specifically, when selecting leaf strips 4 of the plant body with plant hairs, select leaf strips 4 with hairs on the leaf strips 4 arranged in a single row longitudinally.

[0101] Step S1.3, the plant body with plant hairs processed in step S1.2 is flatly fixed on a glass substrate.

[0102] Step S1.4, freezing the plant body with plant hair fixed on the glass substrate by freezing method, and spraying trimethylchlorosilane on the plant body with plant hair during freezing to obtain a hydrophobic plant hair mold with a certain hardness.

[0103] The freezing method comprises:

[0104] Step S1.4.1, spraying deionized water mist on the plant body with plant hair fixed on the glass substrate through the sprayer 3 to obtain a wet plant body with plant hair (such as Figure 1 (as shown in 1c);

[0105] Step S1.4.2, placing the wet plant body with plant hair in a freezing environment 5 for freezing. Specifically, in step S1.4.2, placing the wet plant body with plant hair in a freezing environment 5 at -30°C for freezing for 3 hours (e.g. Figure 1 1d).

[0106] Step S2, using a casting method to cast the plant hair mold to obtain a spray needle model 7 with nanochannels 10 based on plant hair (such as Figure 2 as shown).

[0107] In step S2, the casting method comprises the following steps:

[0108] Step S2.1: Flow the PDMS mixed solution uniformly from the periphery to the center of the plant villi mold and cover the plant villi mold to obtain a PDMS plant villi mold. Specifically, the preparation method of the PDMS mixed solution in Step S2.1 includes: mixing the base material of PDMS and the curing agent at a volume ratio of 5:1, stirring for 5 min to obtain the PDMS mixed solution, and placing the PDMS mixed solution in a vacuum chamber for 20 min for degassing to remove the internal bubbles in the PDMS mixed solution (as shown in 2a in Figure 2 ).

[0109] Step S2.2: Place the PDMS plant villi mold on a leveled horizontal platform for curing. Specifically, in Step S2.2, place the PDMS plant villi mold on a leveled horizontal platform and cure it at room temperature for 18 h.

[0110] Step S2.3: Separate the cured PDMS solid 6 in the PDMS plant villi mold from the plant villi mold to obtain a syringe needle model 7 with nanochannels 10. Specifically, in Step S2.3, after separating the cured PDMS solid 6 in the PDMS plant villi mold from the plant villi mold (as shown in 2b in Figure 2 ), the following steps are further included: Place the syringe needle model of PDMS with nanochannels 10 facing down in deionized water in an ultrasonic cleaner 2 for ultrasonic cleaning (as shown in 2c in Figure 2 ) to remove the residual plant villi in the nanochannels 10; and place it on a hot plate 8 for heating to obtain a clean syringe needle model 7 with nanochannels 10 (as shown in 2d in Figure 2 ). More specifically, in Step S2.3, place the syringe needle model 7 with nanochannels 10 concave side down, the power of ultrasonic cleaning is 100 W to remove the residual plant villi; the heating temperature for placing it on the hot plate 8 for heating is 60 °C, and the heating time is 20 min.

[0111] Step S3: Use a laser method to etch a microchannel 11 above the syringe needle model 7 with nanochannels 10 obtained in Step S2 to obtain a micro-nano syringe needle.

[0112] The steps of using a laser method to etch a microchannel 11 above the syringe needle model 7 with nanochannels 10 obtained in Step S2 to obtain a micro-nano syringe needle in Step S3 include the following steps:

[0113] As shown in Figure 3As shown, a clean needle model 7 with a nanochannel 10 is placed on a laser three-dimensional platform, and a micron channel 11 with a diameter of 50 μm connected to the nanochannel 10 in the needle model 7 is printed on the clean needle model 7 with a nanochannel 10 by laser etching. Each micron channel 11 is connected to several nanochannels 10 to obtain a needle model 7 with micron channels 11 and nanochannels 10.

[0114] In one embodiment, when a single-channel micro-nano spray needle is to be prepared, the micro-nano spray needle obtained in step S3 is a single-channel micro-nano spray needle, comprising the following steps:

[0115] Place the clean needle model 7 with nanochannel 10 on a laser three-dimensional platform (such as Figure 3 As shown in 3a1, a micron channel 11 with a diameter of 50 μm (as shown in FIG. 3a1 ) is printed one-to-one on the clean needle model 7 having the nanochannel 10 and connected to the nanochannel 10 in the needle model by laser etching. Figure 3 As shown in 3b1 in the figure, each micron channel 11 is connected to a corresponding nanochannel 10, and a single-pass needle model having a micron channel 11 and a nanochannel 10 is obtained (as shown in Figure 3 3c1 in the figure); wherein the printing laser is a carbon dioxide laser, the laser power is 10W, and the speed is 20mm / s; a single-pass needle model having a connected micro-channel 11 and a nano-channel 10 is grouped and segmented using a coating tool (such as Figure 3 As shown in 3d1, the steel needle 12 treated with oxygen plasma hydrophilicity is inserted into the micron channel 11 for interference fit to obtain a single-channel micro-nano spray needle (as shown in 3d1). Figure 4 as shown).

[0116] In another embodiment, when a multi-channel micro-nano spray needle is to be prepared, the micro-nano spray needle obtained in step S3 is a multi-channel micro-nano spray needle, comprising the following steps:

[0117] Place the clean needle model 7 with nanochannel 10 on a laser three-dimensional platform (such as Figure 3 As shown in 3a1 , a micron channel 11 with a diameter of 50 μm connected to the nanochannel 10 in the spray needle model is printed one-to-one on the clean spray needle model 7 with the nanochannel 10 by laser etching, and each micron channel 11 is connected to a nanochannel 10 (as shown in Figure 3 3b1), a multi-channel needle model with a micron channel 11 and a nanochannel 10 is obtained (as shown in Figure 3as shown in Fig. 3c2; wherein the printing laser is a carbon dioxide laser, the laser power is 10 W, and the speed is 20 mm / s; the multi-channel micro-needle model with micro-channels 11 and nano-channels 10 is cut in parts using a coated tool, and each part has 2 connected micro-channels 11 and nano-channels 10 (as Figure 3 shown in Fig. 3d2), and a steel needle 12 treated by oxygen plasma hydrophilization is inserted into the micro-channel 11 for interference fit to obtain a multi-channel micro-nano needle (as Figure 5 shown).

[0118] In another embodiment, when preparing an array of micro-nano needles, the micro-nano needle obtained in step S3 is an array of micro-nano needles, including the following steps:

[0119] Place the clean needle model 7 with nano-channels 10 on a laser three-dimensional platform (as Figure 3 shown in Fig. 3a2), and use laser etching to print a micro-channel 11 with a diameter of 50 μm connected to the nano-channel 10 in the needle model above the clean needle model 7 with nano-channels 10 (as Figure 3 shown in Fig. 3b2), and each 1 micro-channel 11 corresponds to 2 connected nano-channels 10 to obtain an array needle model with micro-channels 11 and nano-channels 10 (as Figure 3 shown in Fig. 3c3), wherein the printing laser is a carbon dioxide laser, the laser power is 20 W, and the speed is 20 mm / s; the array needle model with micro-channels 11 and nano-channels 10 is cut in parts using a coated tool, and each part has 1 micro-channel 11 corresponding to 2 connected nano-channels 10 (as Figure 3 shown in Fig. 3d3), and a steel needle 12 treated by oxygen plasma hydrophilization is inserted into the micro-channel 11 for interference fit to obtain an array of micro-nano needles (as Figure 6 shown). Embodiment 2

[0120] As Figures 1-6 shown, to achieve the above object, the technical solution adopted by the present invention is: a method for manufacturing a micro-nano needle based on plant villi, including the following steps:

[0121] Step S1, preparing a plant villi mold by a freezing method.

[0122] Preparing a plant villi mold by a freezing method includes the following steps:

[0123] Step S1.1: Obtain a plant body with plant hairs, and the diameter of the plant hairs includes the nanoscale. In this embodiment, the plant body with plant hairs used for preparing the plant hair mold is Parthenocissus tricuspidata leaf 1. However, it is not limited to this. In other embodiments, other plant bodies with plant hairs can be selected according to actual usage requirements, and the diameter of the plant hairs includes the nanoscale.

[0124] Step S1.2: Pretreat the plant body with plant hairs.

[0125] The pretreatment of the plant body with plant hairs in Step S1.2 includes the following steps:

[0126] Step S1.2.1: Place the plant body with plant hairs in deionized water in an ultrasonic cleaner 2 for ultrasonic cleaning. Specifically, in Step S1.2.1, place the plant body with plant hairs in deionized water for ultrasonic cleaning; the working time is 25 min, the power is 60 W, and the temperature is 30 °C. More specifically, when ultrasonically cleaning the plant body with plant hairs, place the leaf face down, which can effectively protect the plant hairs and facilitate the discharge of dirt between the hairs.

[0127] Step S1.2.2: Dry the plant body with plant hairs after ultrasonic cleaning. Specifically, in Step S1.2.2, place the plant body with plant hairs after ultrasonic cleaning in the open air at room temperature for 6 - 8 h to remove the moisture on the surface of the plant hairs of the plant body and achieve the drying treatment.

[0128] Step S1.2.3: Trim the plant body with plant hairs after drying treatment. Specifically, in Step S1.2.3, use a coated tool to cut the plant body with plant hairs after drying treatment into leaf strips 4 with a width of 10 mm, and select the leaf strips 4 that meet the preparation requirements; thus, trim the plant body with plant hairs after drying treatment. More specifically, when selecting the leaf strips 4 of the plant body with plant hairs, select the leaf strips 4 in which each hair on the leaf strip 4 is arranged longitudinally in a single row.

[0129] Step S1.3: Lay and fix the plant body with plant hairs after being processed in Step S1.2 on a glass substrate.

[0130] Step S1.4: Freeze and fix the plant body with plant hairs fixed on the glass substrate by the freezing method, and spray trimethylchlorosilane on the plant body with plant hairs during freezing to obtain a hydrophobic plant hair mold with a certain hardness.

[0131] The freezing method includes:

[0132] Step S1.4.1: Spray deionized water mist on the plant body with plant villi fixed on the glass substrate through the sprayer 3 to obtain a moist plant body with plant villi.

[0133] Step S1.4.2: Freeze the moist plant body with plant villi in the freezing environment 5. Specifically, in step S1.4.2, the moist plant body with plant villi is frozen in the freezing environment 5 at -15°C for 5 hours.

[0134] Step S2: Use the casting method to cast the plant villi mold to obtain a needle spray model 7 with nanochannels 10 based on plant villi.

[0135] In step S2, the casting method includes the following steps:

[0136] Step S2.1: Let the PDMS mixed solution flow uniformly from the periphery to the center of the plant villi mold and cover the plant villi mold to obtain a PDMS plant villi mold. Specifically, the preparation method of the PDMS mixed solution in step S2.1 includes: mixing the base material of PDMS and the curing agent in a volume ratio of 10:1, stirring for 10 minutes to obtain the PDMS mixed solution, and placing the PDMS mixed solution in a vacuum box for 30 minutes for degassing to remove the internal bubbles in the PDMS mixed solution.

[0137] Step S2.2: Place the PDMS plant villi mold on a leveled horizontal platform for curing. Specifically, in step S2.2, place the PDMS plant villi mold on a leveled horizontal platform and cure it at room temperature for 32 hours.

[0138] Step S2.3: Separate the cured PDMS solid 6 in the PDMS plant villi mold from the plant villi mold to obtain a needle spray model 7 with nanochannels 10. Specifically, in step S2.3, after separating the cured PDMS solid 6 in the PDMS plant villi mold from the plant villi mold, it further includes: placing the nanochannels 10 of the PDMS needle spray model with nanochannels 10 facing down in deionized water for ultrasonic cleaning to remove the residual plant villi in the nanochannels 10; and placing it on the hot plate 8 for heating to obtain a clean needle spray model 7 with nanochannels 10. More specifically, in step S2.3, place the concave surface of the needle spray model 7 with nanochannels 10 facing down, the power of ultrasonic cleaning is 300 W to remove the residual plant villi; the heating temperature for placing it on the hot plate 8 for heating is 90°C, and the heating time is 30 minutes.

[0139] Step S3: Use the laser method to etch microchannels 11 above the needle spray model 7 with nanochannels 10 obtained in step S2 to obtain a micro-nano needle spray.

[0140] In step S3, a laser method is used to etch a microchannel 11 above the needle model 7 with nanochannels 10 obtained in step S2 to obtain a micro-nano needle, including the following steps:

[0141] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use the laser etching method to print a microchannel 11 with a diameter of 200 μm that communicates with the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 communicates with several nanochannels 10 to obtain a PDMS needle model with microchannels 11 and nanochannels 10.

[0142] In one embodiment, when a single-channel micro-nano needle is to be prepared, the micro-nano needle obtained in step S3 is a single-channel micro-nano needle, including the following steps:

[0143] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use the laser etching method to print one-to-one a microchannel 11 with a diameter of 200 μm that communicates with the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 communicates with 1 nanochannel 10 to obtain a single-channel needle model with microchannels 11 and nanochannels 10; wherein, the printing laser is a carbon dioxide laser, the laser power is 20 W, and the speed is 30 mm / s; taking one connected microchannel 11 and nanochannel 10 as a group, use a coating tool to group and divide the single-channel needle model with microchannels 11 and nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit to obtain a single-channel micro-nano needle.

[0144] In another embodiment, when a multi-channel micro-nano needle is to be prepared, the micro-nano needle obtained in step S3 is a multi-channel micro-nano needle, including the following steps:

[0145] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use the laser etching method to print one-to-one a microchannel 11 with a diameter of 200 μm that communicates with the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 communicates with 1 nanochannel 10 to obtain a multi-channel needle model with microchannels 11 and nanochannels 10; wherein the printing laser is a carbon dioxide laser, the laser power is 20 W, and the speed is 30 mm / s; use a coating tool to cut the multi-channel needle model with microchannels 11 and nanochannels 10 in parts, and each part has 4 connected microchannels 11 and nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit to obtain a multi-channel micro-nano needle.

[0146] In another embodiment, when preparing the array micro-nano injection needles, the micro-nano injection needles obtained in step S3 are array micro-nano injection needles, including the following steps:

[0147] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform, and use laser etching to print a microchannel 11 with a diameter of 200 μm connected to the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 corresponds to and is connected to 2 to 4 nanochannels 10 to obtain an array needle model with microchannels 11 and nanochannels 10. The printing laser is a carbon dioxide laser, the laser power is 30 W, and the speed is 30 mm / s; Cut the array needle model with microchannels 11 and nanochannels 10 into parts using a coating tool. Each part has 1 microchannel 11 corresponding to and connected to 2 to 4 nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit to obtain the array micro-nano injection needles. Embodiment III

[0148] As Figures 1-9 shown, to achieve the above object, the technical solution adopted by the present invention is: a method for manufacturing micro-nano injection needles based on plant villi, including the following steps:

[0149] Step S1, prepare a plant villi mold by the freezing method.

[0150] Preparing a plant villi mold by the freezing method includes the following steps:

[0151] Step S1.1, obtain a plant body with plant villi, and the diameter of the plant villi includes the nanoscale. In this embodiment, the plant body with plant villi used for preparing the plant villi mold is Parthenocissus tricuspidata leaf 1. The image of Parthenocissus tricuspidata leaf 1 observed by a high-power microscope in the prior art is as Figure 7 shown. The part similar to a reticular morphology is the surface of the leaf; the leaf itself is not completely flat and there are micron protrusions, that is, the blocky structures in the picture are the micron protrusions of the leaf blade; there are several plant villi on each micron protrusion, that is, the highlighted lines in the figure. However, it is not limited to this. In other embodiments, other plant bodies with plant villi can be selected according to actual usage requirements, and the diameter of the plant villi includes the nanoscale.

[0152] Step S1.2, pre-treat the plant body with plant villi;

[0153] Pre-treating the plant body with plant villi in step S1.2 includes the following steps:

[0154] Step S1.2.1: Place the plant body with plant hairs in deionized water in the ultrasonic cleaner 2 for ultrasonic cleaning. Specifically, in step S1.2.1, place the plant body with plant hairs in deionized water for ultrasonic cleaning; the working time is 20 minutes, the power is 40 W, and the temperature is 25 °C. More specifically, when ultrasonically cleaning the plant body with plant hairs, place the front side of the leaf downward, which can effectively protect the plant hairs and facilitate the discharge of dirt between the hairs.

[0155] Step S1.2.2: Dry the plant body with plant hairs after ultrasonic cleaning. Specifically, in step S1.2.2, place the plant body with plant hairs after ultrasonic cleaning in the air at room temperature for 7 hours to remove the moisture on the surface of the plant hairs of the plant body and achieve the drying process.

[0156] Step S1.2.3: Trim the plant body with plant hairs after drying. Specifically, in step S1.2.3, use a coated tool to cut the plant body with plant hairs after drying into leaf strips 4 with a width of 8 mm, and select the leaf strips 4 that meet the preparation requirements; thus, trim the plant body with plant hairs after drying. More specifically, when selecting the leaf strips 4 of the plant body with plant hairs, select the leaf strips 4 in which each hair on the leaf strip 4 is arranged longitudinally in a single row.

[0157] Step S1.3: Lay and fix the plant body with plant hairs after being processed in step S1.2 on a glass substrate.

[0158] Step S1.4: Freeze and fix the plant body with plant hairs fixed on the glass substrate by the freezing method, and spray trimethylchlorosilane on the plant body with plant hairs during freezing to obtain a hydrophobic plant hair mold with a certain hardness.

[0159] The freezing method includes:

[0160] Step S1.4.1: Spray deionized water mist on the plant body with plant hairs fixed on the glass substrate through the sprayer 3 to obtain a moist plant body with plant hairs;

[0161] Step S1.4.2: Freeze the moist plant body with plant hairs in the freezing environment 5. Specifically, in step S1.4.2, freeze the moist plant body with plant hairs in the freezing environment 5 at -23 °C for 4 hours.

[0162] Step S2: Cast the plant hair mold by the casting method to obtain a needle spray model 7 with nano-channels 10 based on plant hairs.

[0163] In step S2, the casting method includes the following steps:

[0164] Step S2.1: The PDMS mixed solution is evenly flowed from the periphery to the center of the plant villi mold and covers the plant villi mold to obtain a PDMS plant villi mold. Specifically, the preparation method of the PDMS mixed solution in step S2.1 includes: mixing the base material of PDMS and the curing agent in a volume ratio of 8:1, stirring for 8 min to obtain the PDMS mixed solution, and placing the PDMS mixed solution in a vacuum box for 25 min for degassing to remove the internal bubbles in the PDMS mixed solution.

[0165] Step S2.2: The PDMS plant villi mold is placed on a leveled horizontal platform for curing. Specifically, in step S2.2, the PDMS plant villi mold is placed on a leveled horizontal platform and cured at room temperature for 25 h.

[0166] Step S2.3: The cured PDMS solid 6 in the PDMS plant villi mold is separated from the plant villi mold to obtain a needle model 7 with nanochannels 10. Specifically, after separating the cured PDMS solid 6 in the PDMS plant villi mold from the plant villi mold in step S2.3, it further includes: placing the nanochannels 10 of the PDMS needle model with nanochannels 10 facing down in deionized water for ultrasonic cleaning to remove the residual plant villi in the nanochannels 10; and placing it on a hot plate 8 for heating to obtain a clean needle model 7 with nanochannels 10. More specifically, in step S2.3, the concave surface of the needle model 7 with nanochannels 10 is placed facing down, the power of ultrasonic cleaning is 200 W to remove the residual plant villi; the heating temperature for placing it on the hot plate 8 for heating is 75 °C, and the heating time is 20 - 30 min.

[0167] Step S3: A microchannel 11 is etched above the needle model 7 with nanochannels 10 obtained in step S2 by the laser method to obtain a micro - nano needle.

[0168] The steps of etching a microchannel 11 above the needle model 7 with nanochannels 10 obtained in step S2 by the laser method to obtain a micro - nano needle in step S3 include:

[0169] Placing the clean needle model 7 with nanochannels 10 on a laser three - dimensional platform, and using the laser etching method to print a microchannel 11 with a diameter of 120 μm that is connected to the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 corresponds to several nanochannels 10 connected, to obtain a PDMS needle model with microchannels 11 and nanochannels 10.

[0170] In one embodiment, the micro - nano needle obtained in step S3 is a single - channel micro - nano needle, and the steps include:

[0171] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform. Using laser etching method, one-to-one print above the clean needle model 7 with nanochannels 10 a microchannel 11 with a diameter of 120 μm that is connected to the nanochannels 10 in the needle model. Each microchannel 11 corresponds to and is connected to one nanochannel 10 to obtain a single-channel needle model with microchannels 11 and nanochannels 10; wherein, the printing laser is a carbon dioxide laser, the laser power is 15 W, and the speed is 25 mm / s; taking one connected microchannel 11 and nanochannel 10 as a group, use a coated tool to group and divide the single-channel needle model with microchannels 11 and nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit. The steel needle 12 needs to be cleaned in advance and subjected to oxygen plasma surface treatment before being inserted into the microchannel 11 to improve the bonding strength between the steel needle 12 and the microchannel 11 and prevent ink spillage during the printing process, thereby obtaining a single-channel micro-nano needle (as Figure 8 shown).

[0172] In another embodiment, the micro-nano needle obtained in step S3 is a multi-channel micro-nano needle, which includes the following steps:

[0173] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform. Using laser etching method, one-to-one print above the clean needle model 7 with nanochannels 10 a microchannel 11 with a diameter of 120 μm that is connected to the nanochannels 10 in the needle model. Each microchannel 11 corresponds to and is connected to one nanochannel 10 to obtain a multi-channel needle model with microchannels 11 and nanochannels 10; wherein the printing laser is a carbon dioxide laser, the laser power is 15 W, and the speed is 25 mm / s; use a coated tool to cut the multi-channel needle model with microchannels 11 and nanochannels 10 in parts, with each part having 3 connected microchannels 11 and nanochannels 10, and insert a steel needle 12 after oxygen plasma surface treatment into the microchannel 11 for interference fit. The steel needle 12 needs to be cleaned in advance and subjected to oxygen plasma surface treatment before being inserted into the microchannel 11 to improve the bonding strength between the steel needle 12 and the microchannel 11 and prevent ink spillage during the printing process, thereby obtaining a multi-channel micro-nano needle (as Figure 9 shown).

[0174] In another embodiment, the micro-nano needle obtained in step S3 is an array micro-nano needle, which includes the following steps:

[0175] Place the clean needle model 7 with nanochannels 10 on a laser three-dimensional platform. Using the laser etching method, print a microchannel 11 with a diameter of 120 μm that is connected to the nanochannels 10 in the needle model above the clean needle model 7 with nanochannels 10. Each microchannel 11 corresponds to and connects 3 nanochannels 10 to obtain an array needle model with microchannels 11 and nanochannels 10. The printing laser is a carbon dioxide laser, with a laser power of 25 W and a speed of 25 mm / s. Cut the array needle model with microchannels 11 and nanochannels 10 into parts using a coated tool. Each part has 1 microchannel 11 corresponding to and connecting 3 nanochannels 10, and insert a steel needle 12 that has been treated with oxygen plasma hydrophilic treatment into the microchannel 11 for interference fit to obtain an array of micro-nano needles. The steel needle 12 needs to be cleaned in advance and treated with oxygen plasma hydrophilic treatment before being inserted into the microchannel 11 to improve the bonding strength between the steel needle 12 and the microchannel 11 and prevent ink overflow during the printing process, and finally obtain an array of micro-nano needles. Example 4

[0176] On the basis of Example 3, the plant body with plant villi used for preparing the plant villi mold is a lotus flower with nano-scale plant villi. Example 5

[0177] On the basis of Example 3, the plant body with plant villi used for preparing the plant villi mold is a lotus with nano-scale plant villi. Example 6

[0178] On the basis of Example 3, a micro-nano needle based on plant villi is prepared by using a micro-nano needle manufacturing method based on plant villi.

[0179] Working principle:

[0180] A micro-nano needle manufacturing method and micro-nano needle based on plant villi of the present invention; using the freeze-casting method, pour the PDMS mixed solution on the frozen plant body with plant villi through the strategy of "surrounding the center on all sides", and then ingeniously replicate the villi structure on the surface of the plant leaves of the plant body with plant villi to obtain nanochannels 10. Then, use the laser etching technology to etch a microchannel 11 with a diameter above the corresponding nanochannels 10 to obtain a needle model 7 with microchannels 11 and nanochannels 10. Finally, use a coated tool to cut the needle model 7 with microchannels 11 and nanochannels 10 as needed, and insert a steel needle 12 into the microchannel 11 to obtain single-channel micro-nano needles, multi-channel micro-nano needles, and array micro-nano needles. The process of the present invention is simple, low-cost, and easy to realize mass production of needles.

[0181] The present invention can obtain large-area nanochannels by stereolithographically casting frozen nano-scale plant villi, and obtain microchannels by laser drilling, and both are closed channels. On the basis of obtaining nanochannels, as many microchannels as needed for the number of injection needles can be laser drilled, that is, after obtaining nanochannels, one injection needle can be obtained. The array layout of the injection needles can also be arbitrarily cut. The process is simple, highly efficient, and easy to mass-produce.

[0182] The above specific embodiments are specific supports for the proposed solution idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any equivalent changes or equivalent modifications made on the basis of this technical solution according to the technical idea proposed by the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for manufacturing a micro-nano injection needle based on plant villi, characterized in that, It includes the following steps: Step S1, preparing a plant villus mold by the freezing method; Step S2, casting the plant villus mold by the casting method to obtain a needle model with nanochannels based on plant villi; Step S3, etching a microchannel above the needle model with nanochannels obtained in Step S2 by the laser method to obtain a micro-nano needle; The step of preparing a plant villus mold by the freezing method in Step S1 includes the following steps: Step S1.1, obtaining a plant body with plant villi, and the cross-sectional diameter of the plant villi includes the nanoscale; Step S1.2, preprocessing the plant body with plant villi; Step S1.3, laying and fixing the plant body with plant villi after being processed in Step S1.2 on a glass substrate; Step S1.4, freezing and fixing the plant body with plant villi on the glass substrate by the freezing method, and spraying trimethylchlorosilane on the plant body with plant villi during freezing to obtain a plant villus mold; The step of preprocessing the plant body with plant villi in Step S1.2 includes the following steps: Step S1.2.1, placing the plant body with plant villi in deionized water for ultrasonic cleaning; Step S1.2.2, drying the plant body with plant villi after ultrasonic cleaning; Step S1.2.3, trimming the plant body with plant villi after drying treatment; The freezing method includes: Step S1.4.1, spraying deionized water mist on the plant body with plant villi fixed on the glass substrate to obtain a wet plant body with plant villi; Step S1.4.2, freezing the wet plant body with plant villi in a freezing environment.

2. The manufacturing method of a micro-nano injection needle based on plant villi according to claim 1, characterized in that: In Step S2, the casting method includes the following steps: Step S2.1, uniformly flowing the PDMS mixed solution from the periphery of the plant villus mold to the center and covering the plant villus mold to obtain a PDMS plant villus mold; Step S2.2, placing the PDMS plant villus mold on a leveled horizontal platform for curing; Step S2.3, separating the cured PDMS solid in the PDMS plant villus mold from the plant villus mold to obtain a needle model with nanochannels.

3. The manufacturing method of a micro-nano injection needle based on plant villi according to claim 2, characterized in that: The step of etching a microchannel above the needle model with nanochannels obtained in Step S2 by the laser method in Step S3 to obtain a micro-nano needle includes the following steps: Placing the clean needle model with nanochannels on a laser three-dimensional platform, and using the laser etching method to print a microchannel with a diameter of 50 - 200 μm connected to the nanochannels in the clean needle model above the clean needle model with nanochannels. Each microchannel corresponds to and is connected to several nanochannels to obtain a PDMS needle model with microchannels and nanochannels.

4. A method for manufacturing a micro-nano injection needle based on plant villi according to claim 3, characterized in that: The micro-nano needle obtained in Step S3 is a single-channel micro-nano needle, including the following steps: Place the clean injection needle model with nanochannels on the laser three-dimensional platform, and use laser etching method to print one-to-one above the clean injection needle model with nanochannels a microchannel with a diameter of 50 - 200 μm that is connected to the nanochannels in the injection needle model. Each microchannel corresponds to one connected nanochannel to obtain a single-channel injection needle model with microchannels and nanochannels; wherein, the printing laser is a carbon dioxide laser, the laser power is 10 - 20 W, and the speed is 20 - 30 mm / s; taking one connected microchannel and nanochannel as a group, use a coated tool to group and divide the single-channel injection needle model with microchannels and nanochannels, and insert a steel needle after oxygen plasma surface treatment into the microchannel for interference fit to obtain a single-channel micro-nano injection needle; And / or, the micro-nano injection needle obtained in step S3 is a multi-channel micro-nano injection needle, including the following steps: Place the clean injection needle model with nanochannels on the laser three-dimensional platform, and use laser etching method to print one-to-one above the clean injection needle model with nanochannels a microchannel with a diameter of 50 - 200 μm that is connected to the nanochannels in the injection needle model. Each microchannel corresponds to one connected nanochannel to obtain a multi-channel injection needle model with microchannels and nanochannels; wherein the printing laser is a carbon dioxide laser, the laser power is 10 - 20 W, and the speed is 20 - 30 mm / s; use a coated tool to cut the multi-channel injection needle model with microchannels and nanochannels in parts, each part having 2 - 4 connected microchannels and nanochannels, and insert a steel needle after oxygen plasma surface treatment into the microchannel for interference fit to obtain a multi-channel micro-nano injection needle; And / or, the micro-nano injection needle obtained in step S3 is an array micro-nano injection needle, including the following steps: Place the clean injection needle model with nanochannels on the laser three-dimensional platform, and use laser etching method to print above the clean injection needle model with nanochannels a microchannel with a diameter of 50 - 200 μm that is connected to the nanochannels in the injection needle model. Each microchannel corresponds to 2 - 4 connected nanochannels to obtain an array injection needle model with microchannels and nanochannels, wherein the printing laser is a carbon dioxide laser, the laser power is 20 - 30 W, and the speed is 20 - 30 mm / s; use a coated tool to cut the array injection needle model with microchannels and nanochannels in parts, each part having 1 microchannel corresponding to 2 - 4 connected nanochannels, and insert a steel needle after oxygen plasma surface treatment into the microchannel for interference fit to obtain an array micro-nano injection needle.

5. The manufacturing method of a micro-nano injection needle based on plant villi according to claim 4, characterized in that: In step S1.2.1, place the plant body with plant villi in deionized water for ultrasonic cleaning; the working time is 15 - 25 min, the power is 20 - 60 W, and the temperature is 20 - 30 °C; And / or, in step S1.2.2, place the plant body with plant villi after ultrasonic cleaning at room temperature for drying for 6 - 8 h to remove the moisture on the surface of the plant villi of the plant body to achieve drying treatment; And / or, in step S1.2.3, a coated tool is used to divide the dried plant body with plant hairs into leaf strips with a width of 5-10 mm to obtain the leaf strips, thereby achieving the trimming of the dried plant body with plant hairs. And / or, in step S1.4.2, the moist plant body with plant hairs is placed in a freezing environment at -30~-15°C for 3-5 h.

6. The manufacturing method of a micro-nano injection needle based on plant villi according to claim 5, characterized in that: The preparation method of the PDMS mixed solution in step S2.1 includes: mixing the base material of PDMS and the curing agent in a volume ratio of 5:1~10:1, stirring for 5-10 min to obtain the PDMS mixed solution, and placing the PDMS mixed solution in a vacuum box for 20-30 min for degassing to remove the internal bubbles in the PDMS mixed solution. And / or, in step S2.2, the PDMS plant hair mold is placed on a leveled horizontal platform and cured at room temperature for 18-32 h. And / or, in step S2.3, after separating the cured PDMS solid in the PDMS plant hair mold from the plant hair mold, it further includes: placing the PDMS needle model with nanochannels with the nanochannels facing down in deionized water for ultrasonic cleaning to remove the residual plant hairs in the nanochannels; and placing it on a hot plate for heating to obtain a clean needle model with nanochannels.

7. A method for manufacturing a micro-nano injection needle based on plant villi according to claim 6, characterized in that: The plant body with plant hairs used for preparing the plant hair mold includes one of Parthenocissus tricuspidata leaves, lotus flowers, and water lilies. And / or, when ultrasonically cleaning the plant body with plant hairs, placing the leaf face down can effectively protect the plant hairs and facilitate the discharge of dirt between the hairs. And / or, when selecting the leaf strips of the plant body with plant hairs, select the leaf strips in which the hairs on each leaf strip are arranged longitudinally in a single row. And / or, in step S2.3, place the needle model with nanochannels with the concave side down, and the power of ultrasonic cleaning is 100-300 W to remove the residual plant hairs. And / or, in step S2.3, the heating temperature for heating on the hot plate is 60-90°C, and the heating time is 20-30 min.

8. A micro-nano injection needle based on plant villi, characterized in that: The micro-nano needle is prepared by using the method for manufacturing a micro-nano needle based on plant hairs according to any one of claims 1-7.

Images