High-flux piezoelectric polymer spinning method based on electric field assisted airflow field driving

Abstract

The invention relates to the field of high polymer material spinning, in particular to a high-flux piezoelectric polymer spinning method based on electric field assisted airflow field driving, which comprises the following steps: S1, raw material preparation: selecting piezoelectric polymer material particles, performing ultrasonic treatment in water, drying, and melting in a charging barrel for later use; s2, spinning preparation: introducing airflow into the molten material prepared in the S1 through a charging barrel, applying an electric field at a nozzle, setting working parameters, and spinning on a substrate to obtain the microfibers with piezoelectric properties.

Description

Technical Field

[0001] The present application relates to the field of polymer material spinning, and in particular to a high-throughput piezoelectric polymer spinning method based on electric field-assisted airflow field driving and its application. Background Art

[0002] Piezoelectric fibers, due to their unique electromechanical conversion properties, convert mechanical energy from the environment into electrical energy, showing broad application prospects. In the biomedical field, piezoelectric fibers play an important role in research on using electrical stimulation to promote the regeneration of damaged cells in skin, nerves, and other areas, providing new possibilities for tissue repair.

[0003] In the field of health monitoring, piezoelectric fibers are used to develop flexible and wearable devices such as heart rate sensors and motion detectors. They can be used to power small electronic devices or as core components of self-powered sensors. In addition, piezoelectric fibers also show great potential in engineering applications such as sensors, actuators and energy harvesting.

[0004] Electrospinning is currently the most common method for preparing polymers with piezoelectric effects. However, only about 10% of the electrospinning system is polymer, resulting in low spinning efficiency. Furthermore, the organic solvents used in the electrospinning process may not be completely volatilized, and residual solvents may affect the biocompatibility and safety of the product. Furthermore, electrospinning is difficult to accurately control the spinning porosity, which affects its application in the biomedical field. Melt spinning technology uses a porous spinneret to eject a thin stream of melt, which is then rapidly condensed by cold air from a temperature-controlled bellows to form a solidified fiber bundle. While highly efficient, it is difficult to form a heterogeneous nucleating agent without an electric field, making it impossible to obtain a β-phase crystal structure and lacking piezoelectric properties.

[0005] Therefore, it is urgent to design a high-throughput piezoelectric polymer spinning method.

[0006] The information in this background technology section is only intended to enhance understanding of the overall background of the application and is not necessarily regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0007] In order to solve the above problems, the present application provides a high-throughput piezoelectric polymer spinning method based on electric field-assisted airflow field driving, aiming to solve the problems raised in the above background technology.

[0008] In some embodiments of the present application, a high-throughput piezoelectric polymer spinning method based on electric field-assisted air flow field driving is provided, comprising the following steps:

[0009] S1. Raw material preparation: Select piezoelectric polymer material particles, ultrasonically treat them in water, dry them in a barrel and melt them for later use;

[0010] S2. Spinning preparation: The molten material prepared in S1 is spun on a substrate through a device driven by an electric field assisted air flow field, with the working parameters set, to obtain microfibers with piezoelectric properties.

[0011] In some embodiments of the present application, in S1, the piezoelectric polymer material is selected from at least one of poly (L-lactic acid), poly (vinylidene fluoride), poly (vinylidene fluoride-trifluoroethylene) copolymer, and poly (vinylidene fluoride-hexafluoropropylene) copolymer.

[0012] In some embodiments of the present application, air flow is introduced into the barrel, and the air flow provides shear force to break the material into fine fibers.

[0013] In some embodiments of the present application, the airflow is a directional airflow of 0.1-10 m / s.

[0014] In some embodiments of the present application, electric fields are set on both sides of the nozzle to establish a stable electric field between the nozzle and the collecting device, providing a symmetrical electric field force, and the fiber jet is further stretched and oriented during flight.

[0015] In some embodiments of the present application, under the combined action of the electric field force and the airflow shear force, the polymer jet is ejected from the nozzle to form fibers with piezoelectric effect.

[0016] In some embodiments of the present application, in S2, the substrate includes a grounded collection plate, a multi-angle inclined substrate or a rotating collection drum, and the rotation speed can be adjusted to 50-5000 rpm.

[0017] In some embodiments of the present application, the substrate material includes a conductive substrate and a non-conductive substrate. The conductive substrate includes but is not limited to a stainless steel substrate, a copper substrate, etc.; the non-conductive substrate includes but is not limited to a glass substrate, PET, and PDMS substrate.

[0018] In some embodiments of the present application, in S2, the output voltage of the high-voltage power supply is adjusted to adjust the electric field strength, and the output voltage range is 5-50kV, preferably 10-30kV; so that the electric field strength is in the range of 0.5-5kV / cm.

[0019] In some embodiments of the present application, the air flow velocity of the internal air flow generating device is set in the range of 0.5-5 m / s, and the external feed air pressure range is 0-50 KPa.

[0020] In some embodiments of the present application, the distance between the nozzle and the collecting device is adjusted to 2-40 cm.

[0021] In some embodiments of the present application, the temperature range of the barrel and the nozzle is controlled to be 40°C-280°C.

[0022] In some embodiments of the present application, the electric field-assisted airflow field driven device includes an XYZ three-axis motion platform, a clamping assembly, a barrel assembly, an air intake assembly, a heating block assembly, and a power-on assembly;

[0023] The clamping assembly is fixed on the Z axis of the XYZ three-axis motion platform and is used to clamp the barrel assembly;

[0024] The barrel assembly includes a multi-section barrel and a nozzle;

[0025] The air inlet assembly includes a metal tube and a hollow copper tube disposed inside the metal tube; the hollow copper tube assembly passes through the interior of the multi-section barrel to provide the air flow field required for melt spinning;

[0026] The heating block assembly includes a first heating block and a second heating block, the first heating block is arranged on the multi-section barrel, and the second heating block is arranged at the nozzle;

[0027] The electrification component is arranged outside the nozzle and is used to provide the electric field required for melt spinning.

[0028] In some embodiments of the present application, the XYZ three-axis motion platform includes an X-axis, dual Y-axes, and a Z-axis, wherein the X-axis is vertically mounted on the dual Y-axes spaced apart and arranged in parallel to form a gantry structure, and the Z-axis is vertically mounted on the X-axis.

[0029] In some embodiments of the present application, the dual Y-axes can move along the Y-axis direction, and the Z-axis can move up and down to adjust the position of the barrel assembly and the printing trajectory.

[0030] In some embodiments of the present application, the Y-axis is driven by dual motors and the two Y-axis guide rails remain parallel, the X and Z axes are driven by linear motors, and the Y-axis is driven by a stepper motor. Through the movement of the X-axis, dual Y-axes, and Z-axis, the position of the barrel assembly and the printing path can be adjusted.

[0031] In some embodiments of the present application, the clamping assembly includes a fixing plate, a first clip is provided on the fixing plate, a first hinged seat is provided at one end of the first clip, a second clip is provided corresponding to the first clip, a second hinged seat is provided at one end of the second clip, the first hinged seat and the second hinged seat are connected by a first screw; the other ends of the first clip and the second clip are connected by a second screw, and a barrel assembly is clamped between the first clip and the second clip.

[0032] In some embodiments of the present application, the multi-section barrel includes a first barrel section, a second barrel section, a third barrel section, and a fourth barrel section.

[0033] In some embodiments of the present application, a first nut, a second nut, and a third nut are installed on the bottom of the fourth section of the barrel, and a power-on component is installed between the first nut, the second nut, and the third nut at the bottom of the fourth section of the barrel, so that the power-on component can be adjusted up and down.

[0034] In some embodiments of the present application, the air intake assembly further includes a metal pipe joint, to which a metal pipe is connected, a hollow copper pipe is installed in the middle of the metal pipe, and a sealing gasket is provided between the metal pipe joint and the metal pipe.

[0035] In some embodiments of the present application, a hollow copper tube fixing assembly is provided in the first section and the third section of the barrel, and the hollow copper tube fixing assembly includes a fixing frame, on which a plurality of screws evenly distributed around the hollow copper tube are installed to fix and position the hollow copper tube.

[0036] In some embodiments of the present application, the plurality of screws include a third screw, a fourth screw, and a fifth screw.

[0037] In some embodiments of the present application, a first heating block is installed on the third section of the barrel and the fourth section of the barrel.

[0038] In some embodiments of the present application, a first fastening screw is provided on the first heating block, and a second fastening screw is provided on the second heating block.

[0039] In some embodiments of the present application, convex frames are provided at the left and right ends of the power-on component, and a gear rack mechanism is provided inside the convex frame. The gear rack mechanisms at the left and right ends are asynchronous mechanisms, and they work independently without affecting each other. The gear rack mechanism can adjust the wires left and right.

[0040] In some embodiments of the present application, the power-on component includes a support frame, a convex frame is provided at the lower end of the support frame, a rack is installed in the convex frame, a gear is installed above the rack, a keyway is provided inside the gear, a shaft is installed inside the gear, a key is installed above the shaft, a rotating ring is installed at one end of the shaft, electric wires are installed below the rack, and a wire trough is installed on the fixed plate.

[0041] In some embodiments of the present application, the barrel assembly is connected by pipe threads through the first barrel section, the second barrel section, the third barrel section, the fourth barrel section and the nozzle.

[0042] In some embodiments of the present application, the lower end of the first section of the barrel is provided with an internal thread, the upper and lower ends of the second section of the barrel are provided with external threads, the upper and lower ends of the third section of the barrel are provided with internal threads, the lower end of the fourth section of the barrel is provided with internal and external threads, and the nozzle is provided with external threads.

[0043] In some embodiments of the present application, the barrel assembly further comprises a barrel cover, the lower end of which is paved with a rubber layer, and the rubber layer at the lower end of the barrel cover is utilized to strengthen and fix the connection with the first section of the barrel.

[0044] In some embodiments of the present application, a rubber layer is provided at the engaging portions of the first buckle and the second buckle, and the rubber layer is used to strengthen the fixation of the barrel assembly.

[0045] In some embodiments of the present application, a symmetrical second articulated seat is installed at one end of the second clip, the second articulated seat is hingedly connected to the first articulated seat, the first articulated seat is fixedly connected to the first clip, the second articulated seat on the second clip and the first articulated seat on the first clip are articulated, the first articulated seat and the second articulated seat are connected by a first screw, so that the second clip can be flipped, the second clip is connected to the first clip by a second screw to fix the barrel assembly, and then the stepped shaft on the first section of the barrel is connected to the lower ends of the first and second clips.

[0046] In some embodiments of the present application, the sealing gasket is sleeved on the metal pipe joint to connect the metal pipe with the inner and outer pipe threads to seal the air inlet at the upper end of the barrel cover.

[0047] In some embodiments of the present application, a third screw, a fourth screw, and a fifth screw are provided on the fixing frame of the hollow copper tube fixing assembly, and countersunk holes are provided on the first section and the fourth section of the barrel, and the third screw, the fourth screw, and the fifth screw can be inserted into the countersunk holes.

[0048] In some embodiments of the present application, the first section of the barrel and the fourth section of the barrel are provided with circumferentially arranged countersunk holes, and the fixing frame is provided with threaded holes inside. The fixing frame is connected to the first section of the barrel and the fourth section of the barrel respectively through the third screw, the fourth screw, and the fifth screw. The third screw, the fourth screw, and the fifth screw are fixed by being tangent to the hollow copper tube.

[0049] In some embodiments of the present application, the lower end of the fourth section of the barrel has an external thread connected to the first nut, the second nut, and the third nut to fix the support frame. The support frame can be adjusted up and down by the first nut, the second nut, and the third nut and then fixed.

[0050] In some embodiments of the present application, the first heating block is connected to the third section and the fourth section of the barrel through a first fastening screw, and the second heating block is snap-connected to the nozzle through a second fastening screw.

[0051] In some embodiments of the present application, a gear and a rack are installed in the convex frame, and an electric wire is installed at the lower end of the rack. The gear and the rack are driven by meshing, that is, the gear makes a circular motion and the rack makes a linear motion, thereby driving the electric wire to move left and right, and the wire trough fixes the electric wire.

[0052] In some embodiments of the present application, a sealing gasket is installed between the metal pipe joint and the metal pipe, and the sealing gasket is in contact with the top of the barrel cover.

[0053] In some embodiments of the present application, the first section and the fourth section of the barrel are configured as stepped shafts.

[0054] In some embodiments of the present application, the fourth section of the barrel and the power-on component are made of high-temperature resistant insulating materials.

[0055] In some embodiments of the present application, the cartridge assembly further includes a cartridge cover.

[0056] In some embodiments of the present application, the barrel is also connected to a feeding air pressure pump, a feeding air pressure valve and a feeding air pressure gauge, which can be connected to the barrel through a tee, or can be realized through any existing structure that can realize the air supply function, which is used to regulate the feeding speed, etc., to maintain feeding stability.

[0057] In some embodiments of the present application, the hollow copper tube is connected to an air supply pressure pump, an air supply pressure valve and an air supply pressure gauge, which are used to regulate the flow rate of a suitable air flow field, etc., to facilitate the formation of fine three-dimensional structures.

[0058] In some embodiments of the present application, one end of the hollow copper tube is connected to the air supply pressure gauge with a thin rubber hose. Since the diameter of the copper tube is smaller than the diameter of the nozzle, the other end can be inserted into the molten polymer material printing nozzle and deeply flush with the nozzle. Since the hollow copper tube is inside the barrel, the high-speed airflow flowing through the hollow copper tube is also heated by the heating block, so that the material will not cool down too quickly during the injection process.

[0059] In other embodiments of the present application, a high-throughput piezoelectric polymer fiber is provided, which is prepared by one of the above-mentioned spinning methods.

[0060] In some other embodiments of the present application, there is provided an application of a high-throughput piezoelectric polymer fiber in a skin dressing, comprising selecting an antibiotic suitable for skin treatment, dissolving it in a solvent, preparing a solution, loading the drug solution into a syringe of an electrospray device, setting the distance between the nozzle and the fiber, adjusting the voltage of the high-voltage power supply to a preset value, spraying on the fiber surface for a preset time, drying the drug-loaded fiber, and preparing a skin dressing.

[0061] In some embodiments of the present application, a high-throughput piezoelectric polymer fiber is provided for use in preparing a nerve catheter, including using a stainless steel rod as a mold to wind the fiber into a tubular structure; during the winding process, a L-polylactic acid solution is evenly sprayed between the fiber layers, the wound catheter is placed in a vacuum oven to dry, and the stainless steel rod is then pulled out of the catheter to obtain a nerve catheter with a desired inner diameter.

[0062] In some other embodiments of the present application, there is provided an application of a high-throughput piezoelectric polymer fiber in a flexible piezoelectric fiber sensor, including cutting the collected fiber membrane into the required size, preparing a PDMS precursor solution, mixing the base polymer and the curing agent in a preset mass ratio, and fully stirring and degassing; after coating a layer of PDMS membrane on the substrate, waiting for the PDMS membrane to be semi-cured, placing the cut fiber membrane on the semi-cured PDMS layer; attaching electrodes to both ends of the fiber membrane, pouring another layer of PDMS solution to cover the entire fiber membrane and the electrodes, and after the entire structure is dried and cured, peeling it off from the substrate to obtain a flexible piezoelectric fiber sensor.

[0063] The technical solution of this application has at least the following advantages and beneficial effects:

[0064] In the preparation method of this application, the electric field force is primarily responsible for generating and driving the charged microfiber jet, while the airflow shear force assists in further stretching and orienting the fibers. The synergistic effect of the two significantly improves the stability of the spinning process and the degree of fiber orientation. Furthermore, by adjusting parameters such as the electric field intensity, airflow velocity, and airflow direction, the diameter, orientation, and deposition pattern of the microfibers can be precisely controlled, thereby obtaining piezoelectric polymer microfiber materials with specific structures and properties.

[0065] Compared with the existing technology, this application has at least the following technical effects:

[0066] (1) The present application can perform high-throughput fiber jetting, which greatly improves the spinning efficiency, has a high utilization rate of melt direct spinning, and high-throughput spinning increases output, effectively reducing production costs.

[0067] (2) This application enables accurate control of fiber porosity over a wide range. In the field of filtration, filter materials with different pore sizes can be customized according to specific needs; in the biomedical field, the microenvironment required for cell growth can be precisely adjusted; and in sound insulation materials, the sound wave absorption effect can be optimized. This precise control of porosity greatly expands the application range of fibers, enabling them to meet the specific requirements of various different fields.

[0068] (3) The fibers prepared in this application exhibit piezoelectric effect without the need for secondary polarization. This property allows the fibers to be directly applied in a variety of scenarios, such as energy harvesting devices, pressure sensors, and acoustic wave converters. This inherent functionality not only simplifies subsequent processing steps but also provides new possibilities for the development of smart materials and devices.

[0069] (4) This application utilizes a molten material-based preparation process, avoiding the potential problems associated with the use of solvents. This solvent-free process significantly improves the biocompatibility of the product. Furthermore, since no solvent recovery and processing steps are required, the production process is simplified, further reducing production costs.

[0070] (5) The device used in this application can solve the electrostatic adsorption effect of the holes of the hollow metal ring electrode plate on the fibers. This application adopts bilateral single-line power supply, which can effectively avoid the phenomenon of diffused fibers adhering to the hollow metal ring electrode plate during the spinning process.

[0071] (6) The fourth section of the barrel and the power-on assembly are made of high-temperature resistant insulating materials to avoid danger and ensure a safe working environment.

[0072] (7) The hollow copper tube is fixed by a device for fixing the hollow copper tube, which can effectively prevent the hollow copper tube from moving during the spinning process and thus affecting the injection.

[0073] (8) The power supply assembly is provided with a first nut, a second nut, a third nut, a gear and a rack, which can fine-tune the wires up, down, left and right.

[0074] (9) Two convex frames are respectively provided at the left and right ends of the power-on component, and a gear rack mechanism is respectively added in the two convex frames. The gear rack mechanisms at both ends can be asynchronous mechanisms, that is, the gear rack mechanism at one end rotates without affecting the gear rack mechanism at the other end. The two gear rack mechanisms work independently and do not affect each other. Compared with the synchronous mechanism, the advantage of such a setting is that it can avoid the unequal position of the left and right wires from the nozzle caused by installation errors. The position of the wires can be adjusted by the gear rack mechanisms at both ends to make them equal and centered at the nozzle position.

[0075] (10) A dual heating module is used to control the temperature. The heating temperature of the first heating block on the barrel is slightly lower than the heating temperature of the second heating block on the nozzle. When the heating of the first heating block is stable, the second heating block is adjusted to make the nozzle temperature slightly higher than the barrel temperature, and increase in a gradient. The material can be gradually heated in the barrel and nozzle, increasing in a gradient, and finally reach the required printing temperature. This is conducive to better control of the temperature of the printing material at the nozzle, and then stabilize and regulate the viscosity changes of the printing material caused by heating temperature fluctuations.

[0076] (11) The airflow driven electric field assisted spinning adopted in this application combines the advantages of meltblowing and electrospinning in production.

[0077] (12) Different from the traditional spinning device of "external air and internal material", the present application adopts the injection method of "external material and internal air". The traditional "external air and internal material" method requires heating the air. The present device can directly heat the material through the heating block, and also has a certain heating effect on the copper tube. There is no need to waste a lot of energy to heat the air externally, thus saving energy.

[0078] (13) The present application can fix the device on a high-precision XYZ three-axis motion platform through a fixing plate, and can print a macro-controllable and micro-adjustable spinning structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0080] Figure 1 This is a schematic diagram of the overall front structure of the electric field assisted airflow field driven device in some embodiments of the present application.

[0081] Figure 2 Schematic diagram of the cross-sectional structure of the device for electric field assisted air flow driving in some embodiments of the present application.

[0082] Figure 3 This is an exploded diagram of the clamping assembly for this application.

[0083] Figure 4 This is an isometric exploded structural diagram of the barrel assembly of this application.

[0084] Figure 5 This is a schematic diagram of the air intake assembly structure of this application.

[0085] Figure 6 This is a schematic diagram of the top view of the hollow copper tube fixing assembly of this application.

[0086] Figure 7 For this application Figure 6 A schematic diagram of the structure at the center.

[0087] Figure 8 This is an isometric diagram of the heating block assembly of this application.

[0088] Figure 9 This is a schematic diagram of the partial explosion structure of the power-on component in this application.

[0089] Figure 10 The scanning electron microscope images of microfibers with different porosities in some embodiments of the present application are shown. The porosities are 26.3% ( Figure 10 (a))、58.4%( Figure 10 (b))、83.1%( Figure 10 (c)) to meet the culture requirements of different cells.

[0090] Figure 11 The scanning electron microscope images of microfibers with different orientation degrees in some embodiments of the present application are shown. The orientation degrees are 0.53 ( Figure 11 (a))、0.61( Figure 11 (b))、0.87( Figure 11 (c)) to improve the strain detection range and detection sensitivity of the sensor;

[0091] Figure 12 In some embodiments of this application, the PVDF membrane is Figure 12 (a)) and 3MPa( Figure 12 (b) Piezoelectric performance characterization results. DETAILED DESCRIPTION

[0092] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0093] It should be noted that the following detailed description is illustrative and is intended to provide an explanation of the present invention in some embodiments of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0094] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0095] In the present application, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are merely relational words determined for the convenience of describing the structural relationships of the various parts or elements of the present application, and do not specifically refer to any part or element in the present application, and should not be understood as limitations on the present application.

[0096] In this application, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meaning of these terms in this application based on specific circumstances, and they should not be construed as limitations on this application.

[0097] The following combination Figure 1-12 To further illustrate the technical solution of this application.

[0098] In some embodiments of the present application, a high-throughput piezoelectric polymer spinning method based on electric field-assisted air flow field driving is provided, which includes the following steps:

[0099] S1. Weigh 20g of left-handed polylactic acid (PLLA) particles. Place the particles in a beaker and add enough deionized water (about 200mL to completely immerse the particles). Place the beaker in an ultrasonic bath with an ultrasonic frequency of 20kHz and ultrasonicate at room temperature for 15 minutes. Vacuum dry at 40°C for 2 hours to ensure that the particles are completely dry. Transfer the dried particles to a barrel and prepare for melting. According to the melting point of the selected piezoelectric polymer, set the melt temperature to 250°C to completely melt the polymer particles. During the melting process, slowly stir the melt to eliminate possible bubbles and ensure uniformity. Continue for 30 minutes to ensure uniformity.

[0100] S2. Install the barrel containing the piezoelectric polymer particles into the melt extrusion system. Adjust the crushing air pressure to 0.2 MPa and the feed air pressure to 20 kPa. Turn on the high-voltage power supply and adjust the voltage to 12 kV. Control the melt extrusion rate and start the spinning process for 2 minutes. Adjust the print height to 20 cm and use a glass substrate as a receiving device to observe and record the fiber formation. Adjust parameters as necessary.

[0101] Scanning electron microscopy (SEM) was used to examine the fiber morphology and diameter distribution. The fiber diameter is expected to be uniformly distributed within the 2-5 μm range. A distinct β-phase peak should be present in the XRD pattern.

[0102] Mechanical properties of the piezoelectric polymer microfibers prepared by the method of the present invention were tested. Fiber membrane testing was conducted according to ASTM D882. The fiber membranes were cut into dumbbell-shaped specimens and fixed to a dedicated fixture. Tensile testing was performed using a universal material testing machine at a rate of 5-50 mm / min. The stress-strain curves were recorded, and Young's modulus, tensile strength, and elongation at break were calculated. The fibers exhibited excellent mechanical properties: the tensile strength of a single fiber could reach 0.5-2 MPa.

[0103] This piezoelectric d33 coefficient test uses a quasi-static d33 tester to apply a force of 0.25N to the sample and measure the amount of charge generated. The piezoelectric output performance test is performed by preparing a signal output test, sandwiching the fiber membrane between two flexible electrodes, using a linear motor or vibration table to apply periodic stress to the sample, recording the open circuit voltage (Voc) and short circuit current (Isc), and calculating the power density and energy conversion efficiency. The open circuit voltage of the piezoelectric film generator can reach 2.5-10V; after 10 6 After the first cycle of loading, the piezoelectric output performance retention rate exceeded 90%.

[0104] In some embodiments of the present application, a high-throughput piezoelectric polymer spinning method based on electric field-assisted air flow field driving is provided, which includes the following steps:

[0105] S1. Weigh 20 g of left-handed polylactic acid (PLLA) particles, place them in a beaker, add enough deionized water (about 200 mL to completely immerse the particles), place the beaker in an ultrasonic bath with an ultrasonic frequency of 20 kHz, and ultrasonicate at room temperature for 15 minutes. Vacuum dry at 40 ° C for 2 hours to ensure that the particles are dry; transfer the dried particles to a barrel and prepare for melting; according to the melting point of the selected piezoelectric polymer, set the melting temperature to 250 ° C to completely melt the polymer particles. During the melting process, slowly stir the melt to eliminate possible bubbles and ensure uniformity. Continue for 30 minutes to ensure uniformity.

[0106] S2. Install the barrel containing the piezoelectric polymer particles into the electric-field-assisted airflow drive device. Adjust the airflow pressure to 0.2 MPa and the feed pressure to 12 kPa. Turn on the high-voltage power supply and adjust the voltage to 10 kV. Control the melt extrusion rate and begin the spinning process for 2 minutes. Adjust the print height to 20 cm. Use a glass substrate for receiving the print. Observe and record the fiber formation and adjust parameters as necessary.

[0107] As needed, the prepared polymer fiber is used as a skin dressing, which specifically includes the following steps:

[0108] Prepare the drug solution: Select an antibiotic suitable for skin treatment and dissolve it in an appropriate solvent to a concentration of 5 mg / mL. Load the drug solution into the syringe of the electrospray device. Set the distance between the nozzle and the fiber membrane to 15 cm. Adjust the high-voltage power supply to 12 kV and spray evenly on the fiber membrane surface for 5 minutes. Vacuum dry the loaded fiber membrane at 40°C for 2 hours to ensure complete evaporation of the solvent.

[0109] Scanning electron microscopy (SEM) was used to observe the fiber morphology and diameter distribution. The fiber diameter is expected to be uniformly distributed within the range of 0.5-2 μm. A distinct β-phase peak should be present in the XRD pattern.

[0110] The piezoelectric d33 coefficient test uses a quasi-static d33 tester to apply a force of 0.25N to the sample and measure the amount of charge generated. The piezoelectric output performance test is performed by preparing a signal output test, sandwiching the fiber membrane between two flexible electrodes, using a linear motor or vibration table to apply periodic stress to the sample, recording the open circuit voltage (Voc) and short circuit current (Isc), and calculating the power density and energy conversion efficiency. The open circuit voltage of the piezoelectric film generator can reach 2.5-10V; after 10 6 After the first cycle of loading, the piezoelectric output performance retention rate exceeded 90%.

[0111] The drug-loaded piezoelectric fiber dressing was cut into discs (8 mm in diameter) and placed in a 24-well culture plate. Human dermal fibroblasts (HDF) were used for cell compatibility testing. 4 Cells were seeded at a density of 100 μg / mL. After culturing for 24, 48, and 72 hours, cell viability was assessed using a CCK-8 assay. Cell adhesion and spreading on the fibers were observed using a fluorescence microscope.

[0112] In some embodiments of the present application, a high-throughput piezoelectric polymer spinning method based on electric field-assisted air flow field driving is provided, which includes the following steps:

[0113] S1. Weigh 20g of left-handed polylactic acid (PLLA) particles. Place the particles in a beaker and add enough deionized water (about 200mL to completely immerse the particles). Place the beaker in an ultrasonic bath with an ultrasonic frequency of 20kHz and ultrasonicate at room temperature for 15 minutes. Vacuum dry at 40°C for 2 hours to ensure that the particles are completely dry. Transfer the dried particles to a barrel and prepare for melting. According to the melting point of the selected piezoelectric polymer, set the melt temperature to 250°C to completely melt the polymer particles. During the melting process, slowly stir the melt to eliminate possible bubbles and ensure uniformity. Continue for 30 minutes to ensure uniformity.

[0114] S2. Install the barrel containing the PLLA melt into the electric field-assisted airflow driven spinning device. Adjust the internal airflow velocity to 2 m / s and the external feed air pressure to 30 kPa. Turn on the high-voltage power supply and adjust the voltage to 15 kV so that the electric field strength reaches approximately 1.5 kV / cm. Control the melt extrusion rate and start the spinning process for 2 minutes. Adjust the distance between the nozzle and the collecting glass substrate to 15 cm. Tilt the glass substrate at an angle of 85° to obtain oriented fibers.

[0115] The obtained fiber is used to prepare a piezoelectric polymer fiber nerve guide, comprising the following steps:

[0116] Using a 2mm diameter stainless steel rod as a mold, the fiber membrane was wound into a tubular structure. During the winding process, a small amount of L-polylactic acid solution was evenly sprayed between the fiber layers. The wound catheter was then dried in a 60°C vacuum oven for 2 hours. The stainless steel rod was carefully removed from the catheter, resulting in a nerve conduit with an inner diameter of 2mm.

[0117] Scanning electron microscopy (SEM) was used to examine the fiber morphology and diameter distribution. The fiber diameter is expected to be uniformly distributed within the 2-5 μm range. A distinct β-phase peak should be present in the XRD pattern.

[0118] The piezoelectric d33 coefficient test uses a quasi-static d33 tester to apply a force of 0.25N to the sample and measure the amount of charge generated. The piezoelectric output performance test is performed by preparing a signal output test, sandwiching the fiber membrane between two flexible electrodes, using a linear motor or vibration table to apply periodic stress to the sample, recording the open circuit voltage (Voc) and short circuit current (Isc), and calculating the power density and energy conversion efficiency. The open circuit voltage of the piezoelectric film generator can reach 2.5-10V; after 10 6 After the first cycle of loading, the piezoelectric output performance retention rate exceeded 90%.

[0119] Mechanical properties of the piezoelectric polymer microfibers prepared by the method of the present invention were tested. Fiber membrane testing was conducted according to ASTM D882. The fiber membranes were cut into dumbbell-shaped specimens and fixed to a dedicated fixture. Tensile testing was performed at a rate of 5-50 mm / min using a universal material testing machine. The stress-strain curves were recorded, and Young's modulus, tensile strength, and elongation at break were calculated. The fibers exhibited excellent mechanical properties: a single fiber tensile strength of 2-5 MPa was achieved.

[0120] Cytocompatibility testing was performed using rat Schwann cells (RSC96) and rat neural stem cells (NSCs). Cells were seeded at appropriate density onto the inner wall of the conduits. After 3 and 7 days of culture, cell viability was assessed using Live / Dead staining and a CCK-8 assay. Confocal microscopy was used to observe cell adhesion, spreading, and neurite outgrowth on the fibers. Neural cells grew well on the nerve conduits.

[0121] In some embodiments of the present application, a high-throughput piezoelectric polymer spinning method based on electric field-assisted air flow field driving is provided, which includes the following steps:

[0122] S1. Weigh 20 g of polyvinylidene fluoride (PVDF). Place the particles in a beaker and add enough deionized water (about 200 mL to completely immerse the particles). Place the beaker in an ultrasonic bath with an ultrasonic frequency of 20 kHz and ultrasonicate at room temperature for 15 minutes. Vacuum dry at 40 ° C for 2 hours to ensure that the particles are completely dry. Transfer the dried particles to the barrel and prepare for melting. According to the melting point of the selected piezoelectric polymer, set the melting temperature to 250 ° C to completely melt the polymer particles. During the melting process, slowly stir the melt to eliminate possible bubbles and ensure uniformity. Continue for 30 minutes to ensure uniformity.

[0123] S2. Install the barrel containing the PVDF melt into the electric field-assisted airflow driven spinning device. Adjust the internal airflow velocity to 6m / s and the external feed air pressure to 30kPa. Turn on the high-voltage power supply and adjust the voltage to 20kV. Control the melt extrusion rate and start the spinning process for 50 minutes. Adjust the distance between the nozzle and the collection device to 16cm. Use a multi-angle tilted substrate as a collection device to obtain a cross-arranged fiber network structure.

[0124] The prepared fiber is used to prepare a polymer fiber sensor as needed, which specifically includes the following steps:

[0125] Cut the collected fiber membrane into the required size of 2cm×6cm. Prepare the PDMS precursor solution, mix the base polymer and curing agent in a mass ratio of 10:1, stir thoroughly and degas in vacuum. Apply a layer of 0.5mm thick PDMS on the glass plate and semi-cure at 65℃ for 10 minutes. Place the cut fiber membrane on the semi-cured PDMS layer. Stick 5mm wide copper foil electrodes on both ends of the fiber membrane to ensure full contact with the fiber. Pour another layer of about 1mm thick PDMS solution to cover the entire fiber membrane and electrode. Place the entire structure in a 65℃ oven for 4 hours. After the PDMS is completely cured, peel it off from the glass plate to obtain a flexible piezoelectric fiber sensor.

[0126] Mechanical properties of the piezoelectric polymer microfibers prepared by the method of the present invention were tested. Fiber membrane testing was conducted according to ASTM D882. The fiber membranes were cut into dumbbell-shaped specimens and fixed to a dedicated fixture. Tensile testing was performed at a rate of 5-50 mm / min using a universal material testing machine. The stress-strain curves were recorded, and Young's modulus, tensile strength, and elongation at break were calculated. The fibers exhibited excellent mechanical properties: a single fiber tensile strength of 2-5 MPa was achieved.

[0127] The sensor was subjected to cyclical tension and compression for 10,000 cycles (tensile strain 5%, compression force 3N, frequency 1Hz). The piezoelectric output and sensitivity factor of the sensor were measured after every 1,000 cycles. The performance retention after 10,000 cycles was calculated.

[0128] In some embodiments of the present application, an airflow field driven electric field assisted melt spinning preparation device includes an XYZ three-axis motion platform (not shown in the figure), a clamping assembly 1, a barrel assembly 2, an air intake assembly 3, a heating block assembly 5 and a power supply assembly 6;

[0129] The clamping assembly 1 is used to clamp the barrel assembly 2 and is fixed on the Z axis of the XYZ three-axis motion platform;

[0130] The barrel assembly 2 includes a barrel cover 201, a multi-section barrel and a nozzle 206;

[0131] The air inlet assembly 3 is connected to the barrel cover 201 and includes a metal tube 301 and a hollow copper tube 302 disposed inside the metal tube 301; the hollow copper tube 302 assembly passes through the interior of the multi-section barrel to provide the airflow field required for melt spinning;

[0132] The heating block assembly 5 includes a first heating block 501 and a second heating block 502 , wherein the first heating block 501 is disposed on the multi-section barrel, and the second heating block 502 is disposed at the nozzle 206 ;

[0133] The power supply component 6 is disposed outside the nozzle 206 and is used to provide an electric field required for melt spinning.

[0134] In some embodiments of the present application, the clamping assembly 1 includes a fixed plate 101, a first buckle 106 is provided on the fixed plate 101, a first hinge seat 102 is provided at one end of the first buckle 106, a second buckle 107 is provided corresponding to the first buckle 106, a second hinge seat is provided at one end of the second buckle 107, the first hinge seat 102 and the second hinge seat are connected by a first screw 104; the other ends of the first buckle 106 and the second buckle 107 are connected by a second screw 105, and the barrel assembly 2 is clamped between the first buckle 106 and the second buckle 107.

[0135] In some embodiments of the present application, the multi-section barrel includes a first barrel section 202 , a second barrel section 203 , a third barrel section 204 and a fourth barrel section 205 .

[0136] In some embodiments of the present application, a first nut 207, a second nut 208, and a third nut 209 are installed on the bottom of the fourth section 205 of the barrel, and a power-on component 6 is installed between the first nut 207, the second nut 208, and the third nut 209 at the bottom of the fourth section 205 of the barrel, so that the power-on component 6 can be adjusted up and down.

[0137] In some embodiments of the present application, the air intake assembly 3 also includes a metal tube 301 joint 303, the metal tube 301 is connected to the metal tube 301 joint 303, a hollow copper tube 302 is installed in the middle of the metal tube 301, and a sealing gasket 304 is provided between the metal tube 301 joint 303 and the metal tube 301.

[0138] In some embodiments of the present application, a hollow copper tube 302 fixing assembly is provided in the first section 202 of the barrel and the third section 204 of the barrel. The hollow copper tube 302 fixing assembly includes a fixing frame 401, and a plurality of screws evenly distributed around the hollow copper tube 302 are installed on the fixing frame 401 to fix and position the hollow copper tube 302.

[0139] In some embodiments of the present application, the plurality of screws include a third screw 402, a fourth screw 403, and a fifth screw 404.

[0140] In some embodiments of the present application, a first heating block 501 is installed on the third barrel section 204 and the fourth barrel section 205 .

[0141] In some embodiments of the present application, a first fastening screw 503 is provided on the first heating block 501 , and a second fastening screw 504 is provided on the second heating block 502 .

[0142] In some embodiments of the present application, a convex frame 610 is provided at the left and right ends of the power-on component 6, and a gear 603 and rack 604 mechanism is provided inside the convex frame 610. The gear 603 and rack 604 mechanisms at the left and right ends are asynchronous mechanisms, and they work independently without affecting each other. The gear 603 and rack 604 mechanisms can adjust the wire 606 left and right.

[0143] In some embodiments of the present application, the power-on component 6 includes a support frame 601, a convex frame 610 is provided at the lower end of the support frame 601, a rack 604 is installed in the convex frame 610, a gear 603 is installed above the rack 604, a key 608 groove 609 is provided inside the gear 603, a shaft 602 is installed inside the gear 603, a key 608 is installed above the shaft 602, a rotating ring 605 is installed at one end of the shaft 602, an electric wire 606 is installed below the rack 604, and a wire groove 607 is installed on the fixed plate 101.

[0144] In some embodiments of the present application, the barrel assembly 2 is connected by pipe threads through the first barrel section 202 , the second barrel section 203 , the third barrel section 204 , the fourth barrel section 205 and the nozzle 206 .

[0145] In some embodiments of the present application, the lower end of the first section 202 of the barrel is provided with an internal thread, the upper and lower ends of the second section 203 of the barrel are provided with external threads, the upper and lower ends of the third section 204 of the barrel are provided with internal threads, the lower end of the fourth section 205 of the barrel is provided with internal threads and external threads, and the nozzle 206 is provided with external threads.

[0146] In some embodiments of the present application, a rubber layer is laid on the lower end of the barrel cover, and the rubber layer on the lower end of the barrel cover is used to strengthen the fixed connection with the first section 202 of the barrel.

[0147] In some embodiments of the present application, a rubber layer is laid on the engaging parts of the first buckle 106 and the second buckle 107 to strengthen the fixation of the barrel assembly 2 by using the rubber layer.

[0148] In some embodiments of the present application, a symmetrical second articulated seat is installed at one end of the second clip 107, and the second articulated seat is hingedly connected to the first articulated seat 102. The first articulated seat 102 is fixedly connected to the first clip 106, and the second articulated seat on the second clip 107 and the first articulated seat 102 on the first clip 106 are articulated. The first articulated seat 102 and the second articulated seat are connected by the first screw 104 so that the second clip 107 can be flipped. The second clip 107 is connected to the first clip 106 and fixed with the barrel assembly 2 by the second screw 105, and then the stepped shaft 602 on the first section 202 of the barrel is connected to the first clip 106 and the lower end of the second clip 107.

[0149] In some embodiments of the present application, the sealing gasket 304 is sleeved on the joint 303 of the metal tube 301 and connected to the metal tube 301 through internal and external pipe threads to seal the air inlet at the upper end of the barrel cover 201.

[0150] In some embodiments of the present application, a third screw 402, a fourth screw 403, and a fifth screw 404 are provided on the fixing frame 401 of the hollow copper tube 302 fixing assembly, and a countersunk hole 210 is provided on the first section 202 and the fourth section 205 of the barrel, and the third screw 402, the fourth screw 403, and the fifth screw 404 can be inserted into the countersunk hole 210.

[0151] In some embodiments of the present application, the first section 202 of the barrel and the fourth section 205 of the barrel are provided with circumferentially arranged countersunk holes 210, and the fixing frame 401 is provided with threaded holes inside. The fixing frame 401 is connected to the first section 202 of the barrel and the fourth section 205 of the barrel respectively through the third screw 402, the fourth screw 403, and the fifth screw 404. The third screw 402, the fourth screw 403, and the fifth screw 404 are fixed by being tangent to the hollow copper tube 302.

[0152] In some embodiments of the present application, the lower end of the fourth section 205 of the barrel has an external thread that is connected to the first nut 207, the second nut 208, and the third nut 209 to fix the support frame 601. The support frame 601 can be adjusted up and down by the first nut 207, the second nut 208, and the third nut 209 and then fixed.

[0153] In some embodiments of the present application, the first heating block 501 is connected to the third barrel section 204 and the fourth barrel section 205 via a first fastening screw 503 , and the second heating block 502 is snap-connected to the nozzle 206 via a second fastening screw 504 .

[0154] In some embodiments of the present application, a gear 603 and a rack 604 are installed in the convex frame 610, and an electric wire 606 is installed at the lower end of the rack 604. The gear 603 and the rack 604 are driven by meshing, that is, the gear 603 performs circular motion and the rack 604 performs linear motion, thereby driving the electric wire 606 to move left and right, and the wire groove 607 fixes the electric wire 606.

[0155] In some embodiments of the present application, a sealing gasket 304 is installed between the joint 303 of the metal tube 301 and the metal tube 301 , and the sealing gasket 304 is in contact with the top of the barrel cover.

[0156] In some embodiments of the present application, the first barrel section 202 and the fourth barrel section 205 are configured as stepped shafts 602 .

[0157] In some embodiments of the present application, the fourth barrel section 205 and the power-on component 6 are made of high-temperature resistant insulating materials.

[0158] In some embodiments of the present application, the present application provides an airflow-driven electric field-assisted melt spinning preparation device, including a clamping assembly 1, the clamping assembly 1 includes a fixed plate 101, the fixed plate 1 is provided with a first clip 106, the first clip 106 is provided with a first hinge seat 102, a second clip 107 is installed in front of the first clip 106, and a second hinge seat 103 is provided on the second clip 107. The right ends of the first hinge seat 102 and the second hinge seat 103 are installed with a first screw 104, the left ends of the first clip 106 and the second clip 107 are installed with a second screw 105, and the first clip 106 and the second clip 107 are installed between the first clip 106 and the second clip 107. The barrel assembly 2 is engaged with the barrel assembly 2, which includes a barrel cover 201, a first barrel section 202, a second barrel section 203, a third barrel section 204, a fourth barrel section 205 and a nozzle 206. The first barrel section 202 and the fourth barrel section 205 are provided with countersunk holes 210. A first nut 207, a second nut 208 and a third nut 209 are installed on the bottom of the fourth barrel section 205. The barrel cover 201 is connected to an air intake assembly 3, and the air intake assembly 3 includes a metal pipe joint 303. The metal pipe joint 303 is connected to a metal pipe 301. A hollow copper pipe 302 is installed in the middle of the metal pipe 301. A sealing gasket 304 is provided between the head 303 and the metal tube 301. A hollow copper tube fixing assembly 4 is installed in the first section 202 and the third section 204 of the barrel. The hollow copper tube fixing assembly 4 includes a fixing frame 401. A third screw 402, a fourth screw 403, and a fifth screw 404 are installed on the fixing frame 401. A heating block assembly 5 is installed on the barrel assembly 2. A first heating block 501 is installed on the third section 204 and the fourth section 205 of the barrel. A first fastening screw 503 is provided on the first heating block 501. A second heating block 502 is installed on the nozzle 206. A second fastening screw 503 is provided on the second heating block 502. 504, a power-on component 6 is installed between the first nut 207, the second nut 208 and the third nut 209 at the bottom of the fourth section 205 of the barrel, and the power-on component 6 includes a support frame 601, a convex frame 610 is provided at the lower end of the support frame 601, a rack 604 is installed in the convex frame 610, a gear 603 is installed above the rack 604, a keyway 609 is provided inside the gear 603, a shaft 602 is installed inside the gear 603, a key 608 is installed above the shaft 602, a rotating ring 605 is installed at one end of the shaft 602, an electric wire 606 is installed below the rack 604, and a wire groove 607 is installed on the fixed plate 101.

[0159] In some embodiments of the present application, the lower end of the first barrel section 202 is provided with an internal thread, the upper and lower ends of the second barrel section 203 are provided with external threads, the upper and lower ends of the third barrel section 204 are provided with internal threads, the lower end of the fourth barrel section 205 is provided with internal threads and external threads, the nozzle 206 is provided with external threads, and the barrel assembly 2 is connected by pipe threads through the first barrel section 202, the second barrel section 203, the third barrel section 204, the fourth barrel section 205 and the nozzle 206, and the lower end of the barrel cover 201 is paved with a rubber layer, and the rubber layer at the lower end of the barrel cover 201 is used to strengthen the fixed connection with the first barrel section 202.

[0160] In some embodiments of the present application, the front end 106 of the first clip 106 and the rear end of the second clip 107 are both paved with a rubber layer, and the rubber layer is used to strengthen the fixation of the barrel assembly 2. A symmetrical second hinge seat 103 is installed at one end of the second clip 107, and the second hinge seat 103 is hingedly connected to the first hinge seat 102. The rear end of the first hinge seat 102 is fixedly connected to the end of the first clip 106, and the second hinge seat 103 on the second clip 107 and the first hinge seat 102 on the first clip 106 are hinged. The first hinge seat 102 and the second hinge seat 103 are connected by the first screw 104, so that the second clip 107 can be flipped, and the second clip 107 is connected to the first clip 106 and fixed to the barrel assembly 2 by the second screw 105, and then the stepped shaft 602 on the first section 202 of the barrel is connected to the lower ends of the first clip 106 and the second clip 107. The sealing gasket 304 is put on the joint 303 of the metal tube 301 and connected to the metal tube 301 through the internal and external pipe threads to seal the air inlet at the upper end of the barrel cover 201.

[0161] In some embodiments of the present application, the first section 202 of the barrel and the fourth section 205 of the barrel are provided with circumferentially arranged countersunk holes 210, and the fixing frame 401 is provided with threaded holes inside. The fixing frame 401 is connected to the first section 202 of the barrel and the fourth section 205 of the barrel respectively through the third screw 402, the fourth screw 403, and the fifth screw 404. The third screw 402, the fourth screw 403, and the fifth screw 404 are fixed by being tangent to the hollow copper tube 302.

[0162] In some embodiments of the present application, the lower end of the fourth section 205 of the barrel has an external thread that is connected to the first nut 207, the second nut 208, and the third nut 209 to fix the support frame 601. The support frame 601 can be adjusted up and down by the first nut 207, the second nut 208, and the third nut 209 and then fixed.

[0163] In some embodiments of the present application, the first heating block 501 is connected to the third barrel section 204 and the fourth barrel section 205 via a first fastening screw 503 , and the second heating block 502 is snap-connected to the nozzle 206 via a second fastening screw 504 .

[0164] In some embodiments of the present application, a gear 603 and a rack 604 are installed in the convex frame 610, and an electric wire 606 is installed at the lower end of the rack 604. The gear 603 and the rack 604 are driven by meshing, that is, the gear 603 performs circular motion and the rack 604 performs linear motion, thereby driving the electric wire 606 to move left and right, and the wire groove 609 fixes the electric wire 606.

[0165] like Figure 1-9 As shown, the working method of the airflow-driven electric field-assisted melt spinning preparation device described in the present application includes the following steps:

[0166] Step 1: Insert the hollow copper tube 302 into the barrel and slowly adjust the distance between it and the bottom of the nozzle 206. After adjusting the distance, use the fixing frame 401 to cooperate with the third bolt 402, the fourth bolt 403, and the fifth bolt 404 to fix the hollow copper tube 302.

[0167] In some embodiments of the present application, the outer diameter of the circular ring at the lower end of the nozzle 206 used for feeding is 1.3 mm, and the inner diameter is 1.2 mm. The outer diameter of the hollow copper tube 302 is 1 mm, and the inner diameter is 0.8 mm. However, according to different requirements, the outer diameter and inner diameter of the nozzle 206 and the hollow copper tube 302 can be freely selected and are not limited here.

[0168] Step 2: Open the barrel cover 201 and add an appropriate amount of granular or powdered material into the barrel, and turn on the thermostat to adjust the temperature of the heating block assembly 55 to an appropriate temperature and maintain it for a period of time until the material is completely melted. At this time, it can be observed that the molten material slowly flows out from the circular area formed between the hollow copper tube 302 and the bottom of the nozzle 206.

[0169] The heating block assembly 55 for heating the barrel assembly 2 includes a first heating block 501 and a second heating block 502. The temperature adjustment range of the first heating block 501 and the second heating block 502 is 20°C to 350°C. The set temperature is adjusted by the thermostat so that the temperature control error of the first heating block 501 and the second heating block 502 is within ±2°C.

[0170] Step 3: Adjust the air pressure in the hollow copper tube 302 and the metal tube 301 to appropriate values according to different materials through the injection pressure regulating valve and the feed pressure regulating valve.

[0171] The air pressure in the barrel assembly 2 for extruding the polymer solution or melt is 0-200 kPa, i.e., the adjustment range of the feed pressure regulating valve is 0-200 kPa. The air pressure of the high-speed airflow used for pulling, stretching, and thinning the material is 0-900 kPa, i.e., the adjustment range of the injection pressure regulating valve is 0-900 kPa.

[0172] Step 4. Fix the support frame 601 with the first nut 207, the second nut 208, and the third nut 209, then adjust the wire 606 to a suitable position through the gear 603 and the rack 604, and fix the wire 606 with the wire groove 607 to prevent the wire 606 from swinging due to external force when the three-axis 602 motion platform moves during the spinning process. Then, turn on the high-voltage DC power supply and adjust it to a suitable voltage according to the different materials.

[0173] The voltage adjustment range of the high-voltage DC generator used for electric field assistance is 0 to 30 kV.

[0174] Step 5: Open the jet pressure regulating valve switch corresponding to the hollow copper tube 302 until the excess material adhering to the nozzle 206 is blown off, and then open the feed air pressure valve switch corresponding to the metal tube 301 to start feeding and spinning.

[0175] Step 6: Use a receiving plate to receive the fiber, and the spinning trajectory can be controlled by the three-axis 602 motion platform.

[0176] The receiving plate for receiving the finished fiber parts is made of transparent glass, which is insulating and easy to peel off.

[0177] Step 7: After the spraying is completed, first close the feed pressure regulating valve switch corresponding to the metal tube 301, then close the internal air pressure valve switch corresponding to the hollow copper tube 302 to ensure that no large particles of material fall from the nozzle 206, and finally turn off the high-voltage DC power supply.

[0178] Step 8: Finally, remove the three-dimensional microfiber structure adhered to the receiving plate and set aside.

[0179] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving, characterized in that: The following steps are involved: S1. Raw material preparation: Select piezoelectric polymer material particles, ultrasonically treat them in water, dry them in a barrel and melt them for later use; S2. Spinning preparation: The molten material prepared in S1 is passed through the barrel by introducing airflow and applying an electric field at the nozzle. After setting the working parameters, spinning is performed on a substrate to obtain microfibers with piezoelectric properties.

2. The high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving according to claim 1, characterized in that: In S1, the piezoelectric polymer material is at least one selected from the group consisting of poly (L-lactic acid), poly (vinylidene fluoride), poly (vinylidene fluoride-trifluoroethylene) copolymer, and poly (vinylidene fluoride-hexafluoropropylene) copolymer.

3. The high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving according to claim 1, characterized in that: The airflow is a directional airflow of 0.1-10 m / s; in S2, the substrate includes a grounded collection plate, a multi-angle inclined substrate or a rotating collection drum, and the rotation speed can be adjusted to 50-5000 rpm; the substrate material includes a conductive substrate and a non-conductive substrate, preferably, the conductive substrate includes but is not limited to a stainless steel substrate, a copper substrate, etc.; preferably, the non-conductive substrate includes but is not limited to a glass substrate, a polyethylene terephthalate (PET), and a polydimethylsiloxane (PDMS) substrate.

4. The high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving according to claim 1, characterized in that: In S2, the output voltage of the high voltage power supply is adjusted to adjust the electric field strength. The output voltage range is 5-50 kV, preferably 10-30 kV, so that the electric field strength is within the range of 0.5-5 kV / cm.

5. The high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving according to claim 1, characterized in that: In S2, the external feed air pressure range is set to 0-50KPa; and the distance between the nozzle and the collecting device is adjusted to 2-40cm.

6. The high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving according to claim 1, characterized in that: The temperature range of the barrel and nozzle is controlled at 40℃-280℃.

7. The high-throughput piezoelectric polymer spinning method based on electric field assisted air flow field driving according to claim 1, characterized in that: In the above-mentioned S2, an electric field is applied to the nozzle by introducing airflow into the barrel and an electric field is applied to the nozzle, and an electric field-assisted airflow field-driven device is used, which includes an XYZ three-axis motion platform, a clamping assembly, a barrel assembly, an air intake assembly, a heating block assembly and a power-on assembly; The clamping assembly is fixed on the Z axis of the XYZ three-axis motion platform and is used to clamp the barrel assembly; The barrel assembly includes a multi-section barrel and a nozzle; The air inlet assembly includes a metal tube and a hollow copper tube disposed inside the metal tube; the hollow copper tube assembly passes through the interior of the multi-section barrel to provide the air flow field required for melt spinning; The heating block assembly includes a first heating block and a second heating block, the first heating block is arranged on the multi-section barrel, and the second heating block is arranged at the nozzle; The electrification component is arranged outside the nozzle and is used to provide the electric field required for melt spinning.

8. A high-throughput piezoelectric polymer fiber, characterized in that The fiber is prepared by the spinning method according to any one of claims 1 to 6.

9. A use of the high-throughput piezoelectric polymer fiber as claimed in claim 8 in a skin dressing, comprising selecting an antibiotic suitable for skin treatment, dissolving the antibiotic in a solvent, preparing a solution, loading the drug solution into a syringe of an electrospray device, setting a distance between the nozzle and the fiber, adjusting the voltage of the high-voltage power supply to a preset value, spraying the fiber surface for a preset time, and drying the loaded fiber to produce a skin dressing.

10. An application of a high-throughput piezoelectric polymer fiber as described in claim 8 in a flexible piezoelectric fiber sensor, comprising cutting the collected fiber membrane into the required size, preparing a PDMS precursor solution, mixing the base polymer and the curing agent in a preset mass ratio, and fully stirring and degassing; after coating a layer of PDMS membrane on the substrate, waiting for the PDMS membrane to be semi-cured, placing the cut fiber membrane on the semi-cured PDMS layer; attaching electrodes to both ends of the fiber membrane, pouring another layer of PDMS solution to cover the entire fiber membrane and the electrodes, and after the entire structure is dried and cured, peeling it off from the substrate to obtain a flexible piezoelectric fiber sensor.

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