A two-dimensional ultrasonic-assisted electrospinning device

Abstract

The application discloses a two-dimensional ultrasonic-assisted electrospinning device and belongs to the technical field of electrospinning. The device comprises a liquid inlet and gas inlet device, the bottom of the liquid inlet and gas inlet device is connected with an electrospinning jet device, and an auxiliary receiving device is arranged below the electrospinning jet device. The electrospinning jet device comprises a nozzle body, an ultrasonic-assisted electrospinning nozzle is arranged in the lower part of the nozzle body, and the ultrasonic-assisted electrospinning nozzle is provided with an ultrasonic transducer assembly for forming a longitudinal ultrasonic field. The auxiliary receiving device comprises a receiving plate, an ultrasonic wave emitting device is arranged on one side of the receiving plate, and an ultrasonic wave receiving device is arranged on the other side of the receiving plate, so as to form a transverse ultrasonic field above the receiving plate.

Description

Technical Field

[0001] This invention belongs to the field of electrospinning technology, specifically relating to a two-dimensional ultrasonic-assisted electrospinning device. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Electrospinning is a special form of electrostatic atomization of polymer fluids. In this process, the atomized material is not tiny droplets, but rather polymer microjet streams that can travel considerable distances and eventually solidify into fibers. Electrospinning is a specialized fiber manufacturing process where a polymer solution or melt is jetted into fibers within a strong electric field. Under the influence of the electric field, the droplets at the needle tip change from a spherical shape to a conical shape (i.e., a "Taylor cone"), and extend from the tip of the cone to form fine filaments. This method can produce polymer filaments with nanometer-scale diameters. However, electrospinning suffers from defects such as irregular spinneret movement and the inability to achieve the desired forming effect on the collecting plate. Therefore, the trajectory and velocity of the jet are particularly important during electrospinning. To ensure that the jet trajectory and velocity follow the desired pattern, intervention in the jet process is necessary, but currently, there is no mature solution for such intervention.

[0004] A search revealed that D.J. Felicicha et al. of Spray Systems, Illinois, USA, invented an ultrasonic atomizing nozzle with a conical spray characteristic (patent number: ZL200880125586.7). Pressurized air is applied to the nozzle assembly, and interconnected ports, chambers, and channels guide the pressurized air to the atomizing surface. To achieve the conical spray, the ports, chambers, and channels guide the pressurized gas to rotate around the atomizing rod. When the rotating pressurized gas exits the nozzle assembly through the adjacent atomizing surface, atomized droplets are entrained in the gas. The rotating pressurized gas propels the droplets forward, causing them to move circumferentially outward in a conical spray pattern.

[0005] According to a search, Qian Qingrong et al. from the Quanzhou Petrochemical Research Institute of Fujian Normal University invented an ultrasonic-assisted electrospinning device (patent number: ZL201610300805.7). The ultrasonic-assisted system includes an ultrasonic generator, an ultrasonic transducer, a hollow water tank, and a low-temperature constant-temperature water bath. The ultrasonic transducer is fixed to the outside of the hollow water tank and connected to the ultrasonic generator, which provides a high-frequency AC signal to generate ultrasonic waves inside the hollow water tank. The low-temperature constant-temperature water bath is used to control the temperature of the water inside the hollow water tank. During use, this invention continuously disperses the nanoparticles in the sample syringe through ultrasonic waves, solving the problem of precipitation of suspension during long-term electrospinning.

[0006] A search revealed that Kong Qingshan et al. from the Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, invented an ultrasound-assisted electrospinning nanofiber preparation device (patent number: ZL201220603914.3). This device combines an ultrasonic generator with electrospinning technology, leveraging the characteristic of polymer solutions forming microdroplets under ultrasonic waves. It overcomes the surface tension of the solution and the gravity of the droplets, easily forming a jet stream under a high-voltage electric field, thereby forming nanofibers and improving the efficiency of electrospinning nanofiber preparation. Furthermore, this invention features a simple structure and ease of use, and can be used to prepare various nanofiber materials.

[0007] A search revealed that Ke Huizhen et al. from Minjiang University invented an ultrasonic-assisted electrospinning nanofiber preparation device (patent number: ZL201921287240.9). This ultrasonic-assisted electrospinning nanofiber preparation device offers convenient, safe, and automated preparation. It can be equipped with a multi-functional preparation device, including an automated high-voltage electrostatic generator that provides power in real time. It features a simple structure, ease of use, and can be used to prepare various nanofiber materials. Operation is simple, work efficiency is high, and maintenance is safe and convenient. The ultrasonic generator can receive signals in real time, assisting in the preparation of electrospinning nanofibers. Timely reception reduces signal interruption, greatly improving the practicality of electrospinning nanofiber preparation, shortening preparation time, and ensuring safe and reliable preparation, achieving a truly balanced approach.

[0008] A search revealed that He Kunyun et al. of Beijing Yongkang Leyue Technology Development Co., Ltd. invented a combined ultrasonic spray electrospinning device (patent number: ZL202321785516.2). This utility model allows for the installation of a spinning nozzle below the ultrasonic nozzle, enabling electrospinning with simultaneous or opposing spraying, as well as opposing spraying of electrospinning and electrostatic spraying. It also integrates ultrasonic atomization, electrospinning, and electrostatic spraying into a single unit, enriching fiber preparation and modification processes. Furthermore, the device boasts rich compatibility and expandability, wide system compatibility, tight connections between devices, and rapid installation and use. It offers advantages such as environmental controllability, high integration, high efficiency, high circuit regularity, high safety performance, comprehensive functional integration, and convenient operation. It can also adjust the temperature and humidity environment within the equipment chamber according to experimental requirements, providing a convenient and efficient manufacturing method for the composite of nanomaterials or the modification of material surface coatings.

[0009] A search revealed that Qin Xiaohong et al. from Donghua University invented an ultrasonic oscillation electrospinning nozzle and its method (patent number: ZL201110152579.X). This invention utilizes ultrasound to oscillate the solution or melt injected into the nozzle tip, causing the solution to be in a dynamic flow state. Furthermore, the electric field strength is greatest at the top edge of the inner wall of the copper nozzle, which can overcome the surface tension of the spinning solution or melt under the same voltage to form multiple jets, increasing the electrospinning yield and improving the stability of the nozzle spinning process. This enables continuous and large-scale production of nanofibers. The nozzle used in this invention is an open-type, needle-free copper nozzle, avoiding clogging issues associated with needle-type structures. It eliminates the need for frequent replacement and cleaning of the spinneret orifice, significantly improving production efficiency, and is easy to clean after use.

[0010] A search revealed that Wang Gang et al. from Dalian University of Technology invented an ultrasonic atomization-assisted electrospinning technology (patent number: ZL201510913816.8). This technology disperses prepared graphene, graphene oxide, carbon nanotubes, and other nanoparticles into the storage tank of an ultrasonic atomizer, achieving atomized spraying of the nanoparticles and avoiding the nanoparticle clogging problem caused by conventional mixing methods. By combining ultrasonic atomization and electrospinning technologies, the prepared nanoparticle polymer composite membrane exhibits uniform nanoparticle mixing and is less prone to agglomeration. The polymer fiber membrane prepared by this technology has high separation efficiency, good strength, and excellent water resistance, improving the physicochemical properties of the composite membrane material. Compared with existing electrospinning technologies, it can achieve arbitrary doping ratios of graphene and carbon nanotubes, overcomes the clogging problem of conventional electrospinning nozzles, and has significant application prospects in environmental treatment and electrode material preparation.

[0011] According to the search, Wan Yuqin et al. of Jiangnan University invented an ultrasonic-assisted electrospinning instrument (patent number: ZL201510702564.4). This electrospinning instrument can not only effectively reduce the viscosity of the electrospinning solution and melt and expand the electrospinnable concentration range of the machine through the coupling effect of ultrasonic vibration, but also effectively reduce the diameter of the fiber, reduce the structural defects of the fiber, and improve the crystallinity of the fiber, thereby achieving the goal of improving the mechanical properties of electrospun nanofibers.

[0012] According to the search, Sun Daoheng et al. of Xiamen University invented an ultrasonic-assisted array needle tip electrospinning device (patent number: ZL201520778469.8). The device uses an ultrasonic generator to send signals to a transducer to cause the solution surface to oscillate up and down, making it easier for the solution to overcome surface tension. The liquid level controller can control the liquid level height, so that the solution always oscillates up and down at the tip of the array needle tip device. The array needle tip induction device can generate a concentrated electric field at the tip of the needle tip, reduce the starting voltage, and at the same time form multiple jets to increase fiber production.

[0013] A search revealed that Fang Feiyu et al. from Guangdong University of Technology invented an ultrasonic porous bubble electrospinning device (patent number: ZL201510778831.6). This invention involves setting several small holes on an intermediate plate. Under the action of a gas pressure supply device, the solution in the storage tank generates a large number of bubbles through these holes. When the bubbles burst, jets are ejected from the bubbles under the action of an electric field and deposited on the receiving device, forming a large number of three-dimensional nanofibers. The technical solution of this invention can form multiple jets on the liquid surface, greatly increasing the spinning efficiency per unit time. Simultaneously, the receiving device, composed of support arms, has an exhaust device on the rotating shaft. Compared with traditional plate collectors or closed collectors, this effectively allows airflow to pass through, thus avoiding backflow that could affect fiber deposition. Conversely, the airflow can also guide deposition, directionally assisting the deposition of nanofibers obtained by ultrasonic bubble spinning under the thrust and negative pressure attraction of the airflow, forming three-dimensional fiber scaffolds with specific shapes and structures, thus solving the problem of difficult collection of three-dimensional fiber scaffolds.

[0014] According to the search, Xiang Dong et al. of Tsinghua University invented a combined ultrasonic atomizing device (patent number: ZL201010122821.4). In this device, the axis of the first-stage low-frequency ultrasonic atomizing nozzle is configured at a certain angle with the front atomizing surface of the second-stage high-frequency ultrasonic atomizing nozzle array. Based on the formation of a good liquid film on the atomizing surface of the second-stage high-frequency ultrasonic atomizing nozzle array, sufficient amplitude is provided to break the liquid into fine mist droplets under the action of surface waves, thereby increasing the adaptability of liquid atomization.

[0015] A search revealed that Xiang Dong et al. from Tsinghua University invented a phased-array ultrasonic atomizing nozzle (patent number: ZL201010122838.X). The array elements are distributed in a grouped, equally spaced ring array. A support member inlaid with the array elements forms a sandwich structure with the front and rear covers. The tip of the amplitude transformer is the liquid atomization surface, and the liquid to be atomized reaches its surface through the central channel. By employing a phased-array ultrasonic transducer array scheme, the size of the piezoelectric element of each array element is reduced, providing a higher ultrasonic atomization frequency. Furthermore, based on the same amplitude transformer structure, the amplitude of the atomization surface can meet the atomization requirements of liquids with higher viscosity.

[0016] According to the search, Gao Jianmin et al. of Jiangsu University disclosed a two-phase flow ultrasonic atomizing device (application number: ZL201610334607.2). The liquid to be atomized is sprayed out through an air atomizing nozzle and then atomized for the first time. The high-speed droplets sprayed out collide with the high-frequency vibrating ultrasonic transducer and break into even smaller droplets, resulting in a second atomization.

[0017] A search revealed that Gao Jianmin et al. from Jiangsu University disclosed a low-frequency electrostatic ultrasonic atomizing nozzle (application number: ZL201610198692.4). The nozzle's amplitude transformer has a liquid inlet channel at its axial center and an air inlet channel at a position offset from the axial center. The top of the amplitude transformer is machined into a concave spherical surface, on which a suspended ball is mounted. Compressed air moving axially eccentrically causes the suspended ball to rotate at high speed. Electrode energization generates an electric field in the suspended ball, causing the droplets generated by low-frequency ultrasonic atomization to be electrostatically atomized again and imbued with a static charge. These charged droplets are then ejected from the nozzle. This design overcomes the bottleneck of low-frequency ultrasonic atomizing nozzles in generating ultrafine droplets and also increases the droplets' adhesion by imbuing them with static electricity.

[0018] A search revealed that Li Haiying et al. from North China University of Technology disclosed a dual-medium atomizing nozzle with ultrasonic-assisted atomization (application number: ZL201510630442.9). A piezoelectric ultrasonic transducer generates ultrasonic waves, which cavitate the water in the liquid chamber. Simultaneously, the ultrasonic oscillation prevents impurities from accumulating in the liquid chamber and on the nozzle's inner wall, thus avoiding nozzle clogging. The ultrasonic waves cavitate the water in the liquid chamber, assisting in atomization. The cavitated water is ejected from the first nozzle, while high-pressure steam is ejected from the second nozzle, impacting and breaking up the liquid film.

[0019] In summary, current electrospinning equipment suffers from drawbacks such as uneven spinning solution jet velocity, difficulty in control and collection, and prolonged spinning time due to the inability to achieve the desired effect in a short time, resulting in waste of spinning solution. Existing ultrasonic-assisted electrospinning equipment does not fully achieve accurate control of the spinning jet and still has corresponding shortcomings. Summary of the Invention

[0020] To address the shortcomings of existing technologies, the present invention aims to provide a two-dimensional ultrasonic-assisted electrospinning device. This device can constrain the jet by external intervention of ultrasonic waves, especially by simultaneous intervention in both the transverse and longitudinal directions, ultimately achieving better constraint on the jet landing point.

[0021] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0022] In a first aspect, the present invention provides a two-dimensional ultrasonic-assisted electrospinning device, including a liquid inlet and air inlet device, the bottom of which is connected to an electrospinning jetting device, and an auxiliary receiving device disposed below the electrospinning jetting device; the electrospinning jetting device includes a nozzle body, an ultrasonic-assisted electrospinning nozzle is disposed in the lower part of the nozzle body, and the ultrasonic-assisted electrospinning nozzle is provided with an ultrasonic transducer assembly for forming a longitudinal ultrasonic field; the auxiliary receiving device includes a receiving plate, an ultrasonic transmitting device is disposed on one side of the receiving plate, and an ultrasonic receiving device is disposed on the other side, so as to form a transverse ultrasonic field above the receiving plate.

[0023] This electrospinning device forms a longitudinal ultrasonic field at the nozzle body and a transverse ultrasonic field above the receiving plate, which can constrain the spinning jet from both the transverse and longitudinal directions, thus achieving a relatively accurate spinning effect in a shorter time.

[0024] As a further technical solution, the liquid and air inlet device includes a transducer housing, a top cover on the top of the transducer housing, an amplitude transformer inside the transducer housing, a piezoelectric ceramic plate on the top of the amplitude transformer, multiple electrode plates on the piezoelectric ceramic plate, and the electrode plates connected to a power supply device; the bottom of the amplitude transformer is connected to the nozzle body.

[0025] As a further technical solution, the nozzle body has a built-in three-phase flow acceleration chamber, and a spinning solution inlet is provided at the top of the three-phase flow acceleration chamber for the spinning solution to enter; the nozzle body also has a vertical compressed gas channel, and a compressed gas inlet is provided at the top of the vertical compressed gas channel for the compressed gas to enter.

[0026] As a further technical solution, the vertical compressed gas channel is connected to the built-in compressed gas channel, and the built-in compressed gas channel is connected to the three-phase flow acceleration chamber through the swirling compressed gas channel; the swirling compressed gas channel is inclined and tangentially connected to the side wall of the three-phase flow acceleration chamber.

[0027] As a further technical solution, a vortex chamber is provided at the bottom of the three-phase flow acceleration chamber, and the side of the vortex chamber is connected to the vertical compressed gas channel. An ultrasonic-assisted electrospinning nozzle is provided at the bottom of the three-phase flow acceleration chamber.

[0028] As a further technical solution, the ultrasonic transducer assembly includes a transducer, with an ultrasonic source interface at the top of the transducer to transmit ultrasonic waves. The ultrasonic source interface is connected to a spinning solution channel, and a spinning solution injection port is provided at the ultrasonic source interface. The lower part of the transducer has an ultrasonic wave and spinning solution compression channel. The bottom of the ultrasonic wave and spinning solution compression channel is connected to a compressed ultrasonic wave and spinning solution conduction channel, and a spinning solution emission port is provided at the bottom of the compressed ultrasonic wave and spinning solution conduction channel.

[0029] As a further technical solution, the spinning solution channel passes through the ultrasonic-assisted electrospinning nozzle, and the top of the spinning solution channel is connected to the outlet of the three-phase flow acceleration chamber; the ultrasonic-assisted electrospinning nozzle also includes an end cap, with a cover fixedly installed on the top of the end cap, the bottom of the end cap connected to the motor, the bottom of the motor connected to the outer housing, and the motor connected to the power supply device; the ultrasonic transducer assembly is placed in the lower part of the outer housing.

[0030] As a further technical solution, the ultrasonic receiving device is connected to the ultrasonic signal receiving, processing and transmitting device, and a piezoelectric crystal I and a matching device are provided between the ultrasonic receiving device and the ultrasonic signal receiving, processing and transmitting device. The ultrasonic receiving device, the piezoelectric crystal I, the matching device and the ultrasonic signal receiving, processing and transmitting device are all fixed to the outer shell I.

[0031] As a further technical solution, the ultrasonic transmitting device is connected to the ultrasonic generating device, and a piezoelectric crystal II is disposed between the ultrasonic generating device and the ultrasonic transmitting device. The ultrasonic generating device, the piezoelectric crystal II, and the ultrasonic generating device are fixed to a fixing plate, and the fixing plate is fixedly connected to the outer shell II.

[0032] As a further technical solution, the ultrasonic transmitting device and the ultrasonic receiving device are arranged opposite to each other; the receiving plate is detachably fixed to the receiving plate base, and both the outer shell I and the outer shell II are fixedly connected to the receiving plate base. The receiving plate is equipped with a sensor to monitor the spray range of the spinning solution.

[0033] The beneficial effects of the present invention are as follows:

[0034] The electrospinning apparatus of the present invention has a longitudinal ultrasonic field formed by an ultrasonic transducer assembly at the nozzle body to constrain the downward flow velocity of the jet; and a transverse ultrasonic field formed by an ultrasonic transmitter and an ultrasonic receiver above the receiving plate to constrain the spray range of the falling jet. Thus, the spinning jet is constrained from both the transverse and longitudinal directions, which can achieve a more precise spinning effect in a shorter time. By coordinating the transverse and longitudinal ultrasonic fields, the expected effect can be achieved in a short time, while avoiding the waste of spinning solution.

[0035] The electrospinning apparatus of the present invention can control the jet spray range through a transverse ultrasonic generator and control the jet velocity through a longitudinal ultrasonic transducer assembly, thereby effectively reducing raw material waste and accurately and efficiently achieving the expected spinning effect. By controlling the final forming effect of electrospinning through two-dimensional intervention, the shortcomings and defects of existing electrospinning equipment can be greatly improved, enabling the preparation of electrospinned products quickly and efficiently.

[0036] Compared to ordinary electrospinning devices that only provide electric field force for propulsion, this invention combines an ultrasonic generator with the traditional electrospinning jet device. It adds the thrust provided by the ultrasonic field to the electric field force, employing multiple parallel control methods to constrain the trajectory of the spinning solution jet. If the falling velocity is high, the longitudinal ultrasonic generator at the nozzle can be adjusted to change the thrust provided by the longitudinal ultrasonic field, thereby regulating the falling velocity of the spinning solution jet. If the falling range is large, the transverse ultrasonic generator on the receiving plate can be adjusted to change the thrust provided by the transverse ultrasonic field, thereby regulating the falling range of the spinning solution jet.

[0037] The electrospinning apparatus of the present invention has a sensor on the receiving plate that can display the falling range of the spinning solution droplets in real time. This allows for better adjustment of the ultrasonic generator, thereby changing the intensity of the ultrasonic field, which in turn changes the external force applied to the droplets, ultimately altering the falling range of the droplets to achieve the desired spinning effect. Attached Figure Description

[0038] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0039] Figure 1 This is an assembly drawing of the two-dimensional ultrasonic-assisted electrospinning device of the present invention;

[0040] Figure 2 This is a cross-sectional view of the liquid inlet and air inlet device of the present invention;

[0041] Figure 3 This is a cross-sectional view of the connection between the nozzle body and the amplitude rod of the present invention;

[0042] Figure 4 This is a cross-sectional view of the electrostatic spinning jet device of the present invention;

[0043] Figure 5 This is a cross-sectional view of the ultrasonic-assisted electrospinning nozzle of the present invention;

[0044] Figure 6 This is a cross-sectional view of the ultrasonic transducer assembly of the present invention;

[0045] Figure 7 This is a cross-sectional view of the auxiliary receiving device of the present invention;

[0046] Figure 8 This is a schematic diagram of the electrospinning principle.

[0047] Figure 9 This is a diagram showing the trajectory of droplets in the spinning solution of the present invention.

[0048] Figure 10This is a schematic diagram showing the fit between the outer shell II and the connecting plate IV and the fixing plate of the present invention;

[0049] In the diagram: 1-Liquid and air inlet device, 2-Nozzle body connection part, 3-Electrostatic spinning jet device, 4-Auxiliary receiving device, 5-Power supply device;

[0050] 101-Center screw, 102-Spring washer I, 103-Top cover, 104-Transducer housing, 105-Electrical excitation signal line I, 106-Electrode plate I, 107-Threaded hole I; 108-Amplitude rod, 109-Piezoelectric ceramic plate, 1010-Electrode plate II, 1011-Electrical excitation signal line II, 1012-Electrode plate III, 1013-Spring washer II, 1014-Screw I;

[0051] 201-Liquid inlet channel, 202-Air inlet channel, 203-Amplitude rod, 204-Connecting plate I, 205-Screw II, 206-Spring washer III, 207-Screw III, 208-Spring washer IV, 209-Electrostatic spinning nozzle, 2010-Connecting plate II;

[0052] 301-Spinning solution inlet, 302-Compressed gas inlet, 303-Threaded hole II, 304-Nozzle body, 305-Built-in compressed gas channel, 306-Vertical compressed gas channel, 307-Three-phase flow acceleration chamber, 308-Ultrasonic-assisted electrospinning nozzle, 309-Swirling compressed gas channel, 3010-Threaded hole III;

[0053] 308-1-Cover, 308-2-End cap, 308-3-Spinning solution channel, 308-4-Steel retainer ring I, 308-5-Motor, 308-6-Steel retainer ring II, 308-7-Electrostatic spinning nozzle housing, 308-8-Ultrasonic transducer assembly, 308-9-Outer housing, 308-10-Screw IV, 308-11-Screw V, 308-12-Spring washer V, 308-13-Small connecting plate, 308-14-Cover connecting plate, 308-15-Connecting screw, 308-16-Spring washer VI;

[0054] 308-81-Ultrasonic source interface, 308-82-Transducer, 308-83-Ultrasonic and spinning solution compression channel, 308-84-Connecting flange, 308-85-Compressed ultrasonic and spinning solution conduction channel, 308-86-Spinning solution emission port, 308-87-Spinning solution injection port;

[0055] 401-Outer shell I, 402-Ultrasonic receiver, 403-Piezoelectric crystal I, 404-Screw VI, 405-Matching device, 406-Ultrasonic signal receiving, processing and transmitting device, 407-Screw VII, 408-Spring washer VII, 409-Connecting plate III, 4010-Screw VIII, 4011-Spring washer VIII, 4012-Receiver plate base, 4013-Removable receiver plate, 4014-Fixing plate, 4015-Ultrasonic generator, 4016-Piezoelectric crystal II, 4017-Screw IX, 4018-Ultrasonic transmitter, 4019-Outer shell II, 4020-Threaded hole IV, 4021-Screw X, 4022-Connecting plate IV, 4023-Spring washer VII;

[0056] 4024-High voltage electrostatic generator, 4025-Injection pump, 4026-Spinning medium, 4027-Metal electrode, 4028-Fiber jet, 4029-Receiver plate;

[0057] 4030 - Connecting plate Ⅳ placement hole, 4031 - Fixing plate mounting inner hole.

[0058] The distances or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only. Detailed Implementation

[0059] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0060] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0061] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] Terminology Explanation: In this invention, terms such as “installation,” “connection,” “linking,” and “fixing” should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction relationship between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] In a typical embodiment of the present invention, such as Figure 1 As shown, a two-dimensional ultrasonic-assisted electrospinning device is proposed, which includes a liquid and air inlet device 1, a nozzle body connecting part 2, an electrospinning jetting device 3, an auxiliary receiving device 4, and a power supply device 5. The liquid and air inlet device 1 is installed on the top of the nozzle body connecting part 2, the nozzle body connecting part 2 is installed on the top of the electrospinning jetting device 3, and the auxiliary receiving device 4 is correspondingly arranged below the electrospinning jetting device 3. The liquid and air inlet device 1, the electrospinning jetting device 3, and the auxiliary receiving device 4 are all connected to the power supply device 5.

[0064] like Figure 2 As shown, the liquid and air inlet device 1 includes a transducer housing 104, a top cover 103 is provided on the top of the transducer housing 104, and the top cover 103 and the transducer housing 104 are fixedly connected by a spring washer II 1013 and a screw I 1014. A threaded hole I 107 is provided at the bottom of the transducer housing 104.

[0065] The top cover 103, piezoelectric ceramic plate 109, electrode plate I 106, electrode plate II 1010, and electrode plate III 1012 are tightly connected to the amplitude transformer 108 via a center screw 101 and a spring washer I 102. The transducer housing 104, electrode plate I 106, piezoelectric ceramic plate 109, electrode plate II 1010, and electrode plate III 1012 constitute the transducer. The amplitude transformer is used to adjust the electrostatic field strength.

[0066] Specifically, the transducer housing 104 has a central space, and the amplitude transformer 108 is placed in the central space of the transducer housing 104. A piezoelectric ceramic plate 109 is provided on the top of the amplitude transformer 108. Electrode plates I 106, II 1010 and III 1012 are provided at the piezoelectric ceramic plate 109. Electrode plates I 106, II 1010 and III 1012 all extend to the outside of the transducer housing 104. Electrode plate I 106 is connected to the electrical excitation signal line I 105, and electrode plates II 1010 and III 1012 are both connected to the electrical excitation signal line II 1011. Electrical excitation signal lines I 105 and II 1011 are both connected to the power supply device 5.

[0067] Each electrode sheet and the piezoelectric ceramic sheet are bonded together. Three electrode sheets are used to accurately receive the conducted signal.

[0068] During operation, the alternating current is converted into a high-frequency electrical oscillation signal and transmitted to electrode plates I106, II1010 and III1012 through electrical excitation signal lines I105 and II1011, respectively. The high-frequency electrical oscillation signal is then converted into axial high-frequency vibration. The amplitude transformer 108 is tightly connected to the piezoelectric ceramic plate 109 to amplify the amplitude, thereby accelerating the spinning solution to a certain extent.

[0069] like Figure 3 As shown, nozzle body connection part 2 is the part connecting the amplitude transformer of the liquid inlet / air inlet device and the nozzle device. In this figure, amplitude transformer 203 is... Figure 2 The lower extension of the amplitude transformer 108, combined with Figure 1 , Figure 2 The amplitude transformer 203 and amplitude transformer 108 are an integral structure, with the radial dimension of amplitude transformer 203 being larger than that of amplitude transformer 108. The amplitude transformer 203 extends to the outside of the transducer housing 104 and has the same radial dimension as the transducer housing 104. The upper part of the amplitude transformer 203 is fastened to the transducer housing 104 by bolts, with the bolts inserted into threaded holes I107. The lower part of the amplitude transformer 203 is fixedly connected to the electrostatic spinning nozzle 209, which is the upper structure of the electrostatic spinning jet device 3. Specifically, the upper end of the electrostatic spinning nozzle 209 is machined with threaded holes II303 and III3010. The electrostatic spinning nozzle is fixed to the lower end of the amplitude transformer by connecting plate I204 and connecting plate II2010 through screws II205, screw III207, spring washers III206 and IV208.

[0070] A liquid inlet channel 201 and an air inlet channel 202 are provided at the connection between the electrostatic spinning nozzle and the amplitude transformer. The liquid inlet channel 201 and the air inlet channel 202 extend upward and then out of the entire device. The liquid inlet channel 201 is used to inject the spinning solution into the electrostatic spinning jet device, and the air inlet channel 202 is used to inject compressed air into the electrostatic spinning jet device to achieve internal and external air pressure balance.

[0071] like Figure 4 As shown, the electrostatic spinning jet device 3 includes a nozzle body 304, which is fixedly connected to an amplitude transformer. The nozzle body has a complex structure that is not easy to process and manufacture, and it is required to have certain insulation properties. Therefore, ceramic materials are used to process and manufacture it through a rapid prototyping process. Figure 4 The part shown requires high machining precision, so 3D printing is used for manufacturing and processing.

[0072] The nozzle body 304 has a built-in three-phase flow acceleration chamber 307. The top of the three-phase flow acceleration chamber 307 is provided with a spinning solution inlet 301, which is connected to the liquid inlet channel 201 for the spinning solution to enter. The nozzle body 304 is also provided with a vertical compressed gas channel 306. The top of the vertical compressed gas channel 306 is provided with a compressed gas inlet 302, which is connected to the gas inlet channel 202 for the compressed gas to enter.

[0073] The vertical compressed gas passage 306 is connected to the built-in compressed gas passage 305, which in turn is connected to the three-phase flow acceleration chamber 307 via a swirling compressed gas passage 309. The swirling compressed gas passage 309 is inclined and tangentially connected to the side wall of the three-phase flow acceleration chamber 307, allowing the compressed gas to enter the three-phase flow acceleration chamber 307 at a certain tangential velocity.

[0074] The built-in compressed gas channel 305 is vertically set.

[0075] The bottom of the three-phase flow acceleration chamber 307 is provided with a vortex chamber. The side of the vortex chamber is connected to the vertical compressed gas channel 306. The compressed gas entering through the compressed gas inlet 302 passes through the built-in compressed gas channel 305 and the swirling compressed gas channel 309 to enter the mixing chamber at a certain tangential speed. It mixes with the spinning solution entering through the spinning solution inlet 301 to form a three-phase flow. The three-phase flow is accelerated by the three-phase flow acceleration chamber 307 and then enters the vortex chamber. Here, it forms a vortex with the compressed air entering through the vertical compressed gas channel 306, which further mixes the three-phase flow.

[0076] An ultrasonic-assisted electrospinning nozzle 308 is installed at the bottom of the three-phase flow acceleration chamber 307, and the ultrasonic-assisted electrospinning nozzle 308 is located at the bottom of the nozzle body.

[0077] like Figure 5 and Figure 6 As shown, the ultrasonic-assisted electrospinning nozzle 308 includes an end cap 308-2, and a cover 308-1 is fixedly installed on the top of the end cap 308-2. The cover portion forms a vortex chamber. The cover 308-1 and the end cap 308-2 are connected by a cover connecting plate 308-14, a connecting screw 308-15, and a spring washer VI 308-16. That is, the connecting screw 308-15 and the spring washer VI 308-16 are inserted into the cover connecting plate 308-14 to fix it to the cover 308-1 and the end cap 308-2.

[0078] The bottom of end cap 308-2 is connected to motor 308-5, and the bottom of motor 308-5 is connected to outer housing 308-9. End cap 308-2, motor 308-5, and outer housing 308-9 all have a central space for the spinning solution channel 308-3 to pass vertically through. The top of spinning solution channel 308-3 is connected to the outlet of three-phase flow acceleration chamber 307. An electrostatic spinning nozzle housing 308-7 is located in the lower part of outer housing 308-9. An ultrasonic transducer assembly 308-8 is located inside the electrostatic spinning nozzle housing 308-7. The bottom of spinning solution channel 308-3 is connected to the ultrasonic transducer assembly 308-8. Motor 308-5 is connected to power supply 5. Motor 308-5 provides power to the ultrasonic-assisted electrostatic spinning nozzle.

[0079] The motor 308-5 and the end cover 308-2 are fixedly connected by a retaining ring I 308-4, screw IV 308-10, screw V 308-11, spring washer V 308-12 and a small connecting plate 308-13. The retaining ring I 308-4 is placed between the motor 308-5 and the end cover 308-2. The small connecting plate 308-13 is placed vertically on the outside of the motor 308-5 and the end cover 308-2. Screws IV 308-10, screw V 308-11 and spring washer V 308-12 are inserted into the small connecting plate 308-13 to fix the small connecting plate 308-13 to the motor 308-5 and the end cover 308-2.

[0080] The motor 308-5 and the outer housing 308-9 are fixed in the same way. The motor 308-5 and the outer housing 308-9 are assembled and connected by retaining ring II 308-6, screw IV, screw V, spring washer V and small connecting plate.

[0081] like Figure 6 As shown, the ultrasonic transducer assembly 308-8 includes a transducer 308-82. An ultrasonic source interface 308-81 is located at the top of the transducer 308-82, connecting to an ultrasonic source. The ultrasonic source interface 308-81 communicates with a spinning solution channel 308-3, and a spinning solution injection port 308-87 is located at the ultrasonic source interface 308-81. The lower part of the transducer 308-82 has an ultrasonic and spinning solution compression channel 308-83, which is a variable diameter structure. The bottom of the ultrasonic and spinning solution compression channel 308-83 is connected to a compressed ultrasonic and spinning solution conduction channel 308-85 via a connecting flange 308-84. A spinning solution emission port 308-86 is located at the bottom of the compressed ultrasonic and spinning solution conduction channel 308-85.

[0082] The ultrasonic transducer assembly is a high-precision component, therefore it is manufactured using 3D printing. Ultrasonic waves are transmitted through the ultrasonic source interface 308-81, and the spinning solution enters the ultrasonic transducer assembly through the spinning solution injection port 308-87. The spinning solution and ultrasonic waves merge in the spinning solution channel at the transducer 308-82, allowing the spinning solution to flow at a specific and suitable speed under the control of the ultrasonic waves. Compression is achieved at the lower end of the ultrasonic wave and spinning solution compression channel 308-83. The compressed ultrasonic waves and spinning solution pass through the compressed ultrasonic wave and spinning solution conduction channel 308-85 and are then ejected through the spinning solution emission port 308-86 to form droplets. After ejection, the droplets are controllably sprayed towards the surface of the auxiliary receiving device 4 under the influence of electric field force, aerodynamic force, ultrasonic wave propulsion, and gravity.

[0083] like Figure 7 As shown, the auxiliary receiving device 4 includes a receiving plate base 4012, and a detachable receiving plate 4013 is provided on the top surface of the receiving plate base 4012. The detachable receiving plate 4013 can be removed and installed from the receiving plate base 4012. The detachable receiving plate 4013 is positioned directly below the ultrasonic transducer assembly 308-8 of the electrostatic spinning jet device 3, and the droplets ejected from the spinning solution emission port 308-86 fall onto the surface of the detachable receiving plate 4013.

[0084] An ultrasonic transmitter 4018 is provided on one side of the receiver base 4012, and an ultrasonic receiver 402 is provided on the other side. The ultrasonic transmitter 4018 and the ultrasonic receiver 402 are arranged opposite to each other.

[0085] In this embodiment, the ultrasonic transmitter 4018 is disposed on the left side of the receiver base 4012, and the ultrasonic receiver 402 is disposed on the right side of the receiver base 4012. The ultrasonic waves are emitted from the left and received on the right, allowing for further control and constraint of the falling droplets.

[0086] A conical resonant disk is installed at the ultrasonic transmitting device 4018. The ultrasonic transmitting device 4018 is connected to the ultrasonic generating device 4015. A piezoelectric crystal II 4016 is installed between the ultrasonic generating device 4015 and the ultrasonic transmitting device 4018. The ultrasonic generating device 4015, the piezoelectric crystal II 4016, and the ultrasonic generating device 4015 are fixed to the fixing plate 4014 by screw IX 4017. The fixing plate 4014 is fixedly connected to the outer shell II 4019. The outer shell II 4019 has an inner mounting hole. Both ends of the fixing plate 4014 pass through the inner mounting hole and are fixed to the outer shell II 4019 by screw X 4021, connecting plate IV 4022, and spring washer VII 4023. The outer shell II 4019 has a threaded hole IV 4020, which can be used for fixing to other bases or other structures.

[0087] Figure 10 This is a schematic diagram of the fit between the outer casing II 4019 and the connecting plate IV. The outer casing II 4019 has a connecting plate IV placement hole 4030 and a fixing plate mounting inner hole 4031 at the corresponding mounting connection plate IV 4022 and fixing plate 4014. Both adopt a cavity design. The connecting plate IV 4022 is placed into the connecting plate IV placement hole 4030, and the fixing plate 4014 is inserted into the fixing plate mounting inner hole 4031. Before operation, after the fixing plate is inserted, the connecting plate IV 4022 and the fixing plate 4014 are fixed by screw X 4021 and spring washer VII 4023.

[0088] A conical resonant disk is provided at the ultrasonic receiver 402. The ultrasonic receiver 402 is connected to the ultrasonic signal receiving, processing and transmitting device 406. A piezoelectric crystal I 403 and a matching device 405 are provided between the ultrasonic receiver 402 and the ultrasonic signal receiving, processing and transmitting device 406. The piezoelectric crystal I 403 is adjacent to the ultrasonic receiver 402, and the matching device 405 is adjacent to the ultrasonic signal receiving, processing and transmitting device 406. The ultrasonic receiver 402, the piezoelectric crystal I 403, the matching device 405 and the ultrasonic signal receiving, processing and transmitting device 406 are fixed to the outer casing I 401 by screw VI 404.

[0089] The conical resonant disks of the ultrasonic receiver 402 and the ultrasonic transmitter 4018 are arranged opposite to each other, and the outer shell I 401 and the outer shell II 4019 are provided with opposite openings corresponding to the conical resonant disks.

[0090] The outer casing I 401 and outer casing II 4019 are fixedly connected to the receiving plate base 4012. Specifically, the outer casing I 401 and outer casing II 4019 are connected to the receiving plate base 4012 by screw VII 407, spring washer VII 408, connecting plate III 409, screw VIII 4010, and spring washer VIII 4011. The connecting plate III 409 is located at the bottom of the receiving plate base 4012, outer casing I 401, or outer casing II 4019. Screw VII 407 and screw VIII 4010 are inserted into the connecting plate III 409 to fix it to the receiving plate base 4012, outer casing I 401, or outer casing II 4019. Screw VII 407 is fitted with spring washer VII 408, and screw VIII 4010 is fitted with spring washer VIII 4011.

[0091] In the auxiliary receiving device 4, the ultrasonic generator 4015, the ultrasonic transmitter 4018, the ultrasonic receiver 402, and the ultrasonic signal receiving, processing, and transmission device 406 are connected to the power supply device 5.

[0092] After the spinning solution enters the collection area, the ultrasonic transmitter on the left emits ultrasonic waves that apply a transverse ultrasonic field to the spinning solution flowing through it, thereby generating thrust and limiting the falling range of the spinning solution to a smaller area. The ultrasonic receiver on the right receives the ultrasonic waves in real time and displays the falling range of the spinning solution droplets in real time via sensors.

[0093] Through the matcher 405 and the ultrasonic signal receiving, processing and transmitting device 406, the ultrasonic intensity and the falling speed of the spinning solution can be monitored in real time. A sensor is installed on the bottom detachable receiving plate 4013 for the spinning solution, which can monitor the spray range of the spinning solution in real time. This sensor and the ultrasonic signal receiving, processing and transmitting device on the right side work together to adjust the emission speed and ultrasonic intensity of the ultrasonic transmitter 4018 on the left side and the ultrasonic intensity and emission speed of the upper spraying device by the fluctuation of the data. This allows for better adjustment of the emission speed of the spinning solution and the receiving range on the detachable receiving plate 4013, thereby achieving two-dimensional ultrasonic assistance and better controlling the final electrospinning effect to proceed quickly and efficiently according to the expected shape and size.

[0094] If the falling velocity of the spinning solution jet is slow, the ultrasonic transducer assembly of the upper electrostatic spinning jet device needs to be adjusted to change the longitudinal ultrasonic field intensity, thereby altering the falling velocity. If the falling range of the spinning solution is large, the ultrasonic generator on the left side of the receiving plate needs to be adjusted to change the transverse ultrasonic field intensity, thus constraining the radius of the transverse falling range of the spinning solution. By adjusting the transverse and longitudinal ultrasonic fields, the desired spinning effect can be achieved with a smaller amount of spinning solution, thereby saving materials.

[0095] This device allows for better control of the jet's velocity and spray range. During the spinning process, the velocity can be adjusted via a longitudinal ultrasonic field, while the spray range can be adjusted via a transverse ultrasonic field, achieving precise control of the jet and effectively ensuring that the jet spins according to the expected results. The overall structure is compact, easy to disassemble and replace, and convenient and accurate to operate, meeting the electrostatic spinning requirements in most environments.

[0096] The electrospinning mechanism involved in this invention is as follows:

[0097] Electrospinning is a special form of electrostatic atomization of polymer fluids. In this case, the atomized and split substances are not tiny droplets, but polymer micro-jet streams that can travel a considerable distance and eventually solidify into fibers.

[0098] Electrostatic atomization is the phenomenon where electrostatic force overcomes the surface tension of a liquid, causing the liquid to break into tiny droplets. Due to corona discharge, the droplet surface carries a large number of like charges, increasing the surface activity of the liquid and causing a significant directional alignment of surface molecules, thus reducing surface tension. With a constant droplet volume, the surface tension gradually decreases as the charge increases. When the surface tension is insufficient to bind the liquid, it breaks into fine droplets under the mutual repulsion between like charges on the surface and the disturbance of the liquid surface caused by external forces.

[0099] The following is in conjunction with the appendix Figures 8-9 The electrospinning principle of the device of the present invention will be explained.

[0100] like Figure 8 The diagram shown is a schematic representation of the principle of electrospinning. This diagram is for illustrative purposes only and does not limit the structure of the invention. The specific structure of the electrospinning device of the present invention is as described above. The spinning medium 4026 is a polymer solution or melt, which is contained in an injection pump 4025 and has a metal electrode 4027 inserted into it. This electrode is connected to a high-voltage electrostatic generator 4024, which charges the liquid. A grounded receiving plate 4029 serves as the cathode. When the electric field is not activated, the injection pump 4025 provides a continuous and constant thrust to the piston, and the spinning medium 4026 in the injection pump 4025 is extruded into the needle at a fixed rate. When the high-voltage electric field is not activated, the spinning liquid forms droplets suspended at the nozzle under the combined action of its gravity, viscosity, and surface tension. When the electric field is activated, charges are generated on the surface of the polymer solution. The mutual repulsion of charges and the compression of surface charges by the oppositely charged electrodes both generate a force opposite to the surface tension. When the voltage is insufficient, the surface tension of the droplet surface will prevent the droplet from being ejected and keep it at the nozzle. As the applied voltage increases, the hemispherical surface of the about-to-drop droplet twists into a cone. With further increases in voltage, when the voltage exceeds a certain critical value, the charged portion of the solution overcomes the surface tension, forming a charged jet that is ejected from the nozzle. Under the influence of the electric field, when the fiber jet 4028 is stretched to a certain extent, it undergoes bending and further splitting and stretching. At this point, the solvent rapidly evaporates due to the rapid increase in the specific surface area of ​​the fiber jet 4028, and is eventually collected and solidified on the receiving plate to form a nonwoven fiber mat. The high-voltage electrostatic generator 4024 typically uses a voltage of 5–20 kV. Furthermore, a positive voltage field facilitates the release of surface charge on the fiber, while a negative voltage field provides a more stable electric force; both have different effects on the electrospinning formation of different polymers.

[0101] The electrospinning apparatus of the present invention is equipped with ultrasonic emission sources in two directions based on the electrospinning mechanism. The electrospinning jet device 3 forms a longitudinal ultrasonic field, and the auxiliary receiving device 4 forms a transverse ultrasonic field.

[0102] For non-ideal gases and liquids, the constitutive equations for sound waves need to be modified. For example, water and solids. For water, it's generally an isothermal process. However, for special spinning solutions, it's much more complex, as their constitutive equations depend on temperature, pressure, and salinity. Typically, the speed of sound is determined using an empirical formula:

[0103] C = 1490 + 3.6(T0 - 283.16) + 1.610 -6 P0+1.3(S-35) (1);

[0104] Where, temperature T0∈[273K, 293K], pressure P0∈[10 5 Pa,10 7 Pa], salinity S.

[0105] As can be seen from equation (1), the propagation speed of ultrasonic waves varies in different media, especially with high requirements for pressure and salinity. Therefore, temperature control should be carried out before spinning, and the temperature T0, pressure P0 and salinity S should be adjusted to a suitable range so that ultrasonic waves can propagate uniformly in the spinning solution, thereby better controlling the jet speed of the spinning solution and achieving the expected spinning effect.

[0106] When two or more sound sources act on a point, the sounds are superimposed. Sound energy can be algebraically added. Let the sound powers of the two sources be W1 and W2, then the total sound power is:

[0107] W 总 =W1+W2 (2);

[0108] When the sound intensities of the two sound sources at a certain point are l1 and l2, the total sound intensity after superposition is:

[0109] l 总 =l1+l2 (3);

[0110] As shown in equations (2) and (3), the acoustic power and intensity of ultrasound can be superimposed. Therefore, by applying ultrasonic fields from two different directions, transverse and longitudinal, the total acoustic power and intensity generated by the superposition effect can be used to further intervene in the velocity and falling range of the falling spinning solution jet. When adjustments are needed, the total acoustic power and intensity can be changed by altering the acoustic power W1 and W2 and the acoustic intensity l1 and l2, thereby achieving control and adjustment of the jet.

[0111] However, sound pressure levels cannot be directly added together. Total sound pressure level:

[0112]

[0113] In the formula, L pLp1 represents the total sound pressure level in dB; Lp1 and Lp2 represent the sound pressure levels of sound source 1 and sound source 2, respectively.

[0114] If Lp1 = Lp2, then:

[0115] L p =Lp1+10lg2 (5);

[0116] As can be seen from equations (4) and (5), although the sound pressure of ultrasound cannot be directly and simply superimposed, there are traces to follow. Therefore, the change in the total sound pressure level can be used to determine the adjustment of the flow rate and falling range of the spinning solution jet. By adjusting the longitudinal and transverse ultrasonic generators, the intensity of the transverse and longitudinal ultrasound can be changed, thereby changing the total sound power and total sound intensity, and finally achieving the change of the flow rate and falling range of the spinning solution jet.

[0117] A longitudinal ultrasonic field is generated at the ultrasonic source interface 308-81, and a transverse ultrasonic field is generated by the ultrasonic transmitter 4018. This allows for precise intervention of the jet from two different directions. The longitudinal ultrasonic-assisted electrospinning nozzle 308 adjusts and controls the emission velocity of the spinning solution through the longitudinal ultrasonic field. The ultrasonic transmitter 4018 applies an ultrasonic field laterally, further controlling the fall range of the spinning solution and ensuring the jet flows in the desired direction. The ultrasonic transmitter 4018 can limit the jet's landing point, confining it to a smaller area. Simultaneously, the longitudinal ultrasonic-assisted electrospinning nozzle 308 controls the jet's flow velocity and provides ultrasonic vibration to the solution, allowing the jet to flow at a precise and appropriate speed, ultimately achieving the desired effect. Figure 9 The effect shown.

[0118] The basic theory of electrospinning is as follows: When the applied voltage exceeds a critical value, small charged liquid molecules or low-viscosity charged polymers are ejected from the nozzle, forming tiny charged droplets that move in the opposite direction to the electrode, thus forming dispersed micro / nano-scale aerosols or polymer spheres. This process is called electrostatic atomization. If the charged liquid is a polymer solution or melt, its molecular chains are entangled. During the application of high-voltage electrostatics to the liquid, when the repulsive force of the charge on the liquid surface exceeds its surface tension, a polymer jet is ejected at high speed from the Taylor cone surface at the nozzle end. These jets undergo high-speed stretching, solvent evaporation, and solidification under the influence of the electric field over a short distance, eventually depositing on the receiving electrode to form polymer fibers. This process is called electrospinning.

[0119] Therefore, increasing the distance between the needle and the receiving plate extends the flight distance of the nanofibers in the air, and the fiber diameter decreases with increasing distance. Too close a distance hinders the complete evaporation of the solvent, while too far a distance impedes nanofiber collection; generally, the collection distance is set between 5 and 20 cm. When other parameters remain constant, increasing the electrostatic voltage increases the electrostatic field strength, increasing the electrostatic stretching force on the jet, causing the fiber diameter to decrease as the jet becomes finer. However, when the voltage increases beyond a certain level, the jet instability becomes more pronounced, and the fiber diameter distribution widens, resulting in nanofibers with significant differences in thickness. When the high voltage approaches 30 kV, regardless of whether the environment is dry or humid, the high-voltage end is prone to discharge into the air, resulting in significant charge loss and making the electrospinning process more dangerous. Therefore, a high voltage of 5–20 kV is usually sufficient. Furthermore, a positive voltage field facilitates the release of surface charge on the fiber, while a negative voltage field provides a more stable electric field force; both have different effects on the electrospinning of different polymers. The syringe pump is used to deliver and control the flow rate of the spinning solution; the flow rate of the spinning solution from a single nozzle is 0.1–10 mL / h. The needle is the outlet for the spinning solution, and its inner diameter d is typically 0.1–2 mm. The formula for calculating the flow rate is:

[0120] u = Q / A (6);

[0121] In equation (6), Q is the flow rate of the injection pump, which can be changed by adjusting the frequency of the input motor power supply to change the speed and thus the flow rate; A is the cross-sectional area of ​​the injection port.

[0122] As can be seen from equation (6), the falling speed of the spinning solution droplets is also related to the distance between the needle and the receiving plate. Therefore, when the longitudinal falling speed needs to be adjusted, the frequency of the input motor power supply can be adjusted, or the distance between the nozzle and the receiving plate can be changed to change the flow rate and thus change the jetting speed.

[0123] In summary, the spinning solution jet speed and falling range can be controlled comprehensively by adjusting the transverse and longitudinal ultrasonic generators, the distance between the nozzle and the receiving plate, and the frequency of the input motor power supply, so as to achieve the expected spinning effect more accurately and efficiently.

[0124] The electrospinning device of the present invention is lightweight and compact, and easy to disassemble and assemble. With the assistance of ultrasound, a longitudinal ultrasonic field is applied at the longitudinal ultrasonic-assisted electrospinning nozzle to control the falling speed of the spinning solution. It can also be used to make the spinning solution more uniform under the action of ultrasound and avoid internal solute deposition.

[0125] The specific working process of the device of the present invention is as follows:

[0126] The detachable receiving plate 4013 of the auxiliary receiving device 4 is equipped with a horizontal ultrasonic generator and an ultrasonic transmitting device on the left side, and an ultrasonic receiving device and an ultrasonic signal processing and transmission device on the right side.

[0127] The electrostatic spinning jet device 3 is positioned above the auxiliary receiving device 4. The ultrasonic-assisted electrostatic spinning nozzle 308 is installed on the nozzle body 304, and the nozzle body 304 is fixed to the lower end of the amplitude transformer. A liquid inlet channel 201 and an air inlet channel 202 are provided at the connection between the nozzle body and the amplitude transformer.

[0128] Before spinning begins, the amplitude transformer is connected to the nozzle body of the electrostatic spinning jet device, and the liquid and air inlet device 1 is assembled and combined; the ultrasonic-assisted electrostatic spinning nozzle is assembled and connected, and the ultrasonic-assisted electrostatic spinning nozzle and nozzle body are connected, and then assembled to form a complete device.

[0129] First, adjust the distance between the ultrasonic-assisted electrospinning nozzle 308 and the detachable receiving plate 4013. Then, inject the spinning solution into the electrospinning device through the liquid inlet channel 201. After the temperature, pressure and salinity in the device meet the requirements, close the channel and turn on the power supply of the electrospinning input motor. After the ultrasonic generator 4015 and the ultrasonic transmitter 4018 are ready, open the nozzle switch. Under the multiple action of ultrasonic waves, electric field force, aerodynamic force and gravity, it falls at a certain speed.

[0130] The ultrasonic receiver 402 on the right side of the receiving plate receives the ultrasonic waves transmitted from the left. The matching unit 405 and the ultrasonic signal receiving, processing, and transmitting device 406 determine the speed and range of the falling droplets by the real-time change in the total sound pressure level of the ultrasonic waves, and display this information on the display screen. If the falling speed is too fast, the falling speed of the spinning solution droplets can be slowed down by adjusting the longitudinal ultrasonic-assisted electrospinning nozzle 308. If the range of the droplets falling on the receiving plate exceeds the expected range, the falling droplets can be constrained by adjusting the ultrasonic transmitter 4018 on the left side, ultimately achieving the desired effect. Figure 9 The effect shown reduces the splashing of spinning solution droplets, thus achieving the desired effect more quickly and avoiding waste of the spinning solution.

[0131] After electrospinning achieves the desired effect, turn off all power, remove the detachable receiving plate 4013, and take out and properly store the electrospun product. Recover any excess spinning solution from the receiving plate. Disassemble and clean the ultrasonic-assisted electrospinning nozzle 308. Clean all areas through which the spinning solution flows in the electrospinning device to ensure no residual solution interferes with the second use. Clean and wipe the surface of the ultrasonic-assisted receiving plate to prevent residual solution from interfering with the spinning process during the second use. Properly store all precision components to avoid contamination.

[0132] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A two-dimensional ultrasonic-assisted electrospinning device, characterized in that, It includes a liquid inlet and air inlet device, a nozzle body connection part, an electrostatic spinning jet device, an auxiliary receiving device, and a power supply device. The liquid inlet and air inlet device is installed on the top of the nozzle body connection part, the nozzle body connection part is installed on the top of the electrostatic spinning jet device, the bottom of the liquid inlet and air inlet device is connected to the electrostatic spinning jet device, and an auxiliary receiving device is set below the electrostatic spinning jet device. The electrospinning jetting device includes a nozzle body, with an ultrasonic-assisted electrospinning nozzle disposed in the lower part of the nozzle body. The ultrasonic-assisted electrospinning nozzle is equipped with an ultrasonic transducer assembly for forming a longitudinal ultrasonic field. The auxiliary receiving device includes a detachable receiving plate and a receiving plate base. The detachable receiving plate is disposed on the top surface of the receiving plate base. An ultrasonic transmitting device is disposed on the left side of the receiving plate base, and an ultrasonic receiving device is disposed on the right side of the base. The ultrasonic transmitting device and the ultrasonic receiving device are arranged opposite to each other to form a transverse ultrasonic field above the receiving plate. The ultrasonic receiver is connected to the ultrasonic signal receiving, processing and transmitting device. A piezoelectric crystal I and a matching device are provided between the ultrasonic receiver and the ultrasonic signal receiving, processing and transmitting device. The ultrasonic receiver, piezoelectric crystal I, matching device and ultrasonic signal receiving, processing and transmitting device are all fixed inside the outer shell I. The ultrasonic transducer assembly includes a transducer with an ultrasonic source interface at the top for transmitting ultrasonic waves. The ultrasonic source interface is connected to a spinning solution channel, and a spinning solution injection port is provided at the ultrasonic source interface. The lower part of the transducer has an ultrasonic wave and spinning solution compression channel with a variable diameter structure. The bottom of the ultrasonic wave and spinning solution compression channel is connected to a compressed ultrasonic wave and spinning solution conduction channel, and a spinning solution emission port is provided at the bottom of the compressed ultrasonic wave and spinning solution conduction channel. The nozzle body has a built-in three-phase flow acceleration chamber, and a spinning solution inlet is set at the top of the three-phase flow acceleration chamber for the spinning solution to enter; the nozzle body also has a vertical compressed gas channel, and a compressed gas inlet is set at the top of the vertical compressed gas channel for the compressed gas to enter. The vertical compressed gas channel is connected to the built-in compressed gas channel, which is connected to the three-phase flow acceleration chamber through the swirling compressed gas channel; the swirling compressed gas channel is inclined and tangentially connected to the side wall of the three-phase flow acceleration chamber. The bottom of the three-phase flow acceleration chamber is provided with a vortex chamber, and the side of the vortex chamber is connected to the vertical compressed gas channel. The ultrasonic-assisted electrospinning nozzle is provided at the bottom of the three-phase flow acceleration chamber. The spinning solution channel is set through the ultrasonic-assisted electrospinning nozzle, and the top of the spinning solution channel is connected to the outlet of the three-phase flow acceleration chamber. A sensor is installed on the detachable receiving plate to monitor the spray range of the spinning solution in real time. This sensor works in conjunction with the ultrasonic signal receiving, processing and transmission device on the right to adjust the emission speed and intensity of the ultrasonic transmitter on the left and the ultrasonic intensity and emission speed of the upper electrostatic spinning jet device by the fluctuation of the data.

2. The two-dimensional ultrasonic-assisted electrospinning device as described in claim 1, characterized in that, The liquid and air inlet device includes a transducer housing, a top cover on the top of the transducer housing, an amplitude transformer inside the transducer housing, a piezoelectric ceramic plate on the top of the amplitude transformer, multiple electrode plates on the piezoelectric ceramic plate, and the electrode plates connected to a power supply device; the bottom of the amplitude transformer is connected to the nozzle body.

3. The two-dimensional ultrasonic-assisted electrospinning device as described in claim 1, characterized in that, The ultrasonic-assisted electrospinning nozzle also includes an end cap, with a cover fixedly installed on the top of the end cap, the bottom of the end cap connected to the motor, the bottom of the motor connected to the outer housing, and the motor connected to the power supply device; the ultrasonic transducer assembly is located in the lower part of the outer housing.

4. The two-dimensional ultrasonic-assisted electrospinning device as described in claim 1, characterized in that, The ultrasonic transmitting device is connected to the ultrasonic generating device, and a piezoelectric crystal II is disposed between the ultrasonic generating device and the ultrasonic transmitting device. The ultrasonic transmitting device, the piezoelectric crystal II, and the ultrasonic generating device are all fixed to a fixing plate, and the fixing plate is fixedly connected to the outer shell II.

5. The two-dimensional ultrasonic-assisted electrospinning device as described in claim 4, characterized in that, Both outer casing I and outer casing II are fixedly connected to the base of the receiving plate.

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