Magnetic spinning equipment and method for preparing fiber-based flexible circuit by using same
The fiber-based flexible circuit is prepared by magnetic spinning equipment using dynamic magnetic fields, which solves the problems of uncontrolled fiber deposition and high-voltage electric fields in electrospinning, and realizes rapid molding and efficient preparation of flexible circuits, which are suitable for flexible electronic devices.
Patent Information
- Application Number
- CN202311741822.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-18
- Publication Date
- 2025-07-18
AI Technical Summary
When the existing electrospinning technology prepares flexible circuits, fiber deposition is uncontrollable and difficult to form patterns. The high-voltage electric field has safety and high energy consumption problems, and the preparation efficiency is low, so it cannot achieve industrialization.
Using magnetic spinning equipment, a dynamic switching magnetic field is constructed through the relative movement of the micro pump and the fiber receiving plate and the on-off combination of the electromagnet, and a fiber-based flexible circuit with a specific pattern is prepared to avoid high-voltage electric field and achieve single molding.
The rapid molding and efficient preparation of flexible circuits are achieved, and the safety and high energy consumption problems of the electrospinning process are avoided. The prepared fiber-based flexible circuits have good deformation capabilities and electrical conductivity, and are suitable for flexible electronic devices.
Smart Images
Figure CN120343816A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of advanced flexible materials, and particularly to a magnetic spinning device and a method for preparing fiber-based flexible circuits using the device. Background Art
[0002] Since the 21st century, with the development of technology, intelligent medical treatment, wearable devices, industrial manufacturing, robots, etc. have put forward higher and higher requirements for mechanical energy conversion devices, such as miniaturization, lightweight, flexibility, intelligence, etc. People have taken flexible materials as one of the research focuses to achieve energy conservation and device flexibility. At present, the process methods for manufacturing flexible circuit boards are still in the laboratory research stage. Limited by various technical bottlenecks, industrial mass production cannot be achieved yet.
[0003] Fibers are linear materials with an ultra-high aspect ratio and have good flexibility in structure, making them excellent substrates for manufacturing flexible devices. And the diameter of nanofibers is reduced to the nanometer level, further increasing the aspect ratio of the fibers and enhancing their flexible characteristics. They have a higher specific surface area, surface energy, and porosity than ordinary fibers in structure. Therefore, nanofibers can be used as excellent carriers for flexible electronic devices. However, as electronic devices, they should have certain regularity in morphology and structure and meet specific electrical properties. These structural and performance indicators put more stringent requirements on the fiber forming method. The current mainstream approach is to use a polymer doped with metal and its compound nanoparticles as a precursor and form it by methods such as mechanical stretching, biological preparation, or electrospinning.
[0004] Electrospinning technology has now become the main method for preparing composite nanofibers. However, in the unstable stage of whipping during the electrospinning process, the magnitude and direction of the resultant force acting on the charged fibers fluctuate, making the attitude of the fibers uncontrollable when depositing on the fiber receiving plate, and it is difficult to prepare patterned fibers, thus limiting its application in the field of flexible electronics. In recent years, various new electrospinning technologies have emerged, such as patterned fiber receiving plates and near-field spinning, etc., which have improved the deposition controllability of electrospun fibers. However, the prepared spun fibers still need to be subjected to secondary shaping processing before they can be applied. Due to the slender characteristics of the spun fibers, it also has high requirements for the equipment and precision of secondary shaping, and waste will also be caused during the shaping process, reducing the preparation efficiency of flexible circuits; moreover, the problems of the danger and high energy consumption of the high-voltage electric field used in the electrospinning process have still not been fundamentally solved. Summary of the Invention
[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a magnetic spinning device and a method for preparing fiber-based flexible circuits using the device.
[0006] The purpose of the present invention is achieved through the following technical solutions: A magnetic spinning device includes a micro pump. A fiber receiving plate is provided below the micro pump. The micro pump or the fiber receiving plate is installed on a planar servo drive device, so that the micro pump and the fiber receiving plate move relatively in a two-dimensional plane. The fiber receiving plate includes an insulating plate and electromagnets arranged in an array on the insulating plate. Each electromagnet includes an iron core and a coil. The coil is wound around the iron core. One end of the iron core extends beyond the coil winding. Through holes matching the diameter of the iron core are formed on the insulating plate. The iron cores of the electromagnets are installed on the insulating plate through the through holes. Each electromagnet is connected to a controller through a circuit on-off control element. The planar servo drive device is connected to the enabling signal output end of the controller.
[0007] The above-mentioned controller includes a PLC controller. The enabling signal output end of the PLC controller is connected to each electromagnet through a circuit on-off control element one by one. Each circuit on-off control element is integrated on a control board. One circuit on-off control element independently controls the on-off of a corresponding electromagnet. A main power supply and a working switch are also connected to the PLC controller.
[0008] Specifically, the circuit on-off control element is a relay.
[0009] Preferably, the micro pump and its spinneret are made of non-metallic materials.
[0010] Specifically, the iron core is cylindrical.
[0011] A method for preparing a fiber-based flexible circuit using the above magnetic spinning device includes the following steps: S1. Prepare a magnetic polymer mixed solution; S2. Inject the magnetic polymer solution prepared in S1 into the micro pump. Turn on the main switch, set the feeding rate of the micro pump, and adjust the distance between the spinneret of the micro pump and the fiber receiving plate. S3. Set the fiber deposition path in the controller. Start the magnetic spinning device to work. During the spinning process, the magnetic spinning device drives the planar servo drive device according to the set fiber deposition path, controls the relative position between the micro pump and the fiber receiving plate. After reaching the first preset deposition point, the controller controls the corresponding circuit on-off control element to make the corresponding electromagnet energized to generate a magnetic field. When the deposition is completed, the controller controls the circuit on-off control element corresponding to the next deposition point to make the corresponding electromagnet energized to generate a magnetic field, and so on in a cycle. Control the on-off of the electromagnet and the planar servo drive device according to the fiber deposition path, so as to prepare a fiber-based flexible circuit, and package the prepared fiber-based flexible circuit.
[0012] The above packaging material uses a PU film for packaging.
[0013] During the spinning process in the above S3, increase the energizing current of the electromagnet (2.1) midway to obtain a fiber-based flexible circuit with uneven diameters.
[0014] The beneficial effects of the present invention are as follows: 1) The present invention uses a polymer solution doped with magnetic nanoparticles as the spinning dope, develops a novel fiber receiving plate, and constructs a dynamically switched magnetic field through the relative movement between the fiber receiving plate and the micro pump and the mutual cooperation between the energization and de-energization of the electromagnet, and matches the fiber deposition speed, thereby conveniently preparing a fiber-based flexible circuit with a specific pattern in a bundle. Moreover, according to the requirements of the use scenario, a fiber-based flexible circuit with uneven diameters can be prepared. This flexible circuit can achieve rapid prototyping, efficiently directly write pattern fibers, form a shape in one time, and can be directly applied after encapsulation without secondary processing and shaping.
[0015] 2) The present invention uses a magnetic field to replace the high-voltage electric field, thus completely avoiding problems such as the safety, high energy consumption, and instability of the electrospinning process.
[0016] 3) The fiber-based flexible circuit prepared by the magnetic spinning device in the present invention has good resistance to deformation. When subjected to deformations such as stretching, bending, and torsion, it maintains good conductivity and has good anti-interference ability and stability. This preparation method lays a technical foundation for the development of flexible electronic devices and has broad application prospects and good social benefits. Description of the Drawings
[0017] Figure 1 is a schematic diagram of the magnetic spinning device; Figure 2 is an axonometric view of the fiber receiving plate; Figure 3 is an electron microscope image of the fiber spun by a constant current in Example 2; Figure 4 is an electron microscope image of the fiber spun by a non-constant current in Example 3; In the figure, 1 - micro pump, 2 - fiber receiving plate, 2.1 - electromagnet, 2.2 - insulating plate, 3 - first wire, 4 - control board, 5 - relay, 6 - second wire, 7 - PLC controller, 8 - third wire, 9 - main power supply, 10 - working switch. Detailed Embodiments
[0018] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.
[0019] Refer to Figure 1 , the present invention provides a technical solution: A magnetic spinning device includes a micro pump 1 and a fiber receiving plate 2. The micro pump 1 is arranged above the fiber receiving plate 2. The spinneret of the micro pump 1 is located directly above the fiber receiving plate 2. The micro pump 1 and its spinneret are made of non-metallic materials and have no magnetic force interaction with magnetic nanoparticles. The fiber receiving plate 2 is movable in a two-dimensional plane. The fiber receiving plate 2 includes an insulating plate 2.2 and an electromagnet 2.1. The electromagnets 2.1 are arranged in a rectangular array and fixed on the insulating plate 2.2. The electromagnets 2.1 are connected to a relay 5 mounted on a control board 4 through a first wire 3. The relay 5 controls the on-off situation of the electromagnets 2.1. The relays 5 are arranged in an array on the control board 4 and are in one-to-one correspondence with the electromagnets 2.1. The relays 5 are connected to a PLC controller 7 through a second wire 6. The PLC controller 7 controls the working state of the relays 5. Each relay 5 independently and real-time controls the on-off of the electromagnet 2.1. The main power supply 9 is connected to the PLC controller 7 through a third wire 8. A working switch 10 of the entire device is provided on the PLC controller 7.
[0020] According to the actual situation, the distance between the spinneret of the micro pump 1 and the fiber receiving plate 2 can be adjusted between 2 - 20 mm.
[0021] In this embodiment, a planar servo drive device is installed on the fiber receiving plate 2, and a lead screw group is used to realize the movement of the fiber receiving plate 2 in a two-dimensional plane. The movement can also be realized by means of a rack and pinion, etc.
[0022] The electromagnet 2.1 is composed of a cylindrical iron core and a coil winding. According to the actual situation, the outer diameter of the electromagnet 2.1 can be adjusted between 2 - 20 mm, the diameter of the iron core can be adjusted between 1 - 10 mm, the length of the iron core is greater than the length of the coil winding, and one end of the iron core extends beyond the coil winding with an exposed amount of 2 - 12 mm. It is encapsulated with an insulating material to obtain the electromagnet 2.1. In this embodiment, the outer diameter of the electromagnet 2.1 is 5 mm, the diameter of the iron core is 1 mm, and the exposed amount is 2 mm. The iron core of the electromagnet 2.1 can also be a prismatic iron core.
[0023] The thickness of the insulating plate 2.2 can be adjusted between 0.5 - 2 mm. Round holes arranged in a rectangular array are drilled on the insulating plate 2.2, and the hole diameter matches the diameter of the iron core of the electromagnet 2.1. At the round holes of the insulating plate 2.2, the iron core of the electromagnet 2.1 is installed, and the outer extension amount of the iron core is reserved at 0 - 10 mm to complete the production of the fiber receiving plate 2. In this embodiment, the outer extension amount of the reserved iron core is 2 mm, and the thickness of the insulating plate 2.2 is 1.2 mm. The round holes arranged in a rectangular array on the insulating plate 2.2 can also be arranged in a circular array.
[0024] The local magnetic field on the fiber receiving plate 2 will interact with the magnetic field generated by the surrounding electromagnets 2.1, resulting in negative effects. Therefore, the spacing between the iron cores affects the magnetic field distribution in the array. Through theoretical calculations, multiple groups of iron core arrays with different spacings are planned. Through simulation calculations and experimental verification, the optimal iron core array spacing value is obtained as a center distance of 6 mm.
[0025] The insulating plate 2.2 will also affect the magnetic field distribution. As the protruding height of the iron core increases, this influence gradually decreases, but the increase in height will weaken the local magnetic field. Through theoretical calculations, a series of metal micro-columns with different heights are planned, and then through simulation and experimental verification, the most suitable outer protrusion amount of the iron core is determined to be 2 mm.
[0026] In the control board 4, a relay 5 is connected to the coil circuit of each electromagnet 2.1 to control the on or off of the magnetic field of each electromagnet 2.1 in real time. Among them, in addition to the relay 5, other components such as field effect transistors can also be selected as optional control components.
[0027] Example Two: A method for preparing a fiber-based flexible circuit using the electrospinning device in Example One, including the following steps: S1. Configure a magnetic polymer mixed solution according to a weight ratio of 10%, wherein the particle size of the magnetic nanoparticles ≤ 50 nm; S2. Inject the magnetic polymer solution prepared in S1 into the micro pump 1, turn on the working switch 10, set the feeding rate to 2 mL / h, and set the deposition path of the fibers according to the pattern line of the required circuit in the PLC controller 7; the fiber receiving plate 2 is placed horizontally, and the distance between the nozzle of the micro pump 1 and the fiber receiving plate 2 is adjusted to be 10 mm; during electrospinning, the micro pump 1 pushes the magnetic polymer to extrude droplets from the nozzle. At this time, the droplets are subjected to the gravity vertically downward and the tension upward; when the electromagnet 2.1 on the fiber receiving plate 2 is powered on, the electromagnet 2.1 generates a magnetic field of 0.02 - 1 T within a range of 10 mm at the tip of the iron core (no additional electrostatic field is required during the electrospinning process); the droplets are subjected to a downward magnetic force. When the sum of the magnetic force and the gravity exceeds the droplet tension, the droplets are deposited towards the iron core with the strongest magnetic field under the action of the resultant force. The droplets are gradually stretched and refined into fibrous shapes during the deposition process; when the electromagnets 2.1 arranged in an array on the fiber receiving plate 2 are powered on in sequence according to the set program, the magnetic field on the fiber receiving plate 2 is switched, and then combined with the movement of the fiber receiving plate 2 in the horizontal plane, a dynamic magnetic field is formed to guide the magnetic polymer to be deposited in a specific pattern on the fiber receiving plate 2 (deposited at the iron core with the strongest magnetic field). Multiple fibers are repeatedly stacked into bundles to form a fiber-based flexible circuit, and the prepared fiber-based flexible circuit is encapsulated with a PU film.
[0028] Example Three: Different from Example 2, in this example, fibers with different diameters were prepared by changing the magnitude of the electromagnet current during the spinning process, and they were encapsulated to obtain flexible circuits with different electrical conductivity and mechanical properties.
[0029] Example 4: The fiber-based flexible circuits encapsulated in Example 2 and Example 3 were tested. Among them, the fiber-based flexible circuits all met the requirements of the conductivity, and the line widths were all ≤ 2 mm; the electrical conductivities were all > 0.1 S / m, and after being subjected to more than 500 repeated tensile tests, the decrease in electrical conductivity was all ≤ 5%.
[0030] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.
Claims
1. A magnetic spinning device, characterized in that: It includes a micro pump (1), a fiber receiving plate (2) is provided below the micro pump (1), and the micro pump (1) or the fiber receiving plate (2) is installed on a planar servo drive device, so that the micro pump (1) and the fiber receiving plate (2) move relative to each other in a two-dimensional plane. The fiber receiving plate (2) includes an insulating plate (2.2) and electromagnets (2.1) arranged in an array on the insulating plate (2.2). The electromagnet (2.1) includes an iron core and a coil. The coil is wound around the iron core, and one end of the iron core extends beyond the coil winding. A through hole matching the diameter of the iron core is opened on the insulating plate (2.2), and the iron core of the electromagnet (2.1) is installed on the insulating plate (2.2) through the through hole; each electromagnet (2.1) is connected to the controller through a circuit on-off control element, and the planar servo drive device is connected to the enable signal output end of the controller.
2. The electrospinning device according to claim 1, characterized in that: The controller includes a PLC controller (7). The enable signal output end of the PLC controller (7) is connected to each electromagnet (2.1) through a circuit on-off control element one by one. Each circuit on-off control element is integrated on a control board (4). One circuit on-off control element independently controls the on-off of a corresponding electromagnet (2.1). A main power supply (9) and a working switch (10) are also connected to the PLC controller (7).
3. The electrospinning device according to claim 2, wherein: The circuit on-off control element is a relay (5).
4. The electrospinning device according to claim 1, wherein: The micro pump (1) and its spinneret are both made of non-metallic materials.
5. The electrospinning device according to claim 1, characterized in that: The iron core is cylindrical.
6. A method for preparing a fiber-based flexible circuit using the electrospinning device according to any one of claims 1-6, characterized in that: It includes the following steps: S1. Prepare a magnetic polymer mixed solution; S2. Inject the magnetic polymer solution prepared in S1 into the micro pump (1), turn on the main switch, set the feeding rate of the micro pump (1), and adjust the distance between the spinneret of the micro pump (1) and the fiber receiving plate (2); S3. Set the fiber deposition path in the controller, start the operation of the electrospinning device. During the spinning process, the electrospinning device drives the planar servo drive device according to the set fiber deposition path, controls the relative positions of the micro pump (1) and the fiber receiving plate (2). After reaching the first preset deposition point, the controller controls the corresponding circuit on-off control element to make the corresponding electromagnet (2.1) energized to generate a magnetic field. When the deposition is completed, the controller controls the circuit on-off control element corresponding to the next deposition point to make the corresponding electromagnet (2.1) energized to generate a magnetic field, and so on in a cycle. Control the on-off of the electromagnet and the planar servo drive device according to the fiber deposition path, and thus prepare a fiber-based flexible circuit, and package the prepared fiber-based flexible circuit.
7. The method for preparing a fiber-based flexible circuit according to claim 6, wherein: The packaging material uses a PU film for packaging.
8. The method for preparing a fiber-based flexible circuit according to claim 6, wherein: During the spinning process in S3, increase the energizing current of the electromagnet (2.1) midway to obtain a fiber-based flexible circuit with uneven diameters.