Dust particle charging transfer device based on electrostatic field and application

Abstract

The electrostatic field-based dust particle charging transfer device comprises an outer cylinder cover and a sample container, the outer cylinder cover sleeves the outer side of the sample container, the bottom of the outer cylinder cover is open, and a to-be-transferred plane is arranged at the lower part of the outer cylinder cover; the upper part of the sample container is open and the lower part is sealed, a copper ring electrode is arranged at the upper part of the sample container, and the ring structure of the copper ring electrode is coaxially mounted with the sample container and is not in contact with the upper end of the sample container; laying a copper foil on the inner bottom surface of the sample container; the copper ring electrode and the copper foil are electrically connected with the adjustable power supply respectively; target particles are stored in the sample container, potential difference is generated between the copper ring electrode and the target particles, the charged particles jump up in the electric field direction under the action of electrostatic force, the particles rebound after collision, and the particles fall on a target substrate due to gravity. The problems that in the vacuum environment, micron-sized particles are low in charging efficiency, high in experiment cost, difficult in directional transfer after being charged, poor in quantitative control precision or low in transfer rate and the like can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of space environment simulation experiment equipment, and particularly relates to a dust particle charging and transferring device based on an electrostatic field and an application, which can automatically charge micron-level dust (especially lunar soil simulation particles) in a vacuum or atmospheric environment and accurately transfer the micron-level dust to a target substrate, and is used for a pretreatment link of a spacecraft material dustproof performance test. BACKGROUND

[0002] The existing charging and transferring technology mainly adopts deuterium lamp (UV lamp) irradiation charging or rubbing vibration charging, but has the following disadvantages:

[0003] 1. Deuterium lamp (UV lamp) irradiation charging:

[0004] The ultraviolet irradiation of dust particles on the lunar surface mainly comes from the sun, and it is calculated that the ultraviolet irradiation effect of the sun on the lunar dust is approximately equivalent to the intensity of 16 deuterium lamps. The process of charging dust by deuterium lamp irradiation mainly involves a charge transfer mechanism dominated by photoelectric effect, and the core is that the interaction between ultraviolet photons emitted by the deuterium lamp and the dust surface causes electron emission. Under the irradiation of the same ultraviolet irradiation source, the larger the radius of the lunar dust particles, the more the number of charges on the surface, but it is very difficult for micron-level lunar dust particles to be charged under short-time ultraviolet irradiation; under the irradiation of the same diameter lunar dust particles by different irradiation intensity ultraviolet sources, the greater the irradiation intensity, the more the number of charges on the surface of the lunar dust, and if the charging amount of the lunar dust is to be observed, a long enough irradiation time is also required. The deuterium lamp is not only expensive, but also has a very high requirement for the cleanliness of the working environment, and the dust treated by the deuterium lamp will contaminate the optical system in the opposite direction. The dust or dirt in the sample chamber will absorb / scatter ultraviolet light, reduce the effective output energy of the photons, cause the dust charging efficiency to decay by more than 30%, and cause optical path contamination; the dust accumulated on the lamp body heat dissipation structure causes the deuterium lamp to overheat and age rapidly; the dust generated during the dust charging process may further contaminate the deuterium lamp system, forming a "treated dust -> generated new pollution source" dead loop, and its environmental sensitivity and high operation and maintenance cost make it not universal.

[0005] 2. Rubbing vibration charging:

[0006] The dust collides and rubs with the metal surface under vibration to charge by rubbing vibration, and the contact electrification dominated by electron transfer due to the difference in material work function has an important influence on the particle electrostatic charging rate and the saturation amount of charging. Rubbing vibration charging mainly relies on the collision and friction between particles and metal walls and particles and particles, and the effective area of contact between particles and vibrating surfaces is insufficient due to the small particle size of micron-level particles and the easy clustering of particles, resulting in low charging efficiency of rubbing vibration, unprecise control of the charging amount, large error, and difficulty in transferring the charged particles without changing the charging amount.

[0007] There is no existing method in the prior art for charging dust so that it can be directly spread flat on a surface in a vacuum. Charged dust after ultraviolet irradiation or other techniques requires a second transfer in a vacuum environment, during which the vacuum condition must be released and the transfer must be performed manually. Furthermore, it is necessary to ensure that the quantitative transfer is completed without charge loss to ensure that multiple target surfaces are covered with nearly equal amounts of flat dust, which is also inconvenient. The device of the present invention meets the requirements of integrated charging and transfer in a vacuum, and also solves other problems such as the inconvenience of transfer after ultraviolet irradiation charging, possible charge loss, and quantitative control. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a device and method for charging and transferring dust particles using an electrostatic field. This device can address issues such as low charging efficiency for micron-sized particles in a vacuum environment, high experimental costs, difficulty in directional transfer of charged particles, poor quantitative control accuracy, and low transfer rates.

[0009] The technical solution adopted by the present invention to solve the technical problem is:

[0010] In a first aspect, the present invention provides a dust particle charging transfer device based on an electrostatic field, comprising an outer cylinder cover 7 and a sample container 3. The outer cylinder cover 7 is sleeved on the outside of the sample container 3 and the two are fixed together by a connector. The bottom of the outer cylinder cover is open, and a plane to be transferred is provided at the lower part of the outer cylinder cover.

[0011] The sample container is open at the top and sealed at the bottom. A copper ring electrode 2 is provided on the top of the sample container. The ring structure of the copper ring electrode 2 is coaxially mounted with the sample container and does not contact the upper end of the sample container 3. Copper foil is laid on the inner bottom surface of the sample container 3.

[0012] The copper ring electrode is electrically connected to the high potential end of the adjustable power supply, and the copper foil is electrically connected to the low potential end of the adjustable power supply via a wire;

[0013] The target particles are stored in the sample container 3. The copper foil contacts the target particles, and a potential difference is generated between the copper ring electrode and the target particles, causing the free charge to be transferred from the low potential end to the surface of the target particles, forming an equivalent negative electrode. Under the action of the electrostatic force, the charged particles jump along the direction of the electric field and contact the copper ring electrode 2, where charge transfer occurs. After the collision, the particles rebound and eventually fall on the target base due to gravity under the restriction of the outer cylinder cover.

[0014] Furthermore, the outer wall of the outer cylinder cover 7 is fixed in the external vacuum chamber by a clamping component, and a vibration unit is integrated on the clamping component.

[0015] Furthermore, a sealing cover 5 is provided on the upper portion of the outer cylinder cover, and the cylinder wall surface of the outer cylinder cover is combined with the sealing cover to control and collect the jumping particles.

[0016] Furthermore, the outer tube cover and the sample container are both hollow cylindrical, coaxially connected, and the whole is made of resin 3D printing. The relative dielectric constant ε of the resin is r =4.2-5.0; the sample container is located in the lower middle part of the outer tube cover, the inner diameter of the outer tube cover is 30-50mm, and the sample container dimensions are: inner diameter 10-14mm, height 6-8mm; the vertical distance between the lower opening plane of the outer tube cover and the target base plane is ≤20mm;

[0017] The distance between the copper ring electrode and the upper surface of the sample container 3 is 3.5 mm ± 1 mm.

[0018] In a second aspect, the present invention provides a method for transferring dust particles by charging based on an electrostatic field, wherein the method uses the device described above, and the process of the method is:

[0019] The charged transfer particles were sieved and classified into three categories according to particle size: [30, 48] μm, (48, 74] μm, and (74, 100] μm; N target substrates were evenly distributed on the turntable;

[0020] Fill the sample container with each type of particles, turn on and adjust the adjustable power supply to generate a uniform electric field between the copper ring electrode 2 and the copper foil 4; determine the jump voltage of particles in different particle size ranges when they jump out N times in similar amounts;

[0021] The jump voltages are set to U1, U2, ..., UN. At each jump voltage, the mass of particles in the sample container that jump out sequentially is similar. The error in the mass of particles that jump out at two adjacent jump voltages is within ±50 mg. The number of dust particles in the sample container can meet the requirements of N jump voltages. The duration of each jump voltage is determined when no more dust particles jump out.

[0022] The turntable rotates the first target substrate to the lower opening position of the outer cylinder cover, executes the first jump voltage U1, and after the jump is completed, the turntable rotates the second target substrate to the lower opening position of the outer cylinder cover, executes the second jump voltage U2, and so on, until a similar amount of charged particles are laid on all target substrates.

[0023] Furthermore, after completing the charge transfer of similar amounts on the target substrate, the target substrate is replaced, the jump voltage is increased by 2 to 4 kV relative to UN, and the device is vibrated to collect the remaining dust particles in the sample container and the particles adhering to the wall surface. The transfer quality error is <15%.

[0024] In a third aspect, the present invention provides another method for charging and transferring dust particles based on an electrostatic field, wherein the method uses the device described above, sieving the charged transferred particles, and classifying the particles into three categories according to their particle size: [30, 48] μm, (48, 74] μm, and (74, 100] μm;

[0025] Fill the sample container with each type of particles, turn on and adjust the adjustable power supply to generate a uniform electric field between the copper ring electrode 2 and the copper foil 4;

[0026] For particles in the range of [30, 48] μm, the adjustable power supply voltage is set to 10–12 kV, so that the particle charge transfer rate is not less than 97%;

[0027] For particles in the range of (48, 74] μm, the adjustable power supply voltage is set to 8-9 kV, so that the particle charge transfer rate is not less than 97%;

[0028] For particles in the range of (74, 100] μm, the adjustable power supply voltage is set to 5-7 kV, so that the particle charge transfer rate is not less than 97%;

[0029] The particles jump up under the voltage, jump out of the sample container and fall to the target substrate surface under the confinement of the outer cylinder cover.

[0030] In a fourth aspect, the present invention provides an application of the device, wherein the target substrate is arranged on a centrifugal platform, and the high-voltage DC power supply, the vibration element for controlling the vibration of the outer cylinder cover, the centrifugal platform and the control system are electrically connected to test the adhesion between the charged particles and the fabric.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The particle charging and transfer device of the present invention integrates electrostatic charging and directional transfer of micron-sized dust particles in a vacuum or atmospheric environment. This solves the problems of high UV charging costs, inefficient triboelectric charging, the inconvenience of traditional electrostatic fields in controlling particle transfer trajectories, large transfer charge losses, and the inability of transferred particles to be spread evenly on the target surface. It is suitable for dust-proofing testing of lunar probe materials and has the following significant advantages:

[0033] 1. Efficient charging and precise transfer. The device of the present invention realizes the fully automated efficient charging and directional transfer of micron-sized particles in a vacuum or atmospheric environment through an electrostatic field. Under atmospheric conditions, the transfer rate of particles with a particle size of 30-48 μm at a voltage of 10 kV can reach more than 97%, and the transfer rate of particles with a particle size of (48, 74] μm at a voltage of 9 kV is as high as 98%. Under the application of a suitable constant jump voltage, by adjusting the action time (1-10s) of the high-voltage DC power supply (0-50 kV), the transfer mass can be precisely controlled with an error of less than 15%. For example, in Example 8, at a voltage of 10 kV, the target transfer mass is 400 mg, and the actual transfer mass is about 390 mg, with an error of only about 3%.

[0034] 2. Solve technical challenges in vacuum environments. Traditional technologies, such as deuterium lamp irradiation and friction vibration charging, are inefficient in a vacuum. Deuterium lamps are not only expensive but also susceptible to contamination. Friction vibration, on the other hand, is prone to clumping and adhering to micron-sized particles, resulting in insufficient effective contact area. This device directly applies an electrostatic field to the particles, eliminating the need for a gas medium, thus solving the problem of particle charging and transfer in a vacuum.

[0035] 3. Structural Innovation and Automated Control. The device utilizes a nested structure. The inner sample container creates an electrostatic field and stores particles, while the outer cover restricts the particle path and provides a transfer channel. The outer cover, driven by the vibration unit, reduces particle adhesion, ensuring efficient transfer. The device can be linked to the turntable, with computer-integrated control of charging, transfer, and centrifugation operations, achieving full automation. This eliminates the need for manual intervention during vacuum chamber opening, improving experimental repeatability and precision.

[0036] 4. Cost-effectiveness and applicability. Compared to the high cost and complex maintenance of deuterium lamp systems, this device utilizes a high-voltage DC power supply and copper ring electrodes, offering a simple structure, easy maintenance, and significantly reduced costs. The device is suitable for testing the dust resistance of lunar probe materials. It simulates the charged behavior of lunar soil particles in a vacuum environment, providing a reliable pretreatment method for evaluating the dust resistance of spacecraft materials.

[0037] 5. The device of the present invention utilizes an O-shaped copper ring electrode and copper foil to cause particles to bounce off due to repulsion between like charges after jumping. Gravity then forces them to fall in a directed direction, where they are collected directly beneath the lower-open outer cylinder, achieving integrated control of charging and transfer. Through innovative electrostatic field design and structural optimization, the particle charging and transfer device of the present invention achieves efficient charging, precise directional transfer, and automated control of micron-sized particles in a vacuum or atmospheric environment. This addresses the high cost, low efficiency, and poor applicability of existing technologies, and possesses significant practical value and potential for widespread adoption. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1This is a schematic diagram of the three-dimensional structure of an embodiment of the dust particle charging transfer device based on an electrostatic field of the present invention.

[0039] Figure 2 This is a half-section structural schematic diagram of the dust particle charging and transfer device based on the electrostatic field of the present invention during particle charging and migration. In the figure, the arrows indicate the movement path of the particles after charging, showing the process of particles being charged-taking off-repelled and falling.

[0040] Among them, 1 is a high-voltage DC power supply; 2 is a copper ring electrode; 3 is a sample container; 4 is a copper foil; 5 is a sealing cover; 6 is a negative electrode copper wire; 7 is an outer cylinder cover. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the relevant invention and are not intended to limit the invention. It should also be noted that for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0042] It should be noted that, in the absence of conflict, features of the same embodiment and different embodiments of the present invention may be combined with each other.

[0043] Example 1

[0044] The dust particle charging transfer device based on the electrostatic field of this embodiment (hereinafter referred to as the device or transfer device) includes a high-voltage DC power supply 1, an outer cylinder cover 7, and a sample container 3. The outer cylinder cover 7 is coaxially sleeved on the outside of the sample container 3, and the two are coaxially fixed by a connector. The bottom of the outer cylinder cover is open, and a cover 5 can be provided on the upper part. A plane to be transferred is provided at the lower part of the outer cylinder cover; the upper part of the sample container is open and the lower part is sealed. A copper ring electrode 2 is provided on the upper part of the sample container, and the ring structure of the copper ring electrode 2 is coaxially installed with the sample container, and the ring structure of the copper ring electrode has a certain contact with the upper end of the sample container 3. distance, and the two do not touch; the high potential end of the high-voltage DC power supply 1 is electrically connected to the copper ring electrode 2, and the low potential end of the high-voltage DC power supply 1 is connected to the negative copper wire 6 through a wire, and one side of the negative copper wire extends into the bottom of the inner side of the sample container; the inner bottom surface of the sample container 3 is covered with copper foil 4, and the copper foil is electrically connected to the negative copper wire and connected to the negative electrode of the high-voltage DC power supply. The target particles are stored in the sample container 3, and the copper foil contacts the target particles. A potential difference is generated between the copper ring electrode and the target particles, so that the free charge is transferred from the low potential end to the surface of the target particle, forming an equivalent negative electrode.

[0045] The dust particle charging and transfer device of the present invention charges and quantitatively transfers dust particles in a vacuum environment. An electrostatic field is formed between the equivalent negative electrode and the positive electrode formed by the copper ring electrode, causing the dust particles to become negatively charged. Under the action of the electrostatic force, the charged particles leap along the direction of the electric field and contact the copper ring electrode 2, causing charge transfer, which changes the particle's charge from negative to positive. After the leap, the particles repel each other due to like charges. After the collision, the particles rebound according to the law of reflection and ultimately land on the target substrate (fabric) surface due to gravity, effectively charging the micron-sized particles. An integrated vibration element reduces dust particle adhesion to the inner wall of the device, and quantitative transfer with an accuracy of ±10% is achieved through high voltage or segmented voltage control.

[0046] The outer cover of the present invention can also be an irregular shape, such as a hollow truncated cone, a cone, or a polyhedron, ensuring that the lower portion of the outer cover is a blanking opening and that there is space above the outer cover and the sample container for mounting the copper ring electrode. The blanking opening is significantly larger than the diameter of the sample container. If the outer cover is sufficiently high relative to the sample container, a cover may not be required.

[0047] Example 2

[0048] This embodiment is based on the dust particle charging transfer device of the electrostatic field (see Figure 1 ), the outer tube cover 7 is a cylindrical structure, the sample container is also a cylindrical tube, the outer tube cover and the sample container are connected together by a connector, and the whole is made of WENEXT8200 resin 3D printing. r =4.2-5.0; breakdown threshold (electrostatic breakdown strength)>12.8kV / mm.

[0049] The outer wall of the outer tube cover 7 is fixed to the external vacuum chamber via a clamping member. A vibration unit is integrated into the clamping member. The vibration of the vibration unit drives the outer tube cover to vibrate together. The vibration unit is implemented using a micro brushed DC motor in conjunction with an eccentric wheel. The eccentricity is 2-5mm, the vibration frequency is 50-100Hz, and the amplitude is 0.1mm. The micro brushed DC motor is attached to an aluminum heat sink.

[0050] The outer cover is open at the bottom and capped with a lid 5. The outer cover's wall and lid combine to control and collect the lifted particles. The lifted particles, blocked by the lid, are then transferred from the bottom of the outer cover to the target transfer plane. Simultaneously, a vibration unit removes dust particles adsorbed on the inner surface of the outer cover 7. By controlling the voltage and charging time, the particles are automatically transferred in a quantitative manner after charging. This charging and transfer process requires no human intervention, thus meeting the requirements for integrated dust charging and transfer in a vacuum environment.

[0051] Example 3

[0052] In this embodiment, the dust particle charging zone is located within the sample container 3. A copper foil 4 is laid flat on the bottom of the sample container to completely cover it. A negative copper wire connects the copper foil to the negative terminal of the high-voltage DC power supply 1, forming an equivalent negative electrode. Dust particles within the sample container are able to disperse in all directions through the circular electrode (copper ring electrode).

[0053] The sample container is made of non-conductive resin material, and a round hole for the negative copper wire 6 to pass through is opened on the side of the sample container near the bottom. The inner bottom surface of the sample container is covered with copper foil, which is connected to the negative pole of the high-voltage DC power supply 1 through the negative copper wire and the wire.

[0054] The sample container dimensions are designed based on the desired dust volume. In this embodiment, the sample container dimensions are: internal diameter 10 mm, height 7 mm, and wall thickness 1 mm. The outer tube cover has an internal diameter of 30 mm. A copper ring electrode 2 is positioned 3.5 mm from the top of the sample container and connected to the positive terminal of the high-voltage DC power supply 1. In this embodiment, the copper ring electrode can be an O-shaped bare copper ring electrode with a wire diameter of 1 mm and a ring diameter of 10 mm. The vertical distance between the lower opening plane of the outer tube cover and the target substrate plane is ≤ 20 mm.

[0055] The copper ring electrode and the copper foil 4 form an electric potential difference. After being charged, the particles jump along the direction of the electric field and jump out of the sample container. After being blocked by the wall of the outer cylinder cover 7, they naturally fall to the target surface due to gravity.

[0056] Example 4

[0057] The device of this embodiment is used for charging and transferring dust particles in a high vacuum environment. The dust particle charging and transferring device includes:

[0058] High-voltage DC power supply 1, with an adjustable output voltage range of 0-50kV, is implemented using a German JMDC-P-2mA adjustable power supply; an O-shaped copper ring electrode is connected to the positive electrode of the high-voltage DC power supply, and the diameter of the copper ring electrode is 10mm, and the diameter is adjustable within a range; the wire diameter of the copper ring electrode is 1mm;

[0059] Sample container 3 is responsible for building an electrostatic field and storing dust particles. The inner bottom is paved with copper foil and connected to the negative pole of the power supply to accommodate and store dust particles to be charged and transferred.

[0060] The outer cylinder cover 7 is coaxially mounted with the sample container. When the dust particles in the sample container jump out with charge, it can suppress the range of the particles falling naturally, limit the movement path of the particles, and provide a transfer path;

[0061] A wire outlet is provided on the side of the outer tube cover. The circular ring structure of the copper ring electrode is arranged on the upper surface of the sample container 3, and the distance between the two is constant at 3.5 mm ± 1 mm. The lead copper wire portion of the copper ring electrode passes through the wire outlet and is electrically connected to the positive pole of the high-voltage DC power supply 1.

[0062] The outer tube cover and the sample container are nested cylindrical structures. The diameter of the lower opening of the outer tube cover is 3-5 cm, which can be set as needed. The two can be prepared as a whole through 3D printing. The size of the lower opening can be adjusted to meet the transfer requirements of different target planes. The vertical distance between the lower opening plane of the outer tube cover and the receiving base plane is ≤20 mm.

[0063] Example 5

[0064] The device of the present invention is used to test the adhesion between charged particles and fabrics in a vacuum environment. It can realize integrated charging and transfer operations in a vacuum environment, with high charging efficiency and transfer rate, reducing costs and increasing efficiency. When in use, after the transfer device is placed in a vacuum chamber, it can be electrically connected to a high-voltage DC power supply, a vibration element, and a centrifugal platform (the target substrate is located on the centrifugal platform) through an extracavity control system (such as an industrial PC, single-chip microcomputer, PLC, programmable controller, etc.) to integrate control of charging-transfer-centrifugation and other operations, and adjust the centrifugal speed of the centrifugal platform (i.e., turntable) to realize the test of the adhesion between charged particles and fabrics in a vacuum environment and ensure the accuracy of charging transfer.

[0065] Set the voltage U applied between the copper ring electrode and the copper foil (the voltage setting range is 0-50kV). Based on the target transfer mass m, set the maximum mass of the particle that can jump up with the voltage to m0, then m <m0,此时能够调节高压直流电源的作用时长t(时间在1-10s范围内取值),控制转移质量m的取值。在较高的电压下能实现转移质量误差<15%。

[0066] Example 6

[0067] In this embodiment, the particles to be charged and transferred are sieved, first through a 200-mesh sieve, and the particle size range of the undersize portion is no more than 74 μm. Then, the undersize portion of the 200-mesh sieve is sieved through a 300-mesh sieve, and the particle size range of the residue on the 300-mesh sieve is (48, 74] μm.

[0068] For particles in the range of [30, 48] μm, the adjustable power supply voltage is set to 10–12 kV, so that the particle charge transfer rate is not less than 97%;

[0069] For particles in the range of (48, 74] μm, the adjustable power supply voltage is set to 8-9 kV, so that the particle charge transfer rate is not less than 97%;

[0070] For particles in the range of (74, 100] μm, the adjustable power supply voltage is set to 5-7 kV, so that the particle charge transfer rate is not less than 97%;

[0071] The particles jump up at the voltage, jump out of the sample container and fall to the target substrate surface under the restriction of the outer cylinder cover. The transfer rate is calculated when no particles jump up as observed by the naked eye. Within the above voltage range, efficient transfer of particles of corresponding particle size can be achieved.

[0072] Dust particle sizes range from 30-74μm. At 10kV, the charge transfer efficiency for particles 30-48μm reached 97%, while at 9kV, the charge transfer efficiency for particles 48-74μm reached 98%. Tests have shown that the larger the particle size, the lower the voltage required for jump-off. Within the voltage range set in this application, particles in the sample container can completely jump off and land on the target substrate below the sample container. The dust particles can then be properly spread on the target substrate, with good distribution and high charge transfer efficiency.

[0073] Example 7 (Lunar Soil / Dust Charging Transfer Operation):

[0074] 1. 400 mg of 48-74 μm SiO2 particles (density 2657 kg / m 3 ) into the sample container 3; laying the target substrate on the turntable; the size of the target substrate is not less than the size of the lower opening of the outer tube cover;

[0075] 2. Adjust the output voltage of the high-voltage DC power supply 1 so that the copper ring electrode 2 and the copper foil 4 generate a uniform electric field;

[0076] 3. After being negatively charged, the particles are lifted from the sample container 3 by the Coulomb force. After being adsorbed by the copper ring electrode 2, they become positively charged and are separated from the electrode by repulsion, spreading evenly on the target substrate surface. The target substrate surface is 20 mm away from the lower opening of the outer tube cover. Some particles adhere to the inner surface of the outer tube cover.

[0077] 4. Start the vibration element installed on the outer wall of the outer cylinder cover to remove particles adhering to the cover wall and container wall.

[0078] Table 1 shows the comparison results of the total charge of all particles that jump out under different voltages in an atmospheric environment. When testing in this way, only one target substrate is set on the turntable. At the voltage set in Table 1, the turntable is kept at a constant speed (100 rpm) to test the total charge of the particles that can jump out under different voltages. The duration is t = 10s, until no more particles jump out at the current voltage. It can be seen from Table 1 that the total charge of the particles that can jump out is similar.

[0079] Table 1

[0080] Mass / mg Voltage / kV Charged amount / nC 400 8 45.7 400 10 45

[0081] Example 8 (Quantitative charging transfer integrated control):

[0082] 1) The particle charging transfer device is clamped and fixed in a vacuum chamber. A motor-controlled turntable is installed below the lower opening of the outer cylinder cover. The turntable carries three clamps that clamp the fabric. The distance between the end face of the lower opening of the outer cylinder cover and the fabric surface is 10 mm. A vibration motor (vibration unit) is installed on the clamping component of the particle charging transfer device, and a high-voltage DC power supply is connected to the positive and negative electrodes of the particle charging transfer device.

[0083] 2) 400 mg of 48-74 μm SiO2 particles (density 2657 kg / m 3 ) Place the sample container 3 and cover the upper surface of the outer tube cover with a matching cover;

[0084] 3) Close the vacuum chamber and turn on the vacuum pump to evacuate to 10Pa;

[0085] 4) Start the lower turntable and control it to rotate a certain angle so that the target substrate on the turntable is located at the lower opening of the outer cylinder cover;

[0086] 5) The voltage of the high-voltage DC power supply is set, and the copper ring electrode 2 and the copper foil generate a uniform electric field. The particles, after becoming negatively charged, are lifted from the sample container 3 by the Coulomb force, are attracted by the copper ring electrode 2, become positively charged, and are separated from the copper ring electrode by repulsion, falling evenly and flattening onto the target fabric surface on the turntable. Some particles adhere to the inner surface of the outer cylinder cover 7.

[0087] During the charge transfer process, the jump voltages were set to 3kV, 5kV, and 7kV, increasing in an arithmetic progression. At each jump voltage, the mass of dust particles released from the sample container was similar. The turntable rotated the first target substrate to the lower opening of the outer cylinder cover, applying the first jump voltage U1 = 3kV. After the jump, the turntable rotated the second target substrate to the lower opening of the outer cylinder cover, applying the second jump voltage U2 = 5kV. The turntable rotated the third target substrate to the lower opening of the outer cylinder cover, applying the third jump voltage U3 = 7kV, and so on until a similar amount of charged particles were applied to all target substrates. The duration of each jump voltage was determined until no more dust particles were released. Equal amounts of charged SiO2 particles were applied to the three fabric surfaces on the turntable.

[0088] After completing charge transfer of a similar amount on the target substrate, the target substrate was replaced, the jump voltage was set to 10kV, and the device was vibrated to collect the remaining dust particles in the sample container and the particles adhering to the wall surface. The transfer mass error was <3%.

[0089] 6) Turn off the high voltage DC power supply.

[0090] Table 2 shows the results of the cumulative mass of particles dropped onto all target substrates at different voltages in multiple tests under atmospheric conditions. The settings of the first three jump voltages can make particles of similar mass spread evenly on the three target substrates, and further increasing the voltage can achieve a higher transfer rate.

[0091] Table 2

[0092]

[0093] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0094] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A dust particle charging transfer device based on an electrostatic field, characterized in that: The outer tube cover comprises an outer tube cover and a sample container. The outer tube cover is sleeved on the outside of the sample container and the two are fixed together by a connecting piece. The bottom of the outer tube cover is open, and a plane to be transferred is set at the lower part of the outer tube cover. The sample container is open at the top and sealed at the bottom. A copper ring electrode is provided on the top of the sample container. The ring structure of the copper ring electrode is coaxially mounted with the sample container and does not contact the top of the sample container. Copper foil is laid on the inner bottom surface of the sample container. The copper ring electrode is electrically connected to the high potential end of the adjustable power supply, and the copper foil is electrically connected to the low potential end of the adjustable power supply via a wire; The target particles are stored in the sample container, the copper foil contacts the target particles, and an electric potential difference is generated between the copper ring electrode and the target particles, causing the free charge to be transferred from the low potential end to the surface of the target particles, forming an equivalent negative electrode; under the action of electrostatic force, the charged particles jump along the direction of the electric field, contact the copper ring electrode, and charge transfer occurs. After the collision, the particles rebound and finally fall on the target base due to gravity under the restriction of the outer cylinder cover.

2. The device according to claim 1, characterized in that The outer wall of the outer cylinder cover is fixed in the external vacuum chamber through a clamping component, and a vibration unit is integrated on the clamping component.

3. The device according to claim 1, characterized in that A sealing cover is provided on the upper part of the outer cylinder cover, and the cylinder wall surface of the outer cylinder cover is combined with the sealing cover to control and collect the jumping particles.

4. The device according to claim 1, characterized in that The outer tube cover and the sample container are both hollow cylindrical, coaxially connected, and the whole is made of resin 3D printing. The relative dielectric constant of the resin is ε r =4.2-5.0; the sample container is located in the lower middle part of the outer tube cover, the inner diameter of the outer tube cover is 30-50mm, and the sample container dimensions are: inner diameter 10-14mm, height 6-8mm; the vertical distance between the lower opening plane of the outer tube cover and the target base plane is ≤20mm; The distance between the copper ring electrode and the upper surface of the sample container is 3.5 mm ± 1 mm.

5. A method for charging and transferring dust particles based on an electrostatic field, characterized in that: The method uses the device according to any one of claims 1 to 4, and the process of the method is: The charged transfer particles were sieved and classified into three categories according to particle size: [30, 48] μm, (48, 74] μm, and (74, 100] μm; N target substrates were evenly distributed on the turntable; Fill the sample container with each type of particles, turn on and adjust the adjustable power supply to generate a uniform electric field between the copper ring electrode 2 and the copper foil 4; Determine the jump voltage when particles jump out N times in similar amounts in different particle size ranges; The jump voltages are set to U1, U2, ..., UN. At each jump voltage, the mass of particles in the sample container that jump out sequentially is similar. The error in the mass of particles that jump out at two adjacent jump voltages is within ±50 mg. The number of dust particles in the sample container can meet the requirements of N jump voltages. The duration of each jump voltage is determined when no more dust particles jump out. The turntable rotates the first target substrate to the lower opening position of the outer cylinder cover, executes the first jump voltage U1, and after the jump is completed, the turntable rotates the second target substrate to the lower opening position of the outer cylinder cover, executes the second jump voltage U2, and so on, until a similar amount of charged particles are laid on all target substrates.

6. The method according to claim 5, characterized in that After completing the charge transfer of similar amounts on the target substrate, the target substrate is replaced, the jump voltage is increased by 2 to 4 kV relative to UN, and the device is vibrated to collect the remaining dust particles in the sample container and the particles adhering to the wall. The transfer mass error is <15%.

7. A method for charging and transferring dust particles based on an electrostatic field, characterized in that: The method uses the device of claim 2 to charge and transfer particles through a sieve, and the particles are classified into three categories according to particle size: [30, 48] μm, (48, 74] μm, and (74, 100] μm; Fill the sample container with each type of particles, turn on and adjust the adjustable power supply to generate a uniform electric field between the copper ring electrode 2 and the copper foil 4; For particles in the range of [30, 48] μm, the adjustable power supply voltage is set to 10–12 kV, so that the particle charge transfer rate is not less than 97%; For particles in the range of (48, 74] μm, the adjustable power supply voltage is set to 8-9 kV, so that the particle charge transfer rate is not less than 97%; For particles in the range of (74, 100] μm, the adjustable power supply voltage is set to 5-7 kV, so that the particle charge transfer rate is not less than 97%; The particles jump up under the voltage, jump out of the sample container and fall to the target substrate surface under the confinement of the outer cylinder cover.

8. Use of the device according to any one of claims 1 to 4, characterized in that: The target substrate is set on the centrifugal platform, and the high-voltage DC power supply, the vibration element for controlling the vibration of the outer cylinder cover, the centrifugal platform and the control system are electrically connected to test the adhesion between the charged particles and the fabric.

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