CN109049674B - Additive manufacturing device and method for microsystem three-dimensional structure - Google Patents

Additive manufacturing device and method for microsystem three-dimensional structure Download PDF

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CN109049674B
CN109049674B CN201811219025.5A CN201811219025A CN109049674B CN 109049674 B CN109049674 B CN 109049674B CN 201811219025 A CN201811219025 A CN 201811219025A CN 109049674 B CN109049674 B CN 109049674B
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electric field
electrode
deflection
liquid
additive manufacturing
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CN109049674A (en
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王东方
姜新岩
刘睿
殷志富
万胜来
王鼎康
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Jilin University
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Jilin University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/106—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
    • B29C64/112—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material using individual droplets, e.g. from jetting heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/188—Processes of additive manufacturing involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control
    • B29C64/194—Processes of additive manufacturing involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control during lay-up
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/30—Auxiliary operations or equipment
    • B29C64/386—Data acquisition or data processing for additive manufacturing
    • B29C64/393—Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y30/00—Apparatus for additive manufacturing; Details thereof or accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y50/00—Data acquisition or data processing for additive manufacturing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Abstract

The invention relates to an additive manufacturing device and method for a microsystem three-dimensional structure, and belongs to the field of additive manufacturing. The high-viscosity droplet extrusion spray head is fixed on the guide upright post through the support frame, the X-axis moving device is fixed on the base, the Y-axis moving device is fixed on the X-axis moving device, the deflection electric field electrode is installed on the guide upright post through the Z-axis moving device, the dielectric layer is adhered to the electrode array, the electrode array is fixed on the Y-axis moving device, and the polarization module is fixed on the base and is positioned above the dielectric layer. According to the invention, a layered manufacturing technology is utilized, according to the technical characteristics of solidification and formation of liquid material liquid drops under the condition of a pulse electric field, the precise control quantity of additive manufacturing is realized by adopting a pulse electric field separation technology, and the precise injection of micron-sized liquid drops is realized by adjusting voltage parameters, so that the high-frequency injection of high-viscosity liquid is realized.

Description

Additive manufacturing device and method for microsystem three-dimensional structure
Technical Field
The invention belongs to the technical field of additive manufacturing, and particularly relates to an ultra-thin functional layer high-precision quantity and shape control additive manufacturing device and method.
Background
In recent years, research work in the field of manufacturing microsystems at home and abroad is rapidly progressed, and a great deal of research results are obtained in the aspects of two-dimensional integration, micro-nano processing and the like. On the structural design level, chip-level two-dimensional integration of a plurality of microsystems is achieved, the functional density is improved to a certain extent, and the increase of the number of microsystems can lead to the rapid increase of the two-dimensional size of a device. The three-dimensional structure is formed by combining the two-dimensional integrated chips through space optimization, so that the space utilization rate is improved, and the functional density is improved by a plurality of times. In the aspect of manufacturing process, microelectronic manufacturing has advantages over ultra-precise machining in mass production and integration with a control circuit, but the core technology, namely photoetching, is only suitable for two-dimensional chips, and three-dimensional manufacturing of a microsystem cannot be realized, so that the problem is gradually focused by scientists at home and abroad. Additive manufacturing (Additive Manufacturing, AM) technology is an advanced manufacturing technology developed based on the principle of layered manufacturing, which is evolving towards integrated rapid manufacturing of multi-functional multi-material complex structural parts. At present, additive manufacturing technologies using metal, ceramic powder or wire as raw materials mainly comprise laser selective sintering, laser cladding, electron beam forming and the like. The microstructure or phase composition of the part of the existing forming method is uncontrollable, the problem of shape control and quantity control is the bottleneck of the application of material additive manufacturing in the field of micro-sensing systems, and great improvement space is still provided for the additive manufacturing in the aspects of the dimension reduction and the accuracy improvement of the ultra-thin functional layer forming.
Conventional material additive manufacturing relies on point-by-point additive forming, is not limited by manufacturability of the tooling mold and space accessibility of the complex structure, and presents a process advantage in terms of rapid response for complex single-piece or small-lot manufacturing. In terms of controlling the amount, patent application publication nos. KR20140006121, EP2772347, CN103192079A, US8021593B2 utilize forming openings of different inner diameters to regulate the cross-sectional area of the forming openings, but this controlling method requires applying excessive pressure to achieve extrusion, and cannot extrude high viscosity materials. The separation technology theory and experimental analysis of pneumatic diaphragm type metal micro-droplets are researched by the university of Huazhong science and technology, the injection technology of 100 mu m-level metal micro-droplets is primarily perfected, but 100 mu m is still insufficient to meet the precision requirement of MEMS systems. In addition, patent publication No. CN1635933a discloses an injection apparatus for realizing ultra-fine fluid by using an electric field, but the manufacturing efficiency is too low to realize a large-scale high-precision manufacturing, and it is difficult to satisfy the requirements of complex MEMS system manufacturing. The university of illinodia champagne division in the united states proposes the use of Electrohydrodynamic (EDH) to control the separation of high precision microfluidics by the application of pulsed electric fields, whereas the droplet produced by this method is completely uncontrolled in flight and spread on a work platform.
It follows that conventional additive manufacturing techniques have the following disadvantages:
(1) Difficulty of submicron order microfluidic separation: the problem with the extrusion or separation (piezo and thermal bubble) methods currently in common use is that it is not easy to achieve a small amount of liquid of less than 1pl to be ejected.
(2) The drops cannot be precisely positioned on the work platform: for micron-sized liquid drops, the accurate positioning of the liquid drops has high requirements on the position control precision of a printing platform, a piezoelectric linear platform is needed, but the forming range of the liquid drops is only tens of microns, the manufacturing cost is high, the stroke is not suitable for the integrated manufacturing of microsystem devices, the precision of a stepping motor commonly used in engineering is difficult to reach the micron-sized liquid drops, and therefore, the large-scale and high-precision positioning of the liquid drops is a current urgent problem to be solved.
(3) The wettability of the droplet deposition on the forming table is not controllable: conventional spray and additive manufacturing cannot control wettability of droplets finally deposited on a platform, and can only realize spreading of the droplets by kinetic energy in flight, so that ultrathin films are difficult to manufacture.
Disclosure of Invention
The invention provides an additive manufacturing device and method for a three-dimensional structure of a microsystem, and aims to realize high-frequency extrusion of micron-sized liquid drops of a high-viscosity functional material, realize large-scale accurate positioning of the micron-sized liquid drops on a printing platform, realize controllable spreading of the micron-sized liquid drops on the printing platform and provide a technical means for getting rid of constraints of foreign instruments in the manufacturing of the microsystem.
The technical scheme adopted by the invention is as follows: the high-viscosity droplet extrusion spray head is fixed on the guide upright post through the support frame, the X-axis moving device is fixed on the base, the Y-axis moving device is fixed on the X-axis moving device, the deflection electric field electrode is installed on the guide upright post through the Z-axis moving device, the dielectric layer is adhered to the electrode array, the electrode array is fixed on the Y-axis moving device, and the polarization module is fixed on the base and is positioned above the dielectric layer.
The high viscosity droplet extrusion head comprises: the device comprises a spray head shell end part, an electro-hydraulic separation electric field electrode anode, an electro-hydraulic separation electric field electrode cathode, an electrodeless variable domain heating device, a spray head shell, a formed micro-opening and a piezoelectric diaphragm; the piezoelectric diaphragm is fixed at the end part of the spray head shell, the positive electrode of the electrohydraulic separation electric field electrode is fixed at the inner side of the formed micro-opening, the negative electrode of the electrohydraulic separation electric field electrode is fixed at the outer wall of the formed micro-opening, and the electrodeless variable domain heating device is fixed at the inner wall of the spray head shell;
the deflection electric field electrode includes: the deflection electric field X electrodes, the deflection electric field Y electrodes and the insulating connecting layer are columnar small blocks with sector cross sections, the deflection electric field X electrodes and the deflection electric field Y electrodes are fixed on the upper side and the lower side of the insulating connecting layer in pairs, four columnar small blocks are circumferentially and uniformly distributed on the upper side of the insulating connecting layer, the four deflection electric field X electrodes and the two deflection electric field Y electrodes are not contacted in pairs, the two deflection electric field X electrodes are oppositely arranged to form a pair, the two deflection electric field Y electrodes are oppositely arranged to form a pair, and the electrode small blocks which are the same as the upper side are arranged on the lower side of the corresponding insulating connecting layer;
the electrode array comprises an array formed by dielectric wetting electrodes, wherein the dielectric wetting electrodes comprise dielectric wetting electric field cathodes, dielectric wetting electric field anodes, electric grid insulation fillers and a power supply, the power supply is connected with the dielectric wetting electric field cathodes and the dielectric wetting electric field anodes, and the electric grid insulation fillers are arranged between the dielectric wetting electric field cathodes and the dielectric wetting electric field anodes for insulation.
An additive manufacturing method for a microsystem three-dimensional structure comprises the following steps:
(1) In a specific processing example, a user can firstly establish a three-dimensional entity model to be printed through three-dimensional modeling software, or obtain a three-dimensional digital model through reverse engineering in a three-dimensional scanning mode of an entity sample;
(2) Importing a three-dimensional model of a piece to be printed into slicing software of a computer, and disassembling a three-dimensional entity through slicing and layering;
(3) Preparing required printing liquid materials or materials such as wires to be used in a melting heating mode according to actual needs, and recording properties of liquid functional materials such as viscosity coefficient eta, conductivity k, surface tension constant gamma and dielectric constant epsilon;
(4) The geometrical parameters and control parameters of some additive manufacturing equipment, such as the sizes Ux and Uy of the deflecting electric field electrode plates, the pulse voltage U and the position height h of the nozzle at the end of the nozzle, the distance n between the opposite electrode plates of the deflecting electric field electrode, and the geometrical size h of the deflecting electric field electrode plates, are determined by the prior calculation 2 And position dimension h 1 Is adjusted and exchanged;
(5) The additive manufacturing equipment is connected to a control port of a computer, and programming control is carried out through a software window, so that the additive manufacturing equipment can actively adjust voltage parameters such as required voltage U, ux, uy and the like in the printing process;
(6) Adjusting an additive manufacturing device to an initial position, printing, converging molten wire materials or liquid additive manufacturing materials into a hemispherical shape at the end part of an extrusion nozzle, under the action of an electrohydraulic separation electric field, accumulating moving charges on the hemispherical droplet surface at the end part of the nozzle, gradually stretching the liquid materials at the end part of the nozzle into a cone shape by repulsive force between the charges, finally, enabling the electrostatic force to exceed the surface tension of the droplet, separating spherical droplets from the cone-shaped liquid materials at the cone-shaped end part, realizing the dripping of the materials, and setting the voltage to be larger than the pulse voltage capable of realizing the spraying, wherein the pulse voltage and the liquid surface tension constant gamma, the conductivity k of the liquid functional material, the nozzle inner diameter d and the vacuum dielectric constant epsilon are given in a formula (7) 0 The relation between:
from the dielectric relaxation relationship, the pulse voltage U applied to the nozzle tip should not have a pulse frequency higher than the voltage pulse ejection frequency f so as not to affect the normal drop of the droplet, and the formula (12) gives a rough relationship between the voltage pulse ejection frequency and the polarization strength σ of the dipole in the droplet, and the dielectric constant ε of the liquid material:
for different structures of a workpiece to be processed, the electrode part at the nozzle adopts different voltages, and according to the formula (13), the droplet size is larger, the flow is larger, so that the forming speed is higher, and the precision is lower; the droplet size is smaller, the flow is smaller, the forming speed is slow, the precision is higher, and the factors influencing the droplet volume V mainly comprise: the dielectric constant epsilon of the liquid material, the inner diameter d of the nozzle, the flow path length L of the nozzle, the polarization strength sigma of dipoles in liquid drops, the viscosity coefficient eta of flowing fluid, the pulse voltage U applied to the tail end of the nozzle, the conductivity k of the liquid functional material and the surface tension constant gamma of the liquid;
(7) According to the shape of each layer of a workpiece to be processed and the position of an offset position on a forming platform, an X-Y plane moving platform performs coarse positioning at the position to be processed, the accurate position of a current platform can be obtained by utilizing accurate measuring devices such as a laser displacement sensor, and the like, a computer adjusts a deflection electric field according to the deviation between a target position and the current position, after the liquid drops fall down, accurate deflection is realized through the deflection electric field so as to achieve the purpose of small-range accurate positioning, after the printing of the current position is finished, the X-Y moving platform continues to move, the previous steps are repeated, thereby realizing large-range accurate positioning, according to the pattern of each layer of slice, the computer automatically plans the moving path of the forming platform in the printing process of the layer of printing pattern, further accurately controls the dropping position of liquid drops through the deflection action of a deflection electric field electrode, prints the layer of the pattern point by point according to the form of drop dropping down, the influence of the deflection electric field electrode on the accurate positioning of the liquid drops can be obtained by a formula (18), wherein the height h of the lower end part of a nozzle and the center height h of a deflection electric field electrode are repeated 1 The dimension of the polar plate of the deflection electric field electrode in the vertical direction is h 2 The deflection voltages Ux and Uy applied to the deflection electric field electrode plates and the distance n between the opposite plates have influence on the offset distance:
(8) For each dropped droplet, after the droplet is deposited on the forming platform, the computer controls the droplet spreading module based on dielectric wetting to enable one or more dielectric wetting electric field electrode pairs at the droplet to have different voltages, thereby controlling the spreading state of the droplet to obtain a droplet state with controllable thickness, further controlling the thickness of the layer, wherein the influence of the voltage on the wetting angle is known from a formula (19), the wetting angle of the droplet is changed under the control of an electric field, and the shape of the droplet is changed, wherein theta V For the wetting angle after being electrified, theta 0 Is static wetting angle epsilon when not electrified 0 For vacuum dielectric constant, ε r U, which is the relative dielectric constant of the dielectric layer c D is the relative voltage applied between the microelectrode plates c For dielectric layer thickness, γ is the surface tension constant between droplet-air:
(9) After printing the layer of pattern, the computer controls the nozzle to move a slice layer distance along the Z-axis upward direction;
(10) The additive manufacturing process of layer-by-layer printing is realized by repeating the alternation of the steps (7) to (9);
(11) After the additive manufacturing process is finished, the running of software is stopped, the additive manufacturing equipment is closed, the printing piece is taken down, the connection between the additive manufacturing equipment and the computer is disconnected, and unprinted liquid or wire is processed.
The invention can be fixed in the cavity filled with low-pressure inert gas through the base in use so as to realize additive manufacturing of the microstructure.
The invention has the beneficial effects that:
according to the invention, a layered manufacturing technology is utilized, according to the technical characteristics of solidification and formation of liquid material liquid drops under the condition of a pulse electric field, the precise control quantity of additive manufacturing is realized by adopting a pulse electric field separation technology, and the precise injection of micron-sized liquid drops is realized by adjusting voltage parameters, so that the high-frequency injection of high-viscosity liquid is realized.
The deflection electric field and the plane moving device ensure large-scale high-precision positioning of the liquid drops, so that a plurality of liquid drops can keep stable and controllable overlapping rate in the process of accumulating film formation, and further, the thickness of a formed film and the two-dimensional forming precision are indirectly controlled.
After the liquid drops drop on the substrate, the liquid drops cannot be completely spread under the action of gravity to realize thickness reduction due to undersize, so that a dielectric wetting (EWOD) device is adopted to change the solid-liquid interface wetting angle of the liquid drops, and further control over thickness and printing resolution is realized.
The invention can realize the extrusion of liquid with the viscosity of up to 1000cps, the extrusion frequency can reach 5khz, the thickness of the manufactured film can reach submicron level, and the invention provides possibility for the additive manufacturing of microsystem components. The invention can be fixed in the cavity filled with low-pressure inert gas through the base in use so as to realize additive manufacturing of the microstructure. The invention plays a promoting role in the fields of manufacturing of the miniature sensor, integrated manufacturing of the micro-electromechanical system, microelectronic technology, precision machining technology, national defense and military industry and the like.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a schematic diagram of the structure of a high viscosity droplet extrusion head of the present invention;
FIG. 3 is a schematic diagram of the deflection electric field structure of the present invention;
FIG. 4 is a schematic view of an electrode array structure according to the present invention;
fig. 5 is a schematic diagram of the dielectric wetting control of the present invention.
Detailed Description
As shown in fig. 1, the high-viscosity droplet extrusion module 5 is fixed on the guide post 2 through the support frame 4, the X-axis moving device 11 is fixed on the base 1, the Y-axis moving device 10 is fixed on the X-axis moving device 11, the deflecting electric field electrode 6 is mounted on the guide post 2 through the Z-axis moving device 3, the dielectric layer 8 is adhered to the electrode array 9, the electrode array 9 is fixed on the Y-axis moving device 10, and the polarization module 7 is fixed on the base 1 and above the dielectric layer 8.
As shown in fig. 2, the high viscosity droplet extrusion head includes: the spray head shell end 501, the electro-hydraulic separation electric field electrode positive electrode 502, the electro-hydraulic separation electric field electrode negative electrode 503, the electrodeless variable domain heating device 504, the spray head shell 505, the formed micro-port 506 and the piezoelectric membrane 507; the piezoelectric diaphragm 507 is fixed at the end 501 of the spray head shell, the positive electrode 502 of the electrohydraulic separating electric field electrode is fixed at the inner side of the forming micro-opening 506, the negative electrode 503 of the electrohydraulic separating electric field electrode is fixed at the outer wall of the forming micro-opening 506, and the electrodeless variable domain heating device 504 is fixed at the inner wall of the spray head shell 505; the electrodeless variable domain heating device 504 can reduce the surface tension of the material to be processed by heating the material to be processed, and the pressure generated by the piezoelectric membrane 507 during operation acts together with the electric field force between the positive electrode 502 of the electric-hydraulic separation electric field electrode and the negative electrode 503 of the electric-hydraulic separation electric field electrode, so that the liquid drop is promoted to overcome the surface tension, and the extrusion of the liquid drop is realized.
As shown in fig. 3, the deflecting electric field electrode 6 includes: the deflection electric field X electrodes 601, the deflection electric field Y electrodes 602 and the insulating connecting layer 603, wherein the deflection electric field X electrodes 601 and the deflection electric field Y electrodes 602 are columnar small blocks with sector cross sections, the columnar small blocks are fixed on the upper side and the lower side of the insulating connecting layer 603 in pairs, two deflection electric field X electrodes 601 and two deflection electric field Y electrodes 602 are uniformly distributed on the upper side of the insulating connecting layer 603 in the circumferential direction, the four columnar small blocks are not contacted in pairs, the two deflection electric field X electrodes 601 are oppositely arranged to form a pair, the two deflection electric field Y electrodes 602 are oppositely arranged to form a pair, and the electrode small blocks which are the same as the upper side are arranged on the lower side of the corresponding insulating connecting layer 603; in the actual processing process, after the liquid drops are separated from the nozzles, the liquid drops are precisely deflected by a deflection electric field, so that small-range precise positioning can be realized.
As shown in fig. 4, the electrode array 9 includes an array formed by dielectric wetting electrodes, wherein the dielectric wetting electrodes include a dielectric wetting electric field negative electrode 901, a dielectric wetting electric field positive electrode 902, an electric gate insulation filler 903, and a power supply 904, the power supply 904 is connected with the dielectric wetting electric field negative electrode 901 and the dielectric wetting electric field positive electrode 902, and the electric gate insulation filler 903 is insulated between the dielectric wetting electric field negative electrode 901 and the dielectric wetting electric field positive electrode 902.
As shown in fig. 5, which is a schematic diagram of dielectric wetting control, a dielectric layer 8, a dielectric wetting electric field cathode 901, a dielectric wetting electric field anode 902, an electric grid insulation filler 903 and a power supply 904 are shown in the figure, after a droplet is deposited on a forming platform, a control device controls one or more electrode pairs on the forming platform to form an electric field in a specific area where the droplet is located, the size of the electric field voltage influences the wetting angle of the droplet and the forming platform, and the wetting angle of the droplet is changed under the control of the electric field, so that the shape of the droplet is changed. In particular, in the process of forming the ultrathin functional layer, the required structure thickness is extremely small, so that the electrode voltage used is relatively large, and single liquid drops with extremely small thickness are obtained, thereby controlling the maximum thickness of the formed ultrathin functional layer.
The working principle is as follows: by controlling the movements of the X-axis moving device 11, the Y-axis moving device 10, and the Z-axis moving device 3; the voltage connected with the electro-hydraulic separation electric field electrode positive electrode 502, the electro-hydraulic separation electric field negative electrode 503, the electrodeless variable domain heating device 504, the deflection electric field electrode 6, the polarization module 7, the electrode array 9 and the piezoelectric membrane 12 is adjusted; the control device applies pulse signals to the piezoelectric membrane 507, and the piezoelectric membrane 507 obtains the pressure required by working through piezoelectric conversion, so as to serve as auxiliary force to push the liquid functional material; the control device excites the positive electrode 502 of the electrohydraulic separation electric field electrode and the negative electrode 503 of the electrohydraulic separation electric field inside and outside the forming micro-opening 506 through pulse signals, so that a pulse electric field is formed at the forming micro-opening 506, and liquid functional materials in the forming micro-opening 506 are separated from the tail end of the forming micro-opening 506 in sequence in the form of liquid drops along with pulse changes; the specific process is as follows: when the voltage is at the vector voltage V L Time (V) L The maximum voltage value that keeps the drop from dropping), the liquid functional material at the end of the shaped micro-hole 506 forms a taper angle with wide top and narrow bottom, and keeps the shape; when a vector voltage V appears H Pulse time (V) H Greater than V L ) The liquid functional material at the tip of the cone angle is separated under the action of the periodical electric field force to form liquid drops which drop downwards; liquid drop falling processThe deflection electric field is regulated by the control device through the deflection electric field electrode 6, so that the drop obtains the dropping speed in the direction of X, Y, and the accurate positioning of the position in the drop dropping process is realized. If the printed material is a piezoelectric functional material, the voltage of the polarization module 7 can be regulated by the control device to generate a polarized electric field, the polarized electric field acts on the printed material to perform certain polarization treatment on the material, and specific functions such as piezoelectric characteristics and the like are realized.
The optimal parameters of the electrohydraulic separation part are provided, and the geometric parameters and the control parameters of the additive manufacturing equipment can be adjusted by referring to the related parameters so as to realize better effect of additive manufacturing of the three-dimensional structure of the microsystem. The relevant parameters include a fluid viscosity η of 1×10 -3 Pa.s, fluid conductivity k of 5.5X10 -6 S/m, a fluid surface tension constant gamma of 67.91, a nozzle inner diameter d of 2 μm, a nozzle inner flow path length L of 200 μm, a pulse voltage U applied to the nozzle tip of 2000V, and a voltage pulse ejection frequency f of 8.47×10 7 Hz。
An additive manufacturing method for a microsystem three-dimensional structure comprises the following steps:
(1) In a specific processing example, a user can firstly establish a three-dimensional entity model to be printed through three-dimensional modeling software, or obtain a three-dimensional digital model through reverse engineering in a three-dimensional scanning mode of an entity sample;
(2) Importing a three-dimensional model of a piece to be printed into slicing software of a computer, and disassembling a three-dimensional entity through slicing and layering;
(3) Preparing required printing liquid materials or materials such as wires to be used in a melting heating mode according to actual needs, and recording properties of liquid functional materials such as viscosity coefficient eta, conductivity k, surface tension constant gamma and dielectric constant epsilon;
(4) The geometrical parameters and control parameters of some additive manufacturing equipment, such as the sizes Ux and Uy of the deflecting electric field electrode plates, the pulse voltage U and the position height h of the nozzle at the end of the nozzle, the distance n between the opposite electrode plates of the deflecting electric field electrode, and the geometrical size h of the deflecting electric field electrode plates, are determined by the prior calculation 2 And position dimension h 1 Is adjusted and exchanged;
(5) The additive manufacturing equipment is connected to a control port of a computer, and programming control is carried out through a software window, so that the additive manufacturing equipment can actively adjust voltage parameters such as required voltage U, ux, uy and the like in the printing process;
(6) Adjusting an additive manufacturing device to an initial position, printing, converging molten wire materials or liquid additive manufacturing materials into a hemispherical shape at the end part of an extrusion nozzle, under the action of an electrohydraulic separation electric field, accumulating moving charges on the hemispherical droplet surface at the end part of the nozzle, gradually stretching the liquid materials at the end part of the nozzle into a cone shape by repulsive force between the charges, finally, enabling the electrostatic force to exceed the surface tension of the droplet, separating spherical droplets from the cone-shaped liquid materials at the cone-shaped end part, realizing the dripping of the materials, and setting the voltage to be larger than the pulse voltage capable of realizing the spraying, wherein the pulse voltage and the liquid surface tension constant gamma, the conductivity k of the liquid functional material, the nozzle inner diameter d and the vacuum dielectric constant epsilon are given in a formula (7) 0 The relation between:
from the dielectric relaxation relationship, the pulse voltage U applied to the nozzle tip should not have a pulse frequency higher than the voltage pulse ejection frequency f so as not to affect the normal drop of the droplet, and the formula (12) gives a rough relationship between the voltage pulse ejection frequency and the polarization strength σ of the dipole in the droplet, and the dielectric constant ε of the liquid material:
for different structures of a workpiece to be processed, the electrode part at the nozzle adopts different voltages, for example, a thicker substrate structure is processed, the manufacturing precision requirement is not high, and therefore, higher voltage is applied; the ultrathin functional layer, namely the piezoelectric material layer, is extremely thin, and the manufacturing precision requirement is high, so that lower voltage is applied, and according to the formula (13), the droplet size is larger, the flow is larger, the forming speed is higher, and the precision is lower; the droplet size is smaller, the flow is smaller, the forming speed is slow, the precision is higher, and the factors influencing the droplet volume V mainly comprise: the dielectric constant epsilon of the liquid material, the inner diameter d of the nozzle, the flow path length L of the nozzle, the polarization strength sigma of dipoles in liquid drops, the viscosity coefficient eta of flowing fluid, the pulse voltage U applied to the tail end of the nozzle, the conductivity k of the liquid functional material and the surface tension constant gamma of the liquid;
(7) According to the shape of each layer of the to-be-machined part and the position of the offset position on the forming platform, the X-Y plane moving platform performs coarse positioning at the to-be-machined position, the accurate position of the current platform can be obtained by utilizing accurate measuring devices such as a laser displacement sensor, the computer adjusts the deflection electric field according to the deviation between the target position and the current position, after the liquid drops drop down, the accurate deflection is realized through the deflection electric field, the purpose of small-range accurate positioning is achieved, after the printing of the current position is finished, the X-Y moving platform continues to move, and the previous steps are repeated, so that the large-range accurate positioning is realized. According to the pattern of each slice, the computer automatically plans the moving path of the forming platform in the printing process of the printing pattern of each layer, further precisely controls the dropping position of the liquid drops by matching with the deflection action of the deflection electric field electrode, prints the pattern of each layer point by point according to the dropping form of the liquid drops, and the influence of the deflection electric field electrode on the precise positioning of the liquid drops can be obtained by a formula (18), wherein the height h of the lower end part of the nozzle and the center height h of the deflection electric field electrode 1 The dimension of the polar plate of the deflection electric field electrode in the vertical direction is h 2 The deflection voltages Ux and Uy applied to the deflection electric field electrode plates and the distance n between the opposite plates have influence on the offset distance:
(8) For each dropped droplet, after the droplet is deposited on the forming platform, the computer controls the droplet spreading module based on dielectric wetting to enable one or more dielectric wetting electric field electrode pairs at the droplet to have different voltages, thereby controlling the spreading state of the droplet to obtain a droplet state with controllable thickness, further controlling the thickness of the layer, wherein the influence of the voltage on the wetting angle is known from a formula (19), the wetting angle of the droplet is changed under the control of the electric field, further changing the shape of the droplet, for example, in the process of forming an ultrathin functional layer, the required structure thickness is extremely small, the voltage between the electrode pairs required to be set is relatively large, thus obtaining a single droplet with extremely small thickness, further controlling the maximum thickness of the formed ultrathin functional layer, wherein theta V For the wetting angle after being electrified, theta 0 Is static wetting angle epsilon when not electrified 0 For vacuum dielectric constant, ε r U, which is the relative dielectric constant of the dielectric layer c D is the relative voltage applied between the microelectrode plates c For dielectric layer thickness, γ is the surface tension constant between droplet-air:
(9) After printing the layer of pattern, the computer controls the nozzle to move a slice layer distance along the Z-axis upward direction;
(10) The additive manufacturing process of layer-by-layer printing is realized by repeating the alternation of the steps (7) to (9);
(11) After the additive manufacturing process is finished, the running of software is stopped, the additive manufacturing equipment is closed, the printing piece is taken down, the connection between the additive manufacturing equipment and the computer is disconnected, and unprinted liquid or wire is processed.
The invention can be fixed in the cavity filled with low-pressure inert gas through the base in use so as to realize additive manufacturing of the microstructure.
According to the invention, the separation of submicron-level liquid drops is realized by optimizing the structure size and voltage parameters of the spray head of the high-viscosity droplet extrusion module, and the precise quantity control is realized. The control of the micro-droplets can be achieved by designing the geometric parameters of the additive manufacturing equipment, adjusting the voltage states of the parts imparted by the control device.
The correlation theory is deduced as follows:
the liquid functional material enters into a needle-shaped nozzle with a forming micro-opening with an inner diameter d (the inner diameter refers to the diameter of a tail end orifice), the lower end of the fluid is positioned at a position with a height h above an infinite forming platform, L is the length of a nozzle flow path, ρ is the radius of curvature at the boundary of the tail end of a liquid drop, and when the liquid drop is not dropped, the charge is caused at the tail end of the nozzle under the action of an electric field, the charge is focused on a hemispherical part of the tail end of the nozzle, and the charge quantity Q on the liquid drop at the tail end of the nozzle can be approximately expressed by the following formula:
Q＝2πε 0 αUd (1)
wherein ε is 0 Representing the vacuum dielectric constant, α represents a coefficient related to the nozzle geometry, having a value between 1 and 1.5, and when the nozzle inner diameter d is much smaller than the nozzle length l, α is approximately 1, and U represents the pulse voltage applied to the nozzle tip;
electric field intensity value E of liquid functional material at nozzle end l In order to achieve this, the first and second,
wherein k is the conductivity of the liquid functional material;
due to the pressure balance of the liquid functional material acting on the end of the nozzle, the electrostatic pressure P of the liquid functional material at the end of the nozzle under the action of an electric field e (Pa) may be represented by the following formula (3),
wherein S represents the nozzle inner hole area of the nozzle end;
when α=1, formula (4) is obtained from equations (1), (2) and (3),
the surface tension of the liquid passing through the nozzle tip is equivalent to the pressure P when no electric field is applied s To obtain the formula (5),
wherein gamma is the surface tension constant of the liquid functional material, and the condition of electrohydrodynamic spraying is that the electrostatic force is greater than the surface tension, so that the following formula (6) is established,
P e >P s (6)
in summary, when a molded micro-orifice of a certain inner diameter is given, the relationship (6) between the pressure obtained by calculating and comparing the surface tension and the pressure generated by the electrostatic pressure is calculated, and when the inner diameter d of the molded micro-orifice is sufficiently small, the pulse voltage U applied to the nozzle tip is sufficiently large, and the electrostatic force is larger than the surface tension.
The pulse voltage at the nozzle where ejection can be achieved is given by formula (7):
that is, the voltage for separating droplets in the present invention satisfies the condition determined by the formula (7);
the injection pressure deltap (Pa) satisfies the following expression (8),
under the action of a local electric field, the pulse voltage at the nozzle which can realize the injection can be reduced by adopting a mode of a nozzle with a small inner diameter;
the flow q of the nozzle capillary channel is deduced by Poiseuille's Law equation, assuming that the liquid functional material in the formed micro-orifice is cylindrical, the flow q of the flowing liquid functional material is:
wherein η is the viscosity coefficient of the flowing liquid functional material, the flow q is proportional to the fourth power of the inner diameter d of the forming micro-orifice according to the above equation, the flow can be reduced by reducing the inner diameter of the forming micro-orifice, the injection pressure ΔP obtained by the formula (8) is brought into the formula (9) to obtain the formula (10)
To obtain a separated droplet, the duration of the pulse voltage needs to be controlled, and under the action of the electric field, dipoles in the droplet migrate with the electric field, causing the droplet to appear charged, assuming that the time for which the droplet is fully charged is approximately equal to the time constant τ determined by the dielectric relaxation:
where σ is the polarization of the dipoles in the droplet, ε is the dielectric constant of the liquid material, f represents the inverse of the time constant τ, i.e. the voltage pulse ejection frequency,
in summary, when the voltage pulse ejection frequency exceeds f, the generation of liquid drops cannot be responded, and the liquid drops cannot fall off;
from equations (11) and (12), the volume V of the droplet can be estimated as the integral of the flow rate q and the time constant τ,
let the dropped drop be spherical, the dropped drop diameter d V The method comprises the following steps:
according to equation (14), the size of the droplet is determined by the nozzle inner diameter d, the flow path length L in the nozzle, the voltage U, and the liquid functional material properties such as dielectric constant ε, surface tension constant γ, electrical conductivity k, polarization strength σ, viscosity coefficient η, etc.
The realization principle of wide-area high-precision liquid drop positioning is as follows: the plane moving device, the Z-axis moving device 3 and the deflection electric field electrode 6 which are formed by the X-axis moving device 11 and the Y-axis moving device 10 form a wide-area accurate positioning module; the X-axis moving device 11 is fixed on the base 1, the Y-axis moving device 10 is fixed on the X-axis moving device 11, the Z-axis moving device 3 and the guide upright post 2 form a moving pair, and the deflection electric field electrode 6 is fixed at the tail end of the Z-axis moving device 3. The electrode plates of the deflection electric field electrode are annular and consist of 4 plates, and when two opposite electrode plate plates act together, the deflection of liquid drops in one axial direction can be controlled. The control device can adjust the X-axis moving device and the Y-axis moving device by driving the stepping motor, so that the positioning of the in-plane range is realized, after the positioning is finished, the deflection of the liquid drops in the X, Y direction is controlled by utilizing the deflection electric field on the working platform, and the accurate positioning of the drop dropping positions is further realized.
The lower end of the nozzle is positioned at a position with the height h above an infinite forming platform, the center of the deflection electric field electrode is positioned at the position with the height h above the infinite forming platform 1 The dimension of the polar plate of the deflection electric field electrode in the vertical direction is h 2 Assuming that deflection voltage Ux is only applied to a deflection electric field electrode plate for controlling the X direction in a certain control, the distance between the electrode plate and the electrode plate is n, the mass of a small droplet is m, the droplet always receives the action of the universal gravitation g in the falling process, and the droplet is accelerated by constant acceleration and falls on a forming platform, wherein the velocity in the vertical direction is v z ，
In the horizontal direction, in the initial falling stage, the liquid drop is not stressed, and the horizontal speed is generated under the action of the electric field force at the position of the deflection electric field electrode plate, so that the horizontal speed can be expressed as v 'when finally falling on the forming platform'
Δt is the time for the droplet to pass through the area of the deflecting field electrode plate,
by combining (16) and (17), when the liquid drop falls on the forming platform, the displacement of X direction offset is X 1
It can be seen that the distance n between the opposite electrode plates of the deflection electric field electrode is adjusted, and the geometric dimension h of the deflection electric field electrode plate 2 And position dimension h 1 The offset position of the liquid drop on the forming platform can be effectively controlled by the applied deflection voltages Ux and Uy, so as to accurately control the drop landing of the liquid drop.
The electrode array 9, the dielectric layer 8 constitute a droplet spreading module based on dielectric wetting; the electrode array 9 is a rectangular array of electrodes, the electrode array 9 is fixed at the top of the Y-axis moving device 10, the dielectric layer 8 is adhered to the surface of the electrode array 9, the control device forms a dielectric wetting electric field on the surface of a material by adjusting the voltage of the electrode array, and changes the wetting angle of liquid drops, so that the surface tension of the liquid drops is changed, the hydrophilic and hydrophobic characteristics of the material are controlled, and as shown in fig. 5, the specific principle of the dielectric wetting electric field shape control is as follows:
a) Constructing an array base plate formed by multiple microelectrodes on a forming platform, wherein a dielectric layer is covered on an electrode array to prevent liquid drop electrolysis;
b) Each pair of microelectrodes consists of a positive electrode and a negative electrode, and are respectively connected with the positive electrode and the negative electrode of the configuration direct current power supply; the on-off and the size of the direct current power supply are regulated by a control device, so that a local electric field is formed in a specific area (one or more liquid dripping directions) of the forming flat plate, and the wetting angle of liquid drops can be determined by a Young-Lippman formula;
wherein θ V For the wetting angle after being electrified, theta 0 Is static wetting angle epsilon when not electrified 0 For vacuum dielectric constant, ε r U, which is the relative dielectric constant of the dielectric layer c D is the relative voltage applied between the microelectrode plates c For the thickness of the dielectric layer, γ is the liquid surface tension constant;
c) The size of the dc power supply Uc to be set can be determined by the desired drop thickness.

Claims (3)

1. An additive manufacturing method based on an additive manufacturing device for a microsystem three-dimensional structure is characterized by comprising the following steps of: the structure of the additive manufacturing device for the microsystem three-dimensional structure is that a high-viscosity micro-droplet extrusion spray head is fixed on a guide upright post through a support frame, an X-axis moving device is fixed on a base, a Y-axis moving device is fixed on the X-axis moving device, a deflection electric field electrode is arranged on the guide upright post through a Z-axis moving device, a dielectric layer is adhered to an electrode array, the electrode array is fixed on the Y-axis moving device, and a polarization module is fixed on the base and is positioned above the dielectric layer;
the deflection electric field electrode includes: the deflection electric field X electrodes, the deflection electric field Y electrodes and the insulating connecting layer are columnar small blocks with sector cross sections, the deflection electric field X electrodes and the deflection electric field Y electrodes are fixed on the upper side and the lower side of the insulating connecting layer in pairs, four columnar small blocks are circumferentially and uniformly distributed on the upper side of the insulating connecting layer, the four deflection electric field X electrodes and the two deflection electric field Y electrodes are not contacted in pairs, the two deflection electric field X electrodes are oppositely arranged to form a pair, the two deflection electric field Y electrodes are oppositely arranged to form a pair, and the electrode small blocks which are the same as the upper side are arranged on the lower side of the corresponding insulating connecting layer;
the method comprises the following steps:
(1) In a specific processing example, a user can firstly establish a three-dimensional entity model to be printed through three-dimensional modeling software, or obtain a three-dimensional digital model through reverse engineering in a three-dimensional scanning mode of an entity sample;
(2) Importing a three-dimensional model of a piece to be printed into slicing software of a computer, and disassembling a three-dimensional entity through slicing and layering;
(3) Preparing a required printing liquid material or a wire material to be used in a melting heating mode according to actual needs, and recording properties of a liquid functional material, namely a viscosity coefficient eta, a conductivity k, a surface tension constant gamma and a dielectric constant epsilon;
(4) The geometrical parameters and control parameters of the additive manufacturing equipment are determined through the prior calculation, the deflection voltage Ux and the deflection voltage Uy respectively applied to the deflection electric field X electrode and the deflection electric field Y electrode, the pulse voltage U applied to the tail end of the nozzle, the height h of the lower end part of the nozzle above an infinite forming platform, the distance between a pair of deflection electric field X electrodes or the distance n between a pair of deflection electric field Y electrodes, and the geometrical dimension h of the deflection electric field X electrode or the deflection electric field Y electrode in the vertical direction 2 The height h of the center of the deflection electric field electrode above the infinite forming platform 1 Adjusting and exchanging;
(5) The additive manufacturing equipment is connected to a control port of a computer, and programming control is carried out through a software window, so that the additive manufacturing equipment can actively adjust required voltage parameters in the printing process: the pulse voltage U, the deflection voltage Ux and the deflection voltage Uy are respectively applied to the deflection electric field X electrode and the deflection electric field Y electrode;
(6) Adjusting the additive manufacturing device to the initial position, starting printing, converging molten wire material or liquid additive manufacturing material at the end of the extrusion nozzle into a hemispherical shape,under the action of an electrohydraulic separation electric field, moving charges gather on the hemispherical liquid drop surface at the end part of the spray head, repulsive force between the charges gradually stretches the liquid material at the end part of the spray head to be conical, and finally electrostatic force exceeds the surface tension of the liquid drop, the conical liquid material separates spherical liquid drops at the conical end part to realize the dropping of the material, and in order to realize the dropping of the liquid drops under the action of the electric field, the set voltage is larger than the pulse voltage capable of realizing the spraying, as given in a formula (7), the pulse voltage and the surface tension constant gamma of the liquid, the conductivity k of the liquid functional material, the inner diameter d of the nozzle and the vacuum dielectric constant epsilon of the liquid functional material 0 The relation between:
from the dielectric relaxation relationship, the pulse voltage U applied to the nozzle tip should not have a pulse frequency higher than the voltage pulse ejection frequency f so as not to affect the normal drop of the droplet, and the formula (12) gives a rough relationship between the voltage pulse ejection frequency and the polarization strength σ of the dipole in the droplet, and the dielectric constant ε of the liquid material:
for different structures of a workpiece to be processed, the electrode part at the nozzle adopts different voltages, and according to the formula (13), the droplet size is larger, the flow is larger, so that the forming speed is higher, and the precision is lower; the droplet size is smaller, the flow is smaller, the forming speed is slow, the precision is higher, and the factors influencing the droplet volume V mainly comprise: the dielectric constant epsilon of the liquid material, the inner diameter d of the nozzle, the flow path length L of the nozzle, the polarization strength sigma of dipoles in liquid drops, the viscosity coefficient eta of flowing fluid, the pulse voltage U applied to the tail end of the nozzle, the conductivity k of the liquid functional material, the surface tension constant gamma of the liquid and the flow rate q of the flowing liquid functional material; a time constant τ determined by the dielectric relaxation;
(7) According to the shape of each layer of a workpiece to be processed and the position of an offset position on a forming platform, an X-Y plane moving platform performs coarse positioning at the position to be processed, the accurate position of the current platform can be obtained by utilizing a laser displacement sensor accurate measurement device, a computer adjusts a deflection electric field according to the deviation between a target position and the current position, after the liquid drops drop down, accurate deflection is realized through the deflection electric field so as to achieve the purpose of small-range accurate positioning, after the printing of the current position is finished, the X-Y moving platform continues to move, the previous steps are repeated, thereby realizing large-range accurate positioning, according to the pattern of each slice, the computer automatically plans the moving path of the forming platform in the printing pattern printing process of the layer, further accurately controls the dropping position of liquid drops through the deflection action of a deflection electric field electrode, prints the layer pattern point by point according to the dropping form of the liquid drops, the influence of the deflection electric field electrode on the accurate positioning of the liquid drops can be obtained by a formula (18), wherein the height h between the lower end part of a nozzle and the forming platform and the center of the deflection electric field electrode is positioned on the infinite forming platform to be h 1 Geometry h of the deflection field X electrode or the deflection field Y electrode in the vertical direction 2 The deflection voltage Ux and the deflection voltage Uy are respectively applied to the deflection electric field X electrode and the deflection electric field Y electrode, and the distance between the pair of deflection electric field X electrodes or the distance n between the pair of deflection electric field Y electrodes has an influence on the offset distance:
wherein x is 1 The displacement of the X direction offset is that Q is the charge quantity on the liquid drop at the end of the nozzle, and delta t is the time for the liquid drop to pass through the X electrode of the deflection electric field or the Y electrode region of the deflection electric field; m is the mass of the dropped droplets;
(8) For each drop, computer control is based on dielectric wetting after the drop is deposited on the forming stageThe droplet spreading module of (2) is characterized in that one or more dielectric wetting electric field electrode pairs at the droplet are provided with different voltages, so that the spreading state of the droplet is controlled, the state of the droplet with controllable thickness is obtained, the thickness of the layer is further controlled, the influence of the voltage on the wetting angle is known from a formula (19), the wetting angle of the droplet is changed under the control of the electric field, and the shape of the droplet is further changed, wherein theta is as follows V For the wetting angle after being electrified, theta 0 Is static wetting angle epsilon when not electrified 0 For vacuum dielectric constant, ε r U, which is the relative dielectric constant of the dielectric layer c D is the relative voltage applied between the microelectrode plates c For dielectric layer thickness, γ is the surface tension constant between droplet-air:
(9) After printing the layer of pattern, the computer controls the nozzle to move a slice layer distance along the Z-axis upward direction;
(10) The additive manufacturing process of layer-by-layer printing is realized by repeating the alternation of the steps (7) to (9);
(11) After the additive manufacturing process is finished, the running of software is stopped, the additive manufacturing device is closed, the printing piece is taken down, the connection between the additive manufacturing equipment and the computer is disconnected, and unprinted liquid or wire is processed.
2. Additive manufacturing method based on additive manufacturing devices for microsystems three-dimensional structures according to claim 1, characterized in that: the high viscosity droplet extrusion head comprises: the device comprises a spray head shell end part, an electro-hydraulic separation electric field electrode anode, an electro-hydraulic separation electric field electrode cathode, an electrodeless variable domain heating device, a spray head shell, a formed micro-opening and a piezoelectric diaphragm; the piezoelectric diaphragm is fixed at the end part of the spray head shell, the positive electrode of the electrohydraulic separation electric field electrode is fixed at the inner side of the formed micro-opening, the negative electrode of the electrohydraulic separation electric field electrode is fixed at the outer wall of the formed micro-opening, and the electrodeless variable domain heating device is fixed at the inner wall of the spray head shell.
3. Additive manufacturing method based on additive manufacturing devices for microsystems three-dimensional structures according to claim 1, characterized in that: the electrode array comprises an array formed by dielectric wetting electrodes, wherein the dielectric wetting electrodes comprise dielectric wetting electric field cathodes, dielectric wetting electric field anodes, electric grid insulation fillers and a power supply, the power supply is connected with the dielectric wetting electric field cathodes and the dielectric wetting electric field anodes, and the electric grid insulation fillers are arranged between the dielectric wetting electric field cathodes and the dielectric wetting electric field anodes for insulation.
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