Enhanced micro-droplet printing device

Abstract

The utility model relates to an enhanced micro-droplet printing device, which is used for printing fluid and comprises a chamber main body internally provided with a fluid path and at least one fluid chamber; the fluid cavity is communicated with the fluid path, and at least one spray hole is formed in the fluid cavity; an actuator configured to perform a mechanical motion in response to the pulse signal; the at least two linear actuating pieces are inserted into the same fluid chamber; the linear actuating piece is configured to enable the linear actuating piece to do reciprocating rectilinear motion between a first position and a second position along a linear path relative to the chamber main body under the action of the actuator, so that vibration waves acting on fluid are formed in the fluid chamber; the midpoint of the first position and the second position is used as a wave source, the vibration waves can be overlapped with each other, and periodic constructive interference points are formed at the spray holes. Micro-nano level liquid drop printing can be achieved, energy concentration at a specific position is achieved by means of the interference enhancement principle, and therefore fluid with higher viscosity can be printed, the requirement for an actuator is lowered, and spray hole blocking is reduced.

Description

Technical Field

[0001] This utility model relates to printing devices, and more particularly to an enhanced microdroplet printing device. Background Technology

[0002] In traditional printing technology, especially those methods based on pressure pulse extrusion, the generated droplet diameter is typically larger than or equal to the nozzle size. Even with the use of satellite points to generate smaller droplets, it remains difficult to achieve submicron or nanometer-scale droplets. Due to current manufacturing process and cost limitations, achieving the printing of submicron or nanometer-scale droplets remains quite challenging.

[0003] Especially when printing high-viscosity fluids, the high viscosity of the fluid introduces greater resistance, requiring more energy to overcome this viscous resistance in order to successfully form droplets. In addition, nozzle clogging is a persistent and difficult problem to solve in technological development. These challenges are key issues that urgently need to be overcome in current technological research and development. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing an enhanced microdroplet printing device that can achieve micro-nano-level droplet printing. It utilizes the principle of interference enhancement to achieve energy concentration at specific locations, thereby enabling the printing of fluids with higher viscosity, reducing the requirements for actuators, and minimizing nozzle clogging.

[0005] This utility model discloses an enhanced microdroplet printing device for printing fluids, comprising:

[0006] The chamber body has a fluid path and at least one fluid chamber inside; the fluid chamber is connected to the fluid path, and at least one nozzle is provided in the fluid chamber;

[0007] An actuator is configured to respond to a pulse signal to perform mechanical motion;

[0008] At least two linear actuators are inserted into the same fluid chamber; the linear actuators are configured to reciprocate linearly relative to the chamber body along a linear path between a first position and a second position under the action of the actuator, so as to form a vibration wave acting on the fluid within the fluid chamber; with the midpoint between the first position and the second position as the wave source, the vibration waves can be superimposed to form a periodic structural interference point at the nozzle.

[0009] In one embodiment, each of the linear actuators has a first central axis, and the linear path is parallel to the first central axis.

[0010] In one embodiment, the midpoint between the first and second positions of any linear actuator inserted in the same fluid chamber is equidistant from the nozzle located in the fluid chamber.

[0011] In one embodiment, a linear actuator inserted into the same fluid chamber is connected to the same actuator.

[0012] In one implementation, the linear actuators have the same shape and size characteristics.

[0013] In one embodiment, the nozzle has a second central axis, and the first central axis is parallel to the second central axis.

[0014] In one embodiment, linear actuators inserted into the same fluid chamber are arranged in a ring array uniformly around the second central axis of the nozzle located in the fluid chamber.

[0015] In one embodiment, the distance between the first central axis of any linear actuator inserted in the same fluid chamber and the second central axis of the nozzle located in the fluid chamber is equal.

[0016] In one embodiment, the distance between the first central axis of the linear actuator and the second central axis of the nozzle located in the fluid chamber is taken as the vertical distance, and the projection of the cross-section of the nozzle is located within a circle with a radius equal to the vertical distance from the first central axis of each linear actuator to the second central axis of the nozzle.

[0017] In one embodiment, the inner wall of the fluid chamber is symmetrically arranged around a third central axis, and the first central axis is aligned with the third central axis.

[0018] As one embodiment, it also includes a seal; the chamber body is provided with an insertion hole adapted to the linear actuator, the central axis of the insertion hole is aligned with the first central axis of the corresponding linear actuator, and the seal is disposed between the linear actuator and the insertion hole.

[0019] In one embodiment, the linear actuator is connected via a connecting portion located outside the chamber body; the connecting portion has a fourth central axis aligned with the second central axis; the fourth central axis is connected to the actuator.

[0020] By adopting the above structure, this utility model has the following advantages compared with the prior art:

[0021] This invention employs the actuation principle of reciprocating linear motion along a linear path by the aforementioned linear actuator, which can form submicron or nanometer-sized droplets, thus improving printing accuracy. Furthermore, it utilizes the principle of interference enhancement to achieve energy concentration at specific locations, enabling the printing of fluids with higher viscosity, reducing the requirements for the actuator, and minimizing nozzle clogging. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of one embodiment of the present invention.

[0023] Figure 2 This is a cross-sectional view of another embodiment of the present invention.

[0024] Figure 3 This is a top view schematic diagram of the actuator and linear actuator according to one embodiment of the present invention.

[0025] Figure 4 This is a top view schematic diagram of the actuator and linear actuator according to another embodiment of the present invention.

[0026] Figure 5 This is a cross-sectional view of the main body of the chamber according to one embodiment of the present invention.

[0027] Figure 6 This is a first state diagram of the fluid at the nozzle of this utility model.

[0028] Figure 7 This is a second state diagram of the fluid at the nozzle of this utility model.

[0029] 1. Chamber body; 11. Fluid path; 12. Fluid chamber; 13. Spray hole; 14. Insertion hole; 15. Second central axis; 16. Third central axis;

[0030] 2. Actuator;

[0031] 3. Linear actuator; 31. First central shaft;

[0032] 4. Sealing components;

[0033] 5. Connecting part, 51. Fourth central shaft. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] Printing technology has evolved from continuous printing and piezoelectric printing to thermal printing, continuously improving the precision of the nozzle 13 and the compatibility of fluid components, laying the foundation for printing micro-droplets. However, due to the limiting mechanism of droplet ejection, the precision of traditional printing is limited by its nozzle size; moreover, due to processing technology and cost limitations, it is difficult to achieve submicron or nanometer-sized or even smaller droplet volumes. In reality, high-viscosity fluids have greater viscous resistance, requiring more energy to overcome the fluid's viscous resistance to form droplets. In particular, printing micro-droplets is even more difficult when achieving submicron or nanometer-sized or even smaller droplet volumes. For printing technologies that generate droplets through vibration, this greater energy requirement means that the vibration wave needs a larger amplitude, which increases the spatial requirements for the amplitude direction and requires the superposition of multiple actuators to achieve a larger amplitude to generate sufficient energy, thus increasing costs. In addition, nozzle clogging is more likely to occur when printing submicron or nanometer-sized or even smaller droplet volumes.

[0036] This invention systematically studies the process of using a driving pulse to stimulate damped oscillations in a liquid, thereby triggering the fluid to form droplets through the liquid surface constraint of the nozzle 13. However, this technique requires sufficient potential energy to be generated at the nozzle to form droplets. It also has limitations in applications with high-viscosity fluids. This solution is developed to address this challenge.

[0037] like Figure 1 , Figure 2 and Figure 5 This application relates to an enhanced microdroplet printing device for printing fluids, comprising:

[0038] The chamber body 1 has a fluid path 11 and at least one fluid chamber 12 inside; the fluid chamber 12 is connected to the fluid path 11, and at least one nozzle 13 is provided in the fluid chamber 12.

[0039] Actuator 2 is configured to respond to pulse signals to perform mechanical motion;

[0040] At least two linear actuators 3 are inserted into the same fluid chamber 12; the linear actuators 3 are configured to reciprocate linearly relative to the chamber body 1 along a linear path S between a first position B and a second position A under the action of the actuator 2, so as to form a vibration wave acting on the fluid in the fluid chamber 12; with the midpoint of the first position B and the second position A as the wave source, the vibration waves can be superimposed to form a periodic structural interference point at the nozzle 13.

[0041] The specific principle of this utility model is explained as follows. From a microscopic perspective, in the initial state, the end of the linear actuator 3 is located at the first position B. Under the driving action of the actuator 2, the linear actuator 3 moves along the linear path S away from the nozzle 13, that is, the end of the linear actuator 3 moves from the first position B to the second position A. For example... Figure 6 As shown, the fluid surface at nozzle 13 slightly contracts, forming a curved surface. At this time, the end of the linear actuator 3 is located at the second position A. Under the reverse drive applied by the actuator 2, the linear actuator 3 reciprocates along the linear path S towards the nozzle 13, that is, the end of the linear actuator 3 reciprocates between the second position A and the first position B.

[0042] The vibration wave generated by any of the linear actuators 3 takes the middle of the first position B and the second position A of the linear actuator 3 as the wave source. The end of the linear actuator 3 moves back and forth from the second position A and the first position B, and gradually propagates longitudinal waves outward along the reciprocating movement direction. When the fluid molecules near the linear actuator 3 are disturbed by the reciprocating movement and move along the linear path S, they will drive the surrounding fluid molecules to move along the linear path S as well. This interaction causes the vibration to gradually propagate outward as transverse waves located in the plane perpendicular to the reciprocating movement direction.

[0043] Because the vibration waves of the different linear actuators 3 superimpose, periodic structural interference points can be formed at the nozzle. An enhanced pressure wave is generated at the nozzle 13, causing the liquid surface to bulge outwards. Moving linearly towards or away from the nozzle 13 drives the liquid surface at the nozzle 13 to extend outwards until the deformation peak is reached. The linear actuator 3 moves along the linear path S away from the nozzle 13, and viscous and inertial forces hinder the backflow of fluid outside the orifice. The newly formed liquid surface continues to expand outwards under the action of residual energy, and small droplets detach from the curved liquid surface due to surface vibration, and under the action of the flow field into the fluid chamber 12, such as... Figure 7 As shown, the liquid surface contracts from the edge of the nozzle 13 to form droplets.

[0044] The periodic structural interference points allow the amplitude of the pressure wave at nozzle 13 to increase geometrically; the higher the energy density, the stronger the driving force on the liquid. Energy density refers to the energy per unit volume. Only when the energy density is high enough can the surface tension and viscous forces of the liquid be overcome, forcing the liquid out of the nozzle to form a stable droplet. Even when acting on high-viscosity fluids, it can provide several times the energy to overcome the viscous resistance of the high-viscosity fluid, causing the liquid surface to bulge outward. Moreover, for printing technology that generates droplets through vibration, the solution of this application does not increase the spatial requirements of the amplitude direction, does not require stacking multiple actuators to achieve a larger amplitude, and can achieve a larger amplitude of the vibration wave at a specific location.

[0045] In addition, the vibration generated by high-intensity energy can disturb the blockage, loosen it, and eventually remove it, thus providing the side effect of preventing nozzle clogging.

[0046] Wherein, the chamber body 1, as Figure 5 As shown, the fluid path 11 includes an inlet and an outlet. Fluid enters from the inlet, passes through the internal space, and is used to guide fluid at a constant pressure. The fluid chamber 12 contains the fluid within a spatial range and facilitates the precise ejection of the fluid from the nozzle 13. Multiple fluid chambers 12 are independent of each other to avoid crosstalk between adjacent chambers. The chamber body can be made of polymer material. For applications requiring high temperature resistance or corrosion resistance, metal or ceramic materials can also be used. The chamber body can be manufactured by injection molding or machining. The fluid can be ink, additives, liquid metal, or other fluid liquids that need to be ejected.

[0047] The actuator 2, such as Figure 1 As shown, energy conversion from pulse signals to mechanical energy can be achieved. For example, piezoelectric actuator 2 changes shape and generates displacement due to the action of an electrical signal. The signal generation module applies the energy to drive the pulses, while actuator 2 is the component that responds to these pulses and performs mechanical motion. The signal generation module can be an arbitrary waveform generator, direct digital synthesizer, microcontroller, phase-locked loop, etc., which generates voltage or current pulses according to a predetermined program or algorithm. The signal generation module generates appropriate electrical signals according to the required control strategy. The electrical signals are transmitted to actuator 2 via a cable. Actuator 2 receives the pulse signals and converts them into mechanical motion to perform the required task.

[0048] For example, actuator 2 can be a piezoelectric actuator 2, which uses voltage to drive the piezoelectric material to deform, thereby generating mechanical motion. Their response time can be very fast, reaching the microsecond level or even shorter. Piezoelectric actuators 2 not only have a fast response speed but also very high positional accuracy and repeatability, making them suitable for applications requiring high-precision control. Alternatively, other materials can be used; for example, when using photosensitive materials or structures, some photoactuators 2 can achieve very fast responses. These materials deform rapidly under light stimulation; shape memory alloys (such as nickel-titanium alloys) can rapidly change shape under the influence of temperature or current, generating mechanical motion. Although the response time of a typical electromagnetic actuator 2 (such as a solenoid valve or relay) may be in the millisecond range, high-performance electromagnetic actuators 2 can be designed with extremely short response times.

[0049] The linear actuator 3, such as Figure 1-5 As shown, this is used to convert the mechanical motion of the actuator into linear motion within the chamber body 1, driving a piston or push rod within the chamber body. One end of the linear actuator is connected to the actuator, and the other end is connected to the piston or push rod within the chamber body. Figure 1-2 As shown, the linear actuator 3 can be cylindrical, conical, or other components capable of linear reciprocating motion. The material can be a metal alloy, piezoelectric ceramic, piezoelectric polymer, composite material, or silicon-based material. When the linear actuator 3 and actuator 2 are made of the same material, they can be integrated into a single design. When the linear actuator 3 and actuator 2 are made of different materials, they can be bonded, welded, or connected using other methods. Other flexible materials can also be provided between the linear actuator 3 and actuator 2, for example, to aid in sealing the chamber body 1.

[0050] The constructed interference points, such as Figure 3-4 Structural interference refers to the phenomenon where, when two or more waves meet, the portions vibrating in the same direction superimpose, resulting in an increase in amplitude. At specific locations, this superposition reaches its maximum, forming a structural interference point.

[0051] Each of the linear actuators 3 has a first central axis 31. Preferably, the linear path S is parallel to the first central axis 31. The reciprocating motion of the linear actuator 3 along the first central axis 31 ensures that the trajectory of the linear actuator 3 is a straight line. Due to the linear motion, the propagation direction of the generated vibration waves will also be highly consistent, all along the direction of the first central axis 31. This is beneficial for strengthening the energy of the longitudinal waves and avoiding energy dispersion. If the vibration directions of the wave source are inconsistent, the generated longitudinal waves will propagate in different directions. When these longitudinal waves meet, interference may occur due to the difference in phase, resulting in a weakening of the wave energy. Linear motion can effectively avoid this situation. Moreover, due to the consistency of the reciprocating motion direction, the consistency of the trajectory and distance of different movements and different components is improved, which is beneficial for achieving high-precision positioning and control. The endpoints of the linear path S are the first position B and the second position A. The reciprocating motion on the linear path S forms vibration waves based on the propagation of the wave source in various directions.

[0052] In one implementation, the midpoint between the first position B and the second position A of any linear actuator 3 inserted in the same fluid chamber 12 is equidistant from the nozzle 13 located in the fluid chamber 12. This means that the transmission distance of the vibration wave generated from the end of each linear actuator 3 to the nozzle is equal. This reduces the difference in attenuation of vibration waves from different linear actuators 3 during transmission, while ensuring that the time difference between the arrival of each vibration wave at the nozzle is consistent, thereby forming a stable structural interference point.

[0053] As one implementation, the linear actuator 3, inserted into the same fluid chamber 12, is connected to the same actuator 2. Multiple linear actuators connected to the same actuator: By connecting multiple linear actuators to the same actuator, it can be ensured that the frequency and amplitude of the vibration waves of the multiple linear actuators are the same, further improving the control accuracy of fluid flow.

[0054] Preferably, the linear actuators 3 have the same shape and size characteristics. Different shapes and sizes of the linear actuators 3 may result in different natural frequencies and different responses to the same actuator. Having the same shape and size characteristics can prevent the effects caused by different natural frequencies. Furthermore, the linear actuators 3 experience fluid resistance when moving in a fluid. The magnitude and direction of this resistance will differ for linear actuators 3 with different shapes. For example, streamlined objects experience less resistance than blunt bodies.

[0055] In one embodiment, the nozzle 13 has a second central axis 15, and the first central axis 31 is parallel to the second central axis 15.

[0056] In one embodiment, the linear actuators 3, inserted into the same fluid chamber 12, are uniformly arranged in a ring array around the second central axis 15 of the nozzle 13 located in the fluid chamber 12. By arranging the linear actuators 3 in a ring uniformly around the nozzle, a balanced and symmetrical vibration field can be formed. The symmetrical vibration field ensures that more concentrated energy is generated at the nozzle, thereby improving the droplet generation efficiency and stability. In addition, the ring arrangement can better control the flight direction of the droplets.

[0057] In one embodiment, the distance between the first central axis 31 of any linear actuator 3 inserted in the same fluid chamber 12 and the second central axis 15 of the nozzle 13 provided in the fluid chamber 12 is equal.

[0058] In one implementation, the distance between the first central axis 31 of the linear actuator 3 and the second central axis 15 of the nozzle 13 located in the fluid chamber 12 is taken as the perpendicular distance. The projection of the cross-section of the nozzle 13 lies within a circle with a radius equal to the perpendicular distance from the first central axis 31 of the linear actuator 3 to the second central axis of the nozzle 13. This constraint ensures that the vibration wave can generate sufficient energy density at the nozzle, thereby effectively driving the vibration of the liquid. When the vibration wave propagates to the nozzle, if the area of ​​the nozzle is too large, the energy will be dispersed over a larger area, resulting in a decrease in energy density per unit area.

[0059] Furthermore, preferably, the inner wall of the fluid chamber 12 is symmetrically arranged around the third central axis 16, and the first central axis 31 is aligned with the third central axis 16. This further enhances the symmetry of the system and improves its stability.

[0060] More specifically, this application may further include a seal 4; the chamber body 1 is provided with an insertion hole 14 adapted to the linear actuator 3, the central axis of the insertion hole 14 is aligned with the first central axis 31 of the corresponding linear actuator 3, and the seal 4 is disposed between the linear actuator 3 and the insertion hole 14. By providing a seal 4 at the insertion hole, fluid leakage can be effectively prevented, ensuring stable pressure within the chamber.

[0061] As a specific implementation method, the linear actuators 3 are connected via a connecting part 5, which is located outside the chamber body 1. The connecting part 5 has a fourth central axis 51, which is aligned with the second central axis 15. The fourth central axis is connected to the actuator 2. By providing a connecting part outside the chamber body, it is convenient to centrally control multiple linear actuators 3, thereby improving the reliability of the system.

[0062] In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Although embodiments of the present invention have been shown and described above, they should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All changes made within the scope of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. An enhanced microdroplet printing device for printing fluids, characterized in that, include: The chamber body (1) has a fluid path (11) and at least one fluid chamber (12) inside; the fluid chamber (12) is connected to the fluid path (11), and at least one nozzle (13) is provided in the fluid chamber (12); Actuator (2) is configured to respond to pulse signals to perform mechanical motion; At least two linear actuators (3) are inserted into the same fluid chamber (12); the linear actuators (3) are configured to reciprocate linearly between a first position and a second position along a linear path relative to the chamber body (1) under the action of the actuator (2), so as to form a vibration wave acting on the fluid in the fluid chamber (12); with the midpoint of the first position and the second position as the wave source, the vibration waves can be superimposed to form a periodic structural interference point at the nozzle (13).

2. The enhanced microdroplet printing device according to claim 1, characterized in that, Each of the linear actuators (3) has a first central axis (31), and the linear path is parallel to the first central axis (31).

3. The enhanced microdroplet printing device according to claim 2, characterized in that, Furthermore, the midpoint between the first and second positions of any linear actuator (3) inserted in the same fluid chamber (12) is equidistant from the nozzle (13) located in the fluid chamber (12).

4. An enhanced microdroplet printing device according to claim 1, 2 or 3, characterized in that, A linear actuator (3) inserted into the same fluid chamber (12) is connected to the same actuator (2).

5. An enhanced microdroplet printing device according to claim 4, characterized in that, The linear actuators (3) have the same shape and size characteristics.

6. An enhanced microdroplet printing device according to claim 2, characterized in that, The nozzle (13) has a second central axis (15), and the first central axis (31) is parallel to the second central axis (15).

7. An enhanced microdroplet printing device according to claim 6, characterized in that, The linear actuators (3) inserted in the same fluid chamber (12) are arranged in a ring array around the second central axis (15) of the nozzle (13) provided in the fluid chamber (12).

8. An enhanced microdroplet printing device according to claim 6 or 7, characterized in that, The distance between the first central axis (31) of any linear actuator (3) inserted in the same fluid chamber (12) and the second central axis (15) of the nozzle (13) provided in the fluid chamber (12) is equal.

9. An enhanced microdroplet printing device according to claim 7, characterized in that, The distance between the first central axis (31) of the linear actuator (3) and the second central axis (15) of the nozzle (13) provided in the fluid chamber (12) is taken as the vertical distance, and the projection of the cross section of the nozzle (13) is located in a circle with the vertical distance from each of the first central axis (31) to the second central axis (15) as the radius.

10. An enhanced microdroplet printing device according to claim 2, characterized in that, The inner wall of the fluid chamber (12) is symmetrically arranged around the third central axis (16), and the first central axis (31) is aligned with the third central axis (16).

11. An enhanced microdroplet printing device according to claim 1, characterized in that, It also includes a sealing element (4); the chamber body (1) is provided with an insertion hole (14) adapted to the linear actuator (3), the central axis of the insertion hole (14) is aligned with the first central axis (31) of the corresponding linear actuator (3), and the sealing element (4) is disposed between the linear actuator (3) and the insertion hole (14).

12. An enhanced microdroplet printing device according to claim 8, characterized in that, The linear actuator (3) is connected by a connecting part located outside the chamber body (1); the connecting part has a fourth central axis, which is aligned with the second central axis (15); the fourth central axis is connected to the actuator (2).

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