Valveless micropump based on parallel double vibration pieces and air pumping method

Abstract

The invention discloses a valveless micropump based on parallel double vibration pieces and an air pumping method. The valveless micropump comprises a vibration element, a vibrating diaphragm layer, a flow channel layer and a resonance layer which are arranged in a stacked mode. The vibrating diaphragm layer and the resonant layer form a vibrating sheet structure with two fixed ends and a free middle part through two gaps arranged at intervals. The edges of the two sides of the vibration piece structure are aligned with the two side walls of the air pumping cavity correspondingly. The vibration element is used for driving the vibrating diaphragm layer and the resonance layer to perform synchronous reverse wave-shaped vibration. The vibrating diaphragm layer and the resonant layer are periodically separated and contacted at one or more discontinuous current limiting sites. The discontinuous flow limiting sites are arranged in the length direction of the air pumping cavity. And part or all of the discontinuous flow limiting sites are correspondingly provided with through-flow structures communicated with the external environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of piezoelectric micropumps, and in particular relates to a valveless micropump based on parallel double-vibration plates and a gas pumping method. Background Art

[0002] As a micro device with strong coupling across multiple disciplines such as materials, structures, fluids, electronics, and processes, the micro piezoelectric pump has the advantages of small size, low power consumption, high specific back pressure, large specific flow rate, high-speed response, and high flow accuracy. It has a wide range of applications in the fields of medical devices and semiconductor thermal management, and is particularly suitable for wearable and portable medical devices and ultra-thin micro-space heat dissipation management applications.

[0003] The application of piezoelectric micropumps in air cooling is primarily reflected in their role as key components in electronic device cooling systems, particularly in thermal management for high-power, miniaturized electronics. Piezoelectric micropumps utilize the piezoelectric effect to generate fluid flow. Their advantages include small size, low power consumption, precise control, and high reliability, making them ideal for integration into portable and miniature electronic devices. They can circulate coolant through microchannels or heat exchangers within electronic devices, effectively dissipating heat and maintaining optimal operating temperatures for electronic components.

[0004] In the field of heat dissipation, micropumps prepared using the synthetic jet principle have a heat dissipation efficiency far superior to that of traditional micropumps. The flow field formed by conventional pump drive has a stable boundary layer, and heat exchange with the external fluid can only be carried out through the boundary layer, resulting in low heat exchange efficiency. The process driven by the synthetic jet micropump is a vortex pair or vortex ring, which has the characteristics of pulsation and suction. The high-frequency pulsating flow field has an unstable boundary, and the low-temperature fluid can directly contact the high-temperature wall surface, greatly improving the heat exchange efficiency. In addition, the vortex rings and vortex pairs ejected by the synthetic jet pump can continuously draw in the low-temperature fluid in the environment during rotation, increasing the net flow rate of the fluid and further improving the heat exchange efficiency. Therefore, the heat exchange of the flow field driven by synthetic jets is 2-3 times the heat exchange capacity of conventional fans or pumps. It has the characteristics of low net flow, low power consumption, and high heat exchange capacity, and has broad application prospects in the field of micro-space heat dissipation.

[0005] The main defects of the prior art are as follows: 1. The structure of an ordinary air-cooled piezoelectric micropump is generally closed, that is, the internal vibration cavity is closed. Therefore, when the vibrator is vibrating, it will be restricted by the closed vibration cavity, causing the amplitude of the vibrator to become smaller. The small amplitude of the vibrator will directly lead to a small flow rate of the piezoelectric micropump.

[0006] 2. The vibrator of an ordinary air-cooled piezoelectric micropump is generally circular, that is, the shape of the piezoelectric micropump is rectangular, and the shape of the piezoelectric vibrator and the vibration cavity inside it are circular. The internal volume utilization rate is not high, and when the circular piezoelectric vibrator and the vibration cavity are arrayed, part of the volume will be unutilized, resulting in a smaller volume change rate, which is not suitable for arraying.

[0007] 3. Conventional air-cooled piezoelectric micropumps typically have vertical air outlet and air inlet. Air-cooled piezoelectric micropumps with vertical air outlet and air inlet dissipate heat through vertical flow field pulses. When synthetic jet technology is used for cooling, a flow field evolution distance of at least 100mm must be reserved in the air outlet direction. When the reserved space is less than 100mm, vortex pairs and vortex rings cannot be generated or evolve insufficiently, resulting in essentially no flow and no heat dissipation effect. Therefore, when vertical air cooling is applied to ultra-thin space heat dissipation, the space in the thickness direction is often extremely limited.

[0008] 4. The existing air-cooled piezoelectric micropump with side-outlet air requires a valve to control the in and out of air. First, after adding the valve, the structure of the entire system becomes more complicated, increasing the difficulty of design and manufacturing. Secondly, the valve is prone to mechanical wear during frequent switching, resulting in a decrease in sealing performance or even failure. Moreover, the air-cooled piezoelectric micropump with a valve cannot be very thin due to the existence of the valve.

[0009] For example, the Chinese patent with patent number CN118622665A discloses a "Piezoelectric Pump, Micro-Air Pump Group and Electronic Device", which specifically discloses the following content: "A circular through hole is opened in the middle of the cavity cover 120, and an air outlet 122 is provided on one side, and the air outlet 122 is connected to the side of the through hole. In this embodiment, the piezoelectric pump 100 is provided with a pump assembly 110 and a cover plate 150, and the pump assembly 110 and the cover plate 150 are respectively located at two opposite ends of the through hole to seal and cover the two ends of the through hole to form a pump chamber 121. The cover plate 150 can be a metal plate similar to the vibrator plate 113, and the vibrator plate 113 and the cover plate 150 can be connected to the cavity cover 120 by bonding. During operation, as the vibrator plate 113 is agitated, the cover plate 150 can be agitated accordingly" (paragraph 0038 of the specification in the comparative document), and then refer to the comparative document. Figures 2 to 4 It can be seen that the vibration cavity inside the piezoelectric pump provided by this patent is closed. When the vibrator vibrates, the vibration cavity inside the piezoelectric pump limits the amplitude, resulting in the amplitude being not large enough and unable to generate a large flow rate.

[0010] For another example, Chinese patent number CN111828289B discloses a "Micropump MEMS device for moving or ejecting fluid", which specifically discloses the following content: "A piezoelectric element is fixed on the back of a vibration plate to form a single membrane. When the piezoelectric element is biased by an AC voltage, the single membrane bends in opposite directions through alternating motion, reducing and increasing the volume of the chamber in the main body. The above-mentioned volume changes alternately cause the fluid to be sucked in from the supply path inlet and discharged through the ejection outlet in an alternating manner. Therefore, through this structure, a small amount of fluid greater than 0.2 ml / min can be moved in a precise manner: therefore, the micro fan can be used to cool electronic equipment using air. However, it is desired to have a micropump device that can move a fluid amount varying from a very low value to a higher value with high precision" (paragraphs 0004 to 0006 of the description in the comparative document). It can be seen that the comparative document is a jet-cooled air-cooled micropump, and its specific working process is "Each actuator element 5 includes a fluid inlet path 10 and an outlet opening 11. In the illustrated embodiment, The fluid inlet path 10 opens on the first main surface 3A through an inlet opening 12. An outlet opening 11 is arranged on the second main surface 3B, with one outlet opening 11 present for each actuator element 5. The inlet opening 12 can be connected to an external fluid circuit (not shown), for example, for drawing in liquid or gas contained in a reservoir, or directly communicate with the external environment, for example, for drawing in ambient air. Similarly, depending on the intended application, the outlet opening 11 can be connected to an external fluid circuit (not shown), or to the outside (paragraph 0021 of the specification in the reference document). It can be seen that the reference document draws in fluid through the inlet on the lower surface and ejects fluid through the outlet on the upper surface. The individual MEMS pumps in this micropump MEMS device are not only relatively thick, but also utilize a circular oscillator. The volume change rate of a single pump is small (the oscillating cavity accounts for a relatively small proportion of the micropump), resulting in a very low flow rate. Therefore, an array of multiple MEMS pumps is required to form an array micropump MEMS device, resulting in a large overall volume to achieve a high flow rate. Furthermore, some volume is wasted during the arraying process.

[0011] For another example, Chinese patent number CN116857159A discloses a “flow-guiding structure and valveless piezoelectric micropump”, which specifically discloses the following: “A spiral Tesla valve 111 is provided on the first side of the body 11, and a first opening 112 and a second opening 113 are provided on the body 11, which are spaced apart and distributed. The first opening 112 is connected to the first end of the Tesla valve 111, and the second opening 113 is connected to the second end of the Tesla valve 111. The Tesla valve 111 has a forward flow direction from the first opening 112 to the second opening 113, and a reverse flow direction from the second opening 113 to the first opening 112” (reference document). 0055 of the specification in the reference document) and "Because the Tesla valve 111 is spirally arranged on one side of the body 11, the Tesla valve 111 can maintain a long path while also utilizing the characteristics of the spiral structure to reduce the volume and occupied space of the body 11, thereby achieving the design purpose of a small-volume flow-guiding structure 10. For example, if a Tesla valve 111 with a length of L is required, the length of the body 11 will be longer when the Tesla valve 111 is linear. In comparison, the Tesla valve 111 in the embodiment of the present invention is spirally shaped, which is conducive to reducing the design size of the body 11" (paragraph 0057 of the specification in the reference document), and then refer to the reference in the reference document. Figures 4 to 6 It can be seen that in order to divert flow, a Tesla valve is set up in the comparative document, that is, "by changing the shape of the pipeline and utilizing the flow inertia of the fluid itself, not only can the backflow of the fluid be reduced, which is beneficial to the directional flow of the fluid in the Tesla valve, but also a larger fluid delivery volume can be achieved, and the overall occupied space of the diversion structure can be reduced, thereby achieving the design purpose of a small-volume diversion structure" (paragraph 0023 of the specification in the comparative document). It can be seen that although the Tesla valve structure can play a role in diversion, the structure of the Tesla valve itself is relatively complex, resulting in an increase in its thickness, and the structure of the piezoelectric pump itself is also more complex, and the processing process is also more complicated. Summary of the Invention

[0012] The purpose of the present invention is to solve the problems of large thickness and small amplitude of the existing air-cooled piezoelectric micropump, and to provide a valveless micropump and air pumping method based on parallel double vibrators. By setting extremely narrow gaps on both sides of the vibrator, intermittent current limiting sites of periodic conduction and current limiting are formed inside the valveless micropump. Since the valve structure is removed, the overall thickness of the valveless micropump of the present invention is reduced, and the presence of the gap makes the amplitude of the valveless micropump of the present invention larger.

[0013] In its first aspect, the present invention provides a valveless micropump based on a parallel dual-diaphragm design. The micropump comprises a stacked vibrating element, a diaphragm layer, a flow channel layer, and a resonant layer. Opposing sides of the diaphragm layer and the resonant layer, along with the sidewalls of the groove within the flow channel layer, form a pumping chamber. Two slits are spaced apart in the diaphragm layer and the resonant layer to form a vibrating plate structure with fixed ends and a free center. The vibrating plate structure corresponds to the position of the pumping chamber.

[0014] The vibrating element is used to drive the diaphragm layer and the resonant layer to vibrate in a synchronous, opposite, wave-like manner. The vibrating diaphragm layer and the resonant layer periodically move away from and toward each other at one or more intermittent flow-limiting locations. These intermittent flow-limiting locations are arranged along the length of the pump air chamber. Some or all of these intermittent flow-limiting locations are correspondingly provided with flow-through structures that communicate with the external environment.

[0015] Preferably, both side edges of the vibration plate structure are aligned with both side walls of the pumping chamber.

[0016] Preferably, the width of the gap is 1 to 5 microns, which can prevent fluid leakage.

[0017] Preferably, the vibration element is completely located between the two gaps of the diaphragm layer.

[0018] Preferably, the vibration element and the vibration plate structure are both rectangular. The vibration element is fixed on the vibration plate structure of the diaphragm layer.

[0019] Preferably, the number of the intermittent flow-restricting sites and the flow-through structures is three. The flow-through structures are sequentially arranged on the sides of the flow channel layer. The intermittent flow-restricting sites on both sides and the intermittent flow-restricting site in the middle move toward and away from each other asynchronously.

[0020] Preferably, the diaphragm layer, the flow channel layer and the resonance layer are all provided with stress seams surrounding the pumping chamber.

[0021] Preferably, a fluid channel is provided on the side of the flow channel layer. The fluid channel crosses the three flow structures. The diaphragm layer has a plurality of flow holes on the side. Each flow hole is connected to a different position of the fluid channel. Each flow hole is staggered with respect to the three flow structures.

[0022] Preferably, the device further includes a rectifying layer. The rectifying layer is connected to the side of the resonant layer facing away from the flow channel layer. The resonant layer and the rectifying layer are provided with one or more mutually aligned through-holes, forming a flow structure that communicates with the external environment. The groove structures on the resonant layer and the rectifying layer together form an output chamber.

[0023] Preferably, both ends of the output chamber are connected to the external environment through flow holes provided in the vibration element, the diaphragm layer and the flow channel layer.

[0024] Preferably, there are three intermittent flow limiting sites; each of the three intermittent flow limiting sites is correspondingly provided with a flow-through structure.

[0025] Preferably, the number of the intermittent flow-limiting sites is three, the number of the flow-through structure is one, and the flow-through structure is aligned with the middle intermittent flow-limiting site.

[0026] Preferably, the vibration element includes an actuating plate and a reinforcing plate that are stacked.

[0027] In a second aspect, the present invention provides a method for pumping air using the aforementioned valveless micropump. The valveless micropump has three intermittent flow-limiting sites. The method comprises: applying a periodic electrical signal to the vibrating element to drive the diaphragm layer and the resonant layer to perform synchronous, reverse, wave-like vibrations, with the intermittent flow-limiting sites on both sides and the intermittent flow-limiting site in the middle alternatingly moving away from and approaching each other; and the flow structures corresponding to each intermittent flow-limiting site periodically drawing air inward or pumping air outward.

[0028] The present invention has the following beneficial effects: 1. The present invention provides two extremely narrow gaps in the diaphragm layer and the resonant layer, thereby forming mutually aligned rectangular diaphragm structures on the diaphragm layer and the resonant layer. This rectangular diaphragm structure, fixed at both ends and free in the middle, can vibrate in a wave-like manner, causing the diaphragm layer and the resonant layer to periodically move away from and toward each other at specific locations, thereby periodically increasing and decreasing the flow resistance of the flow structure, thereby acting similarly to a valve. This allows the present invention to eliminate the complex valve body structure, simplify the micropump structure, and reduce the thickness of the micropump, facilitating the integrated application of the micropump in microdevices and mobile devices.

[0029] 2. In the present invention, the middle part of the rectangular vibrating plate structure formed by two extremely narrow gaps is free, which expands the amplitude of the vibrating plate structure, and the vibration directions of the rectangular vibrating plate structures on the diaphragm layer and the resonance layer are opposite, further increasing the volume change rate of the pump air chamber and improving the flow rate of the valveless micropump.

[0030] 3. In the present invention, the vibration plate structure and the vibration element are both rectangular, which can obtain a rectangular piezoelectric micropump with higher utilization rate. The rectangular piezoelectric micropump is conducive to array.

[0031] 4. When the present invention adopts the lateral air outlet solution, the synthetic jet principle can be used based on the three discontinuous flow limiting sites to form vortex pairs and vortex rings in the lateral flow structure, thereby increasing the flow rate of the valveless micropump. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a front view of the valveless micropump provided in Example 1 of the present invention.

[0033] Figure 2It is a three-dimensional diagram of the valveless micropump provided in Example 1 of the present invention.

[0034] Figure 3 Schematic diagram of the structure of the first gap in the valveless micropump provided in Example 1 of the present invention ( Figure 2 (enlarged view of part A in Figure 3).

[0035] Figure 4 1 is an exploded view of the valveless micropump provided in Example 1 of the present invention.

[0036] Figure 5 Schematic diagram of the fluid output process of the valveless micropump provided in Example 1 of the present invention.

[0037] Figure 6 Schematic diagram of the fluid suction process of the valveless micropump provided in Example 1 of the present invention.

[0038] Figure 7 It is a three-dimensional diagram of the valveless micropump provided in Example 2 of the present invention.

[0039] Figure 8 1 is an exploded view of the valveless micropump provided in Example 2 of the present invention.

[0040] Figure 9 2 is a bottom view of the valveless micropump provided in Example 2 of the present invention.

[0041] Figure 10 This is a schematic diagram of the fluid suction process of the valveless micropump provided in Example 2 of the present invention.

[0042] Figure 11 Schematic diagram of the fluid output process of the valveless micropump provided in Example 2 of the present invention.

[0043] Figure 12 1 is an exploded view of the valveless micropump provided in Example 3 of the present invention.

[0044] Figure 13 This is a schematic diagram of the fluid suction process of the valveless micropump provided in Example 3 of the present invention.

[0045] Figure 14 Schematic diagram of the fluid output process of the valveless micropump provided in Example 3 of the present invention.

[0046] Figure 15 1 is an exploded view of the valveless micropump provided in Example 4 of the present invention.

[0047] Figure 16 This is a schematic diagram of the array pump gas structure provided by Example 4 of the present invention.

[0048] In the figure, 100, actuator plate; 200, reinforcement plate; 300, diaphragm layer; 310, first gap; 320, flow hole; 330, first flow hole; 400, flow channel layer; 410, first parallel flow structure; 420, second parallel flow structure; 430, third parallel flow structure; 440, fixing part; 450, flow part; 460, fluid channel; 500, resonant layer; 510, second gap; 520, internal flow hole; 530, third flow hole; 600, rectifying layer; 610, first external flow hole; 620, second external flow hole; 630, third external flow hole; 640, fluid channel; 700, pump air chamber; 800, output chamber; 900, stress seam. DETAILED DESCRIPTION

[0049] The present invention will be further described below.

[0050] In the following embodiments, the width direction of the valveless micropump is set to be the front-to-back direction, the length direction is set to be the left-to-right direction, and the thickness direction of the valveless micropump is set to be the up-down direction.

[0051] Example 1

[0052] This embodiment provides a valveless micropump with lateral air outlet based on parallel double oscillating plates.

[0053] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, a valveless micropump based on a parallel double-vibration plate comprises an actuator plate 100, a reinforcement plate 200, a diaphragm layer 300, a flow channel layer 400 and a resonance layer 500 stacked in sequence from top to bottom; a plurality of flow-through structures are provided on one side of the valveless micropump; after the actuator plate 100, the reinforcement plate 200, the diaphragm layer 300, the flow channel layer 400 and the resonance layer 500 are connected, the fluid is sucked in or pumped out from the flow-through structure on one side of the valveless micropump based on the parallel double-vibration plate through the vibration of the actuator plate 100.

[0054] Figure 1 This is a front view of a valveless micropump based on parallel double oscillating plates according to the present invention, which specifically shows the components of the valveless micropump in this embodiment.

[0055] The interior of the flow channel layer 400 is provided with a rectangular groove body that passes through the flow channel layer 400 from top to bottom. The opposite sides of the diaphragm layer 300 and the resonance layer 500 and the side walls of the rectangular groove body in the flow channel layer 400 are enclosed to form a pumping air chamber. The cross section of the pumping air chamber is rectangular. The side of the flow channel layer 400 is provided with a fluid channel 460 and three flow structures arranged in sequence; the three flow structures are respectively a first parallel flow structure 410, a second parallel flow structure 420, and a third parallel flow structure 430; the fluid channel 460 extends along the length direction of the pumping air chamber; the three flow structures are arranged in sequence along the length direction of the pumping air chamber. The fluid channel 460 crosses the three flow structures. The outer ends of the three flow structures are connected to the external environment. The inner ends of the three flow structures are connected to the pumping air chamber.

[0056] The pumping chamber is divided into three interconnected working areas along its length: two intake areas and a discharge area located between the two intake areas. The two intake areas are aligned with the first parallel flow structure 410 and the third parallel flow structure 430, respectively. The discharge area is aligned with the second parallel flow structure 420.

[0057] The actuator plate 100 is fixedly connected to the reinforcement plate 200, and the reinforcement plate 200 is fixed at the center position of the upper surface of the diaphragm layer 300. The lower surface of the diaphragm layer 300 is fixedly connected to the upper surface of the flow channel layer 400; the lower surface of the flow channel layer 400 is fixedly connected to the upper surface of the resonance layer 500. When the actuator plate 100 vibrates through the piezoelectric effect, it will drive the reinforcement plate 200, and the reinforcement plate 200 will drive the diaphragm layer 300, and the resonance layer 500 will vibrate in the opposite direction of the diaphragm layer 300; thereby, the actuator plate 100, the reinforcement plate 200, the diaphragm layer 300, and the resonance layer 500 vibrate together.

[0058] Figure 2 This is an isometric diagram of a valveless micropump based on a parallel double-vibration plate of the present invention, which specifically shows the connection relationship and component structure of the valveless micropump provided by this embodiment, such as Figure 2 As shown, in this embodiment, all components of the valveless micropump except the actuator 100 are made of stainless steel; in some other embodiments, all components of the valveless micropump except the actuator 100 may also be made of carbon fiber.

[0059] The actuator plate 100, reinforcement plate 200, diaphragm layer 300, flow channel layer 400, and resonant layer 500 are all rectangular. The actuator plate 100 and reinforcement plate 200 are of the same size and shape. The diaphragm layer 300, flow channel layer 400, and resonant layer 500 are of the same size and shape. The area of ​​the actuator plate 100 and reinforcement plate 200 is smaller than that of the diaphragm layer 300, flow channel layer 400, and resonant layer 500. The actuator plate 100 and reinforcement plate 200 are fixedly connected to the center of the diaphragm layer 300. Figure 1As shown, the diaphragm layer 300 is the thinnest, the sum of the thicknesses of the actuator plate 100 and the reinforcement plate 200 is greater than the thickness of the diaphragm layer 300 and less than the thickness of the resonance layer 500 ; the thickness of the resonance layer 500 is less than the thickness of the flow channel layer 400 .

[0060] The diaphragm layer 300 is symmetrically provided with two first slits 310 extending vertically through the diaphragm layer 300. The first slits 310 extend along the length of the diaphragm layer 300 and are not connected to either end of the diaphragm layer 300. The two first slits 310 are spaced apart along the width of the diaphragm layer 300 and are aligned with the left and right side walls of the pumping chamber within the flow channel layer 400. The two first slits 310 are symmetrical about the midline of the diaphragm layer 300.

[0061] A plurality of flow holes 320 are provided on the side of the diaphragm layer 300. Each flow hole 320 is aligned with and communicates with a corresponding fluid channel 460. Each flow hole 320 is staggered with the three flow-through structures.

[0062] In some embodiments, the circulation holes 320 are in a waist-shaped hole structure, that is, a rectangle with rounded edges on both sides; the number of the circulation holes 320 is six; the six circulation holes 320 include two large circulation holes 320 of the same area and four small circulation holes 320 of the same area; the two large circulation holes 320 of the same area are respectively located between the first parallel flow structure 410 and the second parallel flow structure 420, and between the second parallel flow structure 420 and the third parallel flow structure 430; the four small circulation holes 320 of the same area are respectively located on the side of the first parallel flow structure 410 and the third parallel flow structure 430 away from the second parallel flow structure 420.

[0063] Figure 3 This is an enlarged view of point A in the isometric diagram of a valveless micropump based on parallel double oscillating plates of the present invention. Figure 4 This is an exploded view of a valveless micropump based on a parallel double-vibration plate of the present invention, which specifically shows the specific structure of the gap of the valveless micropump in this embodiment; in this embodiment, as Figure 3 and Figure 4 As shown, the resonant layer 500 is provided with two second slits 510 extending vertically through the resonant layer 500. The two first slits 310 are aligned with the two second slits 510. The first slits 310 and the second slits 510 are both extremely narrow and elongated strips. The first slits 310 and the second slits 510 have the same cross-sectional shape, i.e., the same length and width. Because the thickness of the diaphragm layer 300 is less than that of the resonant layer 500, the first slits 310 and the second slits 510 have different thicknesses.

[0064] Since the flow channel layer 400 has a hollow pump air chamber inside, there is no obstruction between the first gap 310 and the second gap 510, and the valveless micropump is completely connected from top to bottom; the length of the first gap 310 and the second gap 510 is greater than the length of the actuator plate 100 and the reinforcement plate 200, and is smaller than the length of the diaphragm layer 300, the flow channel layer 400 and the resonance layer 500; the width of the first gap 310 and the second gap 510 is much smaller than the overall width of the diaphragm layer 300 and the resonance layer 500. In this embodiment, the width of the first gap 310 and the second gap 510 is 2 microns.

[0065] The two first slits 310 extending through the diaphragm layer 300 form a first diaphragm structure in the middle of the diaphragm layer 300, with fixed ends and a free center. The two second slits 510 extending through the resonant layer 500 form a second diaphragm structure in the middle of the resonant layer 500, with fixed ends and a free center. The first and second diaphragm structures are aligned with the pump chamber and have the same cross-section.

[0066] The first slit 310 and the second slit 510 form free edges on both sides of the first and second oscillating plate structures, respectively, thereby effectively increasing the amplitude of the valveless micropump during vibration and improving the pumping air flow rate. Simultaneously, the first and second oscillating plate structures vibrate in opposite directions in a wave-like manner during operation, forming three sequentially arranged intermittent flow-limiting sites in the pumping air chamber: the first intermittent flow-limiting site, the second intermittent flow-limiting site, and the third intermittent flow-limiting site. The intermittent flow-limiting sites described in this embodiment are not specific structural descriptions, but rather designations for locations that can naturally approach and form flow limits during vibration.

[0067] In some other embodiments, the number of the intermittent current limiting sites is other than three, such as 1, 2, 4, 5, or 6.

[0068] As the opposing sides of the first and second oscillating plate structures periodically move away from and toward each other at the intermittent flow-limiting sites, the first and third intermittent flow-limiting sites move away and toward each other synchronously (with the same phase), while the first and second intermittent flow-limiting sites move away and toward each other asynchronously (with a 180° phase difference). The three intermittent flow-limiting sites are aligned with the three flow-through structures. When the gap between the intermittent flow-limiting sites decreases (the diaphragm layer 300 and the resonant layer 500 move closer together), the flow resistance of the corresponding flow-through structures increases significantly, thereby enabling automatic control of the gas flow direction in the valveless micropump. Consequently, the pumping chambers at the three intermittent flow-limiting sites are capable of periodic conduction and flow restriction with vibration. Due to the vibration characteristics of the actuator 100, reinforcement plate 200, diaphragm layer 300, and resonant layer 500, the flow-through and flow-limiting states of the intermittent flow-limiting sites on the sides are 180° out of phase with the intermittent flow-limiting site in the center.

[0069] Figure 4 This is an exploded view of a valveless micropump based on a parallel double-vibration plate of the present invention, which specifically shows the structure of each layer in this embodiment. In this embodiment, Figure 4 As shown, the flow channel layer 400 includes a fixed portion 440 and a flow portion 450. The flow portion 450 is not connected to the fixed portion 440, but is connected and fixed to the diaphragm layer 300 above the flow channel layer 400 and the resonance layer 500 below the flow channel layer 400; a flow structure is formed between the flow portion 450 and the fixed portion 440.

[0070] In this embodiment, all flow-through structures are arranged on the same side of the flow channel layer 400; the other side of the flow channel layer 400 is completely closed, that is, the porous side-outlet valveless micropump in this embodiment takes in and out air from the same side.

[0071] In some embodiments, stress slits 900 are formed through the diaphragm layer 300, the flow channel layer 400, and the resonator layer 500. These stress slits 900 surround the pumping chamber and are not connected to the pumping chamber. These stress slits 900 employ an intermittent, surrounding structure, whereby multiple stress slits 900 are sequentially and discontinuously connected to form a ring around the pumping chamber (with gaps between adjacent stress slits 900). This prevents the interior and exterior areas of the diaphragm layer 300, the flow channel layer 400, and the resonator layer 500 from being completely isolated. These stress slits 900 disperse the stress of the diaphragm layer 300, the flow channel layer 400, and the resonator layer 500 around each stress slit 900, preventing excessive stress concentration in the through-hole structures of the diaphragm layer 300, the flow channel layer 400, and the resonator layer 500, which could lead to localized excessive stress. Therefore, the stress slits 900 help improve the stability of the valveless micropump during long-term operation and extend the service life of the piezoelectric micropump.

[0072] The working process of a valveless micropump based on a parallel double-vibration plate provided in this embodiment is: a periodic electrical signal of a preset frequency is passed into the actuator plate 100, so that the diaphragm layer 300 and the resonance layer 500 undergo reverse periodic vibration, driving the gas to flow in from the first parallel flow structure 410 and the third parallel flow structure 430, and to flow out from the second parallel flow structure 420, thereby realizing continuous pumping action.

[0073] Each vibration cycle of the actuator plate 100 is divided into a fluid output process and a fluid intake process.

[0074] Figure 5 This is a diagram showing the vibration principle of the valveless micro pump provided in this embodiment during the fluid output process. Figure 5The fluid output process is as follows: when the middle part of the actuator plate 100 vibrates upward through the piezoelectric effect, it drives the middle part of the reinforcement plate 200 to vibrate upward, and the actuator plate 100 and the reinforcement plate 200 drive the middle part of the diaphragm layer 300 below (corresponding to the second discontinuous current limiting position) to vibrate upward, and the middle part of the resonance layer 500 below the diaphragm layer 300 (corresponding to the second discontinuous current limiting position) vibrates downward. At this time, the volume of the middle part of the pump air chamber (corresponding to the second discontinuous current limiting position) increases; and the two sides of the diaphragm layer 300 (corresponding to the first and third discontinuous current limiting positions) are driven by the two side parts of the actuator plate 100 and the reinforcement plate 200, and the two sides of the corresponding resonance layer 500 (corresponding to the first and third discontinuous current limiting positions) are bent downward; The volume of the two side areas in the air chamber (corresponding to the first and third intermittent flow limiting sites) decreases and the pressure increases; at the same time, the diaphragm layer 300 and the resonance layer 500 approach each other at the first and third intermittent flow limiting sites to limit the flow, so that the flow resistance at the first parallel flow structure 410 and the third parallel flow structure 430 increases; under the action of the pressure difference, the fluid flows from both sides of the pump air chamber to the middle (that is, from the first and third intermittent flow limiting sites to the second intermittent flow limiting site), and then flows outward at high speed through the second parallel flow structure 420, thereby realizing the outward output of the fluid; after the flow resistance at the first and third intermittent flow limiting sites increases, only a small amount of fluid is inhaled or flows out from the first parallel flow structure 410 and the third parallel flow structure 430.

[0075] Figure 6 This is a diagram showing the vibration principle of the valveless micro pump provided in this embodiment during the fluid suction process. Figure 6 The fluid suction process is as follows: when the middle part of the actuator plate 100 vibrates downward through the piezoelectric effect, it drives the middle part of the reinforcement plate 200 to vibrate downward. The middle parts of the actuator plate 100 and the reinforcement plate 200 drive the middle part of the diaphragm layer 300 below (corresponding to the second discontinuous current limiting position) to vibrate downward, and the middle part of the resonance layer 500 below the diaphragm layer 300 (corresponding to the second discontinuous current limiting position) vibrates upward. At this time, the volume of the middle part of the pump air chamber (corresponding to the second discontinuous current limiting position) decreases; and the two sides of the diaphragm layer 300 (corresponding to the first and third discontinuous current limiting positions) are driven by the two sides of the actuator plate 100 and the reinforcement plate 200 to bend upward, corresponding to the resonance layer 500. 0 (corresponding to the first and third discontinuous flow-limiting positions) bend downward; the volume of the two side areas in the pump air chamber (corresponding to the first and third discontinuous flow-limiting positions) increases and the pressure decreases; at the same time, the diaphragm layer 300 and the resonance layer 500 approach each other at the second discontinuous flow-limiting position, so that the flow resistance of the second parallel flow-through structure 420 increases; under the action of the pressure difference, the external fluid of the valveless micropump flows into the pump air chamber from the first parallel flow-through structure 410 and the third parallel flow-through structure 430 under the action of the pressure difference, thereby realizing the inward suction of the fluid; after the flow resistance at the second discontinuous flow-limiting position increases, only a small amount of fluid is sucked in or flows out of the second parallel flow-through structure 420.

[0076] Example 2

[0077] This embodiment provides a valveless micropump based on parallel double diaphragms with vertical air outlet; the valveless micropump has a rectangular structure, and the width side of the valveless micropump extends in the front-to-back direction, and the length side extends in the left-to-right direction.

[0078] This embodiment provides a valveless micropump based on parallel dual-vibration plates, which is substantially similar to that of Embodiment 1, except that it also includes a rectifying layer 600. The flow channel layer 400 lacks a flow-through structure on its sides; instead, the resonant layer 500 and rectifying layer 600 each have three vertical flow holes in their central portions. The aligned flow holes on the resonant layer 500 and rectifying layer 600 form a flow-through structure that connects the resonant layer 500 to the external environment.

[0079] like Figure 7 、 Figure 8 and Figure 9 As shown, this embodiment provides a valveless micropump based on a parallel dual-diaphragm structure, comprising an actuator plate 100, a reinforcement plate 200, a diaphragm layer 300, a flow channel layer 400, a resonant layer 500, and a rectifying layer 600 stacked in order from top to bottom. The actuator plate 100 and reinforcement plate 200 have smaller areas than the diaphragm layer 300, flow channel layer 400, and resonant layer 500.

[0080] The flow channel layer 400 is internally provided with a rectangular groove that runs vertically through the flow channel layer 400. The opposing sides of the diaphragm layer 300 and the resonance layer 500, along with the sidewalls of the rectangular groove within the flow channel layer 400, form the pumping chamber 700. The grooves on the upper surfaces of the resonance layer 500 and the rectifying layer 600 form the output chamber 800.

[0081] In this embodiment, the diaphragm layer 300, the flow channel layer 400, and the resonant layer 500 are each provided with one or more aligned flow holes. In some preferred embodiments, the flow holes are located at the left and right ends of the diaphragm layer 300, the flow channel layer 400, and the resonant layer 500, with two holes at each end, meaning that each layer has four flow holes: four first flow holes 330 on the diaphragm layer 300, four second flow holes 410 on the flow channel layer 400, and four third flow holes 530 on the resonant layer 500. The flow holes have the same overall area and extend through the entire layer. Two fluid channels 640 are provided at each end of the groove structure on the rectifying layer 600. The four fluid channels 640 are aligned with and connected to the four third flow holes 530. The fluid channels 640 are rectangular with rounded edges, completely surrounding the flow holes. Each flow hole and fluid channel 640 connects both ends of the output chamber 800 to the external environment.

[0082] The central portion of the rectifying layer 600 is provided with three vertically arranged flow structures, spaced apart along the length of the valveless micropump: a first external flow hole 610, a second external flow hole 620, and a third external flow hole 630. The resonant layer 500 is provided with three internal flow holes 520, aligned with the first external flow hole 610, the second external flow hole 620, and the third external flow hole 630, respectively. The apertures of the internal flow holes 520 are smaller than those of the corresponding external flow holes.

[0083] The diaphragm layer 300 and the resonant layer 500 are respectively provided with a first slit 310 and a second slit 510, which are consistent with those in Example 1. A first diaphragm structure is formed between the two first slits 310. A second diaphragm structure is formed between the two second slits 510. The first diaphragm structure and the second diaphragm structure vibrate in opposite directions in a wave-like manner, forming three sequentially arranged intermittent flow-limiting sites in the pump air chamber 700. The three intermittent flow-limiting sites are aligned with the three internal flow holes 520; when the diaphragm layer 300 and the resonant layer 500 approach each other at the intermittent flow-limiting sites, the flow resistance of the corresponding internal flow holes 520 increases.

[0084] The working process of the valveless micropump based on parallel dual-vibration plates provided in this embodiment is: a periodic electrical signal of a preset frequency is passed to the actuator plate 100, so that the diaphragm layer 300 and the resonance layer 500 vibrate periodically in opposite directions, thereby achieving continuous pumping action.

[0085] Each vibration cycle of the actuator plate 100 is divided into a fluid intake process and a fluid output process.

[0086] like Figure 10As shown, in this embodiment, the fluid suction process is as follows: when the middle part of the actuator plate 100 vibrates upward due to the piezoelectric effect, it drives the middle part of the reinforcement plate 200 to vibrate upward, and the actuator plate 100 and the reinforcement plate 200 drive the middle part of the diaphragm layer 300 below (corresponding to the second discontinuous current limiting position) to vibrate upward, and the middle part of the resonant layer 500 below the diaphragm layer 300 (corresponding to the second discontinuous current limiting position) vibrates downward. At this time, the middle part of the pump air chamber 700 (corresponding to the second discontinuous current limiting position) The volume of the pumping chamber 700 increases. Driven by the actuator plate 100 and the reinforcement plate 200, the two sides below the diaphragm layer 300 (corresponding to the first and third discontinuity flow-limiting locations) bend downward, while the two sides of the corresponding resonant layer 500 (corresponding to the first and third discontinuity flow-limiting locations) bend upward. The volume of the two sides of the pumping chamber 700 (corresponding to the first and third discontinuity flow-limiting locations) decreases, and the pressure increases. Simultaneously, the diaphragm layer 300 and the resonant layer 500 move closer together at the first and third discontinuity flow-limiting locations. Meanwhile, the diaphragm layer 300 and the resonant layer 500 move away from each other at the second discontinuity flow-limiting location. Due to the pressure differential, fluid flows from the outside at the bottom through the second external flow hole 620 into the center of the pumping chamber 700. Simultaneously, the external fluid at the top enters the two sides of the output chamber 800 through the flow holes on both sides of the valveless micropump, as well as the first and third external flow holes 610 and 610.

[0087] like Figure 11 As shown, in this embodiment, the fluid output process is as follows: when the middle part of the actuator plate 100 vibrates downward due to the piezoelectric effect, it drives the middle part of the reinforcement plate 200 to vibrate downward, and the middle parts of the actuator plate 100 and the reinforcement plate 200 drive the middle part of the diaphragm layer 300 below (corresponding to the second discontinuous current limiting position) to vibrate downward, and the middle part of the resonant layer 500 below the diaphragm layer 300 (corresponding to the second discontinuous current limiting position) vibrates upward. At this time, the volume of the middle part of the pump air chamber 700 (corresponding to the second discontinuous current limiting position) is reduced; and the two sides of the diaphragm layer 300 (corresponding to the first and third intermittent current limiting positions) bend upward under the drive of the two side parts of the actuator plate 100 and the reinforcement plate 200, and the two sides of the corresponding resonance layer 500 (corresponding to the first and third intermittent current limiting positions) bend downward; the volume of the two side areas in the pump air chamber 700 (corresponding to the first and third intermittent current limiting positions) increases and the pressure decreases; at the same time, the diaphragm layer 300 and the resonance layer 500 are close to each other at the second intermittent current limiting position, and the airflow in the middle of the output chamber 800 is difficult to enter the pump air chamber 700, and is then output outward from the second external flow hole 620.

[0088] Example 3

[0089] This embodiment provides a valveless micropump based on parallel double diaphragms with vertical air outlet; the valveless micropump has a rectangular structure, and the width side of the valveless micropump extends in the front-to-back direction, and the length side extends in the left-to-right direction.

[0090] This embodiment provides a valveless micropump based on a parallel double-vibration plate, which is substantially the same as that of embodiment 3, except that: Figure 12 As shown, only a first external through-hole 610 is provided at the center of the rectifying layer 600. Only one internal through-hole 520 aligned with the first external through-hole 610 is provided on the resonant layer 500.

[0091] Each vibration cycle of the actuator plate 100 is divided into a fluid intake process and a fluid output process.

[0092] like Figure 13 As shown, in this embodiment, the fluid intake process is as follows: when the middle of the actuator plate 100 vibrates downward due to the piezoelectric effect, it drives the middle of the reinforcement plate 200 to vibrate downward. The middle of the actuator plate 100 and the reinforcement plate 200 drive the middle of the diaphragm layer 300 below to vibrate downward, and the middle of the resonant layer 500 to vibrate upward. Driven by the two side parts of the actuator plate 100 and the reinforcement plate 200, the two sides of the diaphragm layer 300 bend upward, and the two sides of the resonant layer 500 bend downward. During this process, the external fluid enters the pump air chamber and the output chamber through the first external flow hole 610 and the internal flow hole 520. At the same time, the external fluid at the top enters the two side areas of the output chamber through the flow holes on both sides of the valveless micropump.

[0093] like Figure 14 As shown, in this embodiment, the fluid output process is as follows: when the middle portion of the actuator plate 100 vibrates upward due to the piezoelectric effect, it drives the middle portion of the reinforcement plate 200 to vibrate upward. The actuator plate 100 and the reinforcement plate 200 drive the middle portion of the diaphragm layer 300 below to vibrate upward, and the middle portion of the resonant layer 500 to vibrate downward. Driven by the two side portions of the actuator plate 100 and the reinforcement plate 200, the two sides below the diaphragm layer 300 bend downward, while the two sides of the resonant layer 500 bend upward. During this process, the fluid in the pumping chamber and the output chamber is output through the first external flow hole 610 and the internal flow hole 520. At the same time, the external fluid at the top continues to enter the two side areas of the output chamber through the flow holes on both sides of the valveless micropump.

[0094] Compared with Example 2, this embodiment is more likely to cause louder noise.

[0095] Example 4

[0096] This embodiment provides a valveless micropump based on parallel double diaphragms with vertical air outlet; the valveless micropump has a rectangular structure, and the width side of the valveless micropump extends in the front-to-back direction, and the length side extends in the left-to-right direction.

[0097] This embodiment provides a valveless micropump based on a parallel double-vibration plate, which is substantially the same as that of embodiment 1, except that: Figure 15As shown, the flow channel layer 400 is provided with only one parallel flow structure located in the middle.

[0098] In this embodiment, the valveless micropump draws fluid inward when the middle portion of the actuator plate 100 vibrates downward, and discharges fluid outward when the middle portion of the actuator plate 100 vibrates upward.

[0099] Example 5

[0100] like Figure 16 As shown, an array pumping structure includes multiple valveless micropumps arranged in a matrix or array. The valveless micropumps are the valveless micropumps provided in Example 1, 2, 3, or 4. In this embodiment, there are eight valveless micropumps arranged in a 4×2 rectangular pattern. In other embodiments, the number and arrangement of the valveless micropumps are not limited, and other arrangements besides 4×2 may be used, such as 2×1, 3×1, 4×1, or 2×2.

Claims

1. A valveless micropump based on a parallel double-vibration plate, comprising a stacked vibration element, a vibration membrane layer (300), a flow channel layer (400) and a resonance layer (500); characterized in that: The opposite sides of the diaphragm layer (300) and the resonance layer (500) and the side walls of the groove body in the flow channel layer (400) are enclosed to form a pumping air chamber; the diaphragm layer (300) and the resonance layer (500) are each provided with two slits spaced apart to form a vibration plate structure with fixed ends and a free middle; the vibration plate structure corresponds to the position of the pumping air chamber; the vibration element is used to drive the diaphragm layer (300) and the resonance layer (500) to perform synchronous and reverse wave-shaped vibrations; the vibrating diaphragm layer (300) and the resonance layer (500) periodically move away from and approach each other at one or more discontinuous flow limiting locations; and a flow-through structure connected to the external environment is provided at the locations where some or all of the discontinuous flow limiting locations are located.

2. The valveless micropump according to claim 1, wherein: The two side edges of the vibration plate structure are aligned with the two side walls of the pumping chamber respectively.

3. The valveless micropump according to claim 1, wherein: The vibration element and the vibration plate structure are both rectangular; the vibration element is fixed on the vibration plate structure of the diaphragm layer (300).

4. The valveless micropump according to claim 1, wherein: The number of the intermittent flow limiting sites is three; the number of the through-flow structures is one or three; the through-flow structures are arranged on the side of the flow channel layer (400); when the number of the through-flow structures is one, the through-flow structure is aligned with the intermittent flow limiting site located in the middle; when the number of the through-flow structures is three, the three through-flow structures are aligned with the three intermittent flow limiting sites respectively.

5. The valveless micropump according to claim 4, characterized in that: A fluid channel (460) is provided on the side of the flow channel layer (400); the fluid channel (460) crosses the flow structure; a plurality of flow holes (320) are provided on the side of the diaphragm layer (300); each flow hole (320) is connected to the fluid channel (460); and each flow hole (320) is staggered with the flow structure.

6. The valveless micropump according to claim 1, wherein: The diaphragm layer (300), the flow channel layer (400) and the resonance layer (500) are all provided with stress seams (900) surrounding the pumping chamber.

7. The valveless micropump according to claim 1, wherein: The device further comprises a rectifying layer (600); the rectifying layer (600) is connected to the side of the resonance layer (500) facing away from the flow channel layer (400); one or more groups of mutually aligned through holes are provided on the resonance layer (500) and the rectifying layer (600), forming a flow structure communicating with the external environment; the groove structures on the resonance layer (500) and the rectifying layer (600) are combined to form an output chamber (800).

8. The valveless micropump according to claim 7, characterized in that: Both ends of the output chamber (800) are in communication with the external environment via flow holes provided in the vibration element, the diaphragm layer (300), and the flow channel layer (400).

9. The valveless micropump according to claim 1, characterized in that: The vibration element comprises an actuating plate (100) and a reinforcing plate (200) which are stacked.

10. A gas pumping method, characterized in that: A valveless micropump as claimed in claim 1 is used; the number of intermittent flow-limiting sites of the valveless micropump is three; the air pumping method comprises: introducing a periodic electrical signal into the vibration element to drive the diaphragm layer (300) and the resonance layer (500) to perform synchronous and reverse wave-shaped vibrations, and the intermittent flow-limiting sites on both sides and the intermittent flow-limiting site in the middle alternately move away from and approach each other; and the flow structure corresponding to each intermittent flow-limiting site periodically inhales air inward or pumps air outward.

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