MEMS air-cooled heat dissipation device and method of using the same

Abstract

The present invention provides a MEMS air-cooled heat dissipation device and its use method, comprising: a housing, a microvalve assembly, and a motion actuator assembly. The microvalve assembly includes a cantilever beam, a first diaphragm, and an air chamber. The cantilever beam is attached to an actuator to generate a driving force in the normal direction on the cantilever beam, thereby utilizing the cantilever beam to selectively open or close a through hole. The motion actuator assembly includes a second diaphragm attached to the housing to separate a first fluid chamber from a second fluid chamber. The second diaphragm includes an opening, and a diaphragm and a piezoelectric actuator are arranged across the opening. The present invention utilizes the actuator and cantilever beam to construct an active one-way microvalve assembly. The microvalve assembly, in conjunction with the motion actuator assembly, guides cooling gas unidirectionally toward a fluid chamber adjacent to the hot end of the electronic device, thereby discharging heated air and achieving a heat dissipation effect. Utilizing the high operating frequency of the piezoelectric film layer, the ultrasonic waves generated by the vibration are inaudible, resulting in the advantages of being noiseless and having low power consumption.

Description

Technical Field

[0001] The present invention relates to the field of digital sound generation, and in particular to a MEMS heat dissipation device and a method for using the same. Background Art

[0002] With the development of consumer electronics and semiconductor technology, electronic products are trending towards miniaturization and high performance. Electronic products generate a large amount of heat during operation. If heat is not dissipated in a timely manner, the accumulated heat will cause the temperature to rise rapidly, seriously affecting the operating efficiency of electronic components and even damaging the electronic products.

[0003] Currently, electronic products often use cooling fans to dissipate heat. These fans generate airflow, transferring the high-temperature air near the hot end of the electronic product to the surrounding air through convection to assist in heat dissipation. This cooling method requires a mechanical fan design, and the size and noise of the cooling system limit its design and application in miniaturized electronic products.

[0004] It should be noted that the above technical background is merely provided to provide a clear and complete description of the technical solutions of the present invention and to facilitate understanding by those skilled in the art. Simply because these solutions are described in the technical background section of the present invention, it should not be assumed that the above technical solutions are well known to those skilled in the art. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a MEMS air-cooled heat sink and a method of using the same, so as to solve the problems of the existing heat dissipation fan being large in size and making obvious noise during operation.

[0006] To achieve the above-mentioned and other related objectives, the present invention provides a MEMS air-cooled heat sink, comprising:

[0007] A housing, the housing including a base, the housing being provided with an air inlet end and an air outlet end, the air inlet end being configured to introduce cooling gas;

[0008] A one-way microvalve assembly, comprising a cantilever beam, a first diaphragm, and an air chamber separated by the first diaphragm, wherein the air inlet end is fluidically connected to the air chamber, a through hole on the first diaphragm is aligned with the cantilever beam to connect the air chamber fluid to the first fluid chamber, and a first actuator is attached to the cantilever beam to generate a driving force in a normal direction on the cantilever beam to achieve an opening or closing operation of the through hole;

[0009] a motion execution assembly comprising a stacked second diaphragm, a diaphragm, and a second actuator, wherein the second diaphragm is attached to the housing to separate a first fluid chamber and a second fluid chamber, an opening being formed on the second diaphragm, and at least a portion of the diaphragm is suspended above the opening to bend under the drive of the second actuator, thereby achieving unidirectional flow of cooling gas along a first flow path, wherein the first flow path comprises flow from the air chamber through the first fluid chamber and into the second fluid chamber;

[0010] The second actuator is a piezoelectric actuator, the base is removably attached to the hot end of the electronic device, and the exhaust end is configured to provide fluid communication between the second fluid chamber and the external environment.

[0011] Optionally, the shell includes a top cover, the cantilever beam includes a fixed part and a movable part, the fixed part is anchored on the top cover, and the movable part is suspended above the first partition and in direct contact with the first actuator; wherein, the first actuator includes one of an electrostatic actuator and a piezoelectric actuator.

[0012] Optionally, the first actuator and the cantilever beam constitute an electrostatic ultrasonic transducer, which includes a top electrode attached to the cantilever beam and a bottom electrode mounted near the through hole. When a driving signal is applied between the top electrode and the bottom electrode, the movable part of the cantilever beam vibrates back and forth around its fixed part toward or away from the first partition, thereby opening or closing the through hole.

[0013] Optionally, the second partition plate includes a vent hole offset relative to the through hole, for providing fluid communication between the first fluid chamber and the second fluid chamber.

[0014] Optionally, a control unit is further included, which is electrically connected to the first actuator and is used to provide a driving signal instructing the opening or closing of the one-way microvalve assembly.

[0015] Optionally, the motion execution component is configured as a piezoelectric micromechanical ultrasonic transducer, and the control unit is electrically connected to the piezoelectric micromechanical ultrasonic transducer to draw the cooling gas into the first fluid chamber when the diaphragm moves to a negative phase; or, to push the cooling gas from the first fluid chamber into the second fluid chamber when the diaphragm moves to a positive phase.

[0016] Optionally, the exhaust port is configured as an opening located on a side wall of the second fluid chamber, for providing fluid communication between the second fluid chamber and an external environment.

[0017] Optionally, the air inlet end and the through hole are provided on opposite sides of the air chamber; wherein the air inlet end is provided as a plurality of air inlet holes passing through the top cover.

[0018] The present invention also provides a method for using a MEMS air-cooled heat sink, comprising the following steps:

[0019] Attach the aforementioned MEMS air-cooled heat sink to the hot end of the electronic device;

[0020] The control unit applies a pulse sequence of a first driving signal and a second driving signal to the first actuator and the second actuator respectively, so that the cantilever beam and the diaphragm vibrate back and forth, wherein each pulse cycle includes a first time interval and a second time interval: wherein,

[0021] During the first time interval, by making the second driving signal applied to the second actuator have a negative pulse phase, cooling gas is introduced through the air inlet end while the one-way microvalve component remains open;

[0022] During the second time interval, a first driving signal is applied to the first actuator, causing the microvalve assembly to close to airtightly isolate the air chamber from the first fluid chamber, and at the same time, a second driving signal applied to the second actuator has a positive pulse phase, causing a portion of the introduced cooling gas to flow from the first fluid chamber through the second fluid chamber and be discharged to the external environment.

[0023] Optionally, a plurality of MEMS air-cooled heat sinks are arranged in an array at the hot end of the electronic device, each of the plurality of MEMS air-cooled heat sinks having a lateral opening, and the plurality of MEMS air-cooled heat sinks are arranged so that the lateral opening of any MEMS air-cooled heat sink has an opening direction staggered with the lateral opening of an adjacent MEMS air-cooled heat sink.

[0024] As described above, the MEMS air-cooled heat sink of the present invention utilizes an actuator and a cantilever beam to construct an active one-way microvalve assembly, which cooperates with the motion execution assembly to guide the cooling gas in one direction to the fluid chamber adjacent to the hot end of the electronic device, thereby discharging the heated air to achieve a heat dissipation effect; the operating frequency of the piezoelectric film layer of the present invention is extremely high, and the ultrasonic wave generated by the vibration is inaudible. Compared with traditional air-cooled heat sinks, it has the advantages of no noise and low power consumption.

[0025] The MEMS air-cooled heat sink of the present invention is used by attaching one or more MEMS air-cooled heat sinks to the hot end of an electronic device, and utilizing the cooperation of a one-way microvalve assembly and a motion actuator assembly to guide the cooling gas to a fluid chamber adjacent to the hot end of the electronic device, thereby improving the convective heat exchange efficiency with the heated air. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a structural schematic diagram of an example of a MEMS air-cooled heat dissipation device according to an embodiment of the present invention.

[0027] Figure 2 Shown is a structural schematic diagram of another example of a MEMS air-cooled heat sink according to an embodiment of the present invention.

[0028] Figure 3 Shown is an exemplary top view of a MEMS air-cooled heat sink according to an embodiment of the present invention.

[0029] Figure 4 shows Figure 3 The working state diagram of the MEMS air-cooled heat sink is shown in FIG. 1 , wherein, Figure 4A For a three-dimensional isometric diagram, Figure 4B For the Figure 4A Cutaway view of the section shown.

[0030] Figure 5 shows Figure 3 The MEMS air-cooled heat sink shown in the figure is in the working state of discharging heated air; wherein, Figure 5A For a three-dimensional isometric diagram, Figure 5B For the Figure 5A Cutaway view of the section shown.

[0031] Figure 6 Schematic diagram showing an array arrangement of MEMS air-cooled heat sinks according to an embodiment of the present invention.

[0032] Figure 7 Shown are relevant signal waveforms in the method of using the MEMS air-cooled heat sink according to an embodiment of the present invention.

[0033] Explanation of component numbers: 10-air chamber; 20-first fluid chamber; 30-second fluid chamber; 11-top cover; 12-cantilever beam; 13-electrostatic actuator; 101-air inlet; 21-first partition; 31-second partition; 32-diaphragm; 33-piezoelectric actuator; 211-through hole; 311-exhaust hole; 301-exhaust end; 41-base; g-heated air; t1-first time interval; t2-second time interval. DETAILED DESCRIPTION

[0034] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] See also Figures 1 to 7It should be noted that the illustrations provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the form, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0036] The present invention provides a MEMS air-cooled heat dissipation device, comprising a shell, a one-way microvalve assembly and a motion execution assembly, wherein the shell is provided with an air inlet end and an exhaust end, and the air inlet end is configured to introduce cooling gas; the one-way microvalve assembly comprises a cantilever beam, a first partition and an air chamber separated by the first partition, and is used to open or close the flow path from the air inlet end to the first fluid chamber.

[0037] The one-way microvalve assembly includes an air chamber, the air inlet end is connected to the one-way microvalve assembly to introduce cooling gas into the air chamber, and the cantilever beam is attached with a first actuator to generate a driving force in the normal direction on the cantilever beam to realize the opening or closing operation of the through hole. Figure 1 and Figure 2 Schematic diagrams of the structures of MEMS air-cooled heat sinks are shown. In some examples, the first actuator is configured as an electrostatic actuator, which drives the cantilever beam to vibrate back and forth toward and away from the first diaphragm when a drive signal (e.g., a drive voltage) is applied between its top and bottom electrodes. Alternatively, the first actuator can be configured as a piezoelectric film-based actuator.

[0038] like Figure 1 As shown, the shell includes a top cover 11, and the top cover 11, the cantilever beam 12 and the first partition 21 jointly define the air chamber 10. The cantilever beam 12 includes a fixed part and a movable part. The fixed part is anchored on the top cover 11, and the movable part is suspended above the first partition and is in direct contact with the electrostatic actuator 13. The through hole 211 on the first partition 21 is aligned with the cantilever beam to connect the fluid of the air chamber 10 to the first fluid chamber 20.

[0039] The fixed portion of the cantilever beam can be anchored to the top cover 11, and an air inlet end and the through hole 211 are provided on opposite sides of the air chamber. In some examples, the air inlet end is provided as a plurality of air inlet holes penetrating the top cover 11, such as Figure 3 As shown, the air inlet holes 101 are offset relative to the through holes along the spacing direction between the top cover and the first partition. The shape and arrangement of the air inlet holes 101 can be adjusted according to actual needs, for example, they can be circular, square, hexagonal or similar shaped openings arranged in an array. In a preferred example, as Figure 3As shown, the top cover 11 is generally configured as a disc-shaped top cover, and is provided with a plurality of radially arranged air inlet holes 101. Furthermore, the number of the cantilever beams 12 and the connection method with the top cover can be flexibly adjusted according to needs, for example, at least one cantilever beam with double ends fixed, or at least two cantilever beams with single ends. Figure 3 As shown, the cantilever beam 12 is configured as a cantilever beam fixed at one end. A plurality of cantilever beams 12 are attached around the electrostatic actuator 13 , and the gaps between adjacent cantilever beams can also be used to introduce cooling gas.

[0040] Alternatively, as an alternative implementation, the top cover 11 itself is made of a breathable material, such as polytetrafluoroethylene (PTFE).

[0041] The motion execution component is configured to receive the cooling gas introduced by the one-way microvalve component and guide a portion of the introduced cooling gas from the first fluid chamber to the second fluid chamber. The motion execution component includes a stacked second partition, a diaphragm, and a second actuator. The second partition is attached to the housing to separate the first fluid chamber from the second fluid chamber, and an opening is opened in the second partition. Figure 1 As shown, the second actuator can be a piezoelectric actuator 33. A first fluid chamber 20 is defined between a first diaphragm 21 and a second diaphragm 31. The first diaphragm 21 and the second diaphragm 31 can be attached to the housing. The second diaphragm 31 includes an opening formed therein, and a diaphragm 32 and a piezoelectric actuator 33 are arranged across the opening. At least a portion of the diaphragm is suspended above the opening and, driven by the piezoelectric actuator, bends to achieve unidirectional flow of cooling gas along a first flow path, thereby directing the cooling gas from the air chamber 10 to the first fluid chamber 20 and a portion of the introduced cooling gas from the first fluid chamber 20 to the second fluid chamber 30. That is, the first flow path is configured so that the cooling gas flows from the air chamber through the first fluid chamber 20 and into the second fluid chamber 30. The piezoelectric actuator is configured as an actuator based on a piezoelectric film, utilizing the inverse piezoelectric effect of the piezoelectric film to convert simple harmonic vibrations, and the operating frequency of the piezoelectric film layer is extremely high. In practical applications, the shell, the first partition plate and the second partition plate can be an integral structure or a combined structure, and such a deformation has no substantial impact on this embodiment.

[0042] Continue to see Figure 1, the second partition plate 31 is further provided with an exhaust hole 311, and the exhaust hole 311 is configured to connect the first fluid chamber 20 with the second fluid chamber 30. Preferably, the exhaust hole 311 can be offset relative to the through hole 211 on the second partition plate, and the diaphragm 32 guides the cooling gas from the air inlet end to the first fluid chamber 20 when the through hole is open, or exhausts the first fluid chamber 20 when the through hole 211 is closed. In a preferred example, Figure 2 As shown, the exhaust hole 311 is also provided with a one-way valve 312, for example, a pneumatic one-way valve. When the pressure in the first fluid chamber is higher than the pressure in the second fluid chamber, the one-way valve 312 is opened to allow a portion of the cooling gas to be introduced into the second fluid chamber 30. Conversely, when the pressure in the first fluid chamber is lower than or close to the pressure in the second fluid chamber, the one-way valve 312 is closed to prevent the heated gas from the hot end from being introduced back into the first fluid chamber 20.

[0043] The MEMS air-cooled heat sink also includes a control unit, which is electrically connected to the electrostatic actuator to provide a drive signal indicating whether the one-way microvalve assembly is open or closed. In some examples, the electrostatic actuator and the cantilever beam constitute an electrostatic ultrasonic transducer, and the electrostatic ultrasonic transducer includes a top electrode attached to the cantilever beam and a bottom electrode mounted near the through hole. The control unit is used to apply a drive signal between the top electrode and the bottom electrode, causing the movable portion of the cantilever beam to reciprocate around its fixed portion toward or away from the first partition, thereby opening or closing the through hole. In a preferred example, the top electrode is configured to have an area smaller than that of the cantilever beam, and the bottom electrode can be arranged in a grid shape, for example, as Figure 2 The driving signal applied here includes, for example, a DC bias applied between the top electrode and the bottom electrode of the electrostatic ultrasonic transducer, and a voltage superposition for generating an alternating voltage.

[0044] The motion execution component is configured as a piezoelectric micromachined ultrasonic transducer, which may include alternating stacks of piezoelectric film layers and electrode layers, wherein the electrode layers include a positive electrode layer and a negative electrode layer. The diaphragm is in direct contact with one of the positive electrode layer and the negative electrode layer, serving as an insulating layer between the electrode layer and the substrate, thereby reducing parasitic capacitance. By applying a DC bias to the positive and negative electrode layers, as well as a voltage for generating an alternating voltage, the superposition of the two causes the piezoelectric film layer in the piezoelectric ultrasonic transducer to generate periodic mechanical vibrations. The electric field energy is converted into mechanical energy, driving the high-frequency mechanical vibration of the diaphragm and performing work on the gas in the first fluid chamber; that is, compressing or expanding the gas therein.

[0045] In some examples, the control unit is electrically connected to the piezoelectric micromechanical ultrasonic transducer and is used to provide a driving signal instructing the piezoelectric micromechanical ultrasonic transducer to generate ultrasonic vibration, causing the diaphragm to produce a negative phase bending motion, increasing the gap between the first diaphragm and the diaphragm, and reducing the air pressure in the first fluid chamber, thereby drawing the cooling gas into the first fluid chamber; or causing the diaphragm to produce a positive phase bending motion, reducing the gap between the first diaphragm and the diaphragm, and increasing the air pressure in the first fluid chamber, thereby pushing the cooling gas to flow from the first fluid chamber into the second fluid chamber.

[0046] Figure 4 illustrates the MEMS air-cooled heat sink operating during cooling gas extraction. As shown in Figure 4 , the electrostatic actuator 13 can operate in an initial or unactuated state, meaning the one-way microvalve assembly remains open, the cantilever beam 12 is undriven, and the piezoelectric film drives the diaphragm 22 to generate a negative-phase bending motion, altering the pressure differential between the air chamber and the adjacent fluid chamber, thereby drawing cooling gas into the air chamber 10 through the air inlet port.

[0047] Figure 5 illustrates the MEMS air-cooled heat sink operating in the state of exhausting heated air. As shown in Figure 5, the electrostatic actuator can operate in an actuated state, driving the movable portion of the cantilever beam to deflect about its fixed portion toward the first diaphragm. A through-hole 211 is provided on the first diaphragm, aligned with the cantilever beam, to allow the through-hole to close when the cantilever beam abuts the first diaphragm, thereby adjusting the one-way microvalve assembly to a closed state. Simultaneously, under the control of the control unit, the piezoelectric film drives the diaphragm 22 to generate a positive-phase bending motion, causing a portion of the introduced cooling gas to be discharged from the first fluid chamber.

[0048] The MEMS air-cooled heat sink is removably attached to the hot end of the electronic device, and a second fluid chamber is defined between the second partition and the base, and the second fluid chamber is preferably configured as a one-way chamber. Figure 1 As shown, the exhaust port 301 is configured as a lateral opening located on the side wall of the second fluid chamber, for providing fluid communication between the second fluid chamber and the external environment.

[0049] This embodiment also provides a method for using the MEMS air-cooled heat sink described above, including steps S1 to S2. Figure 6-7 , the usage of this embodiment is introduced.

[0050] S1: attaching the aforementioned MEMS air-cooled heat sink to the hot end of the electronic device;

[0051] S2: Using the control unit, applying a pulse sequence of a first drive signal and a second drive signal to the electrostatic actuator and the piezoelectric actuator, respectively, to cause the cantilever beam and the diaphragm to vibrate back and forth, wherein each pulse cycle includes a first time interval and a second time interval:

[0052] During the first time interval, by making the second driving signal applied to the piezoelectric actuator have a negative pulse phase, cooling gas is introduced through the air inlet end while the one-way microvalve component remains open;

[0053] During the second time interval, a first driving signal is applied to the electrostatic actuator, causing the one-way microvalve assembly to close to airtightly isolate the air chamber from the first fluid chamber, and at the same time, a second driving signal applied to the piezoelectric actuator has a positive pulse phase, causing a portion of the introduced cooling gas to flow from the first fluid chamber through the second fluid chamber and be discharged to the external environment.

[0054] Step S1: One or more MEMS air-cooled heat sinks can be fixed to the hot end of the electronic device using thermal adhesive. Figure 6 As shown, multiple MEMS air-cooled heat sinks are arranged in an array at the hot end of the electronic device; preferably, each of the multiple MEMS air-cooled heat sinks has a lateral opening, and the lateral opening of one of the multiple MEMS air-cooled heat sinks has an opening direction staggered with the lateral opening of the adjacent MEMS air-cooled heat sink to reduce the mutual influence between the exhausted heated air. Figure 6 As shown, each of the multiple MEMS air-cooled heat sinks 5 has a lateral opening and is arranged with the same opening orientation to reduce the impact between the exhausted heated air g while providing flexibility in the array design of the heat sink.

[0055] In step S2, a control unit applies pulse sequences of a first drive signal and a second drive signal to the electrostatic actuator and the piezoelectric actuator, respectively. In this embodiment, the first drive signal and the second drive signal are voltage signals, and based on the operating principle of the actuator, the first drive signal and the second drive signal have different amplitudes. Preferably, the frequency of the second drive signal applied to the piezoelectric actuator is close to the natural frequency of the piezoelectric diaphragm, thereby increasing the vibration amplitude of the diaphragm.

[0056] As shown in Figure 4, within the first time interval, the driving voltage applied to the piezoelectric actuator 33 has a negative pulse phase, the diaphragm produces a bending motion with a negative phase, the air pressure in the first fluid chamber drops to generate negative pressure, and the cooling gas is introduced into the first fluid chamber, and the cooling gas is introduced into the air chamber and the first fluid chamber through the air inlet.

[0057] As shown in Figure 5, during the second time interval, the driving voltage applied to the electrostatic actuator 13 causes the one-way microvalve assembly to close, and the driving voltage applied to the piezoelectric actuator has a positive pulse phase, and the diaphragm produces a bending motion with a positive phase. Based on the closing of the one-way microvalve assembly, the air pressure in the first fluid chamber increases to generate positive pressure, thereby pushing a portion of the introduced cooling gas from the first fluid chamber to flow through the second fluid chamber.

[0058] Figure 7 The following is a diagram showing the relevant signal waveforms in the method of using the MEMS air-cooled heat sink. Figure 7 As shown, at step S2, within the first time interval t1, the driving voltage applied to the electrostatic actuator is 0, corresponding to the opening of the one-way microvalve assembly; accordingly, the driving voltage applied to the piezoelectric actuator is -v2, and the diaphragm produces a bending motion with a negative phase; within the second time interval t2, the driving voltage applied to the electrostatic actuator is v1, corresponding to the closing of the one-way microvalve assembly; accordingly, the driving voltage applied to the piezoelectric actuator is v2, and the diaphragm produces a bending motion with a positive phase.

[0059] In summary, a MEMS air-cooled heat sink of the present invention utilizes an actuator and a cantilever beam to construct an active one-way microvalve assembly, which cooperates with the motion execution assembly to guide the cooling gas in one direction to the fluid chamber adjacent to the hot end of the electronic device, thereby discharging the heated air to achieve a heat dissipation effect; the piezoelectric film layer of the present invention has an extremely high operating frequency, and the ultrasonic wave generated by the vibration is inaudible. Compared with traditional air-cooled radiators, it has the advantages of no noise and low power consumption.

[0060] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A MEMS air-cooled heat sink, characterized in that: include: A housing, the housing comprising a top cover and a base, the housing being provided with an air inlet and an air outlet, the air inlet being configured for introducing cooling gas; A one-way microvalve assembly, the one-way microvalve assembly includes a cantilever beam, a first diaphragm and an air chamber separated by the first diaphragm, the inlet end fluid is connected to the air chamber, the first diaphragm is aligned with the cantilever beam and provided with a through hole to connect the air chamber fluid to the first fluid chamber, the cantilever beam is attached with a first actuator to generate a driving force in the normal direction on the cantilever beam, allowing the through hole to be closed when the cantilever beam is against the first diaphragm, causing the one-way microvalve assembly to be adjusted to a closed state, or the through hole to be opened when the cantilever beam is not subjected to a driving force, causing the one-way microvalve assembly to be adjusted to a closed state. The assembly remains in an open state; the cantilever beam includes a fixed portion and a movable portion, the fixed portion is anchored on the top cover, and the movable portion is suspended above the first diaphragm and directly contacts the first actuator, the first actuator and the cantilever beam constitute an electrostatic ultrasonic transducer, and the electrostatic ultrasonic transducer includes a top electrode attached to the cantilever beam and a bottom electrode mounted near the through-hole, and when a driving signal is applied between the top electrode and the bottom electrode, the movable portion of the cantilever beam is caused to reciprocate around its fixed portion toward or away from the first diaphragm, thereby opening or closing the through-hole; a motion execution assembly configured as a piezoelectric micromachined ultrasonic transducer, comprising a stacked second diaphragm, a diaphragm, and a second actuator, wherein the second diaphragm is attached to the housing to separate a first fluid chamber and a second fluid chamber, an opening being formed on the second diaphragm, and at least a portion of the diaphragm is suspended above the opening to generate a bending motion driven by the second actuator, thereby achieving unidirectional flow of cooling gas along a first flow path, wherein the first flow path comprises flow from the air chamber through the first fluid chamber and into the second fluid chamber; a control unit configured to apply a pulse sequence of a first drive signal and a second drive signal to the first actuator and the second actuator, respectively, wherein each pulse cycle includes a first time interval and a second time interval; wherein, during the first time interval, by making the second drive signal applied to the second actuator have a negative pulse phase, cooling gas is introduced through the air inlet end while the one-way microvalve assembly remains open; During the second time interval, a first driving signal is applied to the first actuator to close the microvalve assembly so as to hermetically isolate the gas chamber from the first fluid chamber, and a second driving signal is applied to the second actuator to have a positive pulse phase, so that a portion of the introduced cooling gas flows from the first fluid chamber through the second fluid chamber and is discharged to the external environment; Wherein, the second actuator is a piezoelectric actuator, and the piezoelectric actuator is configured as an actuator based on a piezoelectric film. The frequency of the second driving signal applied to the piezoelectric actuator is close to the natural frequency of the piezoelectric film. The base is removably attached to the hot end of the electronic device; and the exhaust end is configured to provide fluid communication between the second fluid chamber and the external environment.

2. The MEMS air-cooled heat sink according to claim 1, wherein: The second partition plate includes a vent hole offset relative to the through hole, for providing fluid communication between the first fluid chamber and the second fluid chamber.

3. The MEMS air-cooled heat sink according to claim 1, wherein: The system further comprises a control unit electrically connected to the first actuator and configured to provide a driving signal instructing the one-way microvalve assembly to open or close.

4. The MEMS air-cooled heat sink according to claim 3, wherein: The control unit is electrically connected to the piezoelectric micromechanical ultrasonic transducer to draw the cooling gas into the first fluid chamber when the diaphragm moves to a negative phase; or, to push the cooling gas from the first fluid chamber into the second fluid chamber when the diaphragm moves to a positive phase.

5. The MEMS air-cooled heat sink according to claim 1, wherein: The exhaust port is configured as an opening located on a side wall of the second fluid chamber, for providing fluid communication between the second fluid chamber and an external environment.

6. The MEMS air-cooled heat sink according to claim 1, characterized in that: The air inlet end and the through hole are arranged on opposite sides of the air chamber; wherein the air inlet end is arranged as a plurality of air inlet holes penetrating the top cover.

7. A method for using a MEMS air-cooled heat sink, characterized in that: The following steps are involved: Attaching the MEMS air-cooled heat sink as claimed in claim 1 to the hot end of an electronic device; The control unit applies a pulse sequence of a first driving signal and a second driving signal to the first actuator and the second actuator respectively, so that the cantilever beam and the diaphragm vibrate back and forth, wherein each pulse cycle includes a first time interval and a second time interval: wherein, During the first time interval, by making the second driving signal applied to the second actuator have a negative pulse phase, cooling gas is introduced through the air inlet end while the one-way microvalve component remains open; During the second time interval, a first driving signal is applied to the first actuator, causing the microvalve assembly to close to airtightly isolate the air chamber from the first fluid chamber, and at the same time, a second driving signal applied to the second actuator has a positive pulse phase, causing a portion of the introduced cooling gas to flow from the first fluid chamber through the second fluid chamber and be discharged to the external environment.

8. The method of use according to claim 7, characterized in that: A plurality of MEMS air-cooled heat sinks are arranged in an array at the hot end of an electronic device. Each of the plurality of MEMS air-cooled heat sinks has a lateral opening, and the plurality of MEMS air-cooled heat sinks are arranged so that the lateral opening of any MEMS air-cooled heat sink has an opening orientation staggered with the lateral opening of an adjacent MEMS air-cooled heat sink.

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