Gas-driven MEMS micromirror and preparation method thereof

Abstract

The invention discloses a gas-driven MEMS micromirror and a preparation method thereof. The gas-driven MEMS micromirror comprises an upper silicon wafer, a micromirror silicon wafer and a lower silicon wafer, the micro-mirror silicon wafer comprises a rotating shaft and a rotating lens, the rotating shaft and the rotating lens are perpendicular to the upper silicon wafer and the lower silicon wafer, the rotating shaft penetrates through the rotating lens, and a gap is formed between the rotating shaft and the rotating lens; the upper silicon wafer and the lower silicon wafer are respectively bonded on the upper and lower sides of the micro-mirror silicon wafer and are anchored with the upper and lower ends of the rotating shaft; the upper silicon wafer, the lower silicon wafer and the micro-mirror silicon wafer are bonded to form a rotating cavity with an opening in one end, and the rotating lens is located on one side of the opening of the rotating cavity; a wind pressure mechanism is arranged in the rotating cavity and can blow out driving airflow, so that the rotating lens rotates around the rotating shaft in the whole circle. The MEMS micromirror is simple and reliable in structure, the rotation angle of the mirror surface is not limited, the mechanical loss is reduced, and the safety and economical efficiency of the MEMS micromirror are improved.

Description

Technical Field

[0001] The present application belongs to the field of MEMS micromirror processing technology, and in particular relates to a gas-driven MEMS micromirror and a preparation method thereof. Background Art

[0002] A MEMS (Micro-Electro-Mechanical System) micromirror refers to an optical MEMS device manufactured using optical MEMS technology. It integrates a micro-light reflector with a MEMS driver to achieve mirror deflection, and functions such as pointing deflection and image scanning. However, the existing traditional MEMS micromirror relies on the deformation or torsion of an elastic beam to drive the mirror to deflect. This method has a limited rotation angle, and the available angle is too small to achieve 360° rotation. The torsion consumes more current and has higher mechanical losses, making it inconvenient to use. Moreover, whether it is electrostatic drive or piezoelectric drive, it is necessary to process the drive circuit on the chip and etch the leads to provide current, which increases the difficulty and cost of micromirror manufacturing. Moreover, there are some situations in the real environment that are not suitable for circuit operation (such as high temperature environment, etc.), which limits the application of micromirrors. Summary of the invention

[0003] In view of the above problems, the present application discloses a gas-driven MEMS micromirror and a preparation method thereof, so as to overcome the above problems or at least partially solve the above problems.

[0004] In order to achieve the above objectives, this application adopts the following technical solutions:

[0005] According to one aspect of the present application, a gas-driven MEMS micromirror is provided, comprising: an upper silicon wafer, a micromirror silicon wafer, and a lower silicon wafer;

[0006] The micromirror silicon wafer comprises: a rotating shaft and a rotating lens, the rotating shaft and the rotating lens are arranged perpendicular to the upper silicon wafer and the lower silicon wafer, the rotating shaft passes through the rotating lens, and a gap is arranged between the two;

[0007] The upper silicon wafer and the lower silicon wafer are bonded to the upper and lower sides of the micromirror silicon wafer respectively, and are anchored to the upper and lower ends of the rotating shaft; the upper silicon wafer, the lower silicon wafer and the micromirror silicon wafer are bonded to form a rotating cavity with an opening at one end, and the rotating lens is located on the opening side of the rotating cavity; a wind pressure mechanism is arranged in the rotating cavity, and the wind pressure mechanism can blow out a driving airflow to make the rotating lens rotate around the rotating shaft in a full circle.

[0008] In some embodiments, a plurality of wind pressure mechanisms are provided, and the plurality of wind pressure mechanisms are symmetrically arranged about the rotation axis.

[0009] In some embodiments, the wind pressure mechanism is a vent hole, and the vent holes are divided into two groups. The two groups of vent holes are symmetrically arranged about the rotation axis, and the vent holes are connected to an air source mechanism.

[0010] In some embodiments, a ventilation gap is left between the rotating lens and the open side wall of the rotating cavity, and the ventilation gap is symmetrically arranged about the rotation axis.

[0011] In some embodiments, the upper silicon wafer, the micromirror silicon wafer, and the lower silicon wafer are all double-sided polished silicon wafers.

[0012] In some embodiments, the rotating cavity is a square cavity, and the upper silicon wafer, the micromirror silicon wafer and the lower silicon wafer are all provided with rectangular opening grooves, and the rectangular opening grooves of each silicon wafer are bonded to each other to form a square cavity.

[0013] In some embodiments, the upper silicon wafer and the lower silicon wafer are provided with symmetrical balancing electrodes, and the balancing electrodes are used to balance the rotating mirror, so that the rotating mirror and the rotating shaft are kept aligned and do not collide with each other.

[0014] In some embodiments, the balance electrode is in the shape of a continuous ring, is disposed outside the anchor point of the rotating shaft, and is disposed concentrically with the rotating shaft.

[0015] In some embodiments, the rotating mirror is a double-sided reflective mirror, and the micromirror silicon wafer is formed by bonding multiple silicon wafers.

[0016] According to another aspect of the present application, a method for preparing a gas-driven MEMS micromirror is also provided, comprising:

[0017] Preparing a plurality of double-sided polished silicon wafers, etching vent holes on the double-sided polished silicon wafers, and then bonding the plurality of double-sided polished silicon wafers to form a micromirror silicon wafer;

[0018] Etching the micromirror silicon wafer to form a double-sided reflective mirror structure;

[0019] preparing a first silicon wafer, and etching an anchor point region on the first silicon wafer to form an upper silicon wafer;

[0020] preparing a second silicon wafer, and etching an anchor point region on the second silicon wafer to form a lower silicon wafer;

[0021] Bonding the upper silicon wafer to the micromirror silicon wafer, and etching the double-sided reflector structure after bonding, to form a rotating shaft anchored vertically to the upper silicon wafer, and a rotating lens sleeved on the rotating shaft; a gap is provided between the rotating shaft and the rotating lens, and at this time, a constraint is left between the rotating lens and the rotating shaft and is not completely released;

[0022] Bond the lower silicon wafer to the micromirror silicon wafer, and etch away the constraints between the rotating mirror and the shaft to completely release the rotating mirror.

[0023] The advantages and beneficial effects of this application are:

[0024] The gas-driven MEMS micromirror of the present application comprises a micromirror silicon wafer, an upper silicon wafer and a lower silicon wafer, the micromirror silicon wafer comprises a rotating shaft and a rotating lens, the rotating shaft and the rotating lens are arranged perpendicular to the upper silicon wafer and the lower silicon wafer, the upper silicon wafer and the lower silicon wafer are bonded to the micromirror silicon wafer, and are anchored to the upper and lower ends of the rotating shaft, the bonding body forms a rotating cavity, and a wind pressure mechanism is arranged in the cavity, which can blow out airflow to drive the rotating lens to rotate around the rotating shaft. The rotating lens of the present application is not restricted by the torsion beam, and there is no need to achieve mirror rotation through mechanical torsion, so the rotation angle is not limited, and a full rotation of 360° can be achieved. At the same time, because the present application does not need to overcome the torsion of the torsion beam, the mechanical loss is small, the use is flexible, and the driving requirements are reduced. In addition, the present application can also meet the conditions that are not suitable for current operation, such as high temperature and high magnetism, and has a wider applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0026] Figure 1 This is a front view of a gas-driven MEMS micromirror according to an embodiment of the present application;

[0027] Figure 2 This is an isometric diagram of a gas-driven MEMS micromirror according to an embodiment of the present application;

[0028] Figure 3 A perspective schematic diagram of a gas-driven MEMS micromirror according to an embodiment of the present application;

[0029] Figure 4 A schematic diagram of the structure of a gas-driven MEMS micromirror without part of the rotating mirror in one embodiment of the present application;

[0030] Figure 5 A top view of a gas-driven MEMS micromirror according to an embodiment of the present application;

[0031] Figure 6 This is a right side view of a gas-driven MEMS micromirror according to an embodiment of the present application;

[0032] Figure 7 This is a schematic diagram of a method for preparing a gas-driven MEMS micromirror according to an embodiment of the present application;

[0033] Figure 8a-8d The figure is a process diagram of a method for preparing a gas-driven MEMS micromirror according to an embodiment of the present application.

[0034] In the figure: 1, upper silicon wafer; 2, micromirror silicon wafer; 21, rotating lens; 211, side reflection surface; 22, rotating shaft; 23, ventilation hole; 24, ventilation gap; 3, lower silicon wafer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in conjunction with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0036] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] Figures 1 to 7 An embodiment of a gas-driven MEMS micromirror of the present application is schematically shown.

[0043] like Figures 1 to 7 As shown, the present application discloses a gas-driven MEMS micromirror, which includes: an upper silicon wafer 1, a micromirror silicon wafer 2 and a lower silicon wafer 3. The micromirror silicon wafer 2 includes: a rotating shaft 22 and a rotating lens 21, the rotating shaft 22 and the rotating lens 21 are arranged perpendicular to the upper silicon wafer 1 and the lower silicon wafer 3, the rotating shaft 22 passes through the rotating lens 21, and a gap is provided between the two. The upper silicon wafer 1 and the lower silicon wafer 3 are bonded to the upper and lower sides of the micromirror silicon wafer 2, respectively, and are anchored to the upper and lower ends of the rotating shaft 22. The upper silicon wafer 1, the lower silicon wafer 3 and the micromirror silicon wafer 2 are bonded to form a rotating cavity with an opening at one end, and the rotating lens 21 is located on the opening side of the rotating cavity. A wind pressure mechanism is arranged in the rotating cavity, and the wind pressure mechanism can blow out a driving airflow to make the rotating lens 21 rotate around the rotating shaft 22.

[0044] Through the above structural design, the gas-driven MEMS micromirror of the present application includes a micromirror silicon wafer 2, an upper silicon wafer 1 and a lower silicon wafer 3, the micromirror silicon wafer 2 includes a rotating shaft 22 and a rotating lens 21, the rotating shaft 22 and the rotating lens 21 are arranged perpendicular to the upper silicon wafer 1 and the lower silicon wafer 3, the upper silicon wafer 1 and the lower silicon wafer 3 are bonded to the micromirror silicon wafer 2, and are anchored to the upper and lower ends of the rotating shaft 22. The bonding body forms a rotating cavity, and a wind pressure mechanism is arranged in the cavity, which can blow out airflow to drive the rotating lens 21 to rotate around the rotating shaft 22. The rotating lens 21 of the present application is not restricted by the torsion beam, and there is no need to achieve mirror rotation through mechanical torsion, so the rotation angle is not limited, and 360° full-circle rotation can be achieved. At the same time, because the present application does not need to overcome the torsion of the torsion beam, the mechanical loss is small, the use is flexible, and the driving requirements are reduced. In addition, the embodiment of the present application can also meet the situation that is not suitable for current operation such as high temperature, and has a wider applicability, especially for scenes with low precision requirements, strong electromagnetic environment and high temperature environment. The structure of the present application is simple and reliable. It relies on an external gas source to drive the mirror to rotate. It is resistant to high temperatures and strong electromagnetics. In addition, since the gas source pressure and flow are easy to control, a larger torsion angle can be achieved, thereby improving the safety and economy of the micromirror.

[0045] In some embodiments of the present application, Figures 1 to 5 As shown, in the rotating cavity, multiple wind pressure mechanisms are provided, and the multiple wind pressure mechanisms are symmetrically arranged about the rotating shaft 22. By symmetrically designing the wind pressure mechanisms on both sides of the rotating shaft 22, both sides of the rotating lens 21 can be subjected to wind pressure at the same time, so that the rotating lens 21 is positioned at a certain angle through the balance of wind force on both sides, and the mirror surface is driven to rotate in a directional and quantitative manner.

[0046] In some embodiments of the present application, Figures 1 to 6 As shown, the wind pressure mechanism of the embodiment shown in the drawings of the present application is a vent 23, and the vent 23 is divided into two groups. The two groups of vents 23 are symmetrically arranged about the rotating shaft 22. The vent 23 is connected to an air source mechanism, and blowing can be achieved through the external air source mechanism to drive the rotating lens 21 to rotate at a full angle. The gas used is a clean inert gas, such as nitrogen that has been dried and filtered to remove impurities. In the embodiment of the present application, the vent 23 is set to two, and each of the two vents 23 is a group. In some other embodiments of the present application, more even numbers of vents 23 can also be set, and the vents 23 can be divided into two groups, which are symmetrically arranged about the rotating shaft 22.

[0047] In some embodiments of the present application, a ventilation gap 24 is left between the rotating lens 21 and the open side wall of the rotating cavity, and the ventilation gap 24 is also symmetrically arranged about the rotating shaft 22. By setting the ventilation gap 24, it is beneficial to quickly discharge the gas blown in by the wind pressure mechanism out of the rotating cavity, so as to avoid air blockage and high pressure, and avoid the rigid and inflexible movement of the rotating lens 21. Among them, the size of the ventilation gap 24 is determined according to the maximum blowing volume of the wind pressure mechanism, and is set differently for different mirror sizes and different working conditions.

[0048] In some embodiments of the present application, Figures 1 to 6 As shown, the upper silicon wafer 1, the micromirror silicon wafer 2 and the lower silicon wafer 3 are all double-sided polished silicon wafers (i.e., DSP silicon wafers). Double-sided polished silicon wafers are commonly used in semiconductors, microelectromechanical systems (MEMS) and other applications that require strict control of wafer flatness characteristics, and can well meet the needs of silicon wafer processing.

[0049] In some embodiments of the present application, Figures 1 to 6 As shown, the rotating cavity formed by bonding the silicon wafers is a square cavity, and the upper silicon wafer 1, the micromirror silicon wafer 2 and the lower silicon wafer 3 are all provided with rectangular opening grooves, and the rectangular opening grooves of each silicon wafer are aligned and bonded to form the square cavity. Figures 1 to 6 As shown, except for the opening side and the ventilation holes, the other positions of the square cavity are all sealed structures to prevent the external environmental airflow from affecting the wind pressure driving work of the MEMS micromirror.

[0050] In some embodiments of the present application, the upper silicon wafer 1 and the lower silicon wafer 3 are further provided with symmetrical balancing electrodes, which are used to balance the rotating mirror 21 so that the rotating mirror 21 and the rotating shaft 22 remain aligned and do not collide with each other. The balancing electrode does not need to drive the rotating mirror 21 to rotate, but only needs to detect and maintain the strict alignment of the rotating mirror 21 and the rotating shaft 22. The current required is much smaller than the driving current for driving the mirror to rotate, but it can maintain the rotating mirror 21 and the rotating shaft 22 aligned and non-contacting, thereby avoiding mechanical friction, reducing the mechanical loss of the rotating mirror 21, and significantly extending the service life of the micromirror.

[0051] In some embodiments of the present application, the balancing electrode is in a continuous ring shape, arranged outside the anchor point of the rotating shaft 22, and arranged concentrically with the rotating shaft 22. By arranging the balancing electrodes uniformly around the rotating shaft 22 and the rotating lens 21, the real-time centering balance of the rotating lens 21 and the rotating shaft 22 can be achieved, thereby avoiding collision, making the lens rotation more stable and accurate, and reducing mechanical loss.

[0052] In some embodiments of the present application, the rotating mirror 21 is a double-sided reflector, both sides of which are side reflection surfaces 211, which can reflect light on both sides, so as to facilitate full-circle rotation without dead angles. In addition, in some embodiments of the present application, the micromirror silicon wafer 2 can be formed by bonding multiple silicon wafers, thereby obtaining a rotating shaft 22 and a rotating mirror 21 of any desired length.

[0053] According to another aspect of the present application, a method for preparing a gas-driven MEMS micromirror is also disclosed, such as Figure 7 As shown, the method includes:

[0054] Step S710, prepare multiple double-sided polished silicon wafers, etch ventilation holes 23 on the double-sided polished silicon wafers, and then bond the multiple double-sided polished silicon wafers to form a micromirror silicon wafer 2. The number of bonded silicon wafers is determined according to needs. The ventilation holes 23 can be realized by etching ventilation grooves on adjacent double-sided polished silicon wafers and then bonding them together, such as Figure 8a shown.

[0055] Step S720, etching the micromirror silicon wafer 2 to form a double-sided reflector structure. To facilitate subsequent bonding, the double-sided reflector structure has not yet formed a rotating shaft 22 and a rotating mirror 21 that are separated from each other.

[0056] Step S730 , preparing a first silicon wafer, etching an anchor point region on the first silicon wafer to form an upper silicon wafer 1 .

[0057] Step S740 , preparing a second silicon wafer, etching an anchor point region on the second silicon wafer to form a lower silicon wafer 3 .

[0058] Step S750, the upper silicon wafer 1 is bonded to the micromirror silicon wafer 2, and after bonding, a double-sided reflector structure is etched to form a rotating shaft 22 vertically anchored to the upper silicon wafer 1, and a rotating mirror 21 sleeved on the rotating shaft 22. A gap is provided between the rotating shaft 22 and the rotating mirror 21, and at this time, a constraint is left between the rotating mirror 21 and the rotating shaft 22 and is not completely released.

[0059] Step S760, bonding the lower silicon wafer 3 to the micromirror silicon wafer 2, and etching away the constraints between the rotating mirror 21 and the rotating shaft 22, and completely releasing the rotating mirror 21 to form a movable MEMS micromirror.

[0060] In some embodiments of the present application, in step S710, the double-sided reflector structure is located in the middle of the micromirror silicon wafer 2. In steps S730 and S740, the anchor point areas of the upper silicon wafer 1 and the lower silicon wafer 3 are located in the central position. The method also includes: step S770, laser scribing the bonded body of the upper silicon wafer 1, the micromirror silicon wafer 2 and the lower silicon wafer 3 to expose the rotating lens 21. The present application first adopts a closed bonding structure in the bonding manufacturing process, and then cuts to expose the mirror surface, which is conducive to facilitating the bonding operation, can improve the accuracy and precision of the bonding, improve the product yield, and avoid waste of silicon wafers.

[0061] Figures 8a to 8d The figure is a flow chart of a method for preparing a gas-driven MEMS micromirror according to an embodiment of the present application, wherein the micromirror silicon wafer 2 is formed by bonding a DSP silicon wafer No. 1 and a DSP silicon wafer No. 2, the upper silicon wafer 1 is formed by a DSP silicon wafer No. 3, and the lower silicon wafer 3 is formed by a DSP silicon wafer No. 4.

[0062] Figure 8a Corresponding to step S710 and step S720: etching the vent hole 23 and bonding to form a micromirror silicon wafer 2, and then etching the micromirror silicon wafer 2 to form a double-sided reflector structure, wherein a partial thickness of the silicon wafer (not shown) is left between the double-sided reflector structure and the outer surrounding structure for connection and fixation and to facilitate subsequent bonding.

[0063] Figure 8b Corresponding to step S730 and step S750: etching to form the upper silicon wafer 1, bonding the upper silicon wafer 1 to the micromirror silicon wafer 2, and etching the double-sided reflector structure after bonding to form a rotating shaft 22 anchored vertically to the upper silicon wafer 1, and a rotating mirror 21 sleeved on the rotating shaft 22. At this time, the rotating shaft 22 and the rotating mirror 21 are not completely released, and the silicon wafer is constrained.

[0064] Figure 8c Corresponding to step S750 and step S760: etching to form the lower silicon wafer 3; bonding the lower silicon wafer 3 to the micromirror silicon wafer 2, and etching away the constraints between the rotating lens 21 and the rotating shaft 22, completely releasing the rotating lens 21, and forming a movable MEMS micromirror.

[0065] Figure 8d This corresponds to step S770: laser scribing is performed on the bonded body of the upper silicon wafer 1, the micromirror silicon wafer 2 and the lower silicon wafer 3 to expose the rotating mirror 21, so as to complete the complete process of the MEMS micromirror.

[0066] In summary, the gas-driven MEMS micromirror of the embodiment of the present application includes a micromirror silicon wafer, an upper silicon wafer and a lower silicon wafer, the micromirror silicon wafer includes a rotating shaft and a rotating lens, the rotating shaft and the rotating lens are arranged perpendicular to the upper silicon wafer and the lower silicon wafer, the upper silicon wafer and the lower silicon wafer are bonded to the micromirror silicon wafer, and are anchored to the upper and lower ends of the rotating shaft, and the bonding body forms a rotating cavity, and a wind pressure mechanism is arranged in the cavity, which can blow out airflow to drive the rotating lens to rotate around the rotating shaft. The rotating lens of the present application is not restricted by the torsion beam, and there is no need to achieve mirror rotation through mechanical torsion, so the rotation angle is not limited, and 360° full-circle rotation can be achieved. At the same time, because the present application does not need to overcome the torsion of the torsion beam, the mechanical loss is small, the use is flexible, and the driving requirements are reduced. In addition, the present application can also meet the conditions that are not suitable for current operation, such as high temperature and high magnetism, and has a wider applicability.

[0067] The above is only a specific implementation of the present application. Under the above teachings of the present application, those skilled in the art can make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above specific description is only to better explain the purpose of the present application, and the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A gas-driven MEMS micromirror, characterized in that: include: Upper silicon wafer, micromirror silicon wafer and lower silicon wafer; The micromirror silicon wafer comprises: a rotating shaft and a rotating mirror, wherein the rotating shaft and the rotating mirror are arranged perpendicular to the upper silicon wafer and the lower silicon wafer, the rotating shaft passes through the rotating mirror, and a gap is arranged between the two; The upper silicon wafer and the lower silicon wafer are bonded to the upper and lower sides of the micromirror silicon wafer respectively, and are anchored to the upper and lower ends of the rotating shaft; the upper silicon wafer, the lower silicon wafer and the micromirror silicon wafer are bonded to form a rotating cavity with an opening at one end, and the rotating lens is located on the opening side of the rotating cavity; a wind pressure mechanism is arranged in the rotating cavity, and the wind pressure mechanism can blow out a driving airflow to make the rotating lens rotate around the rotating shaft in a full circle.

2. The gas-driven MEMS micromirror according to claim 1, characterized in that: The wind pressure mechanisms are provided in plurality, and the plurality of wind pressure mechanisms are symmetrically arranged about the rotation axis.

3. The gas-driven MEMS micromirror according to claim 2, characterized in that: The wind pressure mechanism is a vent hole, and the vent holes are divided into two groups. The two groups of vent holes are symmetrically arranged about the rotation axis, and the vent holes are connected to an air source mechanism.

4. The gas-driven MEMS micromirror according to claim 3, characterized in that: A ventilation gap is left between the rotating lens and the open side wall of the rotating cavity, and the ventilation gap is symmetrically arranged about the rotating axis.

5. The gas-driven MEMS micromirror according to claim 1, characterized in that: The upper silicon wafer, the micromirror silicon wafer and the lower silicon wafer are all double-sided polished silicon wafers.

6. The gas-driven MEMS micromirror according to claim 1, characterized in that: The rotating cavity is a square cavity. The upper silicon wafer, the micromirror silicon wafer and the lower silicon wafer are all provided with rectangular opening grooves. The rectangular opening grooves of each silicon wafer are bonded to each other to form the square cavity.

7. The gas-driven MEMS micromirror according to claim 1, characterized in that: The upper silicon wafer and the lower silicon wafer are provided with symmetrical balancing electrodes, and the balancing electrodes are used to balance the rotating mirror, so that the rotating mirror and the rotating shaft are kept aligned and do not collide with each other.

8. The gas-driven MEMS micromirror according to claim 7, characterized in that: The balance electrode is in the shape of a continuous ring, is arranged outside the anchor point of the rotating shaft, and is arranged concentrically with the rotating shaft.

9. The gas-driven MEMS micromirror according to any one of claims 1 to 8, characterized in that: The rotating mirror is a double-sided reflecting mirror, and the micromirror silicon wafer is formed by bonding multiple silicon wafers.

10. A method for preparing a gas-driven MEMS micromirror, characterized in that: include: Preparing a plurality of double-sided polished silicon wafers, etching vent holes on the double-sided polished silicon wafers, and then bonding the plurality of double-sided polished silicon wafers to form a micromirror silicon wafer; Etching the micromirror silicon wafer to form a double-sided reflective mirror structure; Preparing a first silicon wafer, and etching an anchor point region on the first silicon wafer to form an upper silicon wafer; preparing a second silicon wafer, and etching an anchor point region on the second silicon wafer to form a lower silicon wafer; Bonding the upper silicon wafer to the micromirror silicon wafer, and etching the double-sided reflector structure after bonding to form a rotating shaft vertically anchored to the upper silicon wafer, and a rotating mirror sleeved on the rotating shaft; a gap is provided between the rotating shaft and the rotating mirror, and at this time, a constraint is left between the rotating mirror and the rotating shaft and is not completely released; The lower silicon wafer is bonded to the micromirror silicon wafer, and the constraint between the rotating mirror and the rotating shaft is etched away to completely release the rotating mirror.

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