Biomimetic-pore-based double-layer multi-beam acceleration sensor and preparation method thereof

Abstract

The application discloses a double-layer multi-beam acceleration sensor based on bionic pores and a preparation method thereof, which comprises a frame, a mass block, a support beam and a sensitive beam. The mass block is arranged at the middle part of the frame. One end of the support beam is connected with the mass block, and the other end is connected with the frame. The support beam is provided with a right-angle bending. The support beam with the right angle is connected around the four sides of the mass block. One end of the sensitive beam is connected with the mass block, and the other end is connected with the frame. The sensitive beam is provided with stress sensing bionic pores. The sensitive beam with the stress sensing bionic pores is connected with the four corners of the mass block. The sensitive beam with the stress sensing bionic pores is connected with the upper surface of the mass block, the support beam is connected with the lower surface of the mass block, and the support beam and the sensitive beam form a double-layer structure. The support beam and the sensitive beam are designed in layers, so that the accelerometer detection is more flexible, the sensitivity of the acceleration sensor is improved, and the inherent frequency of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of acceleration sensor technology, and in particular to a bilayer multi-beam acceleration sensor based on biomimetic apertures and its fabrication method. Background Technology

[0002] Today, the world has entered an era of intelligent sensing and the Internet of Things. Countries worldwide attach great importance to the development of sensor technology, investing significant resources to support it, leading to more in-depth and widespread research into new sensor principles, materials, and technologies. As the most mature type of device in the field of micro-mechanical sensors, MEMS (micro-electronics mechanical systems) piezoresistive accelerometers are core components in many inertial measurement applications and have long been a research hotspot in the MEMS field. However, existing accelerometers generally suffer from the problem of sensitivity and natural frequency being mutually restrictive, limiting their application in high-end fields.

[0003] Therefore, existing technologies still need further improvement and development. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a double-layer multi-beam accelerometer based on biomimetic apertures and a method for its fabrication. By designing a support beam with right angles and a sensitive beam with multiple stress-sensing biomimetic apertures, and by designing the support beam and the sensitive beam in layers, the design of the accelerometer is made more flexible, which can improve the sensitivity of the accelerometer and enhance the natural frequency of the system.

[0005] The technical solution of the present invention is as follows:

[0006] A biomimetic aperture-based double-layer multi-beam accelerometer, comprising:

[0007] frame,

[0008] A mass block, wherein the mass block is disposed in the middle of the frame;

[0009] A support beam, one end of which is connected to a mass block and the other end of which is connected to a frame, wherein the support beam is provided with a right-angle bend; the support beam containing right angles is connected to the four sides of the mass block.

[0010] A sensitive beam, one end of which is connected to a mass block and the other end to a frame, is provided with stress-sensing bionic holes; the sensitive beam with stress-sensing bionic holes is connected to the four corners of the mass block.

[0011] The sensitive beam with stress-sensing bionic pores is connected to the upper surface of the mass block, and the support beam is connected to the lower surface of the mass block, forming a double-layer structure with the support beam and the sensitive beam.

[0012] The aforementioned biomimetic perforated slit-based double-layer multi-beam accelerometer, wherein the support beams are mutually perpendicularly connected support beams containing right angles.

[0013] The aforementioned biomimetic perforated slit-based double-layer multi-beam accelerometer, wherein the sensitive beam with stress-sensing biomimetic perforated slits comprises:

[0014] Stress-sensing biomimetic pores are positioned near the frame or mass block of the sensitive beam.

[0015] A piezoresistor is disposed on the upper surface of the sensitive beam and arranged around the stress-sensing biomimetic aperture.

[0016] The aforementioned biomimetic pore-slit-based double-layer multi-beam accelerometer comprises four sensitive beams extending from the four corners of a mass block. The four sensitive beams are placed along one axis of the mass block, and each sensitive beam is aligned with the edge of the mass block. The four sensitive beams are centrally symmetrically distributed.

[0017] The aforementioned biomimetic perforated slit-based double-layer multi-beam accelerometer, wherein the right-angled support beams are mutually perpendicularly connected, one end of the right-angled support beam is a fixed end connected to the frame, and the other end is a connecting end connected to the lower surface of the mass block.

[0018] The aforementioned biomimetic perforated slit-based double-layer multi-beam accelerometer has a right-angled support beam with one end connected to the frame as a fixed end and the other end connected to a mass block as a connecting end. However, the right-angled support beam may include one or more right angles.

[0019] The aforementioned biomimetic pore-slit-based double-layer multi-beam accelerometer, wherein the number of the sensitive beams is four or less;

[0020] When the number of sensitive beams is four, the four sensitive beams are arranged along one axis of the mass block and aligned with the edge of the mass block.

[0021] The aforementioned biomimetic perforated slit-based double-layer multi-beam accelerometer, wherein the stress-sensing biomimetic perforated slit is a biomimetic transverse slit on the sensitive beam, and the biomimetic transverse slits on each sensitive beam are arranged in parallel.

[0022] The stress-sensing bionic aperture is disposed on the sensitive beam, and the stress-sensing bionic aperture penetrates the sensitive beam; the supporting beam is configured as a spiral multi-right-angle beam.

[0023] The two ends of the stress-sensing bionic slit have a semi-circular structure.

[0024] The aforementioned biomimetic slit-based double-layer multi-beam accelerometer, wherein,

[0025] The dual-layer multi-beam accelerometer includes a first-layer multi-beam accelerometer and a second-layer multi-beam accelerometer connected together.

[0026] The first layer of multi-beam accelerometers includes:

[0027] First framework,

[0028] A first mass block is disposed in the middle of the first frame;

[0029] A support beam, one end of which is connected to the lower surface of the first mass block and the other end of which is connected to the first frame, the support beam having a right-angle bend; a support beam containing right angles, the support beam containing right angles being connected to the four sides of the first mass block;

[0030] The second layer of multi-beam accelerometers includes:

[0031] Second framework,

[0032] The second mass block is disposed in the middle of the second frame;

[0033] A sensitive beam is provided, with one end connected to the upper surface of the second mass block and the other end connected to the second frame. The sensitive beam is provided with stress-sensing bionic holes. The sensitive beam with stress-sensing bionic holes is connected to the four corners of the second mass block.

[0034] A method for fabricating a biomimetic perforated slit-based double-layer multi-beam accelerometer, comprising the following steps:

[0035] Provide the first substrate to fabricate the first layer of the multi-beam accelerometer:

[0036] S1. The uniformity of subsequent piezoresistive ion implantation is improved by thermal oxidation to obtain a silicon dioxide layer to protect the silicon wafer surface, thus obtaining the first substrate;

[0037] S2. Etch the back cavity on the first substrate to obtain the first mass block and the support beam frame containing right angles;

[0038] S3. Photolithography is used to form right-angled support beams around the first mass block on the first substrate to obtain the first multi-beam accelerometer.

[0039] Provide a second substrate for fabricating a second-layer multi-beam accelerometer:

[0040] S21. The back cavity is etched on the second substrate to obtain the first mass block and the sensitive beam frame;

[0041] S22. Etching to form a plurality of second vias, and etching at the second vias to form the sensitive beam with its long axis oriented toward the center of the substrate;

[0042] S23. Etch downwards on the sensitive beam to create stress-sensing biomimetic pores based on the thickness of the sensitive beam;

[0043] S24. Photolithography is used to create the surface of the sensitive beam and the piezoresistive resistors around the stress-sensing biomimetic apertures;

[0044] S25. Metal sputtering is used to fabricate the lead wire, and copper is selected as the top metal of the lead wire to form the second layer of multi-beam accelerometer.

[0045] Making a sensor:

[0046] The first-layer multi-beam accelerometer and the second-layer multi-beam accelerometer are bonded together using silicon-silicon bonding to form a whole, thus obtaining the biomimetic pore-slit-based double-layer multi-beam accelerometer.

[0047] Beneficial Effects: This invention discloses a bilayer multi-beam accelerometer based on biomimetic perforations and its fabrication method, comprising: a mass block, a frame, a right-angled support beam connecting the mass block and the frame, a sensitive beam with stress-sensing biomimetic perforations connecting the mass block and the frame, and stress-sensing biomimetic perforations distributed on the sensitive beam. The invention is characterized in that: the right-angled support beam is connected around the mass block; the sensitive beam with stress-sensing biomimetic perforations is connected around the mass block; the sensitive beam with stress-sensing biomimetic perforations includes: stress-sensing biomimetic perforations disposed near the frame or mass block; a piezoresistor disposed on the upper surface of the sensitive beam, arranged around the perforations; the frame is connected to the right-angled support beam and the sensitive beam with biomimetic stress-sensing perforations; the mass block and the right-angled support beam and sensitive beam constitute a bilayer structure. The right-angled support beam reduces the beam's stiffness, while the right-angle design increases the beam's length, improving the beam's deformation under mass stress and enhancing the sensor's sensitivity. The thin and small sensitive beam and the biomimetic stress-sensing apertures further enhance the sensor's sensitivity. The wider and thicker right-angled support beam and the double-layer structure ensure that the accelerometer has both high sensitivity and a sufficient natural frequency. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the first three-dimensional structure of the accelerometer according to an embodiment of the present invention.

[0049] Figure 2This is a schematic diagram of the second three-dimensional structure of the accelerometer according to an embodiment of the present invention.

[0050] Figure 3 This is a schematic diagram of the acceleration sensor structure containing a right-angled support beam, according to an embodiment of the present invention.

[0051] Figure 4 This is a schematic diagram of the structure of the accelerometer sensing beam according to an embodiment of the present invention.

[0052] Figures 5(a), 5(b), and 5(c) are finite element simulation diagrams of changing the structural frequency in this invention.

[0053] Figures 6(a), 6(b), and 6(c) are finite element simulation diagrams of changing structural stress in this invention.

[0054] Figure 7 (a) Figure 7 (b) Figure 7 (c) Figure 7 (d) Figure 7 (e) Figure 7 (f) Figure 7 (g) Figure 7 (h) is a diagram showing the fabrication of the sensor in this invention.

[0055] Figure 8 This is a top view of the sensor in this invention. Detailed Implementation

[0056] This invention provides a biomimetic perforated slit-based double-layer multi-beam accelerometer. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0058] It should be noted that in the description of this invention, the terms "upper," "lower," "both sides," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0059] Please also refer to Figures 1-6(a) Figure 6(c) illustrates some embodiments of a biomimetic perforated accelerometer based on a double-layer multi-beam accelerometer. The biomimetic perforated accelerometer of this invention includes: a mass block 1, a frame 4, a right-angled support beam 2 connecting the mass block 1 and the frame 4, a stress-sensing biomimetic perforated accelerometer 3 connecting the mass block 1 and the frame 4, and stress-sensing biomimetic perforations 301 distributed on the sensitive beam 3. The right-angled support beam 2 is connected to the four sides of the mass block 1; the sensitive beam 3 with the stress-sensing biomimetic perforations 301 is connected to the four corners of the mass block 1.

[0060] like Figure 1 As shown in Figure 6, a double-layer multi-beam accelerometer based on biomimetic slits according to an embodiment of the present invention includes: a mass block 1, a support beam 2 containing right angles, a sensitive beam 3, and a frame 4.

[0061] Among them, such as Figure 3 As shown, the support beam 2 containing right angles includes a fixed end 201 and a connecting end 202.

[0062] Among them, such as Figure 4 As shown, the sensitive beam 3 with stress-sensing biomimetic perforated slots includes:

[0063] The stress-sensing bionic slit 301 is located near the frame 4 or mass block 1 on the sensitive beam 3.

[0064] A varistor 302 is disposed on the upper surface of the sensitive beam 3 and arranged around the stress-sensing bionic aperture 301; the frame 4 is connected to the support beam 2 containing right angles and the sensitive beam 3 of the stress-sensing bionic aperture 301; the mass block 1 and the support beam 2 containing right angles and the sensitive beam 3 form a double-layer structure.

[0065] In this embodiment of the invention, a right-angled support beam connects the mass block and the frame, and a stress-sensing bionic perforated slit connects the mass block and the frame. The right-angled support beam and the stress-sensing bionic perforated slit are on different planes, and the two constitute a double-layer beam structure.

[0066] In this embodiment of the invention, when the sensor is subjected to acceleration, the mass block causes the cantilever beam to deform under the action of force, which causes strain on the strain resistors to generate strain, resulting in a change in resistance. The Wheatstone bridge formed by these resistors will generate a voltage output when the resistance changes, thus converting the external acceleration change into a change in output voltage.

[0067] In embodiments of the present invention, such as Figure 1As shown, the sensor detection layer is a MEMS structure employing piezoresistive sensing. A force-sensing structure is etched onto it. The cantilever beam consists of a sensitive beam 3 and a support beam 2 containing right angles. The sensitive beam 3 contains a stress-sensing structure. Here, MEMS stands for micro-electronics mechanical system.

[0068] In this embodiment of the invention, a biomimetic slit-based double-layer multi-beam accelerometer, when subjected to acceleration, causes the mass block 1 to move under the action of inertial force, and the cantilever beam connected to it (i.e., the support beam 2 and the sensitive beam 3 together form a cantilever beam) to deform, causing the resistance value of the varistor on the sensitive beam 3 to change. The Wheatstone bridge formed by them will generate a voltage output when the resistance value of the varistor changes, thus converting the external acceleration change into a change in output voltage. The signal acquisition line transmits the sensor signal.

[0069] It is worth noting that, such as Figure 2 As shown, the right-angled support beam 2 is a beam that is perpendicularly connected to each other. One end of the right-angled support beam 2 is connected to the frame 4 as a fixed end, and the other end is connected to the mass block 1 as a connecting end. This invention can increase the length of the beam through the right-angle design. Compared with a straight beam, the right-angled beam has lower stiffness, and the support beam is more likely to deform under stress, thus improving the sensitivity of the sensor. It is worth noting that the right-angled support beam 2 is not limited to one right angle. The number of right angles can be increased according to the needs of the scenario, such as setting it into a spiral multi-right-angle beam structure. In this way, the more right angles there are, the lower the stiffness of the beam, and the greater the deformation under stress. That is, the structural stiffness is reduced, the beam is more likely to deform, and the higher the sensitivity can be measured, which is suitable for high-sensitivity scenarios.

[0070] The stiffness coefficient of the accelerometer in this embodiment of the invention is negatively correlated with the fixed end beam length *a* and the connecting end beam length *b* of the right-angled support beam 2, but positively correlated with the thickness *t* and width *w* of the right-angled support beam. Therefore, the relevant parameters of the beam can be changed according to the application scenario during design. For example, the natural frequency of the accelerometer can be increased by decreasing the fixed end beam length *a* and the connecting end beam length *b* of the right-angled support beam 2 and increasing the beam thickness *t* and width *w*. Preferably, in this embodiment of the invention, the thickness of the sensitive beam can be small and thin, while the thickness and width of the right-angled support beam are relatively large, affecting the natural frequency of the system. For example, the thickness ratio of the right-angled support beam to the sensitive beam is greater than or equal to 2:1, and the sum of their thicknesses is less than the thickness of the mass block.

[0071] In embodiments of the present invention, such as Figure 3As shown, the sensitive beam 3 is provided with stress-sensing bionic perforated slots 301. These slots 301 are located on the sensitive beam 3, which is small and thin. The structure of the stress-sensing bionic perforated slots 301 on the sensitive beam 3 increases the effective stress on the sensitive beam 3, thereby improving the sensor's measurement sensitivity. The stress-sensing bionic perforated slots 301 penetrate the sensitive beam 3 and are bionic transverse slots on the sensitive beam 3. These transverse slots are arranged in parallel on each sensitive beam 3. The number of stress-sensing bionic perforated slots 301 can be determined according to the application scenario. When a more precise stress sensing is required, the number of stress-sensing bionic perforated slots 301 can be increased. By increasing the number of stress-sensing bionic perforated slots 301, more precise stress sensing can be achieved.

[0072] In this embodiment of the invention, the two ends of the stress-sensing bionic aperture 301 are semi-circular structures, which disperse stress and make the structure of the sensitive beam 3 more stable. Preferably, the aspect ratio of the stress-sensing bionic aperture 301 is in the range of 0.1-100, and the length of the piezoresistor on each sensitive beam 3 is less than or equal to the width and length of all the stress-sensing bionic apertures 301 etched on that sensitive beam 3.

[0073] In embodiments of the present invention, such as Figure 1 As shown, there are four sensitive beams 3, which extend from the four corners of the mass block 1 respectively. The four sensitive beams 3 are placed along one axis of the mass block 1 and aligned with the edge of the mass block 1 to increase structural stability. Each side of the mass block 1 is connected to a sensitive beam 3. The four sensitive beams 3 are centrally symmetrically distributed to constrain displacement in non-working directions and reduce cross coupling.

[0074] Of course, in specific embodiments of the present invention, the number of sensitive beams is not limited to four; the number of sensitive beams can be changed according to the application scenario. In this embodiment, the edges of the sensitive beams are aligned with the edges of the mass block to make the system more stable. If greater stress is desired, the number of sensitive beams can be appropriately reduced.

[0075] In one implementation, such as Figure 4 As shown, the biomimetic perforated accelerometer described in this embodiment is fabricated as a double-layer structure. The sensitive beam 3 with stress-sensing biomimetic perforated slits is connected to the upper surface of the mass block 1, and the support beam 2 is connected to the lower surface of the mass block 1. The mass block 1 and the support beam 2 together with the mass block 1 and the sensitive beam 3 form a double-layer structure, which enhances the lateral torsional stiffness.

[0076] In this invention, the support beam with right angles is connected to the lower surface of the mass block; the sensitive beam with biomimetic stress concentration holes is connected to the upper surface of the mass block; the two form a double-layer beam structure, which reduces the distance between the center of mass of the mass block and the center of mass of the beam, and the deformation of the beam is close to the state of direct tension and compression, effectively limiting the torsional effect of the mass block, while increasing the natural frequency of the system.

[0077] Of course, in another embodiment, the layer where the sensitive beam 3 is located and the layer where the right-angled support beam 2 is located are not fixed on a certain layer. The distance between the two layers can be changed according to the application scenario. The smaller the distance between the two layers, the lower the natural frequency of the system; the larger the distance, the higher the natural frequency of the system.

[0078] In this embodiment of the invention, when acceleration is applied in the working direction, the deformation of the microbeams (support beam 2 and sensitive beam 3) is close to that of direct tension and compression, effectively limiting the torsional effect of lateral acceleration on the mass block 1. Finite element analysis shows that Figure 5(a) represents the modal frequencies of the double-layer structure, and Figure 5(b) represents the modal frequencies of the single-layer structure. Compared with the single-layer structure, the system modal frequencies of the double-layer structure are significantly improved. Furthermore, the spacing between the double-layer structures can be changed according to the needs of the application scenario. Figure 5(c) shows that the system modal frequencies decrease when the spacing between the two layers is reduced.

[0079] In a preferred embodiment of the present invention, as shown in Figure 6, finite element analysis shows that setting the support beam 2 as a helical multi-right-angle beam, or changing the number of sensitive beams, can alter the structural stress. Figure 6(a) shows the equivalent stress analysis diagram of four support beams containing one right angle and four sensitive beams; Figure 6(b) shows the equivalent stress analysis diagram of two helical beams containing two right angles and four sensitive beams; Figure 6(c) shows the equivalent stress analysis diagram of four support beams containing right angles and two sensitive beams. The number and shape of the beams can be changed according to the application scenario. When the number of sensitive beams increases, the maximum stress of the system decreases, and the sensitivity decreases; when the number of sensitive beams decreases, the maximum stress of the system increases, and the sensitivity increases. When the number of right angles in the support beams containing right angles decreases, the maximum stress of the system decreases, and the sensitivity decreases. When the number of right angles increases, the maximum stress of the system increases, and the sensitivity increases.

[0080] Further preferably, the dimensions of a biomimetic perforated slit-based double-layer multi-beam accelerometer according to an embodiment of the present invention are as follows: the sensor size is 4300 μm * 4300 μm * 300 μm; the mass block size is 2500 μm * 2500 μm * 300 μm; the right-angled support beam has a connection end size of 500 μm * 200 μm * 100 μm and a fixed end size of 1600 μm * 300 μm * 100 μm; and the sensitive beam size is 600 μm * 300 μm * 50 μm. The bionic aperture slits are 160 micrometers long, 50 micrometers wide, and 50 micrometers apart. A varistor is set on both sides of the bionic aperture slit group. The varistor 302 is 80 micrometers long and 5 micrometers deep on both sides of the sensitive beam 3. The endpoints of the varistor 302 are set on the beam plane at both ends of the varistor. The endpoints are 10 micrometers * 10 micrometers in size and 5 micrometers deep, and are used to export the deformation information of the varistor 302. The copper leads are led out through the spacing between the three aperture slits to the pins located on the outside of the sensor.

[0081] In a preferred embodiment of the present invention, the dual-layer multi-beam accelerometer includes a first-layer multi-beam accelerometer 101 interconnected with each other (e.g., ...). Figure 7 (c) shown) and the second layer multi-beam accelerometer 102 (as shown in the image) Figure 7 (g) shown);

[0082] The first layer multi-beam accelerometer 101 includes:

[0083] First frame 41,

[0084] The first mass block 11 is disposed in the middle of the first frame 41; as shown Figure 7 As shown in (b);

[0085] Support beam 2, one end of which is connected to the lower surface of the first mass block 11 and the other end of which is connected to the first frame 41, the support beam 2 is provided with a right angle bend; it is a support beam containing right angles, the support beam 2 containing right angles is connected to the four sides of the first mass block 11;

[0086] The second-layer multi-beam accelerometer 102 includes:

[0087] Second frame 42,

[0088] The second mass block 21 is disposed in the middle of the second frame 42;

[0089] A sensitive beam 3 is provided, with one end connected to the upper surface of the second mass block 21 and the other end connected to the second frame 42. The sensitive beam 3 is provided with stress-sensing bionic holes 301. The sensitive beam with stress-sensing bionic holes is connected to the four corners of the second mass block.

[0090] In the above embodiments, the first layer multi-beam acceleration sensor 101 (such as...) Figure 7 (c) The second layer multi-beam accelerometer 102 is bonded together with silicon-silicon bonding to form the double-layer multi-beam accelerometer. The first frame 41 and the second frame 42 together form the frame 4 of the biomimetic slit-based double-layer multi-beam accelerometer described in this application. The first mass block 11 and the second mass block 21 together form the mass block 1 of the biomimetic slit-based double-layer multi-beam accelerometer described in this application.

[0091] Based on the above embodiments, such as Figure 7 (a) Figure 7 (b)- Figure 7 (c)- Figure 7 (d)- Figure 7 (e)- Figure 7 (f)- Figure 7 (g)- Figure 7 As shown in (h), the method for manufacturing the biomimetic aperture slit multi-beam accelerometer according to an embodiment of the present invention includes the following steps:

[0092] Step S100: Provide a first substrate (silicon wafer substrate) to fabricate a mass block-sensitive beam layer (i.e., the first layer multi-beam accelerometer 101):

[0093] Specifically, in this invention, a silicon wafer is used as the first substrate 10. A mass block and a stress-sensing structure are fabricated on the first substrate 10 (silicon wafer substrate), and leads are connected to obtain a mass block-sensitive beam layer (i.e., the first layer multi-beam accelerometer 101). Specifically, the process includes the following steps:

[0094] S1. The uniformity of subsequent piezoresistive ion implantation is improved by thermal oxidation to obtain a silicon dioxide layer to protect the silicon wafer surface, that is, to obtain the first substrate (silicon wafer substrate) 10;

[0095] S2. The back cavity is etched on the first substrate 10 (silicon wafer substrate) to obtain the first mass block 11 and the right-angled support beam frame (i.e., the first frame 41); as Figure 7 As shown in (b).

[0096] S3. A plurality of uniform first vias 12 are photolithographically etched around the first mass block 11 on the first substrate (silicon wafer substrate) 10. Right-angled support beams 2 are etched at the first vias 12; thus forming the mass block-sensitive beam layer (first layer multi-beam accelerometer 101). Figure 7 As shown in (c).

[0097] Step S200: Provide a second substrate (silicon wafer substrate) 20 to fabricate a mass block - containing a right-angled support beam layer (i.e., the second multi-beam accelerometer 102):

[0098] Specifically, in this invention, a silicon wafer is used as a substrate. A mass block 1 and a right-angled support beam 2 structure are fabricated on the second substrate (silicon wafer base) to obtain a mass block-right-angled support beam layer. Specifically, as... Figure 7 (e) Figure 7 (f)- Figure 7 (g)- Figure 7 As shown in (h), the steps include:

[0099] S21. The back cavity is etched on the second substrate 20 (silicon wafer substrate) to obtain the second mass block 21 and the sensitive beam frame (i.e., the second frame 42); as Figure 7 As shown in (e);

[0100] S22. Multiple second through holes 13 are etched to form a sensitive beam 3 at the second through holes 13; as shown in the example. Figure 7 As shown in (f);

[0101] S23 etches downwards on the sensitive beam 3, and etches stress-sensing bionic pore 301 according to the thickness of the sensitive beam 3; Figure 7 (g) is shown;

[0102] S24. Photolithography is used to print the surface of the sensitive beam 3 and the piezoresistive resistors 302 around the stress-sensing biomimetic aperture 301; as shown Figure 1 As shown;

[0103] S6. Metal sputtering is used to fabricate the leads, with copper selected as the top layer metal for the leads, forming the mass block-sensitive beam layer (i.e., the second multi-beam accelerometer 102); For example... Figure 7 (g) is shown;

[0104] Step S300: Fabricate the sensor:

[0105] Will Figure 7 (c) shows the mass block-sensitive beam layer (first layer multi-beam accelerometer 101), and... Figure 7(g) The mass block and the right-angled support beam layer (second-layer multi-beam accelerometer 102) shown in the figure are bonded together using silicon-silicon bonding to form a whole, resulting in a biomimetic pore-slit-based double-layer multi-beam accelerometer, as shown in the figure. Figure 8 As shown.

[0106] In summary, this invention discloses a bilayer multi-beam accelerometer based on biomimetic perforations, comprising a mass block, a frame, a right-angled support beam connecting the mass block and the frame, a sensitive beam with stress-sensing biomimetic perforations connecting the mass block and the frame, and stress-sensing biomimetic perforations distributed on the sensitive beam. The right-angled support beam is connected around the mass block; the sensitive beam with stress-sensing biomimetic perforations is connected around the mass block; the sensitive beam with stress-sensing biomimetic perforations includes: stress-sensing biomimetic perforations disposed near the frame or mass block; and a piezoresistor disposed on the upper surface of the sensitive beam, arranged around the perforations; the frame is connected to the right-angled support beam and the sensitive beam with biomimetic stress-sensing perforations; the mass block and the right-angled support beam and sensitive beam constitute a bilayer structure. When an acceleration signal is input, the mass block experiences a corresponding inertial force, causing a change in the resistance of the piezoresistor on the biomimetic microbeam with stress-sensing perforations. The stress concentration in the perforations is converted into a voltage value proportional to the acceleration value via a Wheatstone bridge, thus measuring the acceleration signal. The right-angled support beam and the sensitive beam are connected in two layers, ensuring both a high natural frequency and high sensitivity. The perforations on the sensitive beam concentrate stress, improving the sensor's sensitivity, while the right-angled support beam ensures the accelerometer has both high sensitivity and a sufficient natural frequency. This allows for more flexible accelerometer design, achieving a balanced improvement in both natural frequency and sensitivity.

[0107] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A double-layer multi-beam accelerometer based on biomimetic aperture slits, characterized in that, include: frame, A mass block, wherein the mass block is disposed in the middle of the frame; A support beam, one end of which is connected to a mass block and the other end of which is connected to a frame, wherein the support beam is provided with a right-angle bend; the support beam containing right angles is connected to the four sides of the mass block. A sensitive beam, one end of which is connected to a mass block and the other end to a frame, and the sensitive beam is provided with stress-sensing bionic holes and slots; Sensitive beams with stress-sensing biomimetic perforations are connected to the four corners of the mass block; The sensitive beam with stress-sensing bionic pores is connected to the upper surface of the mass block, and the support beam is connected to the lower surface of the mass block. The support beam and the sensitive beam form a double-layer structure. The stress-sensing bionic slits are bionic transverse slits on the sensitive beams, and the bionic transverse slits on each sensitive beam are arranged in parallel. The stress-sensing bionic aperture is disposed on the sensitive beam, and the stress-sensing bionic aperture penetrates the sensitive beam; the supporting beam is configured as a spiral multi-right-angle beam. The two ends of the stress-sensing bionic slit have a semi-circular structure. The thickness ratio of the support beam containing the right angle to the sensitive beam is greater than or equal to 2:1, and the sum of their thicknesses is less than the thickness of the mass block.

2. The biomimetic aperture-based double-layer multi-beam accelerometer according to claim 1, characterized in that, The support beams are mutually perpendicular and connected at right angles.

3. The biomimetic aperture-based double-layer multi-beam accelerometer according to claim 1, characterized in that, The sensitive beam with stress-sensing biomimetic perforations includes: Stress-sensing biomimetic pores are positioned near the frame or mass block of the sensitive beam. A piezoresistor is disposed on the upper surface of the sensitive beam and arranged around the stress-sensing biomimetic aperture.

4. The biomimetic perforated slit-based double-layer multi-beam accelerometer according to claim 1, characterized in that, The four sensitive beams extend from the four corners of the mass block, are placed along one axis of the mass block, and are aligned with the edge of the mass block. The four sensitive beams are centrally symmetrically distributed.

5. The biomimetic aperture-based double-layer multi-beam accelerometer according to claim 1, characterized in that, The right-angled support beams are beams that are perpendicularly connected to each other. One end of the right-angled support beam is a fixed end connected to the frame, and the other end is a connecting end connected to the lower surface of the mass block.

6. The biomimetic aperture-based double-layer multi-beam accelerometer according to claim 2, characterized in that, A support beam containing right angles has one end connected to the frame as a fixed end and the other end connected to a mass block as a connecting end. However, a support beam containing right angles may include one or more right angles.

7. The biomimetic aperture-based double-layer multi-beam accelerometer according to claim 3, characterized in that, The number of the sensitive beams is four or fewer; When the number of sensitive beams is four, the four sensitive beams are arranged along one axis of the mass block and aligned with the edge of the mass block.

8. The biomimetic aperture-based double-layer multi-beam accelerometer according to claim 1, characterized in that, The dual-layer multi-beam accelerometer includes a first-layer multi-beam accelerometer and a second-layer multi-beam accelerometer connected together. The first layer of multi-beam accelerometers includes: First framework, A first mass block is disposed in the middle of the first frame; A support beam, one end of which is connected to the lower surface of the first mass block and the other end of which is connected to the first frame, the support beam having a right-angle bend; a support beam containing right angles, the support beam containing right angles being connected to the four sides of the first mass block; The second layer of multi-beam accelerometers includes: Second framework, The second mass block is disposed in the middle of the second frame; A sensitive beam is provided, with one end connected to the upper surface of the second mass block and the other end connected to the second frame. The sensitive beam is provided with stress-sensing bionic holes. The sensitive beam with stress-sensing bionic holes is connected to the four corners of the second mass block.

9. A method for fabricating a biomimetic perforated slit-based double-layer multi-beam accelerometer, characterized in that, Includes the following steps: Provide the first substrate to fabricate the first layer of the multi-beam accelerometer: S1. The uniformity of subsequent piezoresistive ion implantation is improved by thermal oxidation to obtain a silicon dioxide layer to protect the silicon wafer surface, thus obtaining the first substrate; S2. Etch the back cavity on the first substrate to obtain the first mass block and the support beam frame containing right angles; S3. Photolithography is used to form support beams with right angles around the first mass block on the first substrate to obtain the first multi-beam accelerometer. Provide a second substrate for fabricating a second-layer multi-beam accelerometer: S21. The back cavity is etched on the second substrate to obtain the first mass block and the sensitive beam frame; S22. Etching to form a plurality of second vias, and etching at the second vias to form the sensitive beam with its long axis oriented toward the center of the substrate; S23. Etch downwards on the sensitive beam to create stress-sensing biomimetic pores based on the thickness of the sensitive beam; S24. Photolithography is used to create the surface of the sensitive beam and the piezoresistive resistors around the stress-sensing biomimetic apertures; S25. Metal sputtering is used to fabricate the leads, with copper selected as the top layer metal to form the second layer of the multi-beam accelerometer sensor; Sensor fabrication: The first-layer multi-beam accelerometer and the second-layer multi-beam accelerometer are connected by silicon-silicon bonding to form a whole, thus obtaining the biomimetic pore-slit-based double-layer multi-beam accelerometer.

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