MEMS structure for removing biological clots

Abstract

The invention relates to the technical field of medical instruments, and discloses an MEMS structure for removing biological clots, the MEMS structure comprises a substrate and a piezoelectric actuating part, the substrate comprises a substrate layer and an SOI layer, the substrate layer is provided with a first flow groove, an extrusion electrode and a second flow groove are defined on the SOI layer, the extrusion electrode can extrude the biological clots in a reciprocating manner, and the piezoelectric actuating part is arranged on the substrate layer. The second flow groove and the first flow groove define a flow cavity, the substrate layer and the SOI layer form a first one-way conduction piece, the first one-way conduction piece is configured to be opened when the volume of the flow cavity is increased and is also configured to be closed when the volume of the flow cavity is decreased, and the extrusion electrode, the first one-way conduction piece and the flow cavity are sequentially distributed in the second direction; and the piezoelectric actuating part can drive the SOI layer directly facing the flow cavity to move along a third direction so as to change the volume of the flow cavity. According to the MEMS structure for removing the biological clots, the biological clots can be more efficiently removed on the premise that damage to blood vessels is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a MEMS structure for removing biological clots. BACKGROUND

[0002] Thrombus aspiration is an interventional therapy for intravascular thrombus obstruction. It reaches the thrombus site through a catheter and directly removes the thrombus by negative pressure. However, for fibrotic old thrombus or high-load thrombus, simple aspiration is inefficient and often incomplete, and even causes distal embolism due to fragmentation of the biological clot. The existing mechanical removal device has a high failure rate when dealing with complex biological clots, and some patients need a second operation, increasing the medical burden. Since biological clot obstruction can cause acute ischemic stroke, myocardial infarction and other severe conditions, there is an urgent need for a device that can efficiently, safely and completely remove biological clots. SUMMARY

[0003] Based on the above, the purpose of the present application is to provide a MEMS structure for removing biological clots, which can more efficiently remove biological clots while reducing damage to blood vessels, thereby increasing the success probability of the operation.

[0004] To achieve the above purpose, the present application adopts the following technical solutions:

[0005] A MEMS structure for removing biological clots, defining two perpendicular first, second and third directions, comprising:

[0006] a substrate comprising a substrate layer and an SOI layer stacked, the substrate layer being provided with a first flow groove, the SOI layer being provided with an extrusion electrode and a second flow groove, the extrusion electrode being capable of driving the biological clots to move along the second direction to reciprocally extrude the biological clots, the second flow groove and the first flow groove forming a flow cavity, the substrate layer and the SOI layer forming a first unidirectional conduction piece, the first unidirectional conduction piece being configured to open when the volume of the flow cavity increases, and being configured to close when the volume of the flow cavity decreases, the extrusion electrode, the first unidirectional conduction piece and the flow cavity being distributed along the second direction in sequence;

[0007] a piezoelectric actuating part arranged on the SOI layer and opposite to the flow cavity, the piezoelectric actuating part being capable of driving the SOI layer opposite to the flow cavity to move along the third direction to change the volume of the flow cavity.

[0008] As a preferred solution of the MEMS structure for removing biological clots, the first one-way conducting piece comprises a first stopper formed on the SOI layer and a first stopper sheet formed on the substrate layer, the first stopper sheet is configured to be separated from the first stopper when the volume of the flow cavity increases, and is configured to be in abutment with the first stopper when the volume of the flow cavity decreases.

[0009] As a preferred solution of the MEMS structure for removing biological clots, the SOI layer further comprises a clamping part and a clamping electrode, the clamping electrode is capable of driving the clamping part to move in a first direction to close the clamping part to clamp the biological clots or to open the clamping part to release the biological clots.

[0010] As a preferred solution of the MEMS structure for removing biological clots, the MEMS structure for removing biological clots further comprises a connecting arm, the clamping electrode is a planar electrode, a movable electrode plate of the planar electrode is arranged on the connecting arm, the SOI layer comprises a clamping cantilever capable of stretching and contracting in a second direction and deforming in the first direction, one end of the clamping cantilever is connected to the connecting arm, the other end of the connecting arm is connected to the clamping part, the clamping part comprises a first clamping jaw and a second clamping jaw arranged opposite to each other, and the inner sides of the first clamping jaw and the second clamping jaw are respectively provided with clamping grooves.

[0011] As a preferred solution of the MEMS structure for removing biological clots, the MEMS structure for removing biological clots further comprises a cover plate, the cover plate is fixed on the side of the SOI layer away from the substrate layer, and the cover plate is provided with a relief hole opposite to the piezoelectric actuating part.

[0012] As a preferred solution of the MEMS structure for removing biological clots, the cover plate is provided with a first relief groove on the side close to the SOI layer, the first relief groove is arranged opposite to the clamping part, the cross-sectional area of the first relief groove gradually increases in the direction close to the flow cavity along the second direction, the substrate layer is provided with a second relief groove opposite to the first relief groove, the cross-sectional area of the second relief groove gradually increases in the direction close to the flow cavity along the second direction, and the cross-sectional area of the region of the clamping part opposite to the first relief groove gradually decreases in the direction close to the flow cavity along the second direction.

[0013] As a preferred solution of the MEMS structure for removing biological clots, the extrusion electrode is an extrusion comb electrode, the extrusion comb electrode comprises a plurality of extrusion fixed combs and a plurality of extrusion movable combs, and the plurality of extrusion fixed combs and the plurality of extrusion movable combs are staggered in sequence.

[0014] As a preferred solution of the MEMS structure for removing biological clots, the piezoelectric actuating part comprises an electric connection layer, a protective layer, and a first piezoelectric layer, a lower electrode layer, a second piezoelectric layer, and an upper electrode layer which are sequentially stacked, the protective layer is wrapped outside the first piezoelectric layer, the lower electrode layer, the first piezoelectric layer, and the upper electrode layer, and the lower electrode layer and the upper electrode layer are electrically connected with the electric connection layer respectively.

[0015] As a preferred solution of the MEMS structure for removing biological clots, the lower electrode layer and the upper electrode layer are both molybdenum layers, the first piezoelectric layer and the second piezoelectric layer are both aluminum nitride layers, and the protective layer is a silicon dioxide passivation layer.

[0016] As a preferred solution of the MEMS structure for removing biological clots, an exhaust port is arranged on the substrate and communicates with the flow cavity, a second one-way valve is arranged upstream of the exhaust port, and the second one-way valve is configured to be closed when the volume of the flow cavity increases and is configured to be opened when the volume of the flow cavity decreases.

[0017] The present application has the following beneficial effects:

[0018] The MEMS structure for removing biological clots disclosed in the present application can repeatedly squeeze and knead the biological clots to squeeze out the particulate matters in the biological clots and reduce the volume of the biological clots, and the piezoelectric actuating part can reciprocate along the third direction to increase or reduce the volume of the flow cavity, so that the air pressure in the flow cavity is reduced or increased, the first one-way valve is opened or closed, and the biological clots with reduced volume are sucked into the flow cavity. Compared with directly sucking the biological clots by means of negative pressure, the damage to the blood vessel wall is smaller, the damage to the blood vessel is reduced, the biological clots can be more thoroughly removed, and the success probability of the operation is increased. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the contents of the embodiments of the present application and the drawings.

[0020] Figure 1 is a schematic diagram of the MEMS structure for removing biological clots provided by the specific embodiments of the present application;

[0021] Figure 2 is a partial structure schematic diagram of the MEMS structure for removing biological clots provided by the specific embodiments of the present application;

[0022] Figure 3is a cross-sectional view of a MEMS structure for removing biological clots provided by specific embodiments of the present application;

[0023] Figure 4 is a top view of a piezoelectric actuating part of a MEMS structure for removing biological clots provided by specific embodiments of the present application.

[0024] in the figure:

[0025] 1, substrate layer; 101, first flow groove; 102, discharge port; 103, second avoiding groove; 11, first baffle; 12, second baffle;

[0026] 2, SOI layer; 20, flow cavity; 201, bottom silicon layer; 202, buried oxygen layer; 203, top silicon layer; 21, squeeze electrode; 211, squeeze fixed comb tooth; 212, squeeze movable comb tooth; 22, first stop block; 23, clamping part; 230, clamping groove; 231, first clamping jaw; 232, second clamping jaw; 24, clamping electrode; 241, planar fixed electrode; 242, planar movable electrode; 25, connecting arm; 26, clamping suspension beam;

[0027] 3, piezoelectric actuating part; 31, electric connection layer; 32, lower electrode layer; 33, first piezoelectric layer; 34, upper electrode layer; 35, second piezoelectric layer; 36, protective layer;

[0028] 4, cover plate; 401, avoiding hole; 402, first avoiding groove. DETAILED DESCRIPTION

[0029] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present application will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] The embodiment provides a MEMS structure for removing biological clots, which defines a first direction, a second direction and a third direction perpendicular to each other, as shown in the figure. Figures 1 to 4 The MEMS structure for removing biological clots comprises a substrate and a piezoelectric actuating part 3, the substrate comprises a substrate layer 1 and an SOI layer 2 stacked together, the substrate layer 1 is provided with a first flow groove 101, and the SOI layer 2 is provided with an extrusion electrode 21 and a second flow groove (not shown in the figure), the extrusion electrode 21 can drive the biological clots to move along the second direction to repeatedly extrude the biological clots, the second flow groove and the first flow groove 101 form a flow cavity 20, and the substrate layer 1 and the SOI layer 2 form a first one-way conducting part, which is configured to open when the volume of the flow cavity 20 increases, and is configured to close when the volume of the flow cavity 20 decreases, and the extrusion electrode 21, the first one-way conducting part and the flow cavity 20 are sequentially distributed along the second direction. The piezoelectric actuating part 3 is arranged on the SOI layer 2 and opposite to the flow cavity 20, and the piezoelectric actuating part 3 can drive the SOI layer 2 opposite to the flow cavity 20 to move along the third direction to change the volume of the flow cavity 20.

[0033] The MEMS structure for removing biological clots provided by the embodiment can repeatedly extrude and knead the biological clots to squeeze out the particulate matters in the biological clots and reduce the volume of the biological clots, and the piezoelectric actuating part 3 can reciprocate along the third direction to increase or reduce the volume of the flow cavity 20, so that the air pressure in the flow cavity 20 decreases or increases, the first one-way conducting part is opened or closed, and the biological clots with reduced volume are sucked into the flow cavity 20. Compared with directly sucking the biological clots by means of negative pressure, the damage to the blood vessel wall is smaller, the damage to the blood vessel is reduced, the biological clots can be more completely removed, and the success probability of the operation is increased.

[0034] Specifically, the biological clots of the embodiment are thrombi, and the particulate matters are red blood cells, and the extrusion electrode 21 can repeatedly extrude and knead the thrombi to squeeze out the red blood cells in the thrombi. As shown in the figure. Figure 3As shown, the SOI layer 2 of the embodiment includes a bottom silicon layer 201, a buried oxygen layer 202, and a top silicon layer 203, the first direction is the X-axis direction, the second direction is the Y-axis direction, and the third direction is the Z-axis direction. In other embodiments, the first direction can also be the Y-axis direction, in which case the second direction is the X-axis direction and the third direction is the Z-axis direction, and the actual setting is based on actual needs. In other embodiments, the biological clot can also be a blood clot, a fibrin clot, or other structures formed by the aggregation of blood components, and the particulate matter can also be cell fragments, micro-particles, or other substances.

[0035] As shown in Figure 1 and Figure 2 , the first one-way conducting piece of the embodiment includes a first stop block 22 formed on the SOI layer 2 and a first stop sheet 11 formed on the substrate layer 1. The first stop sheet 11 is configured to separate from the first stop block 22 when the volume of the flow cavity 20 increases, and is also configured to abut against the first stop block 22 when the volume of the flow cavity 20 decreases. That is, the first stop sheet 11 can swing with the change of the air pressure in the flow cavity 20, abut against or separate from the first stop block 22, realize the closing or opening of the first one-way conducting piece, and thus prevent the biological clot from entering the flow cavity 20 or suck the compressed biological clot into the flow cavity 20.

[0036] As shown in Figure 1 and Figure 2 , the SOI layer 2 of the embodiment further includes a clamping portion 23 and a clamping electrode 24. The clamping electrode 24 can drive the clamping portion 23 to move along the first direction, so as to clamp or release the biological clot. The added clamping portion 23 can clamp the biological clot when the extrusion electrode 21 extrudes the biological clot, preventing the biological clot from moving around.

[0037] Specifically, as shown in Figure 2 , the MEMS structure for removing biological clots further includes a connecting arm 25, the clamping electrode 24 is a planar electrode including a planar fixed electrode 241 and a planar movable electrode 242, the planar movable electrode 242 is arranged on the connecting arm 25, the SOI layer 2 is formed with a clamping cantilever beam 26 that can stretch and contract along the second direction and deform along the first direction, the clamping cantilever beam 26 is connected to one end of the connecting arm 25, the other end of the connecting arm 25 is connected to the clamping portion 23, and the clamping portion 23 includes a first clamping jaw 231 and a second clamping jaw 232 arranged opposite to each other. The inner sides of the first clamping jaw 231 and the second clamping jaw 232 are each provided with a clamping groove 230. The clamping groove 230 can increase the friction between the biological clot and the first clamping jaw 231 and the second clamping jaw 232, reduce the probability of the biological clot being extruded by the extrusion electrode 21, and enable the biological clot to be fully kneaded, so as to completely extrude the particulate matter in the biological clot and facilitate subsequent suction of the biological clot.

[0038] As Figure 1 shown, the MEMS structure for removing biological clots of the embodiment further comprises a cover plate 4 fixed on the side of the SOI layer 2 away from the substrate layer 1, and the cover plate 4 is provided with a clearance hole 401 opposite the piezoelectric actuating part 3, the clearance hole 401 penetrates the cover plate 4 along the thickness direction of the cover plate 4, and the clearance hole 401 can prevent the cover plate 4 from hindering the movement of the piezoelectric actuating part 3 in the third direction, thereby ensuring the normal operation of the piezoelectric actuating part 3.

[0039] Specifically, as Figure 1 shown, the side of the cover plate 4 close to the SOI layer 2 is further provided with a first clearance groove 402 opposite the clamping part 23, the cross-sectional area of the first clearance groove 402 gradually increases along the direction close to the flow cavity 20 in the second direction, and the substrate layer 1 is provided with a second clearance groove 103 opposite the first clearance groove 402, the cross-sectional area of the second clearance groove 103 gradually increases along the direction close to the flow cavity 20 in the second direction, and the cross-sectional area of the region of the clamping part 23 opposite the first clearance groove 402 gradually decreases along the direction close to the flow cavity 20 in the second direction, that is, the front ends of the first clamping jaw 231 and the second clamping jaw 232 are wedge-shaped, and along the flow direction, the flow area between the first clamping jaw 231 and the second clamping jaw 232 gradually decreases. The above-mentioned structure of the MEMS structure for removing biological clots facilitates the entry of biological clots between the first clamping jaw 231 and the second clamping jaw 232, reduces the probability of biological clots entering from the cover plate 4 or the substrate layer 1, facilitates subsequent extrusion of biological clots, ensures that biological clots are fully kneaded, thereby more thoroughly sucking in biological clots, and achieving the removal of biological clots.

[0040] As Figure 2 shown, the extrusion electrode 21 of the embodiment is an extrusion comb electrode, which comprises a plurality of extrusion fixed combs 211 and a plurality of extrusion movable combs 212, and the plurality of extrusion fixed combs 211 and the plurality of extrusion movable combs 212 are staggered and distributed in sequence. Before the biological clots are sucked into the flow cavity 20, the piezoelectric actuating part 3 does not work, the first one-way conducting piece is in a closed state, and the biological clots are blocked outside the first baffle 11, the extrusion movable combs 212 reciprocate along the second direction, the distance between the extrusion movable combs 212 and the extrusion fixed combs 211 along the second direction reciprocally increases and decreases, thereby achieving the extrusion of biological clots and extruding particulate matters in the biological clots, and achieving the effect of reducing the volume of biological clots.

[0041] As Figure 3 and Figure 4As shown, the piezoelectric actuating part 3 includes an electric connection layer 31, a protection layer 36, and a first piezoelectric layer 33, a lower electrode layer 32, a second piezoelectric layer 35, and an upper electrode layer 34 which are sequentially stacked, the protection layer 36 is wrapped outside the first piezoelectric layer 33, the lower electrode layer 32, the first piezoelectric layer 33, and the upper electrode layer 34, and the lower electrode layer 32 and the upper electrode layer 34 are electrically connected with the electric connection layer 31. Further, the lower electrode layer 32 and the upper electrode layer 34 are both molybdenum layers, the first piezoelectric layer 33 and the second piezoelectric layer 35 are both aluminum nitride layers, and the protection layer 36 is a silicon dioxide passivation layer. It should be noted that in other embodiments of the present application, the first piezoelectric layer 33 and the second piezoelectric layer 35 can also be PZT layers or piezoelectric layers made of other piezoelectric materials, the upper electrode layer 34 and the lower electrode layer 32 can also be titanium layers, platinum layers, or other conductive electrode layers, and the protection layer 36 can also be a silicon nitride layer or other passivation layer. The protection layer 36 can be one layer or two layers, which is set according to actual needs.

[0042] As shown in Figure 1 , the substrate of the present embodiment is further provided with a discharge port 102 which communicates with the flow cavity 20, and a second one-way conducting member is arranged upstream of the discharge port 102. The second one-way conducting member is configured to be closed when the volume of the flow cavity 20 increases, and is configured to be opened when the volume of the flow cavity 20 decreases. Specifically, the second one-way conducting member includes a second stop block (not shown in the figure) formed on the SOI layer 2 and a second stop sheet 12 formed on the substrate layer 1. The second stop sheet 12 is configured to abut against the second stop block when the volume of the flow cavity 20 increases, and is configured to be separated from the second stop block when the volume of the flow cavity 20 decreases. That is, the second stop sheet 12 can swing with the change of the air pressure in the flow cavity 20, abut against or be separated from the first stop block 22, so as to realize the closing or opening of the second one-way conducting member, thereby sucking the biological clot into the flow cavity 20 or discharging the biological clot in the flow cavity 20.

[0043] It should be noted that the piezoelectric actuating part 3 shown in the present embodiment Figure 1 and Figure 2 is only a schematic view, and the specific structure is as shown in Figure 3 and Figure 4 . The shape of the piezoelectric actuating part 3 is circular, and the number is two, and the longitudinal section of the flow cavity 20 is rectangular. In other embodiments, the shape of the piezoelectric actuating part 3 can also be rectangular or other shapes, the number of the piezoelectric actuating part 3 can also be one or more than two, and the longitudinal section of the flow cavity can also be other shapes, which is selected and set according to actual needs.

[0044] The MEMS structure for removing biological coagulation of the embodiment has the advantages of structural consistency and process compatibility in structural design, the integrated structure avoids the assembly error and interface effect of the conventional assembled MEMS device, and can ensure the accurate alignment and reliable connection between the functional units; in the manufacturing process, the structure is fully compatible with the conventional MEMS processing technology, such as photolithography, etching, thin film deposition, etc., and can be manufactured in batches by using the standard semiconductor production line, and has the advantages of high yield and low cost; in addition, the MEMS structure for removing biological coagulation is designed as a disposable type, and is particularly suitable for the medical field, and the one-time use characteristic can meet the strict hygiene requirements and the convenience requirement while maintaining high performance. Through optimization of material and process parameters, the MEMS structure for removing biological coagulation realizes economic mass production under the premise of ensuring the integrity of the function.

[0045] It should be noted that the above are only the preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A MEMS structure for clearing biological clots, characterized by, Defining a first direction, a second direction and a third direction perpendicular to each other, comprising: A substrate comprising a substrate layer and an SOI layer stacked, the substrate layer is provided with a first flow groove, the SOI layer is provided with an extrusion electrode and a second flow groove, the extrusion electrode can drive the biological clot to move along the second direction to reciprocally extrude the biological clot, the second flow groove and the first flow groove form a flow cavity, the substrate layer and the SOI layer form a first one-way conducting piece, the first one-way conducting piece is configured to open when the volume of the flow cavity increases, and is configured to close when the volume of the flow cavity decreases, the extrusion electrode, the first one-way conducting piece and the flow cavity are sequentially distributed along the second direction; A piezoelectric actuating part is arranged on the SOI layer and opposite to the flow cavity, the piezoelectric actuating part can drive the SOI layer opposite to the flow cavity to move along the third direction to change the volume of the flow cavity.

2. The MEMS structure for clearing biological clots according to claim 1, wherein, The first one-way conducting piece comprises a first stopper and a first stopper sheet, the first stopper is formed on the SOI layer, the first stopper sheet is formed on the substrate layer, the first stopper sheet is configured to separate from the first stopper when the volume of the flow cavity increases, and is configured to abut against the first stopper when the volume of the flow cavity decreases.

3. The MEMS structure for clearing biological clots according to claim 1, wherein, The SOI layer is further provided with a clamping part and a clamping electrode, the clamping electrode can drive the clamping part to move along the first direction to close or open the biological clot.

4. The MEMS structure for clearing biological clots according to claim 3, wherein, The MEMS structure for removing biological clot further comprises a connecting arm, the clamping electrode is a planar electrode, a movable electrode plate of the planar electrode is arranged on the connecting arm, the SOI layer is provided with a clamping cantilever which can stretch and contract along the second direction and deform along the first direction, one end of the connecting arm is connected with the clamping cantilever, the other end of the connecting arm is connected with the clamping part, the clamping part comprises a first clamping jaw and a second clamping jaw arranged opposite to each other, the inner side of the first clamping jaw and the second clamping jaw are provided with clamping grooves.

5. The MEMS structure for clearing biological clots according to claim 3, wherein, The MEMS structure for removing biological clot further comprises a cover plate, the cover plate is fixed on the side of the SOI layer away from the substrate layer, the cover plate is provided with a avoiding hole opposite to the piezoelectric actuating part.

6. The MEMS structure for clearing biological clots according to claim 5, wherein, The side of the cover plate close to the SOI layer is provided with a first avoiding groove, the first avoiding groove is arranged opposite to the clamping part, the cross-sectional area of the first avoiding groove gradually increases along the direction close to the flow cavity, the substrate layer is provided with a second avoiding groove opposite to the first avoiding groove, the cross-sectional area of the second avoiding groove gradually increases along the direction close to the flow cavity, the cross-sectional area of the region of the clamping part opposite to the first avoiding groove gradually decreases along the direction close to the flow cavity.

7. The MEMS structure for clearing biological clots of claim 1, wherein, The extrusion electrode is an extrusion comb tooth electrode, the extrusion comb tooth electrode comprises a plurality of extrusion fixed comb teeth and a plurality of extrusion movable comb teeth, the plurality of extrusion fixed comb teeth and the plurality of extrusion movable comb teeth are sequentially staggered.

8. The MEMS structure for clearing biological clots of claim 1, wherein, The piezoelectric actuating part comprises an electric connection layer, a protective layer, and a first piezoelectric layer, a lower electrode layer, a second piezoelectric layer and an upper electrode layer which are sequentially stacked, the protective layer is wrapped outside the first piezoelectric layer, the lower electrode layer, the first piezoelectric layer and the upper electrode layer, and the lower electrode layer and the upper electrode layer are electrically connected with the electric connection layer respectively.

9. The MEMS structure for clearing biological clots according to claim 8, wherein, The lower electrode layer and the upper electrode layer are both molybdenum layers, the first piezoelectric layer and the second piezoelectric layer are both aluminum nitride layers, and the protective layer is a silicon dioxide passivation layer.

10. The MEMS structure for clearing biological clots of claim 1, wherein, An outlet is arranged on the base and communicates with the flow cavity, a second one-way conducting member is arranged upstream of the outlet, and the second one-way conducting member is configured to be closed when the volume of the flow cavity increases and is configured to be opened when the volume of the flow cavity decreases.

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