MEMS micropump

Abstract

An MEMS micropump capable of suppressing backflow, the micropump comprising: a silicon layer, which has a first surface and a second surface which are opposite each other, wherein a pump diaphragm, an inlet valve, an outlet valve and a pump cavity are etched on the first surface and the second surface; a first sealing layer, which is connected to the first surface and covers the first surface to form the pump cavity; a second sealing layer, which is connected to the second surface, wherein a driving channel configured to connect a pump diaphragm driver is provided in the portion of the second sealing layer corresponding to the pump diaphragm; and the outlet valve has a first structure which limits deformation in the opposite direction to liquid output and which is configured to ameliorate poor sealing caused by the deformation of the outlet valve when the outlet blocking pressure increases. By means of designing the structure of the outlet valve so as to improve the pressure resistance of the outlet valve, the outlet valve does not easily deform when the outlet blocking pressure increases, thereby avoiding poor sealing due to deformation and reducing the occurrence of backflow.

Description

MEMS micropumps Cross-reference to related applications

[0001] This application claims priority to Chinese patent application No. CN 2025100298733, filed on January 8, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure pertains to a micropump structure designed and manufactured using microelectromechanical systems (MEMS) technology, and particularly relates to a MEMS micropump capable of suppressing backflow. Background Technology

[0003] MEMS micropumps are actuators designed and manufactured using microelectromechanical systems (MEMS) technology, enabling fluid delivery and control on a microscale. Their pumping accuracy and rate are ideal for the injection of sustained-release or micro-volume medications such as insulin, anesthetics, and analgesics.

[0004] The main principle of MEMS micropumps is to utilize the movement of the pump diaphragm to cause a change in the volume of the pump chamber, creating a pressure difference between the chamber and the outside. This pressure difference is used to open and close valves, thereby achieving fluid pumping. See the applicant's prior Chinese patent CN118775225A.

[0005] In practical applications, some medications (such as insulin) crystallize at room temperature, causing blockages in the outlet fluid path and generating blockage pressure. When the pump chamber of the MEMS micropump is under negative pressure, the high blockage pressure can cause the medication to flow back into the insulin pump, reducing pumping accuracy. Therefore, blockage pressure is one of the important performance indicators for insulin pump design.

[0006] For MEMS micropumps, the blocking pressure generally occurs at the outlet. When the blocking pressure is low, the outlet valve of the MEMS micropump can close the valve by its own elasticity (as shown in Figures 1 and 2), preventing the liquid from flowing back into the pump chamber 13. When the blocking pressure is high (>101 kPa), the outlet valve 16 of the MEMS micropump undergoes slight deformation under the pressure, causing the upper valve body 1672 to separate from the top glass 2, resulting in the liquid entering the pump chamber 13 (as shown in Figure 3), i.e., backflow, which affects the pumping accuracy.

[0007] The information disclosed in the background section is only intended to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this disclosure is to provide a MEMS micropump that can suppress backflow, in order to solve the backflow problem that may occur when the outlet pressure of the MEMS micropump is high.

[0009] One aspect of this disclosure provides a MEMS micropump, including a silicon layer, the silicon layer including a body, a pump cavity etched onto the body, and an outlet valve, the outlet valve including a valve body having a liquid outlet channel having an inlet end and an outlet end, the inlet end communicating with the pump cavity; wherein...

[0010] The outlet valve's liquid outlet end is covered by a first diaphragm, which has a first state and a second state. In the first state, there is a gap between the first diaphragm and the valve body that allows liquid to flow out of the pump chamber. In the second state, the first diaphragm adheres to the valve body to seal the liquid outlet end; or,

[0011] The valve body of the outlet valve includes a first valve block and a second valve block. The liquid outlet channel passes through the first valve block and the second valve block in sequence. The first valve block is disposed on the second valve block and extends toward a sealing layer. The first valve block is configured to have a plane that can adhere to the sealing layer under the action of liquid pressure from one side of the second valve block.

[0012] In some embodiments, the valve body includes a first valve body having a first liquid outlet channel having a first liquid inlet and a first liquid outlet, the first liquid inlet communicating with the pump chamber; a first diaphragm configured to cover the first liquid outlet, wherein in the first state, there is a gap between the first diaphragm and the first valve body allowing liquid to flow out of the pump chamber; and in the second state, the first diaphragm adheres to the first valve body to close the first liquid outlet.

[0013] In some embodiments, the first diaphragm is suspended from the body by a first cantilever beam.

[0014] In some embodiments, the body further comprises a cavity corresponding to the first cantilever beam, the cavity and the first valve body being located on the same side of the first diaphragm, the cavity having an open end, and at least a portion of the first cantilever beam covering the open end. In some embodiments, the side of the cavity opposite to the open end is closed by a sealing plate, and the cavity and the first liquid outlet channel are independent of each other and not connected.

[0015] In some embodiments, the first diaphragm is suspended from the body by a plurality of first cantilever beams, the plurality of first cantilever beams being spaced apart along the circumferential direction of the first diaphragm.

[0016] In some embodiments, the first diaphragm and the first cantilever beam are positioned in a plane.

[0017] In some embodiments, a first sink is formed on the surface of the silicon layer, and the first diaphragm is suspended in the first sink. In some embodiments, the first cantilever beam is disposed on the bottom wall of the first sink, and the open end of the cavity corresponding to the first cantilever beam is formed on the bottom wall of the first sink.

[0018] In some embodiments, the first diaphragm is positioned in a plane, and there is a greater than zero gap between the first diaphragm and the surface of the silicon layer.

[0019] In some embodiments, the first diaphragm is placed on the bottom wall of the first settling tank.

[0020] In some embodiments, the first outlet end of the first valve body is formed on the bottom wall of the first settling tank.

[0021] In some embodiments, the silicon layer further includes a second diaphragm surrounding the first valve body, the first valve body being connected to the body via the second diaphragm, the second diaphragm having a thickness less than the thickness of the first valve body so as to be elastically deformable.

[0022] In some embodiments, the first sink is located on a first side of the second diaphragm, and a cavity is provided on a second side of the second diaphragm, wherein the first side and the second side are opposite sides of the second diaphragm.

[0023] In some embodiments, the outlet valve further includes a second valve body, the second valve body having a second liquid outlet channel, the second liquid inlet of the second liquid outlet channel being exposed in the pump chamber, a connecting channel connecting the second liquid outlet of the second liquid outlet channel and the first liquid inlet of the first liquid outlet channel of the first valve body, the first liquid inlet being connected to the pump chamber through the connecting channel and the second liquid outlet channel.

[0024] In some embodiments, the silicon layer has opposite first and second surfaces, with the first liquid outlet end of the first liquid outlet channel and the second liquid inlet end of the second liquid outlet channel close to the first surface and facing the first surface, and the first liquid inlet end of the first liquid outlet channel and the second liquid outlet end of the second liquid outlet channel close to the second surface and facing the second surface.

[0025] In some embodiments, the second valve body is connected to the main body via an annular third diaphragm, the thickness of which is less than that of the second valve body to allow for elastic deformation.

[0026] In some embodiments, a first sealing layer is connected to a first surface of the silicon layer, the second valve body and the first sealing layer are in contact with each other to seal the second inlet end of the second outlet channel through the first sealing layer, and the third diaphragm is capable of allowing the second valve body to move away from the first sealing layer under the action of external force to form a gap that allows liquid to flow from the pump chamber into the second outlet channel.

[0027] In some embodiments, the first sealing layer is provided with an outlet channel that can communicate with the first outlet end of the first outlet channel.

[0028] In some embodiments, a second sealing layer is connected to the second surface of the silicon layer, and a first anti-bonding protrusion is provided on the second sealing layer. The first valve body abuts against the first anti-bonding protrusion, and the first inlet end of the first liquid outlet channel is provided on the side wall of the first valve body.

[0029] In some embodiments, the valve body includes an outlet valve body, wherein the outlet end of the outlet flow channel of the outlet valve body is connected to an outlet flow channel, and viewed along the direction of the outlet flow channel of the outlet valve body, the first valve block of the outlet valve body is a closed ring surrounding the outlet flow channel, and the first valve block is located in the middle of the second valve block of the outlet valve body. The plane that can conform to the sealing layer is the top surface of the first valve block.

[0030] In some embodiments, when viewed along the direction of the liquid outlet flow channel of the outlet valve body, the first valve block and the second valve block are concentric rings, and the dimension of the first valve block along its diameter is smaller than the dimension of the second valve block along its diameter.

[0031] In some embodiments, the valve body includes an outlet valve body comprising a plurality of first valve blocks. Viewed along the liquid outlet channel of the outlet valve body, each first valve block is a closed ring surrounding the liquid outlet channel, and the plurality of first valve blocks are concentric rings. The aforementioned plane capable of conforming to the sealing layer includes the top surface of at least one first valve block.

[0032] In some embodiments, when viewed along the direction of the liquid outlet flow channel of the outlet valve body, one of the plurality of first valve blocks is located at the inner edge of the second valve block of the outlet valve body.

[0033] In some embodiments, a first sealing layer is connected to the first surface of the silicon layer, and when the blocking pressure of the outlet flow channel is greater than a set value, the first valve block remains pressed against the first sealing layer.

[0034] In some embodiments, the second valve block is connected to the body via a thinned film portion; and / or, the liquid outlet channel is disposed on the first sealing layer.

[0035] In some embodiments, the silicon layer further includes an inlet valve etched onto the body, the inlet valve comprising:

[0036] A third valve body has a liquid inlet channel, the liquid inlet channel having a third liquid inlet end and a third liquid outlet end, the third liquid outlet end being connected to the pump chamber; and

[0037] A fourth diaphragm covers the third outlet end. In its first state, the fourth diaphragm and the third valve body have a gap that allows liquid to flow into the pump chamber. In its second state, the fourth diaphragm adheres to the third valve body to close the third outlet end.

[0038] In some embodiments, the fourth diaphragm is suspended from the body by a second cantilever beam.

[0039] In some embodiments, a second sink is formed on the surface of the silicon layer, and the fourth diaphragm is suspended in the second sink.

[0040] In some embodiments, the fourth diaphragm is placed on the bottom wall of the second settling tank.

[0041] In some embodiments, the third outlet end of the third valve body is located on the bottom wall of the second settling tank.

[0042] In some embodiments, the body further comprises a cavity corresponding to the second cantilever beam, the cavity and the third valve body being located on the same side of the fourth diaphragm, the cavity having an open end, and at least a portion of the second cantilever beam covering the open end. In some embodiments, the open end of the cavity is formed on the bottom wall of the second settling tank.

[0043] In some embodiments, a first sealing layer is connected to a first surface of the silicon layer, and a second sealing layer is connected to a second surface of the silicon layer. The first sealing layer or the second sealing layer is provided with an outlet flow channel communicating with the first liquid outlet end of the first valve body. A pump membrane is etched and formed on the body. A portion of the boundary of the pump cavity is defined by the pump membrane. The second sealing layer is provided with a drive channel for engaging a pump membrane driver. At least a portion of the pump membrane is exposed in the drive channel.

[0044] In some embodiments, the first diaphragm is a silicon film formed by etching silicon material, and the first valve body, the first diaphragm, and the main body are integrally formed. The second diaphragm may also be a silicon film formed by etching silicon material.

[0045] Another aspect of this disclosure provides a MEMS micropump capable of suppressing backflow, comprising:

[0046] A silicon layer having a first and a second opposing surface, on which a pump diaphragm, an inlet valve, an outlet valve, and a pump chamber are etched;

[0047] A first sealing layer is attached to the first surface and is configured to cover the first surface to seal the pump cavity;

[0048] The second sealing layer is connected to the second surface, and the second sealing layer has a drive channel for connecting the pump membrane driver at the position corresponding to the pump membrane.

[0049] The outlet valve has a first structure that restricts its own deformation in the opposite direction of liquid discharge, which is used to reduce poor sealing caused by outlet valve deformation when the outlet blockage pressure increases.

[0050] In some embodiments, the first structure is a cantilever beam and a cavity located on the underside of the cantilever beam;

[0051] In some embodiments, the first structure is a first protrusion disposed in the middle;

[0052] In some embodiments, the first structure is a plurality of first bumps.

[0053] In some embodiments, the outlet valve includes a first diaphragm and a first valve body that are separated from each other and attached together. The outlet valve also includes a first cantilever beam, the first diaphragm being connected to the first cantilever beam. A first liquid outlet channel is provided in the first valve body, the first liquid outlet channel having an inlet end and an outlet end. The first diaphragm is covered on the outlet side of the first liquid outlet channel. A second diaphragm is provided on the edge of the outlet end of the first valve body, and a third cavity is etched on the inlet side of the second diaphragm.

[0054] In some embodiments, the second sealing layer is provided with a first anti-bonding protrusion that abuts against the first valve body in the direction of the first diaphragm.

[0055] In some embodiments, a fourth cavity is provided on the liquid-inflow side of the first cantilever beam to reduce micro-forces.

[0056] In some embodiments, the inlet valve includes a fourth diaphragm and a third valve body bonded together. The inlet valve also includes a second cantilever beam. The fourth diaphragm is connected to the second cantilever beam. The third valve body has an inlet channel with an inlet end and an outlet end. The fourth diaphragm covers the outlet side of the inlet channel. A fifth diaphragm is provided at the edge of the outlet end of the third valve body. A first cavity is etched on the inlet side of the fifth diaphragm.

[0057] In some embodiments, the second sealing layer is provided with a second anti-bonding protrusion that abuts against the third valve body in the direction of the fourth diaphragm.

[0058] In some embodiments, a second cavity is provided on the liquid-incoming side of the second cantilever beam to reduce micro-forces.

[0059] In some embodiments, the outlet valve further includes a second valve body, in which a second liquid outlet channel is formed. The second valve body includes an upper valve block and a back valve block connected together. The upper valve block is located on the liquid inlet side of the back valve block, and the second liquid outlet channel passes through the upper valve block and the back valve block.

[0060] In some embodiments, the upper valve block is located at the radial midpoint of the rear valve block from the center to the edge.

[0061] In some embodiments, there are two upper valve blocks, each surrounding the second liquid outlet channel, with one of the upper valve blocks located at the radial center of the rear valve block.

[0062] In some embodiments, one of the upper valve blocks is a closed-loop structure, and the other upper valve block has a notch.

[0063] The MEMS micropump disclosed herein, which can suppress backflow, enhances the pressure resistance of the outlet valve by designing its structure, making the outlet valve less prone to deformation when the outlet blockage pressure increases. This avoids poor sealing caused by deformation and reduces the occurrence of backflow. Attached Figure Description

[0064] The following sections will describe some specific embodiments of this disclosure in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art will understand that these drawings are not necessarily drawn to scale. In the drawings:

[0065] Figure 1 is a cross-sectional view of a pump structure in the prior art along its long side. The content can be found in the applicant's prior Chinese patent "CN118775225A".

[0066] Figure 2 is a cross-sectional view of a pump structure in the prior art along the short side;

[0067] Figure 3 shows the situation when the blockage pressure of the outlet flow channel of the structure in Figure 2 is large, in which the outlet valve is deformed, resulting in poor sealing and easy backflow of medicine.

[0068] Figure 4a is an exploded view of Embodiment 1 of this disclosure, in which a portion of some of the components is cut away along the long side of the micropump;

[0069] Figure 4b shows the first side of a silicon layer according to Embodiment 1 of this disclosure.

[0070] Figure 4c shows the second side of a silicon layer according to Embodiment 1 of this disclosure.

[0071] Figure 5 is an exploded view of Embodiment 1 of this disclosure, in which a portion of some of the components is cut away along the short side of the micropump;

[0072] Figure 6 is an enlarged view of point C in Figure 4;

[0073] Figure 7 is an enlarged view of point D in Figure 5;

[0074] Figure 8 is a schematic diagram of the fluid flow direction during pumping in Embodiment 1 of this disclosure;

[0075] Figure 9 shows the flow direction of fluid in the first valve body and the second valve body in Embodiment 1 of this disclosure;

[0076] Figure 10 is an enlarged view of point F in Figure 9, where the first diaphragm is in the first state;

[0077] Figure 11 is a schematic diagram of the structure in Figure 10 when the outlet blockage pressure is large, where the first diaphragm is in the second state;

[0078] Figure 12 is a schematic diagram of the structure of the outlet valve in Embodiment 2 of this disclosure;

[0079] Figure 13 is a cross-sectional view of Embodiment 2 of this disclosure, showing a cross-section of the fluid flow channel;

[0080] Figure 14 is a schematic diagram of the structure in Figure 13 when the outlet blocking pressure is large.

[0081] Figure 15 is an exploded view of Embodiment 3 of this disclosure, in which a portion of some of the components has been cut away;

[0082] Figure 16 is a cross-sectional view of Embodiment 3 of this disclosure, showing a cross-section of the fluid flow channel;

[0083] Figure 17 is an exploded view of Embodiment 4 of this disclosure, in which a portion of some of the components has been cut away;

[0084] Figure 18 is an exploded view of Embodiment 5 of this disclosure, in which a portion of some of the components has been cut away;

[0085] Figure 19 is an exploded view of the micropump of Embodiment 6 of this disclosure along its long side, with some parts of some components being cut away.

[0086] Figure 20 is an exploded view of the micropump of Embodiment 6 of this disclosure along the short side, with some parts of some components being cut away.

[0087] Figure 21 is a cross-sectional view of the micropump of Embodiment 7 of this disclosure along the short side.

[0088] The reference numerals in the attached figures are explained as follows:

[0089] 1 - Silicon layer; 10 - Body; 11 - First surface; 111 - First settling tank; 112 - Second settling tank; 113 - Intermediate flow channel; 12 - Second surface; 13 - Pump chamber; 14 - Pump diaphragm; 15 - Inlet valve; 151 - Fourth diaphragm; 152 - Third valve body; 1521 - Inlet flow channel; 153 - Second cantilever beam; 154 - Fifth diaphragm; 155 - First cavity; 156 - Second cavity; 16 - Outlet valve; 161 - First diaphragm; 162 - First valve body; 1621 - First outlet flow channel; 1622 - Notch; 163 - First cantilever beam; 164 - Second diaphragm; 165 - Third cavity; 166 - Fourth cavity; 167 - Second valve body; 1671 - Second outlet flow channel; 1672 - Upper valve block; 16721 - Notch; 1673 - Back valve block; 168 - Connecting flow channel; 169 - Third diaphragm;

[0090] 2 - First sealing layer; 21 - Outlet flow channel;

[0091] 3 - Second sealing layer; 31 - Drive channel; 32 - First anti-bonding protrusion; 33 - Inlet flow channel; 34 - Second anti-bonding protrusion;

[0092] 4 – Outlet valve body; 41 – Liquid outlet channel; 42 – First valve block; 421 – Notch; 43 – Second valve block; 45 – Diaphragm section. Detailed Implementation

[0093] The technical solutions of this disclosure will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0094] Example 1

[0095] Figures 4a to 4c and 5 illustrate an embodiment of a MEMS micropump. The MEMS micropump includes a silicon layer 1, a first sealing layer 2, and a second sealing layer 3. The first sealing layer 2 is connected to a first surface 11 of the silicon layer 1, and the second sealing layer 3 is connected to a second surface 12 of the silicon layer 1. The first sealing layer 2, the silicon layer 1, and the second sealing layer 3 are stacked sequentially. The first surface 11 and the second surface 12 are two opposite surfaces of the silicon layer 1.

[0096] Referring to Figures 4b and 4c, silicon layer 1 can be formed by etching a single piece of silicon material, making it a monolithic component. Silicon layer 1 includes a body 10, and further includes a pump chamber 13, a pump diaphragm 14, an inlet valve 15, and an outlet valve 16 etched onto the body 10. The pump diaphragm 14 has a portion of the silicon material that has been thinned by localized etching. A portion of the lower boundary of the pump chamber 13 is defined by the pump diaphragm 14, and the upper boundary of the pump chamber 13 is defined by a first sealing layer 2. The pump chamber 13 is sealed by the first sealing layer 4.

[0097] The first sealing layer 2 or the second sealing layer 3 is provided with an inlet channel and an outlet channel. The inlet channel is connected to an inlet valve 15 to supply liquid to the pump chamber 13, and the outlet channel is connected to an outlet valve 16 to allow liquid to flow out of the pump chamber 13. In this embodiment, the second sealing layer 3 is provided with an inlet channel 33, and the first sealing layer 2 is provided with an outlet channel 21; while in some other embodiments, the outlet channel may be provided on the second sealing layer 2 or the inlet channel may be provided on the first sealing layer 2. The second sealing layer 3 is provided with a drive channel 31 for engaging the pump membrane actuator, and at least a portion of the pump membrane 14 is exposed in the drive channel 31.

[0098] An outlet valve 16 is provided at the fluid outlet of the pump chamber 13. The outlet valve 16 includes a second valve body 167 and a first valve body 162.

[0099] Figure 5 shows that the second valve body 167 includes an upper valve block 1672 and a rear valve block 1673, with a second liquid outlet channel 1671 passing through the middle. The second valve body 167 is adjacent to the pump chamber 13.

[0100] As shown in Figure 7, the outlet valve 16 includes a first diaphragm 161, a first valve body 162, and a first cantilever beam 163, formed by etching the first surface 11 (upper surface) and the second surface 12 (lower surface) of the silicon layer 1. The first diaphragm 161 and the first valve body 162 are phase-separated. A first liquid outlet channel 1621 is provided in the first valve body 162, which has a first inlet end and a first outlet end. A notch 1622 is provided on the side of the first valve body 162, which communicates with the first inlet end of the first liquid outlet channel 1621. During pumping, fluid flows out from bottom to top in the first liquid outlet channel 1621. The first diaphragm 161 covers the first outlet end of the first valve body 162. Three first cantilever beams 163 are provided on the outer edge of the first diaphragm 161. The first cantilever beams 163 provide support for the first diaphragm 161 and use elasticity to reset the first diaphragm 161 downwards. The first valve body 162 acts as the valve seat for the first diaphragm 161.

[0101] Specifically, the first diaphragm 161 is configured to cover the first liquid outlet end, and the first diaphragm 161 has two states. In the first state, there is a gap between the first diaphragm 161 and the first valve body 162 that allows liquid to flow out of the pump chamber 13, as shown in Figure 10; in the second state, the first diaphragm 161 is attached to the first valve body 162 to seal the first liquid outlet end, as shown in Figure 11. A first sink 111 is formed on the surface (first surface 11) of the silicon layer 1, and the first diaphragm 161 is suspended in the first sink 111 by a plurality of first cantilever beams 163. The plurality of first cantilever beams 163 are spaced apart along the circumference of the first diaphragm 161. The first diaphragm 161 and the first cantilever beams 163 are positioned in a plane that is lower than the first surface 11 of the silicon layer 1, thereby providing space for the first diaphragm 161 to deform slightly upward; for example, the first diaphragm 161 can be placed on the bottom wall of the first sink 111. The first outlet end of the first valve body 162 is located on the bottom wall of the first settling tank 161. The outlet channel 21 is connected to the first settling tank 111 and is offset from directly above the first diaphragm 161. When there is a large blocking pressure on the outlet side, the first diaphragm 161 is pressed downward and slightly deformed downward, thereby pressing it against the first valve body 162 to seal the first outlet end and prevent backflow.

[0102] The body 10 also has a cavity (fourth cavity 166) corresponding to the first cantilever beam 163. The fourth cavity 166 and the first valve body 162 are located on the same side of the first diaphragm 161 (both are located on the lower side). The fourth cavity 166 has an open end (upper end). At least a part of the first cantilever beam 163 covers the open end. Thus, when the blocking pressure at the outlet is large, the first cantilever beam 163 deforms downward. Multiple first cantilever beams 163 flatten and unfold the first diaphragm 161, making it tightly fit against the first liquid outlet end of the first valve body 162. In addition, each fourth cavity 166 is an independent closed cavity, independent of the first liquid outlet flow channel 1621 of the first valve body 162, and the two are not connected. Specifically, the open end of the second cavity 156 is opened on the bottom wall of the first settling tank 111, the lower end of the fourth cavity 166 is closed by the second sealing plate 3, and the second cavity 166 is closed by the body 10.

[0103] By providing a fourth cavity 166 on the liquid-incoming side (below) of the first cantilever beam 163, the contact area between the first cantilever beam 163 and the bottom silicon can be reduced, the effects of micro-forces such as electrostatic force and capillary force can be reduced, and the adsorption of the first cantilever beam 163 can be prevented, thus preventing the first diaphragm 161 from opening.

[0104] The first valve body 162 has a second diaphragm 164 at its outlet edge, and the second diaphragm 164 is annular. A third cavity 165 is etched on the inlet side of the second diaphragm 164. The third cavity 165 removes the silicon layer material on the inlet side of the second diaphragm 164. A first anti-bonding protrusion 32 is provided on the second sealing layer 3 to prevent the first valve body 162 from bonding with the second sealing layer 3. The first anti-bonding protrusion 32 can also push the first valve body 162 upward, so that the first valve body 162 and the first diaphragm 161 fit tightly together, increasing the sealing performance. Due to the elasticity of the second diaphragm 164, the first valve body 162 is easily pushed up. The first diaphragm 161, the first cantilever beam 163, the second diaphragm 164 and the first valve body 162 are all formed by etching the silicon material of the silicon layer 1 and are integral with the body 10.

[0105] When pumping fluid, the fluid flow direction is as shown in Figures 8, 9, and 10. The fluid passes through the second valve body 167 and the connecting channel 168 (connecting the second valve body 167 and the first valve body 162) in sequence, pushes up the first diaphragm, and flows out from the outlet channel 21.

[0106] As shown in Figure 11, when the outlet blockage pressure increases, that is, when a blockage appears in the outlet flow channel 21, causing an increase in pressure in the flow channel ahead of the blockage, the pressure acts on the first diaphragm 161, causing the first diaphragm 161 to fit tightly against the first valve body 162. Furthermore, because the first diaphragm 161 is designed to be small, it is not easily deformed, which effectively prevents fluid from entering the micro-pump through the outlet flow channel 21, thus suppressing backflow.

[0107] Furthermore, the outlet valve 16 also includes a second valve body 167, on which a second liquid outlet channel 1671 is provided. The second inlet end of the second liquid outlet channel 1671 can be exposed in the pump chamber 13. A connecting channel 168 connects the second outlet end of the second liquid outlet channel 1671 and the first inlet end of the first liquid outlet channel 1621 of the first valve body 162. The first inlet end is connected to the pump chamber 13 through the connecting channel 168 and the second liquid outlet channel 1671. The first outlet end of the first liquid outlet channel 1621 and the second inlet end of the second liquid outlet channel 1671 are close to and face the first surface 11, that is, they are both located on the upper side; the first inlet end of the first liquid outlet channel 1621 and the second outlet end of the second liquid outlet channel 1671 are close to and face the second surface 12, that is, they are both located on the lower side.

[0108] The second valve body 167 is connected to the main body 10 via an annular third diaphragm 169. The thickness of the third diaphragm 169 is less than that of the second valve body 167 to allow for elastic deformation. The second valve body 167 and the first sealing layer 2 are in contact with each other to seal the second inlet end of the second outlet channel 1671 through the first sealing layer 2. The third diaphragm 169 can allow the second valve body 167 to move away from the first sealing layer 1 under the action of external force to form a gap that allows liquid to flow from the pump chamber 13 into the second outlet channel 1671.

[0109] The second valve body 167 specifically includes an upper valve block 1672 and a rear valve block 1673. The rear valve block 1673 is connected to the main body through a third diaphragm 169. The second valve body 167 is provided with a second liquid outlet channel 1671. During pumping, the fluid flows from the upper end to the lower end of the second liquid outlet channel 1671. The upper end of the second liquid outlet channel 1671 is connected to the pump chamber 13, and the lower end is connected to the outlet channel 21.

[0110] As shown in Figure 6, the inlet valve 15 in this example also has a double-diaphragm structure similar to the outlet valve shown in Figure 7. The inlet valve 15 includes a fourth diaphragm 151, a third valve body 152, and a second cantilever beam 153. The fourth diaphragm 151 is connected to the second cantilever beam 153, which provides support and reset power. The third valve body 152 has an inlet channel 1521 with an inlet end and an outlet end. The fourth diaphragm 151 covers and adheres to the outlet side of the inlet channel 1521.

[0111] Specifically, the fourth diaphragm 151 can cover the third outlet end. In its first state, the fourth diaphragm 151 has a gap between itself and the third valve body 152 that allows liquid to flow into the pump chamber 13; in its second state, the fourth diaphragm 151 is attached to the third valve body 152 to close the third outlet end. The fourth diaphragm 151 is also a thin film etched from silicon material and is integral with the body 10 and the second cantilever beam 153.

[0112] A second sink 112 is formed on the surface (first surface 11) of silicon layer 1, and the fourth diaphragm 151 is suspended in the second sink 112 by multiple second cantilever beams 153. The second sink 112 may be part of or connected to the pump chamber 13, and the second sink 112 provides space for the fourth diaphragm 151 to deform upward.

[0113] A cavity (specifically, a second cavity 156) is provided on the liquid inlet side (bottom) of the second cantilever beam 153. The second cavity 156 can reduce the contact area between the second cantilever beam 153 and the bottom silicon, reduce the effect of micro-forces such as electrostatic force and capillary force, and prevent the second cantilever beam 153 from adsorbing and preventing the fourth diaphragm 151 from being unable to open. The second cavity 156 and the third valve body 152 are located on the same side of the fourth diaphragm 151 (both are located on the lower side). The second cavity 156 has an open end (upper end), and at least a part of the second cantilever beam 153 covers the open end. Thus, when the liquid pressure in the pump chamber 13 is high, the second cantilever beam 153 deforms downward, and multiple second cantilever beams 153 pull the fourth diaphragm 151 flat and unfold, so that it fits tightly against the liquid outlet end of the third valve body 152. Furthermore, each second cavity 156 is an independent closed cavity, independent of the liquid inlet channel 1521 of the third valve body 152, and the two are not connected. Specifically, the open end of the second cavity 156 is opened on the bottom wall of the second settling tank 112, the lower end of the second cavity 156 is closed by the second sealing plate 3, and the second cavity 156 is surrounded by the body 10.

[0114] The third valve body 152 has a fifth diaphragm 154 at its outlet edge, and the fifth diaphragm 154 is annular. A first cavity 155 is etched on the inlet side of the fifth diaphragm 154. The first cavity 155 removes the silicon layer material on the inlet side of the fifth diaphragm 154. Fluid enters the inlet end of the third valve body 152 from the inlet channel 33 (see Figure 4), and then enters the inlet channel 1521.

[0115] Referring to Figures 6 and 4, the second sealing layer 3 is provided with a second anti-bonding protrusion 34, which can prevent the third valve body 152 from bonding with the second sealing layer 3. The second anti-bonding protrusion 34 can also push the third valve body 152 upward, so that the third valve body 152 and the fourth diaphragm 151 are tightly fitted together, increasing the sealing performance.

[0116] Silicon layer 1 can adopt an SOI (Silicon-On-Insulator) structure. The upper part (first surface 11) of silicon layer 1 is etched to form a pump chamber 13, a first sink 111, a second sink 112, a first diaphragm 161, a first cantilever beam 163, a fourth diaphragm 151, and a second cantilever beam 153. The lower part (second surface 12) of silicon layer 1 is etched to form multiple valve bodies and multiple cavities, including a first valve body 162, a third cavity 165, a fourth cavity 166, a third valve body 152, a second cantilever beam 163, and a third cantilever beam 163. The cantilever beam 153, the first cavity 155, and the second cavity 156 are then formed. Next, a thin insulating layer (e.g., a silicon dioxide layer) embedded between the upper and lower parts of the silicon layer 1 is etched to partially remove it, thereby releasing the diaphragm and the cantilever beam. This includes separating the first diaphragm 161 and the second cantilever beam 163 from the bottom wall of the first sink 111 and the first valve body 162 with a small gap, and separating the fourth diaphragm 151 and the second cantilever beam 153 from the bottom wall of the second sink 112 and the third valve body 152 with a small gap.

[0117] The double-layer diaphragm structure of the inlet valve 15 effectively reduces the impact of air bubbles on pumping accuracy. Existing technologies (such as Chinese Patent CN118775225A or as shown in Figure 1) have a narrow gap around the valve body, making it very easy for air bubbles to accumulate during pumping. Since this gap is connected to the pump chamber, the accumulated air bubbles affect pumping accuracy. However, in the double-layer design, the narrow gap around the third valve body 152 (the first cavity 155) is not connected to the pump chamber 13, thus eliminating the impact of air bubbles on pumping accuracy. The first diaphragm 161, the first cantilever beam 163, and the cavity below it constitute a structure that restricts the deformation of the outlet valve 16 in the opposite direction of its own liquid discharge.

[0118] Example 2

[0119] As shown in Figures 12 and 13, the outlet valve in this example has only one outlet valve body 4, corresponding to the structure in Figure 2. The outlet end of the liquid outlet channel 41 of the outlet valve body 4 is connected to the outlet channel 21. The outlet valve body 4 includes a first valve block 42 (corresponding to the upper valve block 1672 in Embodiment 1) and a second valve block 43 (corresponding to the back valve block 1673 in Embodiment 1), and the liquid outlet channel 41 passes through the first valve block 42 and the second valve block 43 in sequence. The second valve block 43 is connected to the body 10 of the silicon layer 1 through a thin film portion 45 with reduced thickness. The first valve block 42 is configured to be pressed onto the first sealing layer 2 by liquid pressure from the side of the second valve block 43. The first valve block 42 is disposed on the second valve block 43 and extends toward the first sealing layer 2 (upward). Viewed along the direction of the liquid outlet channel 41 of the outlet valve body 4, the first valve block 42 of the outlet valve body 4 is a closed ring surrounding the liquid outlet channel 41, and the first valve block 42 is located in the middle of the second valve block 43 of the outlet valve body 4. When the blockage pressure of the outlet flow channel 21 is greater than the set value, the first valve block 42 remains pressed on the first sealing layer 2 to prevent liquid from flowing back into the pump chamber 13.

[0120] Furthermore, looking along the direction of the outlet flow channel 41 of the outlet valve body 4, the first valve block 42 and the second valve block 43 are concentric rings, with the diameter of the first valve block 42 being smaller than that of the second valve block 43. The top surface of the first valve block 42 forms a plane that is always in contact with the first sealing layer 2. During pumping, the fluid flows from the upper end to the lower end of the outlet flow channel 41, with the upper end of the outlet flow channel 41 connecting to the pump chamber 13 and the lower end connecting to the outlet flow channel 21. Relative to the position of the upper valve block in Figure 2, the position of the first valve block 42 in this example is radially outward, approximately at the radial midpoint of the second valve block 43. As shown in Figure 14, when outlet blockage occurs and the pressure increases, the pressure acts on the second valve block 43. Due to the good support provided by the first valve block 42 for the second valve block 43, the second valve block 43 is less prone to deformation as shown in Figure 3, and its top surface remains in contact with the first sealing layer 2. Consequently, the first valve block 42 is less likely to separate from the first sealing layer 2, effectively preventing backflow problems. The first valve block 42 is configured to limit the deformation of the outlet valve 16 in the opposite direction of its own liquid discharge.

[0121] Example 3

[0122] As shown in Figures 15 and 16, the difference from Embodiment 2 is that the first valve block 42 (corresponding to the upper valve block 1672 in Embodiment 1) is provided in two rings, both surrounding the inlet end of the outlet flow channel 41. One ring of the first valve block 42 is located at the inner edge of the second valve block 43 (corresponding to the back valve block 1673 in Embodiment 1). When outlet blockage pressure occurs, the two rings of the first valve block 42 can effectively prevent the back valve block 43 from deforming. The top surface of at least one of the two rings of the first valve block 42 can always remain flat, so that it can always adhere to the first sealing layer 2 when outlet blockage pressure occurs. The two rings of the first valve block 42 constitute a structure that can limit the deformation of the outlet valve 16 in the opposite direction of its own liquid discharge.

[0123] Example 4

[0124] As shown in Figure 17, the difference between this embodiment and embodiment 3 is that the first valve block 42 on the outer ring is provided with a notch 421, which can increase the outflow rate of the fluid.

[0125] Example 5

[0126] As shown in Figure 18, the difference between this embodiment and embodiment 3 is that the first valve block 42 of the inner ring is provided with a notch 421, which can increase the outflow rate of the fluid.

[0127] Example 6

[0128] As shown in Figures 19 and 20, the difference between this example and Embodiment 1 is that the second valve body 167 is replaced with a flow channel orifice, and the first valve body 162 does not have a second diaphragm; instead, the first valve body 162 acts as a valve seat for the first diaphragm 161. The beneficial effect of this embodiment is that by replacing the original second valve body 167 with a flow channel orifice, the size of the outlet position can be further reduced, thereby reducing the overall size of the MEMS micropump and helping to lower the cost of the MEMS micropump.

[0129] Example 7

[0130] As shown in Figure 21, the difference between this embodiment and Embodiment 1 is that the outlet flow channel 21 is disposed on the second sealing layer 3. The silicon layer 1 is provided with an intermediate flow channel 113 extending in the vertical direction. The upper end of the intermediate flow channel 113 is connected to the first sink 111, and the lower end of the intermediate flow channel 113 is connected to the outlet flow channel 21 on the second sealing layer 3.

[0131] In summary, in the above embodiments, the structure of the outlet valve is designed to prevent deformation under outlet blockage pressure, thereby suppressing liquid backflow into the pump chamber 13 and improving pumping accuracy.

[0132] Features of the embodiments of this disclosure are set forth in the following terms:

[0133] Clause 1. A MEMS micropump capable of suppressing backflow, comprising:

[0134] A silicon layer (1) has a first surface (11) and a second surface (12) opposite to each other, on which a pump diaphragm (14), an inlet valve (15), an outlet valve (16) and a pump chamber (13) are etched.

[0135] A first sealing layer (2) is connected to the first surface (11) to cover the first surface (11) to form the pump cavity (13).

[0136] The second sealing layer (3) is connected to the second surface (12), and the second sealing layer (3) has a drive channel (31) for connecting the pump membrane driver at the position corresponding to the pump membrane (14).

[0137] The outlet valve (16) has a structure that restricts deformation in the opposite direction of liquid discharge, which is used to reduce poor sealing caused by deformation of the outlet valve (16) when the outlet blockage pressure increases.

[0138] Clause 2. The MEMS micropump capable of suppressing backflow as described in Clause 1, wherein the outlet valve (16) includes a third diaphragm (161) and a first valve body (162) that are phase-separated and bonded together, the outlet valve (16) further includes a first cantilever beam (163), the third diaphragm (161) is connected to the first cantilever beam (163), the first valve body (162) has a first liquid outlet channel (1621) with an inlet end and an outlet end, the third diaphragm (161) covers the outlet side of the first liquid outlet channel (1621), a fourth diaphragm (164) is provided at the edge of the outlet end of the first valve body (162), and a third cavity (165) is etched on the inlet side of the fourth diaphragm (164).

[0139] Clause 3. The MEMS micropump that can suppress backflow as described in Clause 2, wherein the second sealing layer (3) is provided with a first anti-bonding protrusion (32) that abuts against the first valve body (162) in the direction of the third diaphragm (161).

[0140] Clause 4. The MEMS micropump that can suppress backflow as described in Clause 2, wherein a fourth cavity (166) for reducing microforce is provided on the liquid-incoming side of the first cantilever beam (163).

[0141] Clause 5. The MEMS micropump capable of suppressing backflow as described in Clause 1, wherein the inlet valve (15) includes a first diaphragm (151) and a second valve body (152) bonded together, the inlet valve (15) further includes a second cantilever beam (153), the first diaphragm (151) is connected to the second cantilever beam (153), the second valve body (152) has an inlet channel (1521) with an inlet end and an outlet end, the first diaphragm (151) covers the outlet side of the inlet channel (1521), the outlet end edge of the second valve body (152) is provided with a second diaphragm (154), and the inlet side of the second diaphragm (154) is etched with a first cavity (155).

[0142] Clause 6. A MEMS micropump capable of suppressing backflow as described in Clause 5, wherein the second sealing layer (3) is provided with a second anti-bonding protrusion (34) that abuts against the second valve body (152) in the direction of the first diaphragm (151).

[0143] Clause 7. The MEMS micropump that can suppress backflow as described in Clause 5, wherein the second cantilever beam (153) is provided with a second cavity (156) on the liquid-incoming side to reduce microforces.

[0144] Clause 8. The MEMS micropump capable of suppressing backflow as described in Clause 1, wherein the outlet valve (16) includes a third valve body (167), the third valve body (167) having a through second liquid outlet channel (1671), the third valve body (167) including an upper valve block (1672) and a back valve block (1673) connected together, the upper valve block (1672) being located on the liquid inlet side of the back valve block (1673), and the second liquid outlet channel (1671) penetrating the upper valve block (1672) and the back valve block (1673).

[0145] Clause 9. A MEMS micropump capable of suppressing backflow as described in Clause 8, wherein the upper valve block (1672) is located at the radial midpoint of the rear valve block (1673) from the center to the edge.

[0146] Clause 10. A MEMS micropump capable of suppressing backflow as described in Clause 8, wherein the upper valve block (1672) is provided with two rings around the opening of the second outlet channel (1671), and one of the upper valve blocks (1672) is located at the radial center of the rear valve block (1673).

[0147] Clause 11. A MEMS micropump capable of suppressing backflow as described in Clause 10, wherein one of the upper valve blocks (1672) is a closed-loop structure and the other upper valve block (1672) has a notch (16721).

[0148] As indicated in this specification and claims, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0149] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “the,” and “the” used herein may also include the plural forms. It will be further understood that “multiple” in this disclosure refers to two or more, and other quantifiers are similarly understood.

[0150] It is further understood that the terms "first," "second," etc., are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.

[0151] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0152] The above embodiments are only for illustrating the technical concept and features of this disclosure, and are preferred embodiments. Their purpose is to enable those skilled in the art to understand the content of this disclosure and implement it accordingly, and they cannot be used to limit the scope of protection of this disclosure.

Claims

1. A MEMS micropump, comprising a silicon layer, the silicon layer including a body, a pump cavity etched onto the body, and an outlet valve, the outlet valve including a valve body having a liquid outlet channel having an inlet end and an outlet end, the inlet end communicating with the pump cavity; wherein, The outlet valve's liquid outlet end is covered by a first diaphragm, which has a first state and a second state. In the first state, there is a gap between the first diaphragm and the valve body that allows liquid to flow out of the pump chamber. In the second state, the first diaphragm adheres to the valve body to seal the liquid outlet end; or, The valve body of the outlet valve includes a first valve block and a second valve block. The liquid outlet channel passes through the first valve block and the second valve block in sequence. The first valve block is disposed on the second valve block and extends toward a sealing layer. The first valve block is configured to have a plane that can adhere to the sealing layer under the action of liquid pressure from one side of the second valve block.

2. The MEMS micropump according to claim 1, wherein, The valve body includes a first valve body having a first liquid outlet channel having a first liquid inlet end and a first liquid outlet end, the first liquid inlet end communicating with the pump chamber; a first diaphragm configured to cover the first liquid outlet end, the first diaphragm in the first state having a gap between the first diaphragm and the first valve body allowing liquid to flow out of the pump chamber; the first diaphragm in the second state being attached to the first valve body to seal the first liquid outlet end.

3. The MEMS micropump according to claim 2, wherein, The first diaphragm is suspended from the body by a first cantilever beam.

4. The MEMS micropump according to claim 3, wherein, The body is also provided with a cavity corresponding to the first cantilever beam. The cavity and the first valve body are located on the same side of the first diaphragm. The cavity has an open end, and at least a portion of the first cantilever beam covers the open end.

5. The MEMS micropump according to claim 4, wherein, The side of the cavity opposite to the open end is sealed by a sealing plate, and the cavity and the first liquid outlet channel are independent of each other; And / or, the first diaphragm is suspended from the body by a plurality of first cantilever beams, the plurality of first cantilever beams being spaced apart along the circumferential direction of the first diaphragm.

6. The MEMS micropump according to any one of claims 3 to 5, wherein, The first diaphragm and the first cantilever beam are positioned in a plane.

7. The MEMS micropump according to any one of claims 3 to 5, wherein, A first groove is formed on the surface of the silicon layer, and the first diaphragm is suspended in the first groove; The first diaphragm is positioned in a plane, and there is a gap greater than zero between the first diaphragm and the surface of the silicon layer.

8. The MEMS micropump according to claim 7, wherein, The first diaphragm is placed on the bottom wall of the first settling tank, and the first cantilever beam is located on the bottom wall of the first settling tank.

9. The MEMS micropump according to claim 7 or 8, wherein, The first outlet end of the first valve body is located on the bottom wall of the first settling tank.

10. The MEMS micropump according to claim 9, wherein, The silicon layer also includes a second diaphragm surrounding the first valve body, the first valve body being connected to the body via the second diaphragm, the second diaphragm being thinner than the first valve body so that it can be elastically deformed.

11. The MEMS micropump according to claim 10, wherein, The first settling groove is located on the first side of the second diaphragm, and a cavity is provided on the second side of the second diaphragm. The first side and the second side are opposite sides of the second diaphragm.

12. The MEMS micropump according to any one of claims 2 to 11, wherein, The outlet valve further includes a second valve body, which has a second liquid outlet channel. The second inlet end of the second liquid outlet channel can be exposed in the pump chamber. A connecting channel connects the second outlet end of the second liquid outlet channel and the first inlet end of the first liquid outlet channel of the first valve body. The first inlet end communicates with the pump chamber through the connecting channel and the second liquid outlet channel.

13. The MEMS micropump according to claim 12, wherein, The silicon layer has a first side and a second side with opposite orientations. The first liquid outlet end of the first liquid outlet channel and the second liquid inlet end of the second liquid outlet channel are close to the first side and face the first side. The first liquid inlet end of the first liquid outlet channel and the second liquid outlet end of the second liquid outlet channel are close to the second side and face the second side.

14. The MEMS micropump according to claim 12 or 13, wherein, The second valve body is connected to the main body via an annular third diaphragm, the thickness of which is less than that of the second valve body to allow for elastic deformation.

15. The MEMS micropump according to claim 14, wherein, A first sealing layer is connected to the first surface of the silicon layer. The second valve body and the first sealing layer are in contact with each other to seal the second inlet end of the second liquid outlet channel through the first sealing layer. The third diaphragm can allow the second valve body to move away from the first sealing layer under the action of external force to form a gap that allows liquid to flow from the pump chamber into the second liquid outlet channel.

16. The MEMS micropump according to claim 15, wherein, The first sealing layer is provided with an outlet channel that can communicate with the first liquid outlet end of the first liquid outlet channel.

17. The MEMS micropump according to any one of claims 2 to 16, wherein, A second sealing layer is connected to the second surface of the silicon layer. A first anti-bonding protrusion is provided on the second sealing layer. The first valve body abuts against the first anti-bonding protrusion. The first inlet end of the first liquid outlet channel is located on the side wall of the first valve body.

18. The MEMS micropump according to claim 1, wherein, The valve body includes an outlet valve body, the outlet end of the outlet flow channel of the outlet valve body is connected to an outlet flow channel, and viewed along the direction of the outlet flow channel of the outlet valve body, the first valve block of the outlet valve body is a closed ring surrounding the outlet flow channel, and the first valve block is located in the middle of the second valve block of the outlet valve body.

19. The MEMS micropump according to claim 18, wherein, Viewed along the direction of the liquid outlet flow channel of the outlet valve body, the first valve block and the second valve block are concentric rings, and the dimension of the first valve block along its diameter is smaller than the dimension of the second valve block along its diameter.

20. The MEMS micropump according to claim 1, wherein, The valve body includes an outlet valve body, which includes a plurality of first valve blocks. When viewed along the liquid outlet channel of the outlet valve body, each of the first valve blocks is a closed ring surrounding the liquid outlet channel, and the plurality of first valve blocks are in a concentric ring shape.

21. The MEMS micropump according to claim 20, wherein, Looking along the direction of the liquid outlet flow channel of the outlet valve body, one of the plurality of first valve blocks is located at the inner edge of the second valve block of the outlet valve body.

22. The MEMS micropump according to any one of claims 18 to 21, wherein, A first sealing layer is connected to the first surface of the silicon layer. When the blockage pressure of the outlet flow channel is greater than a set value, the first valve block remains pressed against the first sealing layer.

23. The MEMS micropump according to claim 22, wherein, The second valve block is connected to the body via a thinner membrane portion; and / or, the liquid outlet channel is located on the first sealing layer.

24. The MEMS micropump according to any of the preceding claims, wherein, The silicon layer further includes an inlet valve etched onto the body, the inlet valve comprising: A third valve body has a liquid inlet channel, the liquid inlet channel having a third liquid inlet end and a third liquid outlet end, the third liquid outlet end being connected to the pump chamber; and A fourth diaphragm covers the third outlet end. In its first state, the fourth diaphragm and the third valve body have a gap that allows liquid to flow into the pump chamber. In its second state, the fourth diaphragm adheres to the third valve body to close the third outlet end.

25. The MEMS micropump according to claim 24, wherein, The fourth diaphragm is suspended from the body by the second cantilever beam; the body is also provided with a cavity corresponding to the second cantilever beam, the cavity and the third valve body are located on the same side of the fourth diaphragm, the cavity has an open end, and at least a portion of the second cantilever beam covers the open end.

26. The MEMS micropump according to claim 24 or 25, wherein, A second sink is formed on the surface of the silicon layer, and the fourth diaphragm is suspended in the second sink.

27. The MEMS micropump according to claim 26, wherein, The fourth diaphragm is placed on the bottom wall of the second settling tank.

28. The MEMS micropump according to claim 27, wherein, The third outlet end of the third valve body is located on the bottom wall of the second settling tank.

29. The MEMS micropump according to any of the preceding claims, wherein, A first sealing layer is connected to a first surface of the silicon layer, and a second sealing layer is connected to a second surface of the silicon layer. An outlet flow channel communicating with the liquid outlet end of the valve body is provided on the first sealing layer or the second sealing layer. A pump membrane is etched and formed on the body. A portion of the boundary of the pump cavity is defined by the pump membrane. A drive channel for engaging the pump membrane driver is provided on the second sealing layer. At least a portion of the pump membrane is exposed in the drive channel.

30. The MEMS micropump according to any of the preceding claims, wherein, The first diaphragm is a silicon film formed by etching silicon material, and the valve body, the first diaphragm, and the main body are integral.

31. A MEMS micropump capable of suppressing backflow, comprising: A silicon layer having a first and a second opposing surface, on which a pump diaphragm, an inlet valve, an outlet valve, and a pump chamber are etched; A first sealing layer is attached to the first surface and is configured to cover the first surface to seal the pump cavity; The second sealing layer is connected to the second surface, and the second sealing layer has a drive channel for connecting the pump membrane driver at the position corresponding to the pump membrane. The outlet valve has a first structure that restricts deformation in the opposite direction of liquid discharge, which is used to reduce poor sealing caused by outlet valve deformation when the outlet blockage pressure increases.

32. The MEMS micropump capable of suppressing backflow according to claim 31, wherein, The outlet valve includes a first diaphragm and a first valve body that are separated from each other and attached together. The outlet valve also includes a first cantilever beam. The first diaphragm is connected to the first cantilever beam. A first liquid outlet channel is provided in the first valve body. The first liquid outlet channel has an inlet end and an outlet end. The first diaphragm is covered on the outlet side of the first liquid outlet channel. A second diaphragm is provided on the edge of the outlet end of the first valve body. A third cavity is etched on the inlet side of the second diaphragm.

33. The MEMS micropump capable of suppressing backflow according to claim 32, wherein, The second sealing layer is provided with a first anti-bonding protrusion that abuts against the first valve body in the direction of the first diaphragm.

34. The MEMS micropump capable of suppressing backflow according to claim 32, characterized in that: The first cantilever beam has a fourth cavity on the liquid-incoming side to reduce micro-forces.

35. The MEMS micropump capable of suppressing backflow according to claim 31, wherein, The inlet valve includes a fourth diaphragm and a third valve body that are attached together. The inlet valve also includes a second cantilever beam. The fourth diaphragm is connected to the second cantilever beam. The third valve body has an inlet channel with an inlet end and an outlet end. The fourth diaphragm covers the outlet side of the inlet channel. A fifth diaphragm is provided on the edge of the outlet end of the third valve body. A first cavity is etched on the inlet side of the fifth diaphragm.

36. The MEMS micropump capable of suppressing backflow according to claim 35, wherein, The second sealing layer is provided with a second anti-bonding protrusion that abuts against the third valve body in the direction of the fourth diaphragm.

37. The MEMS micropump capable of suppressing backflow according to claim 35, wherein, The second cantilever beam has a second cavity on the liquid-incoming side to reduce micro-forces.

38. The MEMS micropump capable of suppressing backflow according to any one of claims 31 to 37, wherein, The outlet valve includes a second valve body, in which a second liquid outlet channel is formed. The second valve body includes an upper valve block and a back valve block connected together. The upper valve block is located on the liquid inlet side of the back valve block, and the second liquid outlet channel passes through the upper valve block and the back valve block.

39. The MEMS micropump capable of suppressing backflow according to claim 38, wherein, The upper valve block is located at the radial midpoint of the rear valve block from the center to the edge.

40. The MEMS micropump capable of suppressing backflow according to claim 38, wherein, There are two upper valve blocks, each surrounding the second liquid outlet channel, with one of the upper valve blocks located at the radial center of the back valve block.

41. The MEMS micropump capable of suppressing backflow according to claim 40, wherein, One of the upper valve blocks has a closed-loop structure, while the other upper valve block has a notch.

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