CN112253843B - High leakproofness microvalve based on photocuring 3D prints preparation - Google Patents

Abstract

The invention provides a high-tightness microvalve based on photocuring 3D printing, comprising a microfluidic channel unit, a diaphragm and a microdisplacement unit. The microfluidic channel unit is provided with an inflow channel, an outflow channel, and an inflow channel. The outflow port of the channel is located on the outflow surface of the microchannel unit, and the inflow port of the outflow channel is located on the inflow surface of the microchannel unit; the structure of the diaphragm includes a deformation part and a plug part arranged on the deformation part, The deformation part is arranged opposite to the inflow surface and the outflow surface at the same time, an inflow cavity is formed between the plug part and the outflow surface, and an outflow cavity communicated with the inflow cavity is formed between the deformation part and the inflow surface; The deformation makes the volume of the inflow cavity and the outflow cavity change, so as to realize the adjustment of the flow rate and the on-off state. The invention changes the structure of the flow channel layer and the connection structure between the flow channel layer and the diaphragm, and improves the sealing performance, the flow control precision and the control performance of the on-off state.

Description

A high-tightness microvalve based on photocuring 3D printing

technical field

The invention relates to the technical field of microfluidics, in particular to a high-sealing microvalve made based on photocuring 3D printing.

Background technique

Microfluidics refers to systems that use micropipes (tens to hundreds of microns in size) to process or manipulate tiny fluids. Microfluidic devices are often referred to as microfluidic chips, also known as labs on a chip. (Lab on aChip) and micro-Total Analytical System.

Microvalve is one of the important components of microfluidic chip, which is mainly used to control the precise flow of trace liquid in microfluidic channel. The microvalve mainly includes a flow channel layer, a sealing layer and a control layer. The traditional flow channel layer material is generally glass or silicon wafer, and the sealing layer material is an elastic film (PDMS) or other. Grooves are formed on the surface of the flow channel layer by photolithography or chemical etching, and then the sealing layer is chemically bonded. It is pasted on the surface of the flow channel layer to form a flow channel. This design structure of the flow channel not only has a complicated manufacturing process and high cost, but also has poor sealing performance of the flow channel. Poor cut-off performance.

SUMMARY OF THE INVENTION

The invention provides a high-tightness microvalve made based on photocuring 3D printing, which can strengthen the tightness of the flow channel through the structural design of the micro-channel unit and the connection structure design of the micro-channel unit and the diaphragm.

The technical scheme adopted in the present invention is as follows:

A high-tightness microvalve made based on photocuring 3D printing, comprising a microfluidic channel unit, a diaphragm and a microdisplacement unit, wherein the microfluidic channel unit is provided with an inflow channel and an outflow channel, and the inflow channel is provided with an inflow channel and an outflow channel. The outflow port of the channel is located on the outflow surface of the microfluidic channel unit, the inflow port of the outflow channel is located on the inflow surface of the microfluidic channel unit, and the inflow surface and the outflow surface are in different planes The structure of the diaphragm includes a deformation part and a plug part arranged on the deformation part. An inflow cavity is formed between the inflow surfaces, and an outflow cavity communicated with the inflow cavity is formed between the deformation part and the inflow surface; the inflow cavity and the outflow cavity are formed by the deformation of the deformation part. The volume changes, so as to realize the adjustment of the flow rate and the on-off state.

The upper surface of the micro-channel unit is provided with a concave conical groove, the outflow surface is located on the bottom surface of the groove of the concave conical groove, and the outer ring of the concave conical groove is provided with a sealing groove, Therefore, a relatively convex boss portion is formed between the sealing groove and the concave conical groove, and the inflow port is located on the upper surface of the boss portion.

The lower surface of the diaphragm is provided with a sealing flange that is clamped with the sealing groove, the inner ring of the sealing flange is formed with a sealing groove body, and the middle of the sealing groove body is provided with a downwardly protruding sealing groove. In the deformation part, after the sealing groove and the sealing flange are clamped, resin glue is filled in the gap formed between the two, and at the same time, a communicating inflow cavity and an outlet are formed between the sealing groove body and the inflow surface. fluid chamber.

The plug portion is an outer convex cone formed by the middle part of the deformation portion protruding downward, which is matched with the inner concave cone groove. When the diaphragm is deformed downward by force, the outer convex cone is formed. The shape table extends into the concave conical groove, so that the volume of the inflow cavity and the outflow cavity can be reduced, and the inflow port can be closed, or the inflow cavity and the outflow cavity can be cut off. ;

The taper of the outer convex conical frustum is the same as or different from the taper of the inner concave conical groove.

The micro-channel unit and the membrane are arranged in a separate or integrated form.

The microfluidic channel unit is connected with the diaphragm by bolts, or an integral deformed microfluidic channel unit is directly made by 3D printing.

The structure of the micro-displacement unit includes a micro-displacement motion unit, and the micro-displacement motion unit is driven by the controller to generate displacement and drive the diaphragm to deform.

The micro-displacement movement unit is arranged in a fixed block, and the fixed block is provided with a cavity for accommodating the micro-displacement movement unit; it also includes a pre-tensioner, on which the micro-displacement movement unit is provided. The position of the moving unit in the cavity is adjusted to adjust the thread preloading mechanism of the initial value of the pressing force of the micro-displacement moving unit on the diaphragm.

The pre-tensioner, the fixing block, the diaphragm and the micro-flow channel unit are connected as a whole by fasteners.

The inlet of the inflow channel and the outlet of the outflow channel are respectively located on the surface of the microfluidic unit, and the inlet is connected to the microfluidic upstream module through a pipeline, and the outlet is connected to the microfluidic upstream module through a pipeline. Microfluidic downstream module connection.

The beneficial effects of the present invention are as follows:

The microvalve of the present invention is provided with a sealing connection structure of the sealing flange on the diaphragm and the sealing groove on the microchannel unit, the inflow cavity and the outflow cavity are sealed, and the stability of the connection structure is improved by curing with resin glue It can solve the problem of liquid leakage in the flow channel and improve the reliability of sealing.

The deformation part of the diaphragm of the present invention is provided with a plug, which cooperates with the concave conical groove on the corresponding surface of the micro-channel unit, and can realize the blocking of the outflow port of the inflow channel or the inflow cavity and the outflow cavity. Compared with the plane plugging structure, it greatly improves the tightness of the plug, solves the problem of fluid leakage in the cut-off state, improves the control accuracy of the flow and the control performance of the on-off state, and makes the flow control more effective.

The initial height of the sealing groove body of the micro-valve of the present invention can be set by a pre-tightening mechanism, and can be matched with micro-displacement mechanisms of different strokes.

The present invention can be manufactured by surface light curing 3D printing method, and can be manufactured separately to form a micro-valve unit. The inlet and outlet can be connected with other micro-fluidic modules, and can also be integrated on a micro-fluidic chip. Flexible design.

The membrane sheet and the micro-channel unit of the present invention can be printed in one piece or produced separately according to actual needs, and then connected by fasteners. The production is simple and efficient, and large-scale production can be realized.

Description of drawings

FIG. 1 is an exploded view of the installation structure of the micro-channel unit, the diaphragm and the micro-displacement unit of the present invention.

FIG. 2 is a schematic structural diagram of the microfluidic unit of the present invention.

3 is a perspective view of the microfluidic unit of the present invention.

FIG. 4 is a schematic structural diagram of the diaphragm of the present invention.

FIG. 5 is a cross-sectional view of the connection structure of the first embodiment of the microfluidic unit and the membrane of the present invention.

FIG. 6 is a cross-sectional view of the connection structure of the first embodiment of the microfluidic unit and the membrane of the present invention.

FIG. 7 is a schematic structural diagram of the one-piece deformable micro-channel unit of the present invention.

FIG. 8 is an exploded view of the installation structure of the micro-displacement unit of the present invention.

FIG. 9 is a schematic diagram of the installation structure in the working state of the present invention.

In the figure: 1. Inflow chamber; 2. Outflow chamber; 3. Microfluidic upstream module; 4. Microfluidic downstream module; 100, Microfluidic unit; 200, Diaphragm; 300, Microdisplacement unit; 400. One-piece deformable micro-channel unit; 101, inlet; 102, inflow channel; 103, outlet; 104, inlet; 105, outlet channel; 106, outlet; 107, sealing groove; 108, Concave conical groove; 201, plug head; 202, deformation part; 203, sealing flange; 204, sealing groove body; 301, micro-displacement motion unit; 302, fixing block; 303, threaded bolt installation groove; 304, preload; 305, the controller.

Detailed ways

The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1 , the high-tightness microvalve based on photocuring 3D printing in this embodiment includes a microfluidic channel unit 100 , a diaphragm 200 and a microdisplacement unit 300 ;

As shown in FIGS. 2 and 3 , the microfluidic channel unit 100 is provided with an inflow channel 102 and an outflow channel 105 , and the outflow port 103 of the inflow channel 102 is located on the outflow surface of the microfluidic channel unit 100 . The inflow port 104 of the flow channel 105 is located on the inflow surface of the microchannel unit 100, and the inflow surface and the outflow surface are on different planes;

Specifically, the upper surface of the micro-channel unit 100 is provided with a concave conical groove 108, the outflow surface is located on the bottom surface of the groove of the concave conical groove 108, and the outer ring of the concave conical groove 108 is provided with a sealing groove 107, Therefore, a relatively convex boss portion is formed between the sealing groove 107 and the concave conical groove 108 , and the inflow port 104 is located on the upper surface of the boss portion.

As shown in FIG. 4-FIG. 6, the structure of the diaphragm 200 includes a deformation part 202 and a plug part 201 arranged on the deformation part 202. The deformation part 202 is arranged opposite to the inflow surface and the outflow surface at the same time. An inflow cavity 1 is formed between the outflow surfaces, and an outflow cavity 2 communicating with the inflow cavity 1 is formed between the deformation portion 202 and the inflow surface;

Specifically, the lower surface of the diaphragm 200 is provided with a sealing flange 203 that is snapped with the sealing groove 107, the inner ring of the sealing flange 203 is formed with a sealing groove body 204, and the middle of the sealing groove body 204 is provided with a downwardly protruding After the deformation part 202, the sealing groove 107 and the sealing flange 203 are snapped into place, the sealing groove body 204 and the inflow surface form a communicating inflow cavity 1 and an outflow cavity 2.

Specifically, the plug portion 201 is an outer convex conical table formed by protruding downward from the middle portion of the deformation portion 202 , which is matched with the inner concave conical groove 108 .

Specifically, as shown in FIGS. 5 and 6 , after the sealing groove 107 and the sealing flange 203 are snapped into place, the lower surface of the sealing groove body 204 and the upper surface of the boss portion where the inflow port 104 is located are abutted, and at the same time A cavity is formed between the bottom surface of the deformation portion 202 and the upper surface of the boss portion, that is, the outflow cavity 2 . At the same time, a cavity is formed between the conical surface of the plug portion 201 and the conical surface of the concave conical groove 108 , that is, the inflow cavity 1 , and the inflow cavity 1 is communicated with the outflow cavity 2 .

The volume of the inflow cavity 1 and the outflow cavity 2 is changed by the deformation of the deformation part 202 up and down in the height direction, thereby realizing the adjustment of the flow rate and the on-off state.

Specifically, the depth of the sealing groove 107 needs to be greater than the height of the sealing flange 203, so that after the sealing groove 107 and the sealing flange 203 are clamped, a certain gap is formed between the two, and the resin glue is filled in the interval. , after the resin glue is cured, the two are connected together, and the sealing groove 107 and the sealing flange 203 are sealed without leakage, so that the diaphragm 200 and the micro-channel unit 100 are tightly connected, so that the outlet 103 of the micro-valve is tightly connected. , The inflow port 104 is sealed in the inflow cavity 1 and the outflow cavity 2 to realize the sealing of the flow channel.

Specifically, the sealing flange 203 and the sealing groove 107 extend one circle along the circumference, and the cross section can be optionally set to be rectangular.

When the diaphragm 200 is deformed downward by force, the convex conical platform (plug head 201 ) extends into the concave conical groove 108, so that the volume of the inflow cavity 1 and the outflow cavity 2 is reduced, and the diaphragm 200 is deformed downward to the limit position and during the previous process, the inflow port 104 can be closed or the inflow cavity 1 and the outflow cavity 2 can be cut off;

As shown in FIG. 5 and FIG. 6 , respectively, are schematic diagrams of connection structures in two different implementations where the taper of the outer convex conical table (plug portion 201 ) is the same as that of the concave conical groove 108 .

When the taper is the same, as shown in FIG. 5, the convex conical table (plug portion 201) can be completely embedded in the concave conical groove 108. When the diaphragm 200 is deformed downward to the limit position, the convex conical table The bottom surface and the top surface of the concave conical groove 108 fit together, so that the outflow port 103 can be closed, that is, the cutting function can be realized.

When the tapers are not the same, as shown in FIG. 6 , the convex conical table (plug portion 201 ) cannot be completely embedded into the concave conical groove 108 , when the diaphragm 200 is deformed downward to the limit The conical surface of the stage and the conical surface of the concave conical groove 108 abut, so that the inflow cavity 1 and the outflow cavity 2 are cut off, and the cutting function can also be realized.

The cooperation between the plug part 201 of the deformation part 202 and the concave conical groove 108 where the outflow port 103 is located makes the flow control more effective, and overcomes the disadvantage of laxity when the plane is blocked.

Specifically, the deformation portion 202 is circular or square and is located in the middle of the diaphragm 200. The deformation portion 202 may be formed by a depression in the inner ring of the diaphragm 200. The thickness of the diaphragm in the corresponding area of the deformation portion 202 is between 100um and 300um. Thinner and more deformable than other areas;

Specifically, as shown in FIG. 5 or FIG. 6 , the top surface of the deformation portion 202 is bent downward by the pressure of the micro-displacement motion unit 301 , thereby changing the flow resistance of the flow channel or blocking the flow channel, thereby adjusting the flow rate.

The microfluidic channel unit 100 and the diaphragm 200 are provided in a separate or integrated manner.

The microfluidic channel unit 100 and the diaphragm 200 are connected by bolts, or as shown in FIG. 7 , the microfluidic channel unit 100 and the diaphragm 200 are directly fabricated into an integrated deformed microfluidic channel unit 400 by 3D printing.

The inflow channel 102 and the outflow channel 105 are designed in the integrated deformable microchannel unit 400 as required, and the area close to the upper surface is hollowed out to form the sealing groove 204 and the deformation part 202 , and the corresponding inflow cavity 1 and the outflow chamber 2, and the inflow channel 102 and the outflow channel 105 are respectively connected to the inflow chamber 1 and the outflow chamber 2.

The advantage of the one-piece deformed micro-channel unit 400 is that the parts corresponding to the sealing groove 107 and the sealing flange 203 are integrated, that is, there is no sealing groove 107, the two parts of the sealing flange 203 and the gap between them. There is no need to add resin glue to seal, but to directly form a sealed cavity structure, but the 3D printing process requires high precision of integrated molding. Because it can be selected according to the actual situation and needs.

As shown in FIG. 8 , the structure of the micro-displacement unit 300 includes a micro-displacement moving unit 301 , and the micro-displacement moving unit 301 is driven by the controller 305 to generate displacement and drive the diaphragm 200 to deform.

The micro-displacement movement unit 301 is arranged in a fixed block 302, and the fixed block 302 is provided with a cavity for accommodating the micro-displacement movement unit 301; it also includes a pre-tensioner 304, and the pre-tensioner 304 is provided with a preload for the micro-displacement movement unit 301. The position in the cavity is adjusted to adjust the thread preloading mechanism of the initial value of the pressing force of the micro-displacement motion unit 301 on the diaphragm 200 .

The pretensioner 304, the fixing block 302, the diaphragm 200 and the microfluidic channel unit 100 are integrally connected by fasteners.

Specifically, as shown in FIG. 1 , four corners of the micro-channel unit 100 , the diaphragm 200 and the micro-displacement unit 300 are provided with through holes, and they are connected together by bolts.

Specifically, the controller 305 can receive signals and control the micro-displacement motion unit 301 to generate displacement. The micro-displacement motion unit 301 can use piezoelectric ceramics or a solenoid valve. One end of the micro-displacement motion unit 301 is connected to the upper surface of the diaphragm 200, and It can be set as a hemispherical protrusion structure as shown in FIG. 8 , and the hemispherical protrusion is in close contact with the diaphragm 200 .

The piezoelectric ceramic or solenoid valve can generate micro-displacement under the drive of the controller 305, and can slide along the cavity of the fixed block 302 to squeeze the diaphragm 200 to cause the deformation portion 202 to deform downward.

Specifically, the pre-tightening member 304 includes a mounting block connected to the fixing block 302 , and the thread pre-tightening mechanism is installed on the mounting block through the threaded bolt mounting groove 303 . The displacement movement unit 301 adjusts the initial position of the micro-displacement movement unit 301 by rotating the adjustment bolt to adjust the initial deformation of the diaphragm 200, so as to adjust the initial height (volume) of the sealing groove 204 and the deformation part 202, and make the the preload.

The thread pre-tightening mechanism can be used to adjust the initial deformation of the diaphragm to make the overall rigidity better, so that the deformation recovery speed of the diaphragm 200 is faster, and the range of the initial height can be set between 5um and 60um according to the stroke of the micro-displacement motion unit 301 .

As shown in FIG. 9 , the inlet 101 of the inflow channel 102 and the outlet 106 of the outflow channel 105 are respectively located on the surface of the microfluidic unit 100 , and the inlet 101 is connected to the microfluidic upstream module 3 through a pipeline, and the outlet 106 It is connected to the microfluidic downstream module 4 through a pipeline.

Specifically, the inflow channel 102 and the outflow channel 105 can be designed in shapes such as S-shaped and linear, the minimum cross-sectional size of the microchannel can be 40um, and the cross-sectional shape can be designed as a circle, a rectangle or other customized shapes as required.

Specifically, the inlet 101 and the outlet 106 may be provided with a connection structure for communicating with other microfluidic modules, or the microvalve may be directly integrated on the microfluidic chip for integral printing.

The working process of the present invention:

After the micro-valve is assembled as a whole, the inlet 101 is connected to the microfluidic upstream module 3 through a pipeline, the outlet 106 is connected to the microfluidic downstream module 4 through a pipeline, and the micro-displacement motion unit 301 is controlled by the controller 305 to generate displacement and drive The diaphragm 200 is deformed to change the volume of the inflow cavity 1 and the outflow cavity 2, which can change the flow resistance of the flow channel to adjust the flow, or completely close the flow channel; it is also possible to combine multiple microvalves with different microfluidic chips Flow channel connection, control the closing, opening or flow rate of different flow channels to achieve the purpose of reagent mixing, sample concentration control and sample detection.

The microvalve of the present invention can be processed and manufactured based on the photocuring 3D printing method. The photocuring 3D printing technology is a very hot research direction in recent years, and has unique advantages in forming devices with complex shapes and microstructures.

Surface light curing 3D technology is the most widely used and mature printing technology in light curing 3D printing technology. According to different dynamic mask technology, it can be divided into three printing methods: DMD, LCD and LCOS 3. Surface light curing 3D printing accuracy High and fast. Using surface light curing 3D printing technology to print microvalves can not only simplify the production process, but also make the design of microvalves more free and make microvalves that better meet the needs of researchers.

Specifically, when the microvalve module is printed alone, steel needles can be inserted at the inlet 101 and the outlet 106, and other modules can be connected through a silicone hose. The microvalve can be removed from the microfluidic system and reused. The microvalve module can also be used. The integrated design on the microfluidic chip makes the structure of the microfluidic chip more compact.

The functions of the inflow channel 102, the outflow port 103, the outflow channel 105, the inflow port 104 and other structures described in this embodiment can be adjusted and changed according to actual needs. For example, the fluid can flow in from the inlet 101, pass through The inflow channel 102 and the outflow port 103 enter the inflow chamber 1, and then pass through the outflow chamber 2, and flow out of the microvalve from the inflow port 104 through the outflow channel 105 and the outlet 106. The fluid can also flow in reverse, and the fluid is liquid or fluid substances such as gases.

In the microvalve of the present invention, the shape (size) of the flow channel, the shape (size) of the cross section of the flow channel, and the shape (size) of the inflow cavity and the outflow cavity can be customized according to the needs, and the design freedom is high to meet different design requirements.

Claims (7)

1. The high-sealing-performance micro-valve manufactured based on photocuring 3D printing is characterized by comprising a micro-channel unit (100), a membrane (200) and a micro-displacement unit (300), wherein an inflow channel (102) and an outflow channel (105) are arranged in the micro-channel unit (100), an outflow port (103) of the inflow channel (102) is located on an outflow surface of the micro-channel unit (100), an inflow port (104) of the outflow channel (105) is located on the inflow surface of the micro-channel unit (100), and the inflow surface and the outflow surface are located on different planes;

the diaphragm (200) structurally comprises a deformation part (202) and a plug part (201) arranged on the deformation part (202), the deformation part (202) is arranged opposite to the inflow surface and the outflow surface at the same time, an inflow cavity (1) is formed between the plug part (201) and the outflow surface, and an outflow cavity (2) communicated with the inflow cavity (1) is formed between the deformation part (202) and the inflow surface; the volumes of the inflow cavity (1) and the outflow cavity (2) are changed through the deformation of the deformation part (202), so that the adjustment of the flow and the on-off state is realized;

an inner concave conical groove (108) is formed in the upper surface of the micro-channel unit (100), the outflow surface is located on the groove bottom surface of the inner concave conical groove (108), a sealing groove (107) is formed in the outer ring of the inner concave conical groove (108), a boss portion which is relatively convex is formed between the sealing groove (107) and the inner concave conical groove (108), and the inflow port (104) is located in the upper surface of the boss portion;

a sealing flange (203) clamped with the sealing groove (107) is arranged on the lower surface of the diaphragm (200), a sealing groove body (204) is formed in the inner ring of the sealing flange (203), the middle part of the sealing groove body (204) is provided with the deformation part (202) protruding downwards, a gap formed between the sealing groove (107) and the sealing flange (203) after clamping is filled with resin glue, and meanwhile, an inflow cavity (1) and an outflow cavity (2) communicated with each other are formed between the sealing groove body (204) and the inflow surface;

the plug part (201) is an outer convex conical table formed by downward protrusion of the middle part of the deformation part (202) and matched with the inner concave conical groove (108), when the diaphragm (200) is deformed downwards under stress, the outer convex conical table extends into the inner concave conical groove (108), so that the volumes of the inflow cavity (1) and the outflow cavity (2) are reduced, the inflow opening (104) can be closed, or the inflow cavity (1) and the outflow cavity (2) can be cut off;

the taper of the outer convex conical table is the same as or different from that of the inner concave conical groove (108).

2. The micro-valve with high sealing performance manufactured based on photocuring 3D printing of claim 1, wherein the micro flow channel unit (100) is arranged separately from or integrally with the membrane (200).

3. The high-sealability micro-valve manufactured based on photocuring 3D printing of claim 2, wherein the micro flow channel unit (100) and the membrane (200) are connected by bolts, or directly manufactured into an integrated deformable micro flow channel unit (400) by 3D printing.

4. The high-sealability microvalve manufactured based on photocuring 3D printing of claim 1, wherein the structure of the micro-displacement unit (300) comprises a micro-displacement motion unit (301), and the micro-displacement motion unit (301) is driven by a controller (305) to generate displacement to drive the diaphragm (200) to deform.

5. The micro valve manufactured based on photocuring 3D printing according to claim 4, characterized in that the micro displacement motion unit (301) is arranged in a fixed block (302), and a cavity for accommodating the micro displacement motion unit (301) is arranged in the fixed block (302); the diaphragm pressing device is characterized by further comprising a pre-tightening piece (304), wherein a threaded pre-tightening mechanism for adjusting the position of the micro-displacement motion unit (301) in the cavity so as to adjust the initial value of the pressing force of the micro-displacement motion unit (301) on the diaphragm (200) is arranged on the pre-tightening piece (304).

6. The micro-valve with high sealing performance manufactured based on the photocuring 3D printing as claimed in claim 5, wherein the preload member (304), the fixing block (302), the membrane (200) and the micro flow channel unit (100) are integrally connected through fasteners.

7. The high-tightness micro-valve manufactured based on photocuring 3D printing according to claim 1, wherein an inlet (101) of the inflow channel (102) and an outlet (106) of the outflow channel (105) are respectively located on the surface of the micro-channel unit (100), the inlet (101) is connected with a microfluidic upstream module (3) through a pipeline, and the outlet (106) is connected with a microfluidic downstream module (4) through a pipeline.

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