CN102162140B - Microfluid chip and spinning method thereof - Google Patents

Abstract

The invention relates to a microfluidic chip and a spinning method thereof, in particular to a microfluidic chip whose width of a microfluidic channel gradually and continuously decreases from an inlet to an outlet and a spinning method thereof. A microfluidic chip of the present invention includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel, and the depth c of the microfluidic channel is equal, the width b of the microfluidic channel decreases gradually and continuously from the inlet to the outlet. In the spinning method of a microfluidic chip of the present invention, the spinning stock solution is injected into the inlet of the microfluidic channel of the microfluidic chip, and finally flows out from the outlet of the microfluidic channel, and dry spinning is carried out in the air, or in a polymer coagulation bath Wet spinning in high voltage electric field or electrospinning under high voltage electric field conditions. The chip used in the invention is simple to prepare and low in cost, and can regulate the stretching and shearing conditions required by the solution in the chip according to the requirements of the spinning process, and has good application prospects.

Description

A microfluidic chip and spinning method thereof

technical field

The invention belongs to the technical fields of microfluidics, textile fibers, material science and bionics, and relates to a microfluidic chip and a spinning method thereof, in particular to a microfluidic channel whose width gradually and continuously decreases from the inlet to the outlet. Microfluidic chip and spinning method thereof. the

Background technique

In recent years, the application of microfluidic chips in fiber formation is attracting increasing attention. Microfluidic technology can be spun under normal temperature and pressure conditions, which is very suitable for the processing of materials such as biomacromolecules. At present, microfluidic spinning technology has been well applied in the fields of instant spinning and electrospinning. In addition, the microfluidic spinning system may regulate the composition and structure of the spinning solution through the laminar flow and diffusion characteristics of the microfluid, so as to simulate the structure and function of the biological spinner, and produce fibers with controllable structure and good performance. However, the instant spinning and electrospinning technologies mainly use the laminar flow characteristics of microfluidics, and the viscosity of the spinning solution is not high, the required microfluidic chips are relatively simple, and the requirements for the pipe diameter are not high. The progress of microfluidic chips in fiber formation also provides a new method for the study of special kinds of fibers. The composition regulation of regenerated silk proteins using microfluidic chips has been reported. Patents WO 2007/141131A1 and US2010029553 (A1) designed a microfluidic chip, using the laminar flow characteristics of microfluidics to adjust the pH value and metal ion concentration of regenerated silk fibroin for the preparation of protein products of different forms; Rammensee et al. On the basis of this patent, the effect of shear stress on the assembly of recombinant spider dragline proteins eADF3 and eADF4 was studied by combining rectangular channels of different widths. However, there are no patented inventions and literature reports that use the shape parameters of the biospinning system for spinning. the

For example, in the bionic spinning of regenerated silk fibroin, silkworms and spiders use the water in their bodies as a solvent to dry spin under normal temperature and pressure. The whole process is energy-saving and environmentally friendly. The whole spinning process is a model of low energy consumption and high efficiency. Studies have shown that the flow process of natural animal silk protein in the biological spinning system is a coordinated process integrating pH decrease, metal ion content change and silk fibroin concentration increase. During this process, the gradually changing shape of the spinning tubes of spiders and silkworms provides shear and stretching effects for silk proteins, which promotes the conformation of animal silk proteins from soluble random coils and/or helical conformations to water-insoluble ones. β-sheet conformation. At present, the biomimetic spinning of regenerated silk fibroin is to statically adjust the pH value of the spinning solution, the concentration of calcium ions and silk fibroin, and then stretch it into silk, which does not involve the shear stretching system in the spinning process. Although spider silk has super strength and elasticity, it cannot be obtained in large quantities due to spider silk. Silkworm silk is also a natural fiber with excellent performance. The spinning process of silkworms and spiders is very similar, and silk comes from a wide range of sources. The amino acid composition of silk fibroin and spider silk protein has the highest content of alanine and glycine. Therefore, how to use silk protein as a raw material to prepare regenerated fibers with excellent mechanical properties has become a research topic for scientists. This is of great significance in the fields of polymer materials science and bionics. the

Starting from simulating the spinning process of spiders or silkworms, the present invention designs microfluidic channels, adopts a microfluidic dry spinning process with a higher degree of bionics, uses high-concentration spinning stock solution, and undergoes shearing and stretching to obtain a fiber with excellent performance. fiber. the

Contents of the invention

The object of the present invention is to provide a microfluidic chip and a spinning method thereof, in particular to a microfluidic chip and a spinning method thereof in which the width of a microfluidic channel gradually and continuously decreases from the inlet to the outlet. the

A microfluidic chip of the present invention includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel, and the depth of the microfluidic channel is equal to the whole process , the width of the microfluidic channel decreases gradually and continuously from the left and right of the inlet to the outlet. the

As the preferred technical solution:

A microfluidic chip as described above, the two sides of the microfluidic channel are symmetrical with respect to the central axis of the microfluidic channel; the trace of the intersection of the two sides of the microfluidic channel with the horizontal plane is an exponential function curve, a hyperbola One or a combination of function curves or straight lines. the

According to the above-mentioned microfluidic chip, the exponential function is a second-order exponential function. the

In the above-mentioned microfluidic chip, the depth is 10 μm to 500 μm; the microfluidic channel has an inlet width of 500 μm to 2 mm, and an outlet width of 10 μm to 500 μm. the

The invention also provides a spinning method for the microfluidic chip, injecting the spinning stock solution into the inlet of the microfluidic channel of the microfluidic chip, and finally flowing out from the outlet of the microfluidic channel, performing dry spinning in the air, or spinning in the polymer Wet spinning is carried out in a coagulation bath, or electrospinning is carried out under high-voltage electric field conditions; the depth of the microfluidic channel is equal throughout, and the width of the microfluidic channel gradually and continuously decreases from the entrance to the exit. the

A spinning method for a microfluidic chip as described above, the microfluidic chip includes a substrate and a membrane, the membrane has grooves, and the grooved surface of the membrane is bonded to the substrate to form a microfluidic chip. channel; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel. the

According to the above-mentioned spinning method of a microfluidic chip, the intersection of the two sides of the microfluidic channel and the horizontal plane is one of an exponential function curve, a hyperbolic function curve or a straight line or a combination thereof. the

In the spinning method for a microfluidic chip as described above, the exponential function is a second-order exponential function. the

In the above-mentioned spinning method of a microfluidic chip, the depth is 10 μm to 500 μm; the microfluidic channel has an inlet width of 500 μm to 2 mm, and an outlet width of 10 μm to 500 μm. the

In the spinning method of a microfluidic chip as described above, the injection speed of the spinning solution injected into the microfluidic channel is 0.5-10 μL/min; when performing dry spinning, the air gap from the spinneret to the roll is 1~30cm, the winding speed is 1~5cm/s. the

The preparation method of the microfluidic chip proposed by the present invention is to use the exponential function similar to the glands of spiders or silkworms and the shape function of the spinner as the design model, with the glass slide as the substrate, and the SU-8 photoresist as the anode. Dimethylsiloxane (PDMS) is the microchannel construction material, and photolithography and molding are used as the molding technology. Using a glass slide (75×25mm) as a substrate, the SU-8 photoresist coating was exposed to ultraviolet rays under a mask printed with microchannel patterns. After development, a positive mold with a microchannel pattern can be obtained, and then PDMS is cast on the mold, and a PDMS membrane with a microchannel pattern can be obtained after curing. Finally, the PDMS membrane is directly bonded to the glass slide after plasma treatment. the

The high-concentration spinning solution is injected into the chip at a temperature range of 10-30°C, extruded from the spinneret and solidified directly in the air to form filaments. The injection speed of the spinning solution into the microfluidic channel is 0.5-10 μL/min, the air gap from the spinneret to the roll is 1-30 cm, and the winding speed is 1-5 cm/s. the

Beneficial effect:

(1) The prepared microfluidic channel simulates the shape characteristics of the glands and spinners of spiders or silkworms, which further improves the bionic degree of the spinning process and can be better used for solution spinning technology;

(2) The channel provides different degrees of shearing and stretching for the high-concentration spinning solution to improve the spinning effect. the

Description of drawings

Figure 1 is a schematic diagram of the microfluidic channel

Figure 2 is a schematic diagram of the A-A section of Figure 1

1 is the inlet of the microfluidic channel 2 is the outlet of the microfluidic channel

Detailed ways

The present invention will be further described below in combination with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application. the

A microfluidic chip of the present invention includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel, and the depth c of the microfluidic channel is equal, the width b of the microfluidic channel decreases gradually and continuously from the inlet 1 to the outlet 2, as shown in FIGS. 1 and 2 . the

A microfluidic chip as described above, the two sides of the microfluidic channel are symmetrical with respect to the central axis of the microfluidic channel; the trace of the intersection of the two sides of the microfluidic channel with the horizontal plane is an exponential function curve, a hyperbola One or a combination of function curves or straight lines. the

According to the above-mentioned microfluidic chip, the exponential function is a second-order exponential function. the

A microfluidic chip as described above, the depth c is 10 μm to 500 μm; the microfluidic channel has an inlet width of 500 μm to 2 mm, and an outlet width of 10 μm to 500 μm. the

Example 1

The aqueous solution of regenerated silk fibroin protein with a concentration of 30% by mass percentage was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 0.5 μL/min at a temperature of 30 ° C. After exit extrusion, the dry spinning process is adopted, solidified into filaments in the air and wound on the upper roller; the air gap from the spinneret to the winding roller is 1cm, and the winding speed is 1cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 10 μm, the width b of the microfluidic channel gradually and continuously decreases from the inlet to the outlet, the inlet width is 2 mm, and the outlet width is 10 μm. In the microfluidic channel, the traces where both sides of the channel intersect the horizontal plane are a combination of a second-order exponential function curve and a straight line; the formula of the exponential function is: R(x)=ae ^bx +ce ^dx ; where a=- 0.004886, b=0.0003718, c=53.52, d=-9.989*10 ^-5 ; the length ratio between the curve and the straight line is 2:3; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 2

The aqueous solution of regenerated silk fibroin protein with a mass percentage concentration of 60% was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 10 μL/min at a temperature of 20 ° C. The outlet of the microfluidic channel of the microfluidic chip After extrusion, the dry spinning process is used to solidify into filaments in the air and wind up on the roll; the air gap from the spinneret to the roll is 5 cm, and the winding speed is 5 cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 500 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, the inlet width is 1 mm, and the outlet width is 500 μm. In the microfluidic channel, the traces where both sides of the channel intersect with the horizontal plane are a combination of a hyperbolic function curve and a straight line; the formula of the hyperbolic function is: R(x)=1/2(e ^x -e ^-x ); the length ratio of the curve to the straight line is 1:3; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 3

With the mass percent concentration of 45% regenerated silk fibroin aqueous solution as the spinning solution, the spinning solution was injected into the microfluidic chip at a flow rate of 5 μL/min at a temperature of 10 ° C, and the outlet of the microfluidic channel of the microfluidic chip After extrusion, the dry spinning process is used to solidify into filaments in the air and wind up on the roll; the air gap from the spinneret to the roll is 10 cm, and the winding speed is 3 cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 100 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, as shown in Figures 1 and 2, the inlet width is 500 μm, and the outlet width is 250 μm. In the microfluidic channel, the traces of its two sides intersecting the horizontal plane are first-order exponential function curves; the exponential function formula is: R(x)=e ^a*ln(x) ; wherein a=0.0125; The two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 4

The aqueous solution of regenerated silk fibroin protein with a mass percentage concentration of 55% was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 8 μL/min at a temperature of 20 ° C. The outlet of the microfluidic channel of the microfluidic chip After extrusion, the dry spinning process is used to solidify into filaments in the air and wind up on the roll; the air gap from the spinneret to the roll is 6 cm, and the winding speed is 3 cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 100 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, as shown in Figures 1 and 2, the inlet width is 2 mm, and the outlet width is 100 μm. The intersection of the two sides of the microfluidic channel and the horizontal plane is a straight line; the two sides of the microfluidic channel are symmetrical with respect to the central axis of the microfluidic channel. the

Example 5

The aqueous solution of regenerated silk fibroin protein with a concentration of 30% by mass percentage was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 0.5 μL/min at a temperature of 30 ° C. After exit extrusion, adopt wet spinning process, solidify into silk in 80% ethanol solution and wind up roller; winding speed is 1cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 10 μm, the width b of the microfluidic channel gradually and continuously decreases from the inlet to the outlet, the inlet width is 2 mm, and the outlet width is 10 μm. In the microfluidic channel, the traces where both sides of the channel intersect the horizontal plane are a combination of a second-order exponential function curve and a straight line; the formula of the exponential function is: R(x)=ae ^bx +ce ^dx ; where a=- 0.004886, b=0.0003718, c=53.52, d=-9.989*10 ^-5 ; the length ratio between the curve and the straight line is 2:3; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 6

The aqueous solution of regenerated silk fibroin protein with a mass percentage concentration of 60% was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 10 μL/min at a temperature of 20 ° C. The outlet of the microfluidic channel of the microfluidic chip After extrusion, adopt wet spinning process, solidify into filaments in 80% ethanol solution and wind up the upper roller; the winding speed is 5cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 500 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, the inlet width is 1 mm, and the outlet width is 500 μm. In the microfluidic channel, the traces where both sides of the channel intersect with the horizontal plane are a combination of a hyperbolic function curve and a straight line; the formula of the hyperbolic function is: R(x)=1/2(e ^x -e ^-x ); the length ratio of the curve to the straight line is 1:3; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 7

With the mass percent concentration of 45% regenerated silk fibroin aqueous solution as the spinning solution, the spinning solution was injected into the microfluidic chip at a flow rate of 5 μL/min at a temperature of 10 ° C, and the outlet of the microfluidic channel of the microfluidic chip After extrusion, the wet spinning process is adopted, solidified into filaments in 80% ethanol solution and wound on the upper roller; the winding speed is 3cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 100 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, as shown in Figures 1 and 2, the inlet width is 500 μm, and the outlet width is 250 μm. In the microfluidic channel, the traces where the two side surfaces intersect the horizontal plane are first-order exponential function curves; the exponential function formula is: R(x)=e ^a * ^ln(x) ; wherein a=0.0125; The two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 8

The aqueous solution of regenerated silk fibroin protein with a mass percentage concentration of 55% was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 8 μL/min at a temperature of 20 ° C. The outlet of the microfluidic channel of the microfluidic chip After extrusion, the wet spinning process is adopted, solidified into filaments in 80% ethanol solution and wound on the upper roller; the winding speed is 3cm/s. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 100 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, as shown in Figures 1 and 2, the inlet width is 2 mm, and the outlet width is 100 μm. The intersection of the two sides of the microfluidic channel and the horizontal plane is a straight line; the two sides of the microfluidic channel are symmetrical with respect to the central axis of the microfluidic channel. the

Example 9

Using 30% regenerated silk fibroin aqueous solution as the spinning liquid, the spinning liquid was injected into the microfluidic chip at a flow rate of 0.5 μL/min at a temperature of 30 °C. The metal conduit connected to the inlet of the microfluidic chip was connected to the positive electrode, the sample receiving plate was grounded, and the electrospinning was performed from the outlet of the microfluidic chip under an electric field with a voltage of 30kV and a receiving distance of 6cm. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 10 μm, the width b of the microfluidic channel gradually and continuously decreases from the inlet to the outlet, the inlet width is 2 mm, and the outlet width is 10 μm. In the microfluidic channel, the traces where both sides of the channel intersect the horizontal plane are a combination of a second-order exponential function curve and a straight line; the formula of the exponential function is: R(x)=ae ^bx +ce ^dx ; where a=- 0.004886, b=0.0003718, c=53.52, d=-9.989*10 ^-5 ; the length ratio between the curve and the straight line is 2:3; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 10

Using 60% regenerated silk fibroin aqueous solution as the spinning solution, the spinning solution was injected into the microfluidic chip at a flow rate of 10 μL/min at a temperature of 20 °C. The metal conduit connected to the inlet of the microfluidic chip was connected to the positive electrode, the sample receiving plate was grounded, and the electrospinning was performed from the outlet of the microfluidic chip under an electric field with a voltage of 30kV and a receiving distance of 6cm. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 500 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, the inlet width is 1 mm, and the outlet width is 500 μm. In the microfluidic channel, the traces where both sides of the channel intersect with the horizontal plane are a combination of a hyperbolic function curve and a straight line; the formula of the hyperbolic function is: R(x)=1/2(e ^x -e ^-x ); the length ratio of the curve to the straight line is 1:3; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 11

The aqueous solution of regenerated silk fibroin with a mass percentage concentration of 45% was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 5 μL/min at a temperature of 10 °C. The metal conduit connected to the inlet of the microfluidic chip was connected to the positive electrode, the sample receiving plate was grounded, and the electrospinning was performed from the outlet of the microfluidic chip under an electric field with a voltage of 30kV and a receiving distance of 6cm. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 100 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, as shown in Figures 1 and 2, the inlet width is 500 μm, and the outlet width is 250 μm. In the microfluidic channel, the traces of its two sides intersecting the horizontal plane are first-order exponential function curves; the exponential function formula is: R(x)=e ^a*ln(x) ; wherein a=0.0125; The two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel.

Example 12

The aqueous solution of regenerated silk fibroin with a mass percentage concentration of 55% was used as the spinning liquid, and the spinning liquid was injected into the microfluidic chip at a flow rate of 8 μL/min at a temperature of 20 °C. The metal conduit connected to the inlet of the microfluidic chip was connected to the positive electrode, the sample receiving plate was grounded, and the electrospinning was performed from the outlet of the microfluidic chip under an electric field with a voltage of 30kV and a receiving distance of 6cm. the

The microfluidic chip includes a substrate and a diaphragm, the diaphragm has a groove, and the surface of the diaphragm with the groove is bonded to the substrate to form a microfluidic channel; the depth c of the whole process of the microfluidic channel is equal to 100 μm, the microfluidic channel width b gradually and continuously decreases from the inlet to the outlet, as shown in Figures 1 and 2, the inlet width is 2 mm, and the outlet width is 100 μm. In the microfluidic channel, the trace where one side intersects the horizontal plane is a straight line; the trace where the other side intersects the horizontal plane is a first-order exponential function curve; the exponential function formula is: R(x)=e ^{a *ln(x)} ; where a=0.0125.

Claims (7)

1. A microfluidic chip, comprising a substrate and a diaphragm, the diaphragm has a groove, and the grooved surface of the diaphragm is bonded to the substrate to form a microfluidic channel, which is characterized in that: the whole process of the microfluidic channel The depth (c) of the microfluidic channel is equal, and the width (b) of the microfluidic channel gradually and continuously decreases from the inlet to the outlet; the two sides of the microfluidic channel are symmetrical about the central axis of the microfluidic channel; the microfluidic channel, The trace where the two side surfaces intersect the horizontal plane is one of exponential function curve, hyperbolic function curve or straight line or a combination thereof. 2. A microfluidic chip according to claim 1, wherein said exponential function is a second-order exponential function. 3. A microfluidic chip according to claim 1, characterized in that, the depth (c) is 10 μm to 500 μm; the width of the entrance of the microfluidic channel is 500 μm to 2 mm, and the width of the outlet is 10 μm to 2 mm. 500 μm. 4. A spinning method for a microfluidic chip, characterized in that: the spinning stock solution is injected into the inlet of the microfluidic channel of the microfluidic chip, and finally flows out from the outlet of the microfluidic channel, and dry spinning is carried out in the air, or in the polymerization Wet spinning is carried out in a solidification bath, or electrospinning is carried out under high-voltage electric field conditions; the depth (c) of the microfluidic channel is equal throughout the whole process, and the width (b) of the microfluidic channel gradually decreases continuously from the inlet to the outlet. Small; the microfluidic chip includes a substrate and a membrane, the membrane has grooves, and the grooved surface of the membrane is bonded to the substrate to form a microfluidic channel; the two sides of the microfluidic channel are about The central axis of the microfluidic channel is symmetrical; in the microfluidic channel, the intersection of the two sides and the horizontal plane is one of exponential function curve, hyperbolic function curve or straight line or a combination thereof. 5. The spinning method of a microfluidic chip according to claim 4, wherein the exponential function is a second-order exponential function. 6. The spinning method of a microfluidic chip according to claim 4, characterized in that, the depth (c) is 10 μm to 500 μm; the width of the entrance of the microfluidic channel is 500 μm to 2 mm, and the width of the outlet is The width is 10 μm to 500 μm. 7. The spinning method of a kind of microfluidic chip according to claim 4, it is characterized in that, the injection speed of described spinning solution injection microfluidic channel is 0.5～10 μ L/min; The air gap between the thread mouth and the roll is 1-30cm, and the winding speed is 1-5cm/s.

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