WO2017157304A1

WO2017157304A1 - Microfluid ion source chip and preparation method therefor

Info

Publication number: WO2017157304A1
Application number: PCT/CN2017/076804
Authority: WO
Inventors: 钱翔; 于赐龙; 王晓浩; 余泉; 倪凯
Original assignee: 清华大学深圳研究生院
Priority date: 2016-03-16
Filing date: 2017-03-15
Publication date: 2017-09-21
Also published as: CN105797791A; CN105797791B

Abstract

Provided are a microfluid ion source chip (500) and a preparation method therefor. The microfluid ion source chip comprises a discrete phase layer, a first continuous phase layer and a spraying port. The discrete phase layer comprises a discrete phase storage pool (205) and a discrete phase flow channel (206). The first continuous phase layer comprises a first continuous phase storage pool (207) and a first continuous phase flow channel (208). The first continuous phase flow channel (208) starts from the first continuous phase storage pool (207) and is divided into two first continuous phase flow channel branches (2081, 2082) at a set position. The two first continuous phase flow channel branches (2081, 2082) are converged at a spraying port (204). The discrete phase flow channel (206) is in communication with the discrete phase storage pool (205) and the spraying port (204), and the discrete phase flow channel (206) is located between the two first continuous phase flow channel branches (2081, 2082).

Description

Microfluidic ion source chip and preparation method thereof

[Technical Field]

The invention relates to a microfluidic ion source chip and a preparation method thereof.

【Background technique】

Microfluidic chips, especially integrated microfluidic chips with high density, large scale, high throughput and versatility, have played an important role in the fields of chemistry and biology. Compared with the experimental equipment on a macro scale, this technique significantly reduces sample consumption and improves reaction efficiency. At the same time, it also reduces the environmental pollution caused by the waste generated by the experiment; the parallel advantages of the integrated microfluidic chip operation can realize the high-throughput and automatic control of the experiment; and can be precisely controlled by the micro-valve micro-pump and other fine structures. This makes microfluidic chips an irreplaceable advantage in the field of analysis.

Mass spectrometry is an analytical method for measuring the mass-to-charge ratio of ions. The basic principle is to ionize the components in the sample in the ion source to generate positively charged ions with different mass-to-charge ratios. The ion beam is formed, enters the mass analyzer, and the ions are deflected by the electric field and the magnetic field, and they are respectively focused to obtain a mass spectrum to determine the mass thereof. Mass spectrometers are instruments that use this principle to analyze unknowns. Electrospray Ion-Mass Spectrometer (ESI-MS) has long been used in the field of material analysis. However, while the mass spectrometer has the advantage of high sensitivity, its ion source requirements are often high. The traditional spray needle ion source needs to pre-process the sample on other platforms, and there are problems such as large sample consumption, separation efficiency and low transmission efficiency. The microfluidic electrospray ion source combined with mass spectrometry has emerged. The microfluidic chip can integrate pre-treatment, pre-separation and electrospray functions of the sample, which greatly improves the sensitivity of the detection and reduces the consumption of the sample.

The microfluidic chips with good electrospray effects reported in the study mostly use quartz and glass materials. Another commonly used material is the high polymer polydimethylsiloxane (PDMS), which is difficult to obtain a good electrospray effect. However, it is much cheaper than the first two materials, the production process is simple, the production time is short, and it can be produced in batches. Therefore, it is of great significance and value to carry out innovative research on the material. The structure, materials and preparation methods of a good microfluidic chip can greatly help the analysis system in terms of cost and structural stability.

Since the PDMS-based microfluidic chip currently used in conjunction with mass spectrometry needs to be cut on both sides of the micron-sized flow channel to form a spray tip, this brings huge processing to the microfluidic chip processing. Difficult to cut. At present, the microfluidic chip ion source used for mass spectrometry has only the design of the liquid channel, lacking the function of gas path assisted atomization; and the microfluidic chip ion source used in combination with mass spectrometry needs to apply high voltage to achieve sample ionization. At the same time, liquid driving devices are required to realize the injection of liquid samples, which causes the miniaturization of mass spectrometry microfluidic chips to be severely limited.

[Summary of the Invention]

In order to overcome the deficiencies of the prior art, the present invention proposes a microfluidic ion source chip capable of achieving supersonic automatic injection.

A microfluidic ion source chip comprising a discrete phase layer, a first continuous phase layer and a spray port, the discrete phase layer comprising a discrete phase storage cell and a discrete phase flow channel, the first continuous phase layer comprising a first continuous phase a storage pool and a first continuous phase flow channel, the first continuous phase flow channel starting from the first continuous phase storage pool and being divided into two first continuous phase flow channel branches at a set position, the two a continuous phase flow channel branch merges with the spray port, the discrete phase flow channel communicating with the discrete phase storage cell and the spray port, the discrete phase flow channel being located between two first continuous phase flow channel branches .

Preferably, further comprising a second continuous phase layer between the first continuous phase layer and the second continuous phase layer, the second continuous phase layer comprising a second continuous phase storage pool and a second a continuous phase flow channel, the second continuous phase flow channel starting from the second continuous phase storage cell and being divided into two second continuous phase flow channel branches at the set position, the two second continuous phase flow channels The branches meet at the spray port.

Preferably, the outlet of the discrete phase flow channel is located in the middle of the spray port.

Preferably, the first continuous phase flow channel and the second continuous phase flow channel are used to pass a continuous phase fluid to create a negative pressure at the outlet of the discrete phase flow channel.

Preferably, a bump layer is further included, the first continuous phase layer being located between the land layer and the discrete phase layer.

Preferably, the discrete phase layer comprises a plurality of discrete phase flow channels, the first continuous phase layer comprising a plurality of first continuous phase flow channels.

The invention also provides a method for preparing a microfluidic ion source chip, comprising the following steps:

S1, forming a first photoresist layer on the first substrate, placing a discrete phase mask on the first photoresist layer, exposing toward the discrete phase mask; wherein the discrete The phase mask has a transparent phase storage pool with a discrete phase layer, a discrete phase flow channel, a discrete phase layer mark, and a light transmissive pattern corresponding to a portion of the spray port at a height of the discrete phase layer;

S2, removing the discrete phase mask, forming a second light on the first photoresist layer a layer of a stratified layer, a continuous phase mask disposed on the second layer of photoresist, and a continuous phase layer mark of the continuous phase mask aligned with the discrete phase mark, toward the continuous layer Exposing the mask to remove the continuous phase mask; wherein the continuous phase mask has a continuous phase storage tank with a continuous phase layer, a continuous phase flow channel, a continuous phase layer mark, and a spray port a light transmissive pattern corresponding to a height portion of the continuous phase layer;

S3, immersing the first substrate, the discrete phase layer and the continuous phase layer in the developing solution, so that the portion corresponding to the light transmitting pattern on the first photoresist layer and the second photoresist layer is etched and left Lower unetched portion;

S4. Injecting a high polymer into the etched portion of the first photoresist layer and the second photoresist layer and curing the high polymer to separate the cured first high polymer from the unetched portion.

Preferably, the method further comprises the following steps:

S5, forming a third photoresist layer on the second substrate, placing a continuous phase mask on the third photoresist layer, exposing toward the continuous phase mask; wherein the continuous The phase mask has a continuous phase storage tank with a continuous phase layer, a continuous phase flow channel, and a light transmission pattern corresponding to a height portion of the continuous phase layer of the spray port;

S6, removing the continuous phase mask, and immersing the second substrate and the second continuous phase layer in the developing solution, so that the portion corresponding to the light transmitting pattern on the third photoresist layer is engraved Etching and leaving unetched portions;

S7, injecting a high polymer into the etched portion of the third photoresist layer and curing the high polymer to separate the cured second high polymer from the unetched portion;

S8. Bonding the first high polymer and the second high polymer to obtain a microfluidic ion source chip.

Preferably, the following steps are further included between step S2 and step S3:

Forming a fourth photoresist layer on the second photoresist layer, placing a bump mask layer on the fourth photoresist layer, and forming a bump layer of the bump mask layer The mark is aligned with the continuous phase layer mark, exposed toward the land layer mask, and the land mask is removed.

Preferably, the microfluidic ion source chip is baked.

The supersonic auto-injection microfluidic ion source chip has a spray port (tip) formed on the structural design, and is easily cut by the cutting edge formed by the boss layer. The microfluidic ion source chip not only introduces the auxiliary atomization function of the gas path, but also realizes ionization of the sample without applying a high voltage, and realizes automatic injection of the liquid sample under the driving of the liquid sample-free driving device. It plays an important role in promoting the miniaturization of mass spectrometers. The supersonic auto-injection microfluidic ion source chip is used as an ion source for mass spectrometry. Electrospray is generated under conditions in which a high pressure is applied to the sample, and an electrospray can also be generated under application of a high pressure to ionize the sample.

[Description of the Drawings]

1 is a main flow chart of a method for preparing a microfluidic chip according to the present invention;

2 is a schematic diagram of a discrete phase layer mask according to an embodiment of the present invention;

3 is a schematic view of a continuous phase layer mask according to an embodiment of the present invention;

4 is a schematic view of a land mask of an embodiment of the present invention;

Figure 5 is a schematic view of a spray port according to an embodiment of the present invention;

6 is a schematic view showing a specific process of multiple times of gelatinization and exposure in FIG. 1;

7 is a top plan view of a PDMS structural layer before cutting;

Figure 8 is a top plan view of the PDMS structural layer after cutting;

Figure 9 is a top plan view of the PDMS substrate layer before cutting;

Figure 10 is a top plan view of the PDMS substrate layer after dicing;

Figure 11 is a top plan view and a side cutaway view of the bonded overall PDMS chip;

12 is a schematic diagram of a supersonic auto-injection microfluidic ion source chip combined with a mass spectrometer;

Description of the reference signs:

Silicon substrate 100, mask 101, photoresist 102, PDMS 103, slide 104, PDMS substrate 105, discrete phase mask 201, continuous phase mask 202, raised mask 203 , spray port 204, discrete phase reservoir 205, discrete phase channel 206, continuous phase reservoir 207, continuous phase channel 208, microfluidic ion source chip outline 209, marking structure 210, nozzle outlet 211,

light Glue

300, 301, 302, 303, PDMS structural layer 401, post-cut PDMS structural layer 402, PDMS structural layer spray port 204 three-dimensional view 403, PDMS substrate layer 404, post-cut PDMS substrate layer 405, PDMS substrate layer spray port 204 Three-dimensional view 406, microfluidic ion source chip cutting line 407, complete supersonic auto-injection microfluidic ion source chip top view 500, complete supersonic auto-injection microfluidic ion source chip AA cross-sectional view 501, mass spectrometer inlet 600

【detailed description】

The embodiments described in the following embodiments of the present invention are merely illustrative of the specific embodiments of the present invention and are not intended to limit the scope of the invention. Preferred embodiments of the invention are described in further detail below.

As shown in Figures 8, 10 and 11, a microfluidic ion source chip 500, including bonding together The high polymer PDMS structural layer 402 and the high polymer PDMS substrate layer 405, and the spray ports formed on the high polymer PDMS structural layer 402 and the high polymer PDMS substrate layer 405.

The high polymer PDMS structural layer comprises, in order from bottom to top, a discrete phase layer, a continuous phase layer and a land layer, the discrete phase layer comprising a discrete phase storage cell 205 and a discrete phase flow channel 206, the continuous phase layer comprising a continuous phase storage cell 207 And the continuous phase flow channel 208, the continuous phase flow channel 208 begins in the continuous phase storage cell 207 and is divided into two continuous phase

flow channel branches

2081, 2082 at the set position, and the two first continuous phase

flow channel branches

2081, 2082 meet. At the spray port (ie, recombining a continuous phase flow channel 208, as shown in the AA cross-sectional view of FIG. 1), the discrete phase flow channel 206 is connected to the discrete phase storage cell 205 and the spray port, in the horizontal direction, the discrete phase flow channel Located between two first continuous phase

flow path branches

2081, 2082. In one embodiment, the discrete phase storage cell 205 has a diameter of 2 mm, the discrete phase flow channel 206 is 40 μm wide, is a short DC channel to reduce flow path resistance, the continuous phase storage cell 207 has a diameter of 2 mm, and the continuous phase flow channel 208 and continuous The phase storage cell 207 is connected to a width of 200 μm, the nozzle outlet 211 is 140 μm wide, and the wall width between the continuous phase flow channel 208 and the front end of the discrete phase flow channel 206 is 30 μm. In one embodiment, the continuous phase flow channels 208 are symmetrically distributed across the discrete phase flow channels 206 to ensure implementation of the chip core structure. The high polymer may be polydimethylsiloxane (PDMS). The boss layer is primarily used to form the cutting edge of the nozzle outlet to prevent damage to the nozzle during cutting.

The continuous phase flow channel 208 is parallel to the discrete phase flow channel 206 at the front end of the discrete phase flow channel 206, and the length between the front end of the discrete phase flow channel 206 and the nozzle outlet 211 is in the range of 0-0.5 mm, preferably 0.05-0.2. Between mm, the spray port 204 formed by the discrete phase flow path 206 and the continuous phase flow path 208 is directly released from the mold formed by the photoresist, rather than being cut and trimmed. The discrete phase flow channel 206 and the continuous phase flow channel 208 may be in a staggered multi-channel mode to enable automatic injection of multiple channels within a microfluidic ion source chip.

The high polymer PDMS substrate layer 405 may include, in order from bottom to top, a discrete phase layer, a continuous phase layer, and a land layer, or preferably, the high polymer PDMS substrate layer 405 may include, in order from bottom to top, a continuous phase layer and Stud layer. The discrete phase and continuous phase layers of the high polymer PDMS backing layer 405 are identical to the discrete phase and continuous phase layers of the high polymer PDMS structural layer 402, respectively. As shown in FIG. 1, the discrete phase layer of the high polymer PDMS structural layer 402 and the continuous phase layer of the high polymer PDMS substrate layer 405 are closely bonded and bonded, and in the thickness direction of the microfluidic ion source chip 500, the discrete phase The flow channel 206 is located between the continuous phase flow channel 208 of the high polymer PDMS structure layer 402 and the continuous phase flow channel 208 of the high polymer PDMS substrate layer 405.

The continuous phase storage tank 207 can be used as a gas source for high velocity gas (for example, introduced from the outside) The gas is connected to the continuous phase storage tank 207), and the gas is ejected from the continuous phase storage tank 207 through the continuous phase flow passage 208 to be ejected from the spray port. The discrete phase storage tank 205 can be used as a liquid source for the liquid sample, the continuous phase flow path. The high velocity gas stream of 208 causes a pressure differential between the discrete phase storage cell 205 and the outlet of the discrete phase flow channel 206 (at the end of the spray port), a negative pressure at the outlet of the discrete phase flow channel 206, and the liquid in the discrete phase storage cell 205 is Driven by the differential pressure, it is automatically ejected from the spray port, and under the proper conditions, supersonic injection can be achieved. The exit of the discrete phase flow channel 206 is located just in the middle of the spray port and at the intersection of the continuous phase flow channels 208, thereby ensuring that the discrete phase exits the discrete phase flow channel (206), just after the continuous phase in the continuous phase flow channel 208 The package hangs out.

As shown in FIG. 1 , a method for preparing a microfluidic ion source chip has the following basic process: preparing a mask 101, and the following steps are as follows: Step 1 甩 Photoresist 102 - Step 2 Exposure - Step 3 Developing into a mold - step 4 mixing PDMS into the mold - step 5 curing stripping, dicing - step 6 bonding.

As shown in Figures 2 through 4, a discrete phase mask 201 is used for exposure of the bottommost photoresist to define a discrete phase layer, containing and discrete phase storage (reservoir) cells 205, discrete phase flow paths 206. a discrete phase layer mark 210, and a portion of the spray port corresponding to the height of the discrete phase layer corresponding to the light transmission pattern, the remaining black portion is an opaque portion; the continuous phase layer mask 202 is used for exposure of the upper layer photoresist To define a continuous phase layer, comprising a continuous phase storage (liquid storage) cell 207, a continuous phase flow channel 208, a continuous phase layer mark 210, a microfluidic ion source chip outer contour 209, a continuous phase layer mark 210, and a spray port. The light transmission pattern corresponding to the height portion of the continuous phase layer. The land mask 203 is used for the exposure of the last layer of photoresist to define the formation of a land layer, primarily comprising a microfluidic ion source chip outline 209 and a land mark 210. The masks each contain a marking structure 210 that is used to ensure that the two different masks are aligned with the silicon substrate 100 in the same relative position during the two exposures.

As shown in Figures 2 through 11, in a more specific embodiment, the method of preparing the high polymer PDMS structural layer 402 includes the following steps:

S1, a first photoresist layer 300 is formed on the substrate silicon wafer 100 by a silicone.

The photoresist is made of SU-8 glue, which is a negative, near-ultraviolet photoresist. That is, the ultraviolet irradiation part will produce a crosslinking reaction, and the development process will remain, forming a structure that is spatially complementary to the chip channel. It is suitable for making ultra-thick, high aspect ratio microstructures.

The silicone process consists of three steps: drying, silicone, and pre-baking. The 3 inch silicon wafer 100 is placed in an oxygen plasma machine and plasma is applied; then the silicon wafer 100 is fixed on the vacuum chuck of the homogenizer, and a proper amount of thin SU-8 glue is dropped on the wafer by a dropper. Center, at 2500 rpm The silicone was baked for 30 seconds; it was transferred to a hot plate and baked at 65 ° C for 5 minutes, and then baked at 95 ° C for 10 minutes to complete the pre-baking and air cooling to room temperature. The homogenizer can smear the thin liquid SU-8 photoresist on the silicon substrate 100 to a relatively thin thickness at a relatively fast rotation speed, and slightly reduce the rotation speed of the homogenizer, which can increase the photoresist (301). thickness.

S2, the discrete phase mask 11 is placed on the first photoresist layer 300 and exposed to the discrete phase mask 201.

The exposure process consists of two steps: exposure, post-baking. The pre-baked silicon wafer 100 is placed on a silicon wafer stage of an ultraviolet lithography machine, and the discrete phase mask 201 is lightly attached to the first photoresist 300 to maintain the silicon wafer 100. It is roughly centered with the discrete phase mask 201, and the exposure time is set to 18 seconds after the chucking, and the exposure is started; after completion, the wafer wafer 100 is carefully transferred to the hot plate, baked at 65 ° C for 15 minutes, and then 95. Dry at °C for 10 minutes to complete the post-baking process.

S3, removing the discrete phase mask layer 201, forming a second photoresist layer 301 on the first photoresist layer 300, and placing the continuous phase mask 202 on the second light. On the engraved layer 301, the continuous phase layer mark 210 of the continuous phase layer mask 202 is aligned with the discrete phase layer mark 210, and exposed to the continuous phase layer mask 210, and the continuous phase layer mask is exposed. The board 210 is removed.

S4, forming a third photoresist layer on the second photoresist layer 301, placing a bump layer mask 203 on the third photoresist layer toward the bump layer mask 203 exposure.

As shown in FIG. 6, the production process of the discrete phase layer mask 201 is completed only once, and the process of the continuous phase layer mask 202 is completed one or more times. The corresponding process of the bump layer mask 203 also completes one or more times of the glue and exposure process. Thus, the thickness of the continuous phase flow channel 208 is about 160 μm thicker than the thickness of the discrete phase flow channel 206 (about 30 μm thick), thereby facilitating the discrete phase to flow out of the discrete phase flow channel 206 and then suspended in the continuous phase without the flow channel. Wall contact.

S5. The bump layer mask 203 is removed, and the substrate wafer wafer 100 is immersed in the developing solution together with the photoresist thereon to develop, so that the portion corresponding to the light transmitting pattern on the photoresist layer is The etched and left unetched portions form a PMDS mode.

The development process is specifically as follows: the cooled wafer wafer 100 is transferred to a large petri dish containing a developing solution to ensure that the developer can be completely immersed in the silicon wafer, developed for 5 minutes, taken out, and rinsed with ethanol.

S6. Pour the PDMS mixture into the PDMS mold. After curing and demolding, the PDMS structure formed on the silicon wafer 100 is used as the PDMS structural layer 401, and the cutting is formed by the blade along the microfluidic ion source chip outer contour 209. The edge is cut to obtain a cut PDMS structural layer 402. Among them, the ratio of curing agent to PDMS in the PDMS mixture was mixed at a ratio of 1:5 and 1:10, respectively, and the two mixing ratios were used to form two upper and lower PDMS, respectively, to increase the bonding strength of the two PDMS. The mixed PDMS polymer was poured into a petri dish, and the silicon substrate 100 covered with the exposed photoresist was previously placed on the bottom of the culture dish, and the PDMS was peeled off from the silicon substrate 100 after curing. The cured PDMS 103 is a transparent circular colloid 401 having a diameter of the inner diameter of the culture dish and having a thickness of about 1 to 1.5 cm.

In a preferred embodiment, the high polymer PDMS substrate layer 405 may include, in order from bottom to top, a continuous phase layer and a land layer, the preparation of which is substantially identical to the high polymer PDMS structure layer 402, as shown in FIG. The high polymer PDMS substrate layer 44 formed on the wafer wafer is then diced to obtain a high polymer PDMS substrate layer 405 as shown in FIG.

Under the microscope, the cutting is performed along the microfluidic ion source chip outline 209 with a blade to obtain a post-cut PDMS structural layer 402 and a post-cut PDMS substrate layer 405. Since the microfluidic ion source chip is designed, it is not necessary to form a spray tip by cutting. So it is easy to complete the chip cutting production. The two PDMSs are then aligned under the microscope and bonded to form a complete supersonic autosampler microfluidic ion source chip, as shown in FIG. After cutting along the designed chip outline 209, a hole is punched in one of the PDMS polymer reservoirs.

According to the preparation method of the present invention, the finally obtained supersonic auto-injection microfluidic ion source chip is placed in an oven, baked at 80 ° C for 24 hours, or longer.

The entire fabrication process of the PDMS chip in this embodiment is as described above, and the preparation method is also embodied in this embodiment. The supersonic auto-injection microfluidic ion source chip in this embodiment is mainly used to realize the automatic injection ionization of the sample, and is used for detection by the mass spectrometer. The schematic diagram of the microchip and the mass spectrometer is shown in FIG. The discrete phase is a liquid sample in this embodiment, and the continuous phase is a gas in this embodiment. After the liquid sample is ejected from the supersonic auto-injection microfluidic ion source chip, it enters the mass spectrometer through the mass spectrometer inlet 600 for sample analysis. The supersonic auto-injection microfluidic ion source chip can be applied to fields requiring inkjet printing, biopharmaceutical, microfiber spinning, mass spectrometry, etc., which require automatic injection of spray.

The above is a further detailed description of the present invention in combination with specific/preferred embodiments, and it is not intended that the specific embodiments of the invention are limited to the description. For example, the invention is not limited to the use of two masks. It will be apparent to those skilled in the art that <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; It belongs to the scope of protection of the present invention.

Claims

A microfluidic ion source chip, comprising: a discrete phase layer, a first continuous phase layer and a spray port, the discrete phase layer comprising a discrete phase storage pool and a discrete phase flow channel, the first continuous phase layer comprising a first continuous phase storage tank and a first continuous phase flow channel, the first continuous phase flow channel starting from the first continuous phase storage pool and being divided into two first continuous phase flow channel branches at a set position, The two first continuous phase flow channel branches meet at the spray port, the discrete phase flow channel communicates with the discrete phase storage pool and the spray port, and the discrete phase flow channel is located at two first continuous phase flow channels Between the branches.
The microfluidic ion source chip of claim 1 further comprising a second continuous phase layer, said discrete phase layer being between said first continuous phase layer and said second continuous phase layer, said The two continuous phase layers include a second continuous phase storage tank and a second continuous phase flow channel, the second continuous phase flow channel starting from the second continuous phase storage pool and being divided into two second continuous phase flows at a set position The road branch, the two second continuous phase flow path branches meet at the spray port.
The microfluidic ion source chip of claim 2 wherein the outlet of said discrete phase flow channel is located intermediate said spray port.
The microfluidic ion source chip of claim 2 wherein said first continuous phase flow channel and said second continuous phase flow channel are for passing a continuous phase fluid to cause a negative of said discrete phase flow channel outlet Pressure.
The microfluidic ion source chip of claim 1 further comprising a land layer, said first continuous phase layer being between said land layer and said discrete phase layer.
The microfluidic ion source chip of claim 2 wherein said discrete phase layer comprises a plurality of discrete phase flow channels, said first continuous phase layer comprising a plurality of first continuous phase flow channels.
A method for preparing a microfluidic ion source chip, comprising the steps of:

S1, forming a first photoresist layer on the first substrate, placing a discrete phase mask on the first photoresist layer, exposing toward the discrete phase mask; wherein the discrete The phase mask has a transparent phase storage pool with a discrete phase layer, a discrete phase flow channel, a discrete phase layer mark, and a light transmissive pattern corresponding to a portion of the spray port at a height of the discrete phase layer;

S2, removing the discrete phase mask, forming a second photoresist layer on the first photoresist layer, and placing a continuous phase mask on the second photoresist layer Aligning a continuous phase layer mark of the continuous phase mask with the discrete phase mark, exposing toward the continuous phase mask, removing the continuous phase mask; wherein the continuous The phase mask has a continuous phase storage tank with a continuous phase layer, a continuous phase flow channel, a continuous phase layer mark, and a light transmission pattern corresponding to a height portion of the continuous phase layer of the spray port;

S3, immersing the first substrate, the discrete phase layer and the continuous phase layer in the developing solution, so that the portion corresponding to the light transmitting pattern on the first photoresist layer and the second photoresist layer is etched and left Lower unetched portion;

S4. Injecting a high polymer into the etched portion of the first photoresist layer and the second photoresist layer and curing the high polymer to separate the cured first high polymer from the unetched portion.
The method of preparing a microfluidic ion source chip according to claim 7, further comprising the steps of:

S5, forming a third photoresist layer on the second substrate, placing a continuous phase mask on the third photoresist layer, exposing toward the continuous phase mask; wherein the continuous The phase mask has a continuous phase storage tank with a continuous phase layer, a continuous phase flow channel, and a light transmission pattern corresponding to a height portion of the continuous phase layer of the spray port;

S6, removing the continuous phase mask, and immersing the second substrate and the second continuous phase layer in the developing solution, so that the portion corresponding to the light transmitting pattern on the third photoresist layer is engraved Etching and leaving unetched portions;

S7, injecting a high polymer into the etched portion of the third photoresist layer and curing the high polymer to separate the cured second high polymer from the unetched portion;

S8. Bonding the first high polymer and the second high polymer to obtain a microfluidic ion source chip.
The method of preparing a microfluidic ion source chip according to claim 7, wherein the step of step S2 and step S3 further comprises the following steps:

Forming a fourth photoresist layer on the second photoresist layer, placing a bump mask layer on the fourth photoresist layer, and forming a bump layer of the bump mask layer The mark is aligned with the continuous phase layer mark, exposed toward the land layer mask, and the land mask is removed.
The method of preparing a microfluidic ion source chip according to claim 8, wherein the microfluidic ion source chip is baked.